text:
\section{Introduction}\label{sec:intro}

In the cores of relaxed clusters and groups of galaxies the cooling
time for the hot X--ray emitting intracluster medium (ICM) can be
substantially less than the Hubble time (e.g., Edge et al. 1992;
Sanderson et al. 2006). In the absence of any substantial sources of
heating, the gas in these regions will cool and recombine, constituting
a cooling flow (Fabian \& Nulsen 1977; Cowie \& Binney 1977). However,
high resolution X--ray imaging and spectroscopy, using the {\it Chandra}
and {\it XMM--Newton} observatories, reveal unusually low quantities of
cooling gas compared to the expectations from the standard cooling flow
model (e.g., Fabian 1994), showing that, even in the cores, the gas temperature
does not fall below $\sim$1--2 keV (e.g., Peterson et al. 2003; Kaastra et
al. 2004). The fate of the cooling gas, and the possible involvement of
additional heating ({\it feedback}) to compensate for the observed radiative
losses and regulate the cooling by (re--)heating the gas, remains the
subject of an extensive debate.

One of the most promising sources of feedback is the active galactic
nucleus (AGN) harbored in the central dominant galaxy in these systems
(e.g., Tabor \& Binney 1993; Nusser et al. 2006; Nulsen et al. 2006;
see also the recent review by McNamara \& Nulsen 2007, and references
therein). Indeed, radio and X--ray images provide direct evidence of
the widespread existence of AGN--driven phenomena in an increasing number
of cool core clusters and groups. Evidence of strong interactions between
the radio and thermal plasma can be found in the detection of X--ray
disturbances in the hot gas, such as cavities, edges and filaments,
which appear correlated with the structure of the central radio galaxy
(see for instance the review by Blanton 2004). However, the mechanism of
the energy transfer from the radio source to the surrounding thermal gas
(e.g., shocks, gravity waves, turbulence) is still unclear, as is the
mechanism of the distribution of energy throughout the cooling region
(e.g., McNamara \& Nulsen 2007).
\\
\\
The combination of high quality X--ray imaging and high sensitivity
radio observations is a powerful tool to investigate the ICM/AGN
connection in clusters and groups. In particular, the examination
of radio images at multiple frequencies (especially at frequencies
$\le$1~GHz) is important to study the cycle of radio activity and
elucidate the timescales and physical mechanisms of the energy
injection. With this aim in mind we recently have embarked upon a
low radio--frequency survey of a sample of groups of galaxies with
the Giant Metrewave Radio Telescope (GMRT). High quality X--ray
images from {\it Chandra} and/or {\it XMM--Newton} observations show
that most of these systems have a structure in the X--ray suggestive
of strong interaction between the central radio source and the intragroup
gas (Giacintucci et al. in preparation). The survey aims to investigate
the radio source properties over a broad frequency range, examine
the effects of the AGN at various phases of its activity, and study
the geometry, timescales and physical mechanisms of the energy injection.

In this paper we present new GMRT radio images, obtained at 235 MHz,
327 MHz and 610 MHz of the poor cluster of galaxies AWM\,4, which belongs
to the sample selected for the survey. The cluster hosts the radio source
4C\,+24.36, which is associated with the central giant elliptical galaxy
NGC\,6051. The general properties of the system are summarised in
Tab.~1, where we provide the following information: J2000 coordinates,
redshift, absolute R magnitude of NGC\,6051; 1.4 GHz flux density of
4C\,+24.36 from the NRAO VLA Sky Survey (NVSS; Condon et al. 1998),
and the corresponding radio power calculated at the redshift of the optical galaxy\footnote{Throughout the paper we assume H$_0$ = 70 km sec$^{-1}$ Mpc$^{-1}$,
$\Omega_m$ = 0.3, and $\Omega_{\Lambda}$ = 0.7.}; we also list the cluster
optical velocity dispersion from Koranyi \& Geller (2002), and
emission--weighted gas temperature of the ICM from O'Sullivan et al.
(2005; hereinafter OS05). The linear scale, at the redshift of NGC\,6051
given by the cosmology adopted in this paper, is 0.624 kpc per arcsec.

The 1.4 GHz radio power of 4C\,+24.36 and absolute magnitude of the host
galaxy (Tab.~1) place the source on the lower end of the FRI--FRII transition
region (e.g., Owen \& Ledlow 1994). The source is extended at the
5$^{\prime \prime}$ resolution and sensitivity (0.15 mJy b$^{-1}$) of the
1.4 GHz image from the FIRST survey (Becker et al. 1995), and shows curved
jets traceable up to $\sim$50 kpc from the nucleus along the overall direction
of the galaxy minor axis.

\begin{table}[h!]
\label{tab:prop}
\caption[]{General properties of the AWM\,4 system.}
\begin{center}
\begin{tabular}{llc}
\hline\noalign{\smallskip}
NGC\,6051 & & \\
& RA$_{J2000}$ (h,m,s) & 16 04 56.8 \\
& DEC$_{J2000}$ ($^{\circ}$, $^{\prime}$, $^{\prime \prime}$) & +23 55 56 \\
& z & 0.0312 \\
& M$_{\rm R}$ & $-$23.01 \\
&& \\
4C\,+24.36 & & \\
& S$_{\rm 1.4\,GHz, \, NVSS}$ (mJy) & 608 \\
& logP$_{\rm 1.4\,GHz}$ (W Hz$^{-1}$) & 24.15 \\
&& \\
AWM\,4 && \\
& $\sigma_{\rm v}$ (km s$^{-1}$) & 400 \tablenotemark{(a)}\\
& kT (keV) & 2.5 \tablenotemark{(b)}\\
&& \\
& linear scale & 0.624 kpc$ / ^{\prime \prime}$ \\
\noalign{\smallskip}
\hline
\end{tabular}
\end{center}
\tablenotetext{(a)}{Koranyi \& Geller (2002);}
\tablenotetext{(b)}{O'Sullivan et al. (2005).}
\end{table}

The outline of the paper is as follows: in Sec.~\ref{sec:obs}
we describe the GMRT radio observations and data reduction;
the radio images of 4C\,+24.36 are presented in Sec.~\ref{sec:images};
in Sec.~\ref{sec:spectra} we study the integrated radio spectrum and
spectral index image of the source, and derive its physical parameters;
the results of the radio analysis are discussed in Sec.~\ref{sec:disc};
in Sec.~\ref{sec:xray} we discuss the X--ray properties of the
cluster environment in the context of its radio properties.
The summary and conclusions are given in Sec.~\ref{sec:summary}.

\section{GMRT observations and data reduction}
\label{sec:obs}

\begin{table*}[h!]
\caption[]{Details of the GMRT observations of 4C\,+24.36}
\begin{center}
\begin{tabular}{ccccccc}
\hline\noalign{\smallskip}
$\nu$ &  $\Delta \nu$ &  Date  & Observation  & HPBW, PA  &   rms      \\
 (MHz)  &   (MHz)         &          &  time (min)      &
	    ($^{\prime \prime} \times^{\prime \prime}$, $^{\circ}$) & (mJy b$^{-1}$) \\
\noalign{\smallskip}
\hline\noalign{\smallskip}
235   & 16 & 2006 Jul 08 & 120 & 12.7$\times$10.4, 75  & 0.80 \\
327   & 32 & 2006 Jun 16 & 100 & 9.0$\times$7.8, 53 & 0.40 \\
610   & 32 & 2006 Aug 24 & 160 & 5.0$\times$4.0, 43 & 0.05 \\
\hline{\smallskip}
\end{tabular}
\end{center}
\label{tab:obs}
\end{table*}

\begin{figure*}[h!]
\centering
\plotone{f1.eps}
\caption{GMRT 610 MHz radio contours of 4C\,+24.36,
overlaid on the red optical image from the Sloan Digital
Sky Survey. The 1$\sigma$ level in the radio image is
50 $\mu$Jy b$^{-1}$. The contour levels are 0.2, 0.4,
0.8, 1.6, 3.2, 6.4 (black), 12.8, 25.6, 51.2 and 102.4
(white) mJy b$^{-1}$. The contour peak flux is 121.7 mJy
b$^{-1}$. The restoring beam is $5.0^{\prime \prime}
\times 4.0^{\prime \prime}$, p.a. 43$^{\circ}$. The white
cross in the insert shows the position of the radio core (see
Fig.~3).}
\label{fig:hr_image610}
\end{figure*}

\begin{figure*}[h!]
\centering
\plottwo{f2a.eps}{f2b.eps}
\caption{GMRT radio contours at 327 MHz ({\it left panel}) and
235 MHz ({\it right panel}) of 4C\,+24.36. The 1$\sigma$ level
in the image is 0.4 mJy b$^{-1}$ at 327 MHz and 0.8 mJy b$^{-1}$
at 235 MHz. Contour levels start from $\pm$3$\sigma$, and scale
by a factor 2. The contour peak flux is 199.8 mJy b$^{-1}$ at
327 MHz and 427.8 mJy b$^{-1}$ at 235 MHz. The restoring beam
is $9.0^{\prime \prime} \times 7.8^{\prime \prime}$, p.a.
53$^{\circ}$ in the left panel and $12.7^{\prime \prime}
\times 10.4^{\prime \prime}$, p.a. 75$^{\circ}$ in the right
panel. The black cross in both images indicates the position
of the radio core (see Fig.~3).}
\label{fig:hr_images}
\end{figure*}

We observed the radio source 4C\,+24.36 using the GMRT at the
frequencies of 235 MHz, 327 MHz and 610 MHz. We summarise the
details of the observations in Tab.~\ref{tab:obs}, where we provide
the frequency and total bandwidth, observation date, total time
on source, half power beamwidth (HPBW) of the full array, and rms level
(1$\sigma$) in the full resolution image. The observations were performed
using both the upper and lower side band (USB and LSB) at each frequency,
for a total observing band of 32 MHz at 327 and 610 MHz, and 16 MHz at 235
MHz (Tab.~2). The data were collected in spectral--line mode with 128
channels/band at 327 and 610 MHz, and 64 channels/band at 235 MHz
(the spectral resolution is 125 kHz/channel). At all frequencies, the USB
and LSB datasets were calibrated and reduced individually using the NRAO
Astronomical Image Processing System (AIPS) package. The
flux density scale was set using the sources 3C\,286 and 3C\,48
as amplitude calibrators and the Baars et al. (1977) coefficients.
Careful editing was necessary to identify and remove the data affected
by radio frequency interference at 235 and 327 MHz.
\\
In order to find a compromise between the size of the dataset and
the need to minimize bandwidth smearing effects within the primary
beam, the central channels in each individual dataset were averaged
to 6 channels of $\sim$1 MHz each at 235 MHz, and $\sim$2 MHz each at
327 and 610 MHz after bandpass calibration. At each step of the data
reduction we implemented the standard wide--field imaging technique.
After a number of phase self--calibration cycles, the final USB and
LSB datasets were further averaged from 6 channels to 1 single channel
and then combined together to produce the final images of the source.
All images were corrected for the primary beam attenuation.
The residual amplitude errors are of the order of
$ \,{}^<_\sim\, $ 5 \%.

\section{The radio images}\label{sec:images}

The GMRT 610 MHz image of 4C\,+24.36 is presented in
Fig.~\ref{fig:hr_image610}, superposed on the red optical image from
the Sloan Digital Sky Survey. The images at 327 and 235 MHz are
shown in the left and right panels of Fig.~\ref{fig:hr_images},
respectively. The radio galaxy exhibits a very similar morphology
at all frequencies and resolution, with twin continuous jets and
extended radio lobes slightly bent toward the North. It can be classified
as a wide--angle--tail (WAT) source, although the angle between
the tails is rather large, i.e. $\sim 140^{\circ}$. For comparison, the
angle between the tails of the radio galaxy 3C\,465, which is considered
the prototype of WAT sources, is $\sim 90^{\circ}$ (e.g., Eilek et al. 1984).
Its total angular extent is $\sim$250$^{\prime \prime}$ along
the South--East/North--West axis in all the images shown in
Figs.~\ref{fig:hr_image610} and \ref{fig:hr_images}. The corresponding
largest linear size is $\sim$ 160 kpc.

\begin{table*}[t]
\caption[]{Radio properties of 4C\,+24.36}\label{tab:table3}
\begin{center}
\begin{tabular}{lccccc}
\noalign{\smallskip}
\hline\noalign{\smallskip}
& S$_{\rm 235\,MHz}$  & S$_{\rm 327\,MHz}$ &S$_{\rm 610\,MHz}$ & $\alpha_{\rm 235\,MHz}^{\rm 610\,GHz}$ & LS \\
\noalign{\smallskip}
& (Jy) & (Jy)  &  (Jy) & ($\pm 0.03$) &  (kpc $\times$ kpc) \\
\hline\noalign{\bigskip}
Total source & 2.75$\pm$0.14 & 2.20$\pm$0.11  & 1.45$\pm$0.07  & 0.67 & 160 $\times$ 40  \\
&&&&& \\
Jet West &  1.09$\pm$0.05 & 0.92$\pm$0.05 & 0.62$\pm$0.03 & 0.59  & 45$\times$15 \\
Jet East &  1.01$\pm$0.05 & 0.82$\pm$0.04 & 0.60$\pm$0.03 & 0.55  & 35$\times$15 \\
&&&&& \\
Lobe West & 0.32$\pm$0.02 & 0.23$\pm$0.01 & 0.12$\pm$0.01 & 1.03  & 40$\times$36 \\
Lobe East & 0.33$\pm$0.02 & 0.24$\pm$0.01 & 0.11$\pm$0.01 & 1.15  & 40$\times$36 \\
\noalign{\smallskip}
\hline\noalign{\smallskip}
\end{tabular}
\end{center}
\label{tab:source}
\end{table*}

\begin{figure*}
\centering
\plotone{f3.eps}
\caption{Radio components of 4C\,+24.36. The grey scale image
is the 610 MHz image (same as contour image in
Fig.~\ref{fig:hr_image610}).
The black contour level is 0.2 mJy b$^{-1}$, the white
contour is 0.4 mJy b$^{-1}$. The white cross indicates
the position of the radio core, as determined from
the 0.7$^{\prime \prime} \times 0.4^{\prime \prime}$
image at 4.9 GHz (from VLA archival observations),
shown in the insert (contours are spaced by a factor 2 starting
from $\pm$0.15 mJy b$^{-1}$). The white cross in the insert
indicates the position of the radio core (see Fig.~3).}
\label{fig:cartoon}
\end{figure*}

Figure \ref{fig:cartoon} sketches the most prominent components of the
source, i.e. the two bright well--collimated jets (labelled as jet West
and jet East), extending in opposite directions with respect to the position
of the radio core (white cross), and two roughly round and very extended
radio lobes (lobe West and lobe East). Since the core of the radio source is
undetected in our GMRT images (Figs.~\ref{fig:hr_image610} and
\ref{fig:hr_images}), its position has been determined using a 4.9 GHz image
at the resolution of 0.7$^{\prime \prime} \times 0.4^{\prime \prime}$,
obtained from a new reduction of archival Very Large Array (VLA) data
(Obs. Id. AK360). The 4.9 GHz image is shown as insert in Fig.~\ref{fig:cartoon}.

The most relevant properties of the source and its components, derived
from the observations presented here, are summarised in Table \ref{tab:source},
where we provide the flux density at 235, 327 and 610 MHz, the spectral index
in the 235--610 MHz frequency range (defined according to S$\propto
\nu^{-\alpha}$), and the linear size (LS). It is clear from
Figs.~\ref{fig:hr_images} and \ref{fig:cartoon} and Tab.~\ref{tab:source},
that both the jets and both the lobes are rather symmetric in total
flux density, spectral index and extent. In particular, the western jet has
a flux density which is only $\sim 3-10$ \% higher (depending on the frequency)
than the eastern jet, while the lobe West is $\sim$3--8 \% fainter than the
other. The high symmetry observed in 4C\,+24.36 suggests that the radio source
major axis lies close to the plane of the sky.

\subsection{The radio jets}\label{sec:jets}

The 610 MHz image of 4C\,+24.36 (Figs.~\ref{fig:hr_image610}
and \ref{fig:cartoon}) shows that the radio jets are
characterized by a strikingly complex morphology,
with a number of wiggles, almost symmetrically placed on
either sides within a projected distance of $\sim$ 25 kpc
from the core.

In order to analyze the jet behaviour, we constructed
a grid of 1$^{\prime \prime}$ wide strips, parallel
to each other and transverse to the source major axis.
The strips were set in order to cover the whole jet
region on the 610 MHz image (Fig.~\ref{fig:hr_image610}).
We determined the position of the surface brightness
peak in each stripe, and used it to reconstruct the jet
{\it trajectory} (projected on the plane of the sky)
given in Fig.~\ref{fig:profile}. The figure shows that
both jets initially emerge from the core region, bent
with a relative angle of $\sim$130$^{\circ}$. Going outward
they undergo four prominent sharp bends (labelled W1 to W4 for
the western jet, and E1 to E4 for the eastern jet), which
occur at similar projected distances from the galaxy nucleus.
In particular, the first two bends E1 and W1 are observed
at $\sim$7 kpc from the core, W2 and E2 occur at a distance
of $\sim$ 13 kpc, while W3 and E3 take place at $\sim$ 16 kpc.
After the last change of direction in W4 and E4 (at $\sim$
25 kpc from the center), the jets travel roughly straight
for a while, and finally flare into the diffuse lobes.

\begin{figure*}
\centering
\plotone{f4.eps}
\caption{Projected distribution of the radio surface
brightness peaks at 610 MHz along the jets of 4C\,+24.36.
The position of the jet bends are labelled from W1 to W4
for the jet West, and from E1 to E4 for the jet East.
0$^{\prime \prime}$ corresponds to the position of the radio
core.}
\label{fig:profile}
\end{figure*}

\subsection{The radio lobes}\label{sec:lobes}

Both radio lobes of 4C\,+24.36 show a regular and
roughly round morphology, and lack the presence of
hotspots (Fig.~\ref{fig:hr_image610}). The only
feature with a significant surface brightness
contrast with respect to the rest of the lobe is the
shell--like edge visible in the outermost region of
the eastern lobe (Fig.~\ref{fig:hr_image610}). The lobes
are very symmetric in total flux density, size and
spectral index (see Fig.~\ref{fig:cartoon} and
Tab.~\ref{tab:source}). They are slightly
asymmetric in the projected distance from the core:
the centroid of the lobe West is at $\sim$65 kpc from the
center, while that of the lobe East is at $\sim$ 50
kpc.

\section{Radio spectral analysis and physical parameters}\label{sec:spectra}

The radio observations presented in this paper,
coupled with archival and literature data, allowed us
to determine the integrated radio spectrum of 4C\,+24.36,
and to produce the image of the spectral index distribution
over the source (Sec.~\ref{sec:tot_sp}). This information
allowed us to derive the physical parameters of 4C\,+24.36
(Sec.~\ref{sec:parfis}). The analysis is carried out using
the Synage++ package (Murgia 2000).

\subsection{Spectral analysis}\label{sec:tot_sp}

In order to derive the broad--band radio spectrum of
4C\,+24.36, we used the databases CATS\footnote{http://cats.sao.ru}
(Verkhodanov et al. 1997) and NED\footnote{http://nedwww.ipac.caltech.edu}
to compile flux densities at different frequencies from the
literature, and added our GMRT measurements (Tab.~\ref{tab:source}).
The values from the literature are reported in Tab.~4. The flux
densities marked with the symbol $\diamond$ in Tab.~4 were corrected
for consistency with the absolute flux density scale of Baars et
al. (1977) used in this paper and for the other measurements in
Tab.~4. The correction factors were taken from Helmboldt et al. (2008).
The 74 MHz value was measured on the image from the VLA Low--frequency
Sky Survey (VLSS\footnote{http://lwa.nrl.navy.mil$/$VLSS$/$}),
and was corrected for the {\it clean bias} as described in
Cohen et al. (2007). The flux density at 327 MHz was measured
on the VLA--C array image of 4C\,+24.36, obtained from a new
reduction of public archival data (Obs.Id. AC598).

The source integrated spectrum between 26 MHz and
10.7 GHz is shown in Fig.~\ref{fig:spectrum}. The GMRT
data points align well with the data from the literature.
We notice the extremely good agreement of the GMRT 327 MHz
flux density with the measurement from the VLA image at the
same frequency (Tab.~4). The flux density at 26 MHz (empty
square) was derived from observations with the Clarke Lake
Radio Observatory with a resolution of $\sim$0.5 deg$^2$
(Viner \& Erickson 1975), and thus powerful nearby radio sources
might contribute to the total flux density reported in Tab.~4.
For this reason this value is very uncertain, and will not
be included in the following analysis of the radio spectrum.
\\
The spectrum in Fig.~\ref{fig:spectrum} can be described
as a single power--law over the entire range 74 MHz--10.7 GHz,
with a spectral index of $\alpha_{\rm obs}$=0.82.
The solid line in the figure represents the fit with a
simple power--law model, which provides $\alpha$=0.82$\pm$0.03.

\begin{table}\label{tab:flux2}
\caption[]{Literature radio data for 4C\,+24.36}
\begin{center}
\begin{tabular}{rcc}
\noalign{\smallskip}
\hline\noalign{\smallskip}
$\nu$     & Flux density & Reference\\
 (MHz)    &   (Jy)     &       \\
\hline\noalign{\smallskip}
26   & 26.00 $\pm$ 7.00 & (1) \\
74   &  6.12 $\pm$ 0.47 & (2) \\
$\diamond$ 178 & 2.77 $\pm$ 0.42 & (3) \\
327  &  2.19 $\pm$ 0.11 & (4) \\
$\diamond$ 365 & 1.43 $\pm$ 0.07 & (5)\\
$\diamond$ 408 & 1.76 $\pm$ 0.14 & (6) \\
1400 &  0.68 $\pm$ 0.03 & (7) \\
1400 &  0.67 $\pm$ 0.03 & (8) \\
1410 &  0.60 $\pm$ 0.04 & (9) \\
2700 &  0.33 $\pm$ 0.02 & (10) \\
2700 &  0.37 $\pm$ 0.02 & (9) \\
4860 &  0.19 $\pm$ 0.01 & (11) \\
4850 &  0.21 $\pm$ 0.03 & (12) \\
5000 &  0.20 $\pm$ 0.02 & (9) \\
10700&  0.11 $\pm$ 0.01 & (13)\\
\hline\noalign{\smallskip}
\end{tabular}
\end{center}
\tablerefs{(1) Viner \& Erickson (1975); (2) VLSS image,
Cohen et al. (2007); (3) 4C; Pilkington \& Scott (1965), Gower et
al. (1967); (4) VLA archival data (Obs. Id. AC598); (5) TXS,
Douglas et al. (1996); (6) B2, Colla et al. 1970, Fanti et al. (1974);
(7) FIRST, White et al. (1997);
(8) NVSS, Condon et al. (1998); (9) PKS90, Wright \& Otrupcek (1990);
(10) Bridle, Kesteven \& Brandie (1977); (11) GB6, Gregory et al. (1996);
(12) Gregory \& Condon (1991); (13) Reich et al. (2000).}

\tablenotetext{}{The values marked with $\diamond$ were corrected for
consistency with the Baars et al. (1997) scale.}
\end{table}

\begin{figure}
\centering
\plotone{f5.eps}
\caption{Radio spectrum of 4C\,+24.36 between 26 MHz and
10.7 GHz. The empty symbols are literature data (see
Table~\ref{tab:table3}), while the filled circles are the
GMRT 235, 327 and 610 MHz values (Tab. 4). The solid line
is the power--law fit to the data. The uncertain
26 MHz data point (empty square) was not included in the fit
(see text). The value of $\alpha$ provided by the
fit, along with the reduced $\chi^2$, are reported.}
\label{fig:spectrum}
\end{figure}

\begin{table}[h!]
\caption[]{Results of the point--to--point analysis}
\begin{center}
\begin{tabular}{ccccc}
\noalign{\smallskip}
\hline\noalign{\smallskip}
  & $\alpha_{inj}$ & $\nu_{\rm br}$ & t$_{\rm rad}$ & v$_{\rm growth}$ \\
  &            & (MHz)              &  ($10^{8}$) yr & (c)  \\
\hline\noalign{\bigskip}
jet+lobe West\tablenotemark{(b)} & 0.48$^{+0.07}_{-0.07}$ & 359$^{+37}_{-31}$ & 1.6  & 0.0017   \\
jet+lobe East \tablenotemark{(b)} & 0.45$^{+0.07}_{-0.07}$ & 316$^{+29}_{-26}$  & 1.7  & 0.0015   \\
&&&&\\
\hline\noalign{\smallskip}
\end{tabular}
\end{center}
\end{table}

We obtained the image of the 235--610 MHz spectral index
distribution over the source using two images produced
with the same u--v range and same cellsize, restored with
the same beam of $13.0^{\prime \prime} \, \times \,
11.0^{\prime \prime}$, and corrected for the primary beam
attenuation. The images were aligned, clipped at the
3$\sigma$ level, and finally combined to obtain the spectral
index image presented in Fig.~\ref{fig:spix}. The figure
shows the presence of a flat region ($\alpha \sim 0.3 \pm0.1$)
at the source center, corresponding to the inner $\sim$ 10 kpc
portion of the jets (see Fig.~\ref{fig:cartoon}). On a larger scale,
the spectral index gradually steepens along the jets up to
$\alpha \sim 0.9 \pm 0.1$ where the jets merge into the lobes.
Finally, a further steepening is observed in the lobe region where
the spectral index has an average value $<\alpha>=1.5 \pm 0.2$.

\begin{figure}
\centering
\plotone{f6.eps}
\caption{Colour scale image of the spectral index
distribution between 235 MHz and 610 MHz over 4C\,+24.36.
The image has been computed from images with a restoring
beam of $13.0^{\prime \prime} \, \times \, 11.0^{\prime \prime}$.
Overlaid are the 235 MHz contours at levels 3,6,12,24,48,96 and
192 mJy b$^{-1}$. The white cross shows the position of the
radio core.}
\label{fig:spix}
\end{figure}

Following Parma et al. (1999 and 2007; see also Giacintucci et
al. 2007), we performed a fit of the observed spectral index trend
along the source axis. We determined the average spectral index in
7.5$^{\prime \prime}$ radius circular regions starting from the source
center and going outwards toward the lobes (see insert in
Fig.~\ref{fig:steepening}). The size of the region was chosen to be larger
than one beam, in order to sample independent regions. The derived 235--610
MHz spectral index distribution as a function of the distance from the
core is shown in Fig.~\ref{fig:steepening}. We notice that the two spectral
trends are very similar once errors are taken into account.

\begin{figure}
\centering
\plotone{f7.eps}
\caption{Spectral index distribution, calculated
from the 235 and 610 MHz observations, along the
source as a function of the distance from the core, derived
using the circular regions shown in the insert. The radius
of each region is 7.5$^{\prime \prime}$. The ellipse in the
upper--left corner of the insert indicates the size of the
radio beam (HPBW=$13.0^{\prime \prime} \, \times \,
11.0^{\prime \prime}$). The contours correspond
to the 235 MHz image (same as in
Fig.~\ref{fig:spix}). The solid lines represent the best fit
of the radiative model described in the text. The values of
$\alpha_{\rm inj}$ and $\nu_{\rm br}$ provided by the fit,
along with the reduced $\chi^2$, are also reported. The data
point at $d\!=\!0$ (empty circle) was not used in the fit.}
\label{fig:steepening}
\end{figure}

We fitted these trends using a JP model (Jaffe \& Perola 1974), in
which the timescale for continuous isotropization of the electrons
is assumed to be much shorter than the radiative timescale. We also
assumed that the break frequency $\nu_{\rm br} \, \propto
\, d^{-2}$, where $d$ is the distance from the core. Such a relation
is expected under the assumption that the expansion velocity of the
source is constant (i.e. $d \, \propto \, t$), and reflects the fact
that the age of the radio emitting electrons increases as one moves
away from the nucleus, which is appropriate for FR I radio galaxies
such as 4C\,+24.36. The best fit to the observed spectral trend is
shown as solid line in Fig.~\ref{fig:steepening}. Note that the data
point at d$=$0 (empty circle) was not used in the fit. The model
yields similar values of the injection spectral index and break
frequency for both regions, with $\alpha_{\rm inj} \sim 0.5$
and $\nu_{\rm break} \sim 360$ and $\sim$ 320 MHz for the western and
eastern parts, respectively (see also Tab.~5).

\subsection{Physical parameters of 4C\,+24.36}\label{sec:parfis}

We assume that the relativistic particle and magnetic field
energy densities are uniformly distributed over the source volume
and in energy equipartition. The equipartition parameters
are derived adopting a low--energy cut--off of $\rm \gamma_{min}$
in the energy distribution of the radiating electrons (where
$\gamma$ is the electron Lorentz factor), instead of the 10
MHz--100 GHz frequency interval normally used in the standard
equipartition equations (e.g. Pacholczyk 1970). This choice
allows us to take into account the contribution from low energy
electrons, since the assumption of a low frequency cut--off of
10 MHz in the synchrotron spectrum tends to neglect the input from
electrons with energy lower than $\gamma \sim$1500--500 for typical
equipartition magnetic fields of $\sim$1--10 $\mu$G, respectively
(Brunetti, Setti \& Comastri 1997). We adopt $\rm \gamma_{min}\!=\!10$
which corresponds to an energy cut--off of $\sim$5 MeV (Brunetti, Setti
\& Comastri 1997; see also Parma et al. 2007). Furthermore, we use the
flux density measurement at 235 MHz (Tab.~2), since the electron aging
is less relevant at lower frequencies. A spectral index of 0.5,
consistent with the values of the injection spectral index
$\alpha_{\rm inj}$ derived in Sec.~\ref{sec:tot_sp} (Tab.~5), is adopted.
Finally, we assume a relativistic proton energy to electron energy ratio
$\kappa$=1, and a filling factor $\phi$ of unity.

\begin{table*}[t]
\label{tab:parfis}
\caption[]{Physical parameters of 4C\,+24.36 and its components}
\begin{center}
\begin{tabular}{ccccc}
\noalign{\smallskip}
\hline\noalign{\smallskip}
 & B$_{\rm eq}$ & P$_{\rm min}$ & U$_{\rm min}$ & u$_{\rm min}$ \\
 & ($\mu$G) & ($10^{-13}$ dyne cm$^{-2}$) & (10$^{57}$ erg) & ($10^{-12}$ erg cm$^{-3}$) \\
\hline\noalign{\bigskip}
total source & 5.00 & 7.8 & 3.7 & 2.3 \\
&&&&\\
jet+lobe West & 5.04 & 8.0 & 1.9 & 2.4 \\
jet+lobe East & 4.97 & 7.9 & 1.8 & 2.3  \\
&&&&\\
lobe West    & 3.14 & 3.1 & 0.9 & 0.9 \\
lobe East    & 3.17 & 3.1 & 0.9 & 0.9 \\
&&&&\\
jet West      & 8.99 & 25.0 & 0.7 & 7.5 \\
jet East     & 9.42 & 27.3 & 0.5 & 8.2 \\
\hline\noalign{\smallskip}
\end{tabular}
\end{center}
\end{table*}

The equipartition magnetic field B$_{\rm eq}$ computed in
this way is listed in Tab.~6 for the entire source, and for
parts thereof. We found B$_{\rm eq} \sim 5$ $\mu$G both for
the whole source and the western and eastern jet+lobe regions
analysed in Sec.~\ref{sec:tot_sp}. A lower estimate is obtained
for the lobes separately (B$_{\rm eq} \sim 3$ $\mu$G), while
the highest values are found in the jets where B$_{\rm eq}
\sim 9$ $\mu$G. We also derived the total energy U$_{\rm min}$,
energy density u$_{\rm min}$, and minimum pressure
p$_{\rm min}$ for the source and its components (Tab.~6).

The break frequency derived in Sec.~\ref{sec:tot_sp}
can be used to estimate the radiative age $\rm t_{\rm rad}$
of 4C\,+24.36. If the expansion losses can be neglected
and the magnetic field is uniform across the source and
constant over its lifetime, $\rm t_{\rm rad}$ (expressed in
Myrs) is given by the following equation:

\begin{equation}\label{eq:trad}
{\rm t_{rad} = 1590\frac{B^{0.5}}{(B^2 + B_{CMB}^2)} [(1+z) \nu_{br}]^{-0.5}}
\end{equation}

\noindent where B is the magnetic field intensity in $\mu$G,
$\nu_{\rm br}$ is in GHz, and $\rm B_{CMB} (\mu G)= 3.2 \times
(1+z)^2$ is the magnetic field strength with energy density
equal to that of the CMB the redshift z. Adopting
the equipartition magnetic fields (Tab.~6) in Eq.~\ref{eq:trad},
we estimate ${\rm t_{rad}} \sim 160$ Myr and $\sim$170 Myr for
the western and eastern parts of 4C\,+24.36, respectively (also
reported in Tab.~5). A growth velocity of $\rm v_{growth}
\sim 0.002$c is found for both regions (Tab.~5). The latter quantity
was derived as $\rm v_{growth} = LLS/t_{rad}$, i.e. assuming
a constant velocity and using the largest linear size given
in Tab.~2. It is worth noting the good agreement between the results
obtained for two regions.

\section{Discussion of the radio results}\label{sec:disc}

\subsection{Jet orientation and velocity}\label{sec:theta}

The radio galaxy 4C\,+24.36 has WAT morphology in all the
images presented in this paper (Figs.~\ref{fig:hr_image610}
and \ref{fig:hr_images}), with two bright continuous jets
and very extended radio lobes. Such components are very
symmetric in total flux density and extent (Tab.~2), as
well as in spectral index properties and physical parameters
(Tabs.~5 and 6). These results suggest that the major axis
of 4C\,+24.36 most probably lies close to the plane of the sky.
\\
We searched for further hints of the source orientation
in the plane of the sky by means of a standard analysis based
on the jet asymmetry. Assuming that the jets are intrinsically
symmetric with respect to the source core, the jet to counterjet
brightness ratio $R$ can be used to constrain the geometry and
velocity of the jets in the context of a relativistic beaming
model (e.g. Lind \& Blandford 1985) according to

\begin{equation}\label{eq:ratio}
R=(1+\beta cos \theta)^{q}(1-\beta cos \theta)^{-q},
\end{equation}

\noindent where $\beta$ is the ratio of the jet velocity to
the speed of light, $\theta$ is the orientation angle of the
jet with respect to the line of sight, and $\alpha$ is the
jet spectral index. If the jet emissivity is isotropic
with no preferred direction for the magnetic field (Pearson
\& Zensus 1987), the exponent $q$ is given by $2+\alpha$.

Using the 0.7$^{\prime \prime} \times 0.5^{\prime \prime}$
resolution image at 4.9~GHz (see insert in Fig.~\ref{fig:cartoon}),
and assuming the jet East to be the counterjet, we estimated
$R$ within the inner $\sim 5$ kpc from the core. Assuming
$\alpha=0.5$ for the jet emission, we found $R=1.3$ which
yields $\beta \cos \theta$=0.05 (Eq.~\ref{eq:ratio}).
Fig.~\ref{fig:beta} shows the corresponding constraints
on $\theta$ and the intrinsic jet velocity $\beta$ (solid
black curve). Jetha, Hardcastle \& Sakelliou (2006) found that the average value
for the inner jet speed in a relatively large sample of WAT radio
galaxies is $\beta=0.5\pm0.2$. This velocity is in general agreement
with the values found for FRI radio galaxies, whose properties are
consistent with the hypothesis that jets slow down from relativistic
to sub--relativistic velocities on scales of 1--10 kpc (Parma et al.
1994). Adopting $\beta=0.5\pm0.2$ for 4C\,+24.36, the black solid
curve in Fig.~\ref{fig:beta} shows that the allowed jet orientation
angle is in the range $\theta \sim 81^{\circ} $-- $87^{\circ}$
(red dashed region). This suggests that the source probably lies
at a very small angle with respect to the plane of the sky.
\\
If we use the exponent $q=3+2\alpha$ in Eq.~\ref{eq:ratio}, which
is valid in the case of a perfectly ordered magnetic field
parallel to the jet axis (Begelman 1993), we obtain very similar
constraints for the jet orientation, as shown by the solid blue
curve in Fig.~\ref{fig:beta}. In this case $\theta \sim
84^{\circ}$--$88^{\circ}$.

\begin{figure}
\centering
\plotone{f8.eps}
\caption{Constraints on the angle $\theta$ between
the jet and the line of sight, and the intrinsic
jet velocity $\beta$ for 4C\,+24.36. The solid black
line is the curve obtained from the jet--counterjet
ratio in the isotropic case (i.e., using $q=2+\alpha$
in Eq.~\ref{eq:ratio}), while the solid blue curve is
given by $q=3+2\alpha$. The long-dashed line, corresponding
to $\beta=0.5$, is an average value for the jet speed
in WATs (the black dashed region represents the
1$\sigma$=0.2 dispersion). The red dashed region shows the
allowed values for $\theta$ in 4C\,+24.36 in the isotropic
case, corresponding to $\beta=0.5\pm0.2$.}
\label{fig:beta}
\end{figure}

\subsection{Morphological distortions}\label{sec:morph}

The radio structure of 4C\,+24.36 is characterised
by clear distortions occurring over different linear
scales. One of most prominent features is the number
of sharp wiggles which the jets undergo within the
central $\sim 25$ kpc (projected) from the core
(Fig.~\ref{fig:profile}). On the large scale, the
overall structure of the source appears slightly
bent toward the North in a C--shape which is typical
of WAT sources (Fig.~\ref{fig:hr_image610} and
Fig.~\ref{fig:hr_images}). This suggests that
different physical processes may play a role in the
origin of the morphological distortions observed on the
different scales.

\subsubsection{Jet wiggles}\label{sec:wiggles}

Jet oscillations have been observed in other FRI
radio sources of similar luminosity as 4C\,+24.36,
e.g. the well studied radio galaxies
3C\,31 (e.g., Blandford \& Icke 1978; Andernach et
al. 1992; Laing \& Bridle 2002) and 3C\,449 (e.g., Andernach et al. 1992;
Feretti et al. 1999). Both sources are characterized
by a very large total extent (LLS $\sim$ 800 kpc and
600 kpc, respectively) which places them among the
class of giant radio galaxies. They are associated
with the dominant members of two nearby poor groups
of galaxies (z=0.17), and both galaxies are likely
undergoing a gravitational encounter with a close
bright companion.

\begin{figure*}[t]
\centering
\epsscale{0.75}
\plotone{f9.eps}
\caption{Comparison of the radio morphology of
4C\,+24.36, 3C\,31 and 3C\,449 (note that the last
one has been reversed in order to better highlight the
similarities). {\it Upper panel} -- 1.4 GHz image of 4C\,+24.36
obtained from the combination of VLA A and B--Array observations
from the public archive (Obs.Id. 074). The HPBW is
3.6$^{\prime \prime} \times 1.8^{\prime \prime}$,
p.a. -65$^{\circ}$. The first contour is 0.15
mJy b$^{-1}$. {\it Central panel} -- VLA--BnA 1.4
GHz image of 3C\,31 from the public archive (Obs.Id.
AF263). The HPBW is 4.1$^{\prime \prime} \times 3.7^{\prime \prime}$,
p.a. -65$^{\circ}$. The first contour is 0.25 mJy b$^{-1}$.
{\it Lower panel} -- VLA--B 1.4 GHz image of
3C\,449 from the public archive (Obs.Id. AK319). The
HPBW is 4.5$^{\prime \prime} \times 3.9^{\prime \prime}$,
p.a. 86$^{\circ}$. The first contour is 0.35 mJy b$^{-1}$.}
\label{fig:morph}
\end{figure*}

In Fig.~\ref{fig:morph} we compare the radio morphology
of 4C\,+24.36 (upper panel) to the structure of
the well-known radiogalaxies 3C\,31
and 3C\,449 (central and lower panels, respectively).
All images were obtained from a new reduction of 1.4 GHz
observations  from the VLA public archive, and have a resolution
of $\sim 4^{\prime \prime}$ (see Figure caption for details).
Note that the images of 3C\,31 and 3C\,449 have been rotated
and reversed in order to highlight the morphological
similarities. We also point out that the image of 3C\,449
shows only the central region of the source, whose total
extent at this resolution is $\sim 20^{\prime}$ (i.e. $\sim$
420 kpc; see Feretti et al. 1999). Despite the different
linear size, the similarity of the pattern of wiggles in
the three sources is striking. However we can notice some
important differences: {\it i)} the wiggles in 4C\,+24.36
occur over a smaller projected distance from the nucleus
(i.e. between $\sim$7 kpc and $\sim$25 kpc; see Fig.~\ref{fig:profile})
than in 3C\,31 and 3C\,449, where the first bend is observed
at $\sim 20$ kpc; {\it ii)} the inner jets in 4C\,+24.36
show a much stronger deviation from linearity than 3C\,31
and 3C\,449. In particular, the western jet appears
already bent at $\sim$3 kpc only from the core (see insert
in Fig.~\ref{fig:cartoon}).
\\
\\
Jet oscillations can be ascribed to various reasons, which
include {\it a)} orbital motion, {\it b)} precession
of the nuclear collimator, and {\it c)} jet instabilities,
such as Kelvin-Helmholtz (K--H) instabilities, at
the jet boundary.

\begin{itemize}

\item [{\it a)}] The orbital motion is expected to generate
a single oscillation wavelength with fixed amplitude and
mirror symmetry of the jet with respect to the core. Given the
presence of a close bright companion, it has been
suggested that the orbital motion might indeed be responsible for
the jet wiggles in 3C\,31 (Blandford
\& Icke 1978) and 3C\,449 (Perley, Willis \& Scott 1979).
However no bright companion is visible on the available
optical images of 4C\,+24.36 (e.g. Fig.~\ref{fig:hr_image610}),
thus it seems difficult to ascribe the jet oscillations to
the presence of an orbiting system. Furthermore, with plausible
galaxy masses and the orbital separation required to produce
the observed lateral displacement of the jets, the orbital
period would be far larger than the jet age allows.

\item [{\it b})] Precessional motion is expected to lead to a
single oscillation wavelength with amplitude linearly growing
with the distance from the nucleus and anti--symmetric pattern.
Given the approximate mirror symmetry of the initial jet
oscillations in 4C\,+24.36, we can reasonably rule out the
precessional model.

\item [{\it c})] Confined radio jets are known to be unstable
against K--H instabilities at their boundary (Hardee 1987). The
jet oscillations can be then interpreted as the result of helical
motion arising from small perturbations at the jet origin,
amplified by growing K--H instabilities (Hardee 2003; Savolainen
et al. 2006). These instabilities can be triggered for example
by random perturbations of the jet flow (e.g., by jet--cloud
interactions; G\'omez et al. 2000), or by variation in the jet
injection direction from the nucleus (e.g., due to the
orbital motion of a supermassive binary black hole in the host
galaxy). It has been shown that the K--H helical distortion
waves propagating along the jet are able to displace the whole
jet and produce large scale helical structures (Hardee 1987).
Thus K--H instabilities are an appealing possibility to interpret
the wiggles observed in 4C\,+24.36. Unfortunately the resolution of
our present radio data is not high enough to allow us to
determine the characteristics of a possible K--H wave propagating
along the jet.
\end{itemize}

Further information on the fine brightness structure and
polarization properties of the jets from higher resolution
radio observations would be required to shed light on the
possible mechanisms responsible for the oscillations.
Moreover, forthcoming high resolution X--ray {\it Chandra}
observations (Cycle~9) will allow us to carry out a
detailed structural comparison of the radio and X--ray
emission in the jet regions.

\subsubsection{Large scale bending}\label{sec:bending}

The investigation of the physical mechanism responsible for the
wide--angle tail formation poses a number of interesting problems
which are not completely understood yet. The earliest models developed
for the origin of WATs invoked ram pressure resulting
from the motion of
the associated galaxy through the surrounding intracluster medium
(e.g., Owen \& Rudnick 1976; Begelman, Rees \& Blandford 1979).
However, WATs are usually associated with the central dominant galaxies
in groups and clusters, and they are not expected to have large velocities
relative to the ICM (Burns 1981), as they usually reside at the center
of the cluster gravitational potential well (Merritt 1984; Bird 1994).
Thus, ram pressure alone seems unable to explain the bends observed
in most of the WATs (e.g., Eilek et al. 1984; O'Donoghue, Eilek \& Owen
1993).
\\
One possibility is that if the radio jets are less dense than the
external gas, buoyancy forces might contribute to the bending of the tails,
as they drag the radio plasma towards lower density regions in the ICM
(e.g., Burns \& Balonek 1982). In real situations, both ram pressure by
the galaxy motion and buoyancy are expected to play a role, with buoyancy
forces dominant at larger radii (Sakelliou et al. 1996). An alternative
scenario is that the large scale bulk motions in the ICM, resulting from
cluster mergers, may provide the necessary ram pressure to distort the
structure of the central dominant radio galaxy (e.g., Pinkney, Burns
\& Hill 1994; G\'omez et al. 1997). Large scale X--ray substructure
and merging signatures have been indeed observed in many clusters hosting a
WAT (Burns et al. 1994). Finally, an appealing possibility to explain
the existence of WATs at the center of non--merging clusters is the possible
connection of the radio source bending with the process of gas sloshing in
the cluster core thought to be responsible for the formation of cold fronts
(Ascasibar \& Markevitch 2006). For example, such a connection might be
present in A\,2029, a very relaxed cluster hosting a WAT and a pair of cold
fronts at its center (Clarke, Blanton \& Sarazin 2004; Ascasibar \&
Markevitch 2006 ).
\\
\\
The optical and X--ray properties of AWM\,4 (Koranyi \& Geller 2002 and
OS05, respectively) indicate that the cluster has not
recently experienced major episodes of merging (see also Sec.~\ref{sec:environment}).
Moreover, the XMM--Newton images do not show any sharp surface brightness
edges suggestive of the existence of cold fronts in the core (OS05). For
these reasons we interpret the bending in 4C\,+24.36 as a result of the
interplay of ram pressure (driven by the motion of NGC\,6051) and buoyancy
forces. Following Sakelliou et al. (1996), we can derive a constraint on
the galaxy velocity relative to the ICM, as a function of the ratio of the
jet density to the ICM density, at the point where the components of ram
pressure and buoyancy in the direction orthogonal to the jet balance
each other (the {\it turnover point}). At smaller distances than this point, the jet
bending is expected to be mostly determined by ram pressure, while
buoyancy forces dominate at larger distances. Furthermore, the bending
does not depend on the jet velocity at the turnover point (Sakelliou et
al. 1996).
\\
We assume that the radio jets can be described as a steady
flow of a non--relativistic plasma (Bridle \& Perley 1984), and adopt
a coordinate system in which the axes always lie parallel and perpendicular
to the jet. At the {\it turnover} point the component of the galaxy
velocity in the plane of the sky ($\rm v_{gal}$) can be expressed as
(see Sakelliou et al. 1996, and Smol\v{c}i\'{c} et al. 2007 for details),
\begin{equation}\label{eq:vgal}
\rm v_{gal}^2 = \frac{ 3\beta k T_{gas} h }{ \mu m_p r_c }
            \frac { { r_{to}/r_c} }{ 1 +  \left ({ r_{to} / r_c }\right ) ^2}
            \frac{\bf \hat{r}\cdot \hat{n}}{{\bf \hat{v}_{gal}\cdot \hat{n}}}
            \left( 1 - \frac{\rho_{jet}}{\rho_{gas}}\right),
\end{equation}
\noindent
where $\rm \bf{\hat{n}}$ is the normal vector to the jet in the plane
of the sky, $\rm \bf{\hat{v_{gal}}}$ is the unity vector in the direction of
the galaxy velocity, $\rm \bf{\hat{r}}$ is the unity vector in the direction from
the cluster center, $\beta$ and $\rm r_c$ are the slope and core radius of the
X--ray surface brightness when fit to a hydrostatic $\beta$ model, kT is the
ICM temperature, $\rm r_{to}$ is the projected distance of the turnover point
from the cluster center, h is the width of the jet at this point (corrected for
the resolution of the telescope), $\mu$ is the mean molecular weight ($\mu$=0.6),
$\rm m_p$ is the proton mass, and $\rm \rho_{gas}$ are the density of the jet
and ICM.

A close examination of Figs.~\ref{fig:hr_image610} and \ref{fig:profile}
suggests that the last change in direction of the jets (points E4 and W4)
might be identified as the turnover point for 4C\,+24.36.
In this case $\rm r_{to} \sim 25$ kpc. The average gas temperature
in AWM\,4 is kT=2.5 keV (Tab.~1), and the fit of the radial profile
of the cluster X--ray surface brightness with a single $\beta$ model
provides $\rm r_c=67$ kpc and $\beta=0.67$ (OS05). Thus, if $h\!=\!8$ kpc,
as estimated from Fig.~\ref{fig:hr_image610}, then from Eq.~\ref{eq:vgal}
we can derive the galaxy velocity as a function of $\rm \rho_{jet} /
\rho_{gas}$ (Fig.~\ref{fig:vgal}). In the limit $\rm \rho_{jet} /
\rho_{gas} \rightarrow 0$, we obtain an upper limit for the NGC\,6051
velocity relative to the ICM of $\rm v_{gal}  \,{}^<_\sim\,  120$ km s$^{-1}$.
\\
We stress that $\rm v_{gal}$ is the velocity component in the plane
of the sky, therefore the derived value is a lower limit on the
total speed of NGC\,6051. On the other hand, the comparison of the NGC\,6051
redshift to the average redshift of the other cluster members provides
an estimate of the line of sight component of its velocity. Koranyi \&
Geller (2002) report a recession velocity of 9703$\pm$46 km s$^{-1}$
for NGC\,6051, and an average velocity for the cluster members within
a radius of 0.5 $h^{-1}$ Mpc of 9722$\pm$98 km s$^{-1}$.
Thus NGC\,6051 seems to be relatively at rest with respect to the
potential well of AWM\,4. This is consistent with the fact that the
galaxy position is coincident with the peak of the cluster X-‐ray
emission (Koranyi \& Geller 2002; OS05), and is also in agreement
with the velocities usually found for the dominant galaxies in
non--merging groups and poor clusters of galaxies (e.g., Beers et
al. 1995).

\begin{figure}
\centering
\epsscale{1.00}
\plotone{f10.eps}
\caption{The transverse component of the
velocity of NGC\,6051 (in the plane of the sky), as a function
of the ratio of the jet density to external gas density.}
\label{fig:vgal}
\end{figure}

\subsection{Source age}\label{sec:age}

Our spectral analysis led us to an estimate of the synchrotron age
of 4C\,+24.36 of $t_{\rm rad} \sim 160$ Myr (Tab.~5). This age is
significantly higher than the typical values derived
(using a similar approach to the one adopted in Sec.~\ref{sec:parfis})
for currently active radio galaxies of similar luminosity, as for
example the sources in the B2 sample which have a median age of 16
Myr (Parma et al. 1999, 2007). The age of 4C\,+24.36 is indeed more
similar to the values derived by Parma et al. (2007) for a sample of
candidate dying radio galaxies, which have a median age of 63 Myr,
with values up to 170 Myr.
\\
 Giacintucci et al. (2007) have recently analysed a sample
of cD radio galaxies in rich and poor clusters of galaxies,
and found radiative ages $ > 10^{8}$ years for 4 of the 7 sources
with available estimates of the age. They argued that one of them
(A\,2372) is a restarted radio galaxy, where both the new activity
and the relic radio plasma from the previous AGN burst are
visible. Another two sources (A\,2622 and MKW\,3s) are most likely dying
radio galaxies, where the nuclear engine has switched off and a relic
phase is currently ongoing. However, the total spectral index of
4C\,+24.36 ($\alpha \sim 0.8$ in the 74 MHz--10.7 GHz range) is
typical of a currently active radio galaxy rather than a relic source,
where $\alpha$ can be much steeper ($ \,{}^>_\sim\, $2; e.g. Parma et al. 2007;
Giacintucci et al. 2007). Furthermore, 4C\,+24.36 clearly shows active
nuclear emission at high frequencies
(see insert in Fig.~\ref{fig:hr_image610}).
Thus it seems rather unlikely that we are dealing with a dying radio
galaxy.

We would like to point out here that the estimate of the radiative age
in Tab.~5 is based on the assumption
that the energy losses due to the source expansion can be neglected,
and that the spectral steepening is due to electron aging in a magnetic
field which is constant and uniform across the source.
The role of a decreasing magnetic field along the source structure
has been considered in alternative models for classical double radio
galaxies (e.g., Blundell \& Rawlings 2000, and references therein),
where the magnetic field decrease is reflected in a steepening of
the spectral index, with no direct implication for the source aging.

A detailed calculation of the evolution of the electron energy
spectrum under the combined effect of radiative losses and adiabatic
expansion is difficult, and it is beyond the purpose of the present
work. However, we can derive a crude estimate of the effects of
possible expansion losses in 4C\,+24.36 by considering that the cross
section of the radio plasma increases by a factor of $\sim$2 in the
transition from the jets to the lobes (Fig.~\ref{fig:hr_image610}; Tab.~3).
If we further consider that the Inverse Compton losses are as important
as synchrotron losses ($\rm B \sim B_{CMB} = 3.4$ $\mu$G; Tab.~5), we may
expect that the break energy could be lower by an extra factor of $\sim$ 0.6 due
to the expansion of the source. Moreover, because of the conservation of
the magnetic field flux, we would expect a decrease of the magnetic field
strength by a factor of $\sim$ 0.25. The combination of these effects
would lead to a break frequency which is about one order of magnitude lower
with respect to the case in which there is no expansion of the source.
As a result, given that $\rm t_{rad} \propto \nu_{br}^{-0.5}$
(Eq.~\ref{eq:trad}), the age of the source would artificially appear a
factor of $\sim$ 3 higher than its real value. This implies that in the
case of 4C\,+24.36, the real age would be of the order of $\sim$ 50 Myr.
Thus the age reported in Tab.~5 should be considered an upper limit to
the real age of the source, and consequently the computed velocity
growth as a lower limit.

\section{Gas heating at the core of AWM\,4?}\label{sec:xray}

The XMM--Newton observation of the core of AWM\,4 (Obs. ID. 0093060401;
OS05) reveals that the ICM is isothermal at about 2.5~keV out
to at least 160 kpc from the center, even though the cooling
time in the middle is about 2~Gyr. In such systems, to account for
the absence of the establishment of a cool core, many possible heating
mechanisms have been proposed, including gravitational heating due to
orbital motion and dynamical friction (e.g., Dekel \& Birnboim 2008),
galaxy and sub-cluster mergers (e.g., G{\'o}mez et al. 2002),
supernovae (e.g., Efstathiou 2000), turbulent mixing in the ICM
(e.g., Kim \& Narayan 2003a), thermal conduction from the outer parts
of the cluster (e.g., Kim \& Narayan 2003b), and conduction of energy
from cosmic rays (e.g., Guo \& Oh 2008). However, the most promising
energy injection models invoke the presence of a central AGN, and various
modes of transport of the output energy from the supermassive black hole
to the ICM have been considered (e.g., Binney \& Tabor 1995; Roychowdhury et
al. 2004; Mathews et al. 2004; Nusser et al. 2006; Jetha et al. 2008).
Here we conclude the detailed study of the remarkable radio galaxy 4C\,+24.36,
in the core of the relaxed yet isothermal cluster AWM\,4, by assessing
the role of the AGN in the prevention of the establishment of a
cool core in this system.

\subsection{4C\,+24.36 and the cluster environment}\label{sec:environment}

The overall optical properties of AWM\,4 have been investigated by
Koranyi \& Geller (2002). It is a relatively poor cluster containing
about 30 members centered on NGC\,6051, within a projected radius of
$0.5\,h^{-1}$ Mpc, with a velocity dispersion of $\sigma_{\rm} = 439$
km s$^{-1}$ (Tab.~1). Morphological segregation is clearly evident
within the cluster galaxy population, with the early--type galaxies more
concentrated toward the core region (i.e., around NGC\,6051) than the
late--type galaxies. No substructure has been detected in the projected
galaxy distribution and/or in the velocity space, suggesting that AWM\,4
is a relatively relaxed cluster, which has not recently experienced major
mergers or infall of substantial subclusters.
\\
The relaxed nature of this system is further supported by the
analysis of the XMM--Newton observations of the cluster by OS05
(see also the recent study by Gastaldello et al. 2008). In
Fig.~\ref{fig:xmm}, we show the XMM--Newton image of AWM\,4
(contours, adaptively smoothed from a combination of the MOS and PN
data), on which the GMRT 610 MHz image of 4C\,+24.36 (grey scale) has
been superposed. The cluster X--ray surface brightness shows a very
regular and relaxed appearance free of any visible substructures,
with a steep increase of the brightness toward the center. The radio
source extends over the whole core region of the cluster (core radius
$\sim 70$ kpc as provided by the fit of the X--ray surface brightness
to a single hydrostatic $\beta$ model; OS05). No significant feature
in the hot gas distribution seems associated with the region filled by
the radio emission or surrounding it. In particular, at the location
of the radio lobes, we do not observe any depression in the X--ray
surface brightness, which might indicate the presence of cavities in
the ICM, evacuated by the radio galaxy, as is often observed in many
relaxed clusters and groups of galaxies (see for instance the reviews
by Blanton 2004, McNamara \& Nulsen 2007, and references therein).

\begin{figure}
\centering
\plotone{f11.eps}
\caption{Overlay of the grey--scale radio image
at 610 MHz of 4C\,+24.36 (same as Fig.~\ref{fig:hr_image610})
on the X--ray contours of AWM\,4 from the XMM--Newton
adaptively smoothed image, obtained by combining the
observations with
the PN and MOS cameras. The X--ray contour levels
are logarithmically spaced by a factor $\sqrt{2}$ .}
\label{fig:xmm}
\end{figure}

\subsection{Pressure balance}

\begin{figure}
\centering
\plotone{f12.eps}
\caption{Radial profile of the thermal gas pressure
in the central region of AWM\,4 from the XMM--Newton
data (O'Sullivan et al. 2005). The dashed error
region is for 1$\sigma$ uncertainties. Dashed lines
indicate the minimum synchrotron pressure in the radio
jets and lobes of 4C\,+24.36.}
\label{fig:pressure}
\end{figure}

Fig.~\ref{fig:pressure} shows the profile of the thermal
gas pressure ($\rm P_{gas}$) as a function of the distance
from the cluster center, inferred from the best fitting
X--ray temperature and density models as part of the mass
analysis described in OS05. In this plot, we also show the
minimum pressure $\rm P_{min}$ of the radio
jets and lobes of 4C\,+24.36 (dashed lines), estimated assuming
equipartition arguments (Sec.~\ref{sec:parfis}; Tab.~6). From
Fig.~\ref{fig:pressure} it is clear that the jet minimum
pressure is comparable to $\rm P_{gas}$ over most of the jet
length. On the contrary, the radio lobes appear underpressured
with respect to the external medium by a factor ranging
from $\sim$3 to $\sim$5. We point out that the assumption
of standard equipartition equations, i.e., without the
low--energy cut--off of $\rm \gamma_{min}$ in the electron energy
distribution (Sec.~\ref{sec:parfis}), would lead to
a higher pressure imbalance in the lobe regions of the
order of $\rm P_{gas}/P_{min} \sim 6-12$. We also notice
that projection effects are not expected to play a
significant role in the comparison in Fig.~\ref{fig:pressure},
as the source is approximately in the plane of the sky
(Sec.~\ref{sec:theta}).

A similar lack of pressure balance has been found in the large
scale components of other FRI radio sources, where, based
on standard equipartition arguments, the ratio $\rm P_{th}/P_{min}$
is usually $>1$, with values up to $\sim$100 (e.g., Feretti,
Perola \& Fanti 1992). This suggests a departure from the
minimum energy condition within the radio lobes. In particular,

\begin{itemize}

\item[{\it i)}] the lobes could be far from equipartition,
with a higher relativistic particle or magnetic field energy
density.

\item[{\it ii)}] Assuming that equipartition still holds,
the lobes may contain an energetically dominant population of
non--radiating relativistic particles (protons) which contribute
to the internal pressure. The minimum pressure is a weak function
of the energy ratio $\kappa$ between relativistic protons and
electrons, i.e., P$_{\rm min} \propto (1+\kappa)^{4/7}$.
The values of P$_{\rm min}$ in Tab.~6 were estimated
assuming $\kappa=1$. Thus, in order to achieve pressure balance
in the lobe regions of 4C\,+24.36, we should require a
contribution of relativistic protons such as $\kappa \sim$ 6--22,
which is in agreement with the estimates for other radio
sources of similar luminosity (e.g. Feretti, Perola \& Fanti 1992).

\item[{\it iii)}] The balance could also be achieved (in the equipartition
hypothesis) assuming that the plasma has a filling factor
$\phi \sim 0.05$--$0.2$ (according to P$_{\rm min} \propto
\phi^{-4/7}$), instead of unity. Filamentary structures
have been detected in high resolution radio images of a number of
radio sources which may indeed indicate filling factors smaller
than 1 (e.g., Fornax A; Fomalont et al. 1989; M87, Hines, Owen \& Eilek 1989).

\item[{\it iv)}] An additional pressure component might be
provided by the presence of thermal plasma within the lobes. The
jets could accrete material as they move through the external
medium (e.g., Bicknell 1994) and transport it into the lobes.
This would be in line with the fact that the pressure imbalance
increases with the distance from the nucleus (Fig.~\ref{fig:pressure}).

\end{itemize}

\subsection{Energy output from 4C\,+24.36}

The analysis of the {\it XMM-Newton} observations in OS05
revealed that AWM\,4 occupies an unusual place among groups and clusters (see
also Gastaldello et al. 2008). The combination of the regular X--ray
emission and monotonic increase of brightness toward the center would
usually suggest a relaxed cluster with a well--established cool core.
Such an expectation would be further supported by the abundance profile
which shows a clear metallicity decline going from the cluster center
to larger radii (OS05; Gastaldello et al. 2008). However, the X--ray
spectral fitting reveals that AWM\,4 does not possess a cool core.
The azimuthally averaged temperature profile is approximately constant
out to a distance of at least $\sim$160 kpc from the center, without
any sign of the substantial temperature drop in the center expected in
an ordinary cool core cluster (OS05; Gastaldello et al. 2008).

Given the absence of any significant signature of a recent merger
event which may have disrupted the cool core in AWM\,4
(Sec.~\ref{sec:environment}), OS05 suggested that the AGN in the
central galaxy NGC\,6051 has been active for enough time to (re--)heat
the surrounding gas in the core. Assuming that a cool core existed
in the cluster before the re--heating process, OS05 estimated
that the total energy required to produce the observed isothermal
profile is $\sim 9 \times 10^{58}$ erg.

Using a spectral index $\alpha=0.5$ (consistent with the injection
spectral index provided by the spectral fit; Tab.~5), we calculate
the total radio luminosity of 4C\,+24.36 over the frequency range
10 MHz--100 GHz to be L$_{\rm radio} \sim 5.8 \times 10^{41}$
erg s$^{-1}$. In Sec.~\ref{sec:parfis} we estimate a synchrotron
lifetime of the radiating electrons in the source of $\rm t_{rad}
\sim$ 160 Myr (Tab.~5). This value implies that the energy deposited
in the ICM by the source over its lifetime is E$_{\rm tot,\, radio}
\sim 2.9 \times 10^{57}$ erg. Thus the radio source seems to be at
least a factor of $\sim$30 too underluminous to balance the cooling in
this system. Indeed, in the sample of clusters studied by B\^irzan et
al. (2004, see also McNamara et al. 2007), the median ratio of the jet
power to the synchrotron power is  $\epsilon\sim 120$, the mean
value $\langle \epsilon \rangle\sim 4700$ being dominated by a few
extreme cases. In the case of AWM4, we should point out that this ratio
could be much higher than 30, if we consider that the age of the source
might be up to $\sim$ 3 times less than the value of 160 Myr quoted
above, as we have discussed in Sec.~\ref{sec:age}.

On the other hand, the total energy output of a radio source can be
considerably higher than what estimated from its synchrotron luminosity,
since the total radio power is thought to be dominated by the mechanical
work done by the jets on the ICM during the source expansion (e.g. Scheuer 1974).
One mode of doing so is by inflating bubbles filled with a relativistic fluid
in the ICM, which would expand and rise, imparting energy to the ICM
(Churazov et al. 2002,  Nulsen et al. 2003, Nusser et al. 2006, McNamara
\& Nulsen 2007). This is supported by the direct detection of significant
cavities in the X--ray surface brightness of several clusters, which might
represent these rising bubbles (Fabian et al. 2000,
B\^irzan et al. 2004 \& 2006, Allen et al. 2006, Gitti, Feretti \& Schindler 2006,
Jetha et al. 2008).

The enthalpy H of a rising adiabatic bubble is the sum of the $pV$ work
done to displace the X--ray emitting gas, and its thermal energy, and
is given by $\frac{\gamma}{\gamma - 1} pV$, where $p$ is the pressure of
the surrounding ICM, $V$ the volume of the bubble and $\gamma$
the ratio of specific heats of the gas. For an ideal
relativistic gas,
$\gamma\!=\! 4/3$, and $H=4pV$. In case of a non-relativistic
plasma filling the bubble, and also in the presence of significant
magnetic fields in the lobes, the value of enthalpy
could be a factor of 2 lower. Churazov
et al. (2002) argue that almost all of this enthalpy can be
transferred as thermal energy to the ICM.

To assemble the equivalent of $\sim 9 \times 10^{58}$~erg of mechanical
energy, which is needed to produce the isothermal profile in the core of
AWM\,4, as estimated by OS05, with the lobe pressure being $p=3.1\times
10^{-13}$ dyne~cm$^{-2}$ (see Table~6), would require the entire
enthalpy ($=4pV$) of a spherical bubble of radius of over $\sim$80
kpc. Inflating this bubble against a pressure as high as jet
pressure, which is an order of magnitude higher, would require a bubble
of half this size, whereas a value of enthalpy that is lower than
$4pV$ would only require a larger bubble. Such an extensive
displacement of plasma in the ICM would be easily apparent in the
{\it XMM--Newton} observation of AWM\,4, where no such features are seen
within the inner 200~kpc, in the gas associated with the radio lobes
of 4C\,+24.36. Even if the heating is due to an abundance of buoyant
bubbles, the larger ones should have been evident in the deep X--ray
image. A forthcoming deep X--ray observation (80 ks) at higher
angular resolution, to be obtained by {\it Chandra} during Cycle~9,
will possibly yield a better insight into the presence or absence of
cavities in this system.

\section{Summary and Conclusions}\label{sec:summary}

In this paper we presented a detailed morphological and spectral
analysis, at radio wavelengths, of the WAT radio galaxy 4C\,+24.36,
located at the core of the poor galaxy cluster AWM\,4, based on new
high sensitivity observations at 235~MHz, 327~MHz and 610~MHz, using
the GMRT, and literature and archival data at other frequencies.

The large scale source structure appears bent in a very similar WAT
morphology at all frequencies, and all resolutions afforded by
our GMRT images. We interpret this bending to be the result of the
interplay of ram pressure (driven by the motion of the host galaxy
NGC\,6051) and buoyancy forces. In the framework of this model, we
estimate that the velocity of the galaxy NGC\,6051, with respect to
the cluster, is $ \,{}^<_\sim\, $ 120 km s$^{-1}$, in the plane of the
sky. Combined with the upper limit on the radial velocity of
NGC\,6051, which is $ \,{}^<_\sim\, $ 20 km s$^{-1}$ with respect to the mean
radial velocity, out to $0.5\,h^{-1}$~Mpc, of the cluster AWM4
(Koranyi \& Geller 2002), our result indicates that the galaxy is
expected to be relatively at rest in the potential well of the
cluster.

On the small scale, the radio jets show prominent symmetric
oscillations within the central $\sim$25 kpc from the core. An
appealing possibility to explain these features is the development of
Kelvin--Helmholtz helical instabilities propagating along the
jets. However the resolution of our images is not high enough to
investigate the fine structure of the jets, and to determine the
characteristics of a possible distortion wave. Deep radio observations
at higher resolution, combined with polarisation information, are
necessary to carry out a more detailed analysis of the jet regions.

Combining the new GMRT observations, with data from the
literature at various other frequencies (see Tab.~4), we derived the
broadband radio spectrum of 4C\,+24.36, and found that it is
well fitted by a power--law with $\alpha=0.82 \pm 0.03$ between
74 MHz and 10.7~GHz.
From the GMRT images at 235 and 610 MHz, evaluating the spectral
index distribution at discrete intervals along each jet, we showed
(Fig.~7) how the spectral index gradually steepens along the jet to
about $0.9\pm 0.1$ where the jets merge into the lobes, and further
steadily steepens within the lobes to $\alpha \!>\! 1.5$.

Assuming equipartition of energy between the relativistic particles and
the ambient magnetic field, and adopting a lower energy cutoff equivalent to
the minimum Lorentz factor of the radiating electrons ($\gamma_{\rm min}$=10,
$E_{\rm min}\sim 5$ MeV), we find that the equipartition value of
the magnetic field varies between 3 to 9$\mu$ G from the lobes to the jets.
The radiative age for  4C\,+24.36 was found to be around 160~Myr from
this estimate.

We used the jet to counterjet brightness ratio to constrain the
geometry and velocity of the jet. Assuming a typical value for the
inner jet velocity in WAT radio galaxies, we found that the source is
likely oriented at a large angle ($\sim$ 81$^{\circ}$--88$^{\circ}$)
with respect to the line of sight. This result is consistent with the
high level of symmetry found in the total flux density, extent,
spectral index properties and physical parameters of the lobes and
jets.

Even though the host cluster AWM04 has a hot X--ray emitting ICM
of relaxed morphology and uniform temperature profile out to
at least 160~kpc from the center, its cooling time in the core
is about 2~Gyr, indicating the presence of significant sources of
energy injection that prevents the catastrophic cooling expected in
the core of the cluster. Based on the above values of the jet power
and the estimated radiative age, the total energy output from the
radio source falls short by almost two orders of magnitude
of the energy required for the isothermal temperature profile
obtained from the {\it XMM--Newton} observation of the cluster.
The latter observation enables us to measure the pressure of the hot
gas as a function of radius within the cluster, which is found to be
comparable to the pressure in the jets over most of their lengths, but
higher than the pressure in the lobes by a factor $>$5.  Several
interpretations of this pressure imbalance are discussed. Finally, it
is found that for any reasonable value of gas pressure in the range
between the value in the lobes and that in the jets, if the
central source were to transfer mechanical energy to the ICM, in terms
of the enthalpy of buoyant bubbles of relativistic fluid, it would
require bubbles of tens of kpc in radius, which would have been detected
in the existing XMM-Newton observations of O'Sullivan et al. (2005). We look
forward to a forthcoming deeper {\it Chandra} observation of this system
for further insight into morphological evidence of this energy transfer.

\acknowledgments

We thank the staff of the GMRT for their help during the observations.
GMRT is run by the National Centre for Radio Astrophysics of the Tata
Institute of Fundamental Research. E.O'S. acknowledges support from NASA
grant NNX06AE90G. J.M. Vrtilek acknowledges support from NASA
grant NNX07AE95G. Basic research in radio astronomy at the NRL is
supported by 6.1 Base funding. We would like to thank R. Fanti,
G. Brunetti and M. Markevitch for useful discussion. This research has
made use of the NASA/IPAC Extragalactic Database (NED) which is operated
by the Jet Propulsion Laboratory, California Institute of Technology.
The authors made use of the database CATS (Verkhodanov et al. 1997) of the
Special Astrophysical Observatory (Russia).

redpajama_set_name: RedPajamaArXiv


text:
Cincinnati Gazette
The Best of Cincinnati and Northern Kentucky
James Partin February 11, 2017
Summerland at Cincinnati Playhouse in the Park
The world premiere of the mysterious and suspenseful new play Summerland by Arlitia Jones debuts Feb. 4 and runs through March 5 at Cincinnati Playhouse in the Park's Thompson Shelterhouse Theatre.
Based on mesmerizing true events, Summerland tells the riveting tale of William H. Mumler, a spirit photographer with a talent for taking haunting images of ghostly visitors. Set in 1869, the story follows Mumler's meteoric rise and fall, from his wildly successful studio business, which boasted Mary Todd Lincoln as a client, to his indictment for fraud.
"Arlitia Jones has written a fascinating story," says Associate Artist Michael Evan Haney, director of the play. "When I first read Summerland, I was hanging on every word, not knowing what was going to happen. Coming right after the Civil War and the advent of photography (a mysterious new technology), there was a real belief that we could break through the veil and talk to people who had passed on to the other side. Whatever you think about the afterlife, this play makes you think about what we believe and don't believe."
Jones is an award-winning poet, playwright and co-founder of TossPot Productions in Anchorage, AK. The spirit photography used by Mumler that inspired her story can be traced to American Spiritualist Movement, which peaked from the 1840s through the 1920s. Followers of the movement believed that the dead have the ability to communicate with the living.
Tickets for Summerland start at $35; prices vary depending on seat location and performance day and are subject to change. Tickets for teens and students are $30. Student tickets are just $15 on the day of the show. Sunday is College Night, with Summerland Page 2 tickets to all 7 p.m. performances just $10. In addition to calling the Box Office (513-421-3888), tickets can also be purchased by visiting the Playhouse website at http://www.cincyplay.com.
Summerland is sponsored by Barbara and Bill Weyand. Leon Meyer serves as Honorary Producer. Additional support is provided by The Harold and Mimi Steinberg Charitable Trust. Design Sponsor is JRA.
The 2016-17 Thompson Shelterhouse Theatre season is presented by Heidelberg Distributing Co., and the Thompson Shelterhouse Theatre season design sponsor is the Allan Berliant and Jennie Rosenthal Berliant Family Fund. The season sponsor of new work is the Lois and Richard Rosenthal Foundation.
The Playhouse is supported by the generosity of more than 40,000 contributors to the ArtsWave Community Campaign. The Ohio Arts Council helps fund the Playhouse with state tax dollars to encourage economic growth, educational excellence and cultural enrichment for all Ohioans. The Playhouse also receives funding from the Shubert Foundation and the National Endowment for the Arts.
Arcade Bar in Cincinnati
Pyramid Hill Light Show!
Christmas Pasta!
Michael W. Smith Christmas Special
It's beginning to look alot like Christmas!
James Partin on Goodbye My Bad Ass Gentle…
James Partin on An Evening with Groucho at Cin…
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Views of Taste of Cincinnati 2019
Get your BUZZZZZZZZZZZzzzzzz On! Liquid Sweetness Part 1
Star Wars Smithsonian exhibit coming to Cincinnati Museum Center

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text:
Why the Fed Didn't Change Interest Rates
By Reuters On 6/15/16 at 7:19 PM EDT
A man walks past the Federal Reserve Bank in Washington, D.C., December 16, 2015. Kevin Lamarque/File Photo/Reuters
Business Federal reserve Janet Yellen Interest rates Banks
WASHINGTON (Reuters) - The U.S. Federal Reserve kept interest rates unchanged on Wednesday and signaled it still planned to raise rates twice in 2016, though it said slower economic growth would crimp the pace of monetary policy tightening in future years.
The central bank's decision to stick with its 2016 rate path, however, appeared shakier, with six of its 17 policymakers projecting just one increase this year. Only one Fed policymaker had done so when economic forecasts were last issued in March.
A sharp slowdown in U.S. hiring in May had fueled doubts about the strength of the labor market going into the Fed's two-day policy meeting. Fed Chair Janet Yellen acknowledged the need to see clear signs of economic strength before lifting rates.
"We do need to make sure that there's sufficient momentum," Yellen told a news conference.
The Fed also said the economy would grow only 2 percent this year and in 2017, 0.1 percentage point lower than previously forecast for each year.
It also cut its longer-term view of the appropriate federal funds rate, its benchmark lending rate, by a quarter point to 3 percent and indicated it would be less aggressive in raising rates after the end of this year.
Yellen was not clear on whether a rate increase could come at the next policy meeting in late July or whether the central bank would wait for a slew of firmer data as it headed into its September meeting.
"I'm not comfortable to say it's in the next meeting or two, but it could be," Yellen said. "It's not impossible that by July, for example, we would see data that led us to believe that we are in a perfectly fine course."
Yellen said the U.S. economy appeared to have gained momentum since April, but that the labor market had lost some steam.
She acknowledged Britain's possible exit from the European Union was one of the factors in the latest rate decision, saying the June 23 referendum would have "consequences for economic and financial conditions in global financial markets."
Financial markets all but priced out a rate increase this year after the Fed statement, and U.S. short-term interest rate futures contracts rose. U.S. stocks closed lower.
'LITTLE STOMACH'
The rate decision was unanimous, with Kansas City Fed President Esther George, considered among the policymakers most eager to raise rates, voting with her colleagues on the FederalOpen Market Committee (FOMC). George dissented at the prior two meetings.
"This FOMC clearly has little stomach to raise rates," said Stephen Stanley, an economist at Amherst Pierpont Securities.
The Fed's benchmark overnight lending rate remains in a range of 0.25 percent to 0.50 percent.
The central bank raised rates in December for the first time in nearly a decade and initially signaled four increases were likely for 2016. Concerns about a global economic slowdown and volatility in financial markets subsequently reduced that number to two.
Worries about the health of the global economy have eased, however, and more recent U.S. data have indicated that last month's jobs report may have been a blip.
Economists polled by Reuters had seen virtually no chance that the Fed would raise rates on Wednesday.
Cyber Breaches Plague Federal Reserve, Records Show
Paul, Sanders Join Forces Against Federal Reserve
Bernie Sanders: Bankers Have 'Hijacked" the Fed


text:
Aegeon
Brendan Heard
Iásonas Lupus
The Roman Family Clan
"I do not think that any unprejudiced man will deny that the Roman family is one of the most glorious achievements of the human mind, one of those heights which cannot be scaled twice, and to which the most distant generations will look up in admiration, making sure at the same time that they themselves are not straying too far from the right path" – Joseph Chamberlain
If one were interested in reviving or re-imagining the Roman family model, one must adopt a certain pagan view to life, at least in the veneration of family itself, in the observance of rites to ancestors. In addition one must think, always, towards building a framework for future family, as the hereditary extension of the individual soul. The larger, more important part of it.
There is no reason for Christians to not consider this, keeping in mind the more archaic habits of their worship link back to pagan times, and a good deal of their values are traceable to Platonism. Christians associating 'all things pagan' with the devil is a doctrine they need to revise, much as other biblical claims have also required revision.
To see worth in oneself is to wish to see it magnified in one's children and descendants. Personalized, unique family sigils, logos, house gods, mannerisms, fashion, art, and culture should be the goal of the sitting patriarch of any clan. Not the homogenization of the family to 'fit in', in all manner and habit, with the flabby conglomerate mass of the TV-directed 'public'. Necessary imitation of the mass is the illusion of the false culture, a remnant from times when the nation was the larger family. Now they are only the dancing marionettes of the borderless economic-zone.
In Roman times the country at large could be said to be a family extension. Sadly this has (for now) dissipated, and the clan-limit is very much closer. While the gibbering, soft-hearted globalists believe they make the world one big family, they instead make each family a more isolated island. Regardless, this essential genealogical strength is the foundation of the larger organism, and of everything worthwhile in life.
In the Roman conception of the family, the godfather of the extended family is the priestly patriarch of Jupiter – performing fire-rituals to the sky father with his sacred dagger, while giving offerings to the gods and the ancestral spirits of the dead. For those of a more Catholic extraction something like this should not be out of the question, or at least, not to be expected from a worthy godfather.
Young members of the family clan MUST study classical literature and philosophy, otherwise what they are doing is not education at all. They must become accustomed to ancient virtues (the only virtue). The family should create its own sacred rituals and cultivate a personal patriarchal concept of familial valor, so that the family name can gain honour, and retain it as blood-earned and sacrosanct. Minor families who cultivate a eugenic heredity of values can accumulate honour, which can be then blood-bound to their name. The true tenets of honour do not revolve around simplistic pities and petty forgivenesses.
The Roman head of the family (the pater familias) was in charge of even adult males in the familia (including slaves). Today such apater familias would be equally responsible for transmitting the family morality, reputation, and heirlooms across generations, to safeguard the passing of these in hopes that they increase. To fail in this due to selfishness is a paramount sin. But just like everything else, no family is functional without the order of hierarchy.
There is nothing more important than strong families and communities. What is the opposite? It is the lone commodified individual. It is the obese lesbian who learned she can 'have it all' from Sex and the City', or the anemic bugman who learned about valor from marvel films. Both sterile, aspiritual, vapid, and morbidly indulged. A genealogical dead-end of the blood.
This atomization of the family clan occurs by instilling rebellion in the young, who are naturally predicated to rebellion, of a certain sort. But it can incite them to rebel against everything good, everything they need, in the confusing chaos of the outer-family (the larger clan, or country) being at war with the immediate family.
Evil enters our societies in gradual steps, by cleverly disguising itself as compassion, to people with no conception of nuance, who have only a superficial (or symbolic) grasp of concepts. People who believe they are being 'good' because they use the word 'good'. True good, in the classical sense, is a deep understanding of a long term blood-good, the determination of which requires, above all, balance. Part of that balance is understanding the absolute necessity of taking action, and making hard decisions, for a better future.
This is why the family clan must keep their ritual fire of worship burning, so the unique ancestral folk wisdom remains for generations to come. Genuine change is incremental, not radical. The Romans educated their own young, and tended their own hearth, and were there to venerate and remember their own deceased ancestors. Somebody in the future who is blood-connected must venerate those who have passed, to keep cohesion of the larger organism.
Every pairing of a man and woman is the potential seed of an empire, both personally and in a wider sense.
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The Leftist Desire To Rewrite History
INFOWARS, MEMETICS & HEGEL December 21, 2022
Thoughts on Italo Calvino's The Complete Cosmicomics: an Italian Phantasm December 19, 2022
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Pagan Futures: London June 25, 2022
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Molidustat ist ein HIF-Prolylhydroxylase-Inhibitor, der die Produktion von Hämoglobin und Erythrozyten stimuliert. Es wurde im Januar 2021 in Japan unter dem Namen Musredo (Bayer Yakuhin) zugelassen zur oralen Behandlung der Anämie ("Blutarmut") infolge einer chronischen Nierenerkrankung (CDK).

Hintergrund
Anämie ist eine häufige Komplikation einer chronischen Nierenerkrankung, da die in ihrer Funktion gestörten Nieren nicht mehr genügend Erythropoietin (EPO) produzieren, um den normalen Gehalt an roten Blutkörperchen aufrechtzuerhalten. Die Leber ist nicht in der Lage, die verminderte EPO-Produktion der Nieren zu kompensieren. EPO bewirkt die Produktion von Hämoglobin und roten Blutkörperchen (Erythrozyten) und sorgt somit für die Sauerstoffversorgung der Gewebe. Seit der Einführung in die klinische Anwendung im Jahr 1989 ist das rekombinante humane EPO (rhEPO) zur Standardtherapie der renalen Anämie geworden, die jedoch mit einem erhöhten Risiko für kardiovaskuläre Ereignisse verbunden sein kann.

Wirkungsmechanismus
Molidustat ist eine niedermolekulare Verbindung, deren Struktur ausgehend von Treffern aus dem Hochdurchsatz-Screening entwickelt wurde. Zielstruktur ist das Enzym HIF-PH2 (hypoxia-inducible factor prolyl hydroxylase 2, auch PHD2, prolyl hydroxylase domain-containing protein 2, genannt). Der Hypoxie-induzierter Faktor (HIF) ist an der Regulation der Sauerstoffversorgung der Zellen beteiligt. Bei normaler Sauerstoffversorgung (Normoxie) ist eine Untereinheit des HIF an zwei spezifischen Prolyl-Resten hydroxyliert – katalysiert durch die Prolylhydroxylase 2. Bei mangelnder Sauerstoffversorgung (Hypoxie) ist die Hydroxylierung der HIF-Untereinheit gehemmt, in deren Folge die Erythropoietin-Bildung aktiviert wird.

Molidustat hemmt HIF-PH2 und täuscht dadurch einen Sauerstoffmangel vor. Dies bewirkt eine vermehrte Bildung von Erythrozyten.

Sonstiges
Die Entwicklung von Molidustat für die Anwendung außerhalb Japans wurde abgebrochen. Pharmazeutisch eingesetzt wird das Molidustat-Natrium. HIF-PH-Hemmer ("HIF-Stabilisatoren") könnten potentiell zur Leistungsbeeinflussung bei Ausdauersportlern – vergleichbar mit dem EPO-Doping – missbraucht werden.

Siehe auch
 Vadadustat
 Roxadustat

Einzelnachweise

Arzneistoff
Morpholin
Triazol
Dihydropyrazolon
Pyrimidin

redpajama_set_name: RedPajamaWikipedia


Once you enter this 'end of the road' property, you will experience a unique ocean and canal front getaway. The main house, with 3 bedrooms and 3 baths, features 180 degree, unobstructed views of the Atlantic Ocean including Indian Key and Alligator Light. The adjacent 'cottage' house has 2 bedrooms and 1 bath. This recently renovated property accommodates large families, groups and water enthusiasts. The recently renovated dock provides nearly 220 feet of canal dockage with two boat slips and a fish cleaning station. The location and water access is ideal for boating, diving, fishing and water sports. Bird and nature enthusiasts will also enjoy this spot.The large deck is the perfect spot for sipping cocktails with friends and family, or catching a spectacular sunset!


The South African telecommunications is currently moving towards greater liberalisation – but it is still unclear whether this will result in more competition or fizzle out as a damp squib.
BMI-TechKnowledge has announced the publication of its latest report, "SA Telecommunications Services Changing Landscape", which focuses on the changing telecoms regulatory environment in South Africa and the resulting changes in the market.
According to Fezekile Mashinini, co-author of the report, the telecoms market can be said to be in "the second wave of sector reform", a stage that is normally characterised by a more vigorous move towards greater sector liberalisation.
However, the question that may be asked is whether this will induce a radical shift in competition levels, or a somewhat muted reaction from the industry, which some players have called a "damp squib".
While the market outlook for telecommunications services is looking positive and competitive – for instance like broadband services have enjoyed significant price cuts over the past year and a half, coupled with new services from Neotel and Telkom – the danger remains that heightened takeover activity could be seen in the near term as bigger players attempt to consolidate their market positions.
Icasa has been busy with licence conversions and issuing of draft regulations on issues such as market definitions and pricing, the report states.
The biggest recent development was the Pretoria High Court's ruling that former Value-Added Network Service providers (VANS) must be allowed to self-provide. While the industry applauded the ruling as a majot step towards liberalisation, it remains to be seen if and how the market will open up in light of this development.
It is significant that not all VANS will be able to afford their own networks, with a likely scenario being a combination of own network and a leasing model.
Although the self provision ruling has a potential of increasing competition in the market, BMI-T believes that – due to the already heightened levels of competition in the market and the high cost of network roll-out – very limited new rollout will be seen from the new I-ECNS licensees.
Global experience has shown that infrastructure-based competition is most effective in terms of bringing down rices in telecoms markets, but Icasa will also need to speed up services-based competition by means of its facilities leasing regulations coupled with favourable wholesale pricing, according to the market researcher.
The overall market outlook is positive, says the report, with all the different segments forecast to exude growth over the forecast period.
Combined fixed and mobile revenues for out of bundle minutes are forecast to grow at a CAGR of 4,5% with the individual fixed and mobile segments growing at -1,9% and 7,2% respectively.
Expectations are high that with the pending commissioning of the Seacom undersea cable in June 2009, international bandwidth prices will be reduced thereby allowing service providers to either reduce their retail prices or offer significantly more bandwidth at the existing prices.


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Advertising & Marketing Agency SWOPEX
SWOPEX Agency is a public relations and digital communications agency.
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This entry was posted in media on June 28, 2019 by ad.
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Why is Lindsay Lohan so obsessed with Taylor
Swift? Actress basically hijacks singer's Instagram Live.
Taylor Swift might have been keen to get on her Instagram and chat together with her fans last night, as she released a recent single; however she has no bigger fan than Lindsay Lohan by the looks of things.
Or, no larger troll, depending on how you dissect Lindsay's overzealous commenting on Swizzle's video overnight.
As 29-year-old Taylor had a chat along with her band of loyal followers, 32-year-old Lindsay logged on and began leaving a swag of messages, encouraging Taylor to respond.
We don't want to bring in a Mean girls reference (who are we kidding, yes we do) but, like, why are you so obsessed with Taylor, Lindsay?
As she began her dive for Swift, she was drowned out by a lot of other punters keen to make their voices detected in the chatter.
Keen to make sure she got a look in, Lindsay wrote: 'Omg love you! So does my sis @alianalohan'.
And again: 'We think you're nice.'
Cool it, Lindsay, stop attempting to make Taysay happen.
What Libra cryptocurrency means for users.
It will be on the market sometime in 2020.
Would you trust Facebook with your money?
On Tuesday, Facebook confirmed it would launch a digital global currency kind of like Bitcoin, called Libra, aimed at users around the world who don't have bank accounts.
But there's one more reason Facebook is introducing Libra, said Wedbush analyst Michael Pachter: It's an opportunity to get some of its over 2 billion users to shop through the platform.
"Facebook is simply making an attempt to facilitate commercial activity for its customers, and the endgame is to offer links to brands they care about," he said.


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1 sent to hospital after shooting in Harvey Park neighborhood
The victim has non-life threatening injuries and there is no information on the suspect, according to DPD.
Author: Caitlin Hendee
DENVER — One male victim was transported to a nearby hospital after a shooting in the 2500 block of Osceola Street, according to the Denver Police Department (DPD).
That's near South Osceola Street and West Harvard Avenue in Denver's Harvey Park neighborhood.
The victim has non-life-threatening injuries, DPD said.
DPD has not released suspect information and said the investigation is ongoing. No arrests have been made.
SUGGESTED VIDEOS | Local stories from 9NEWS


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Strange Wilderness
Steve Zahn, Jonah Hill, and Justin Long star in a film written by Peter Gaulke and Fred Wolf and directed by Wolf.
By Indy Staff
Thu Feb 07, 2008 | 6:00am
Self-respecting intellectuals (and pseudo-intellectuals) may not fess up to it, but there's a strange, kinda goofy charm to be found in a romp like Strange Wilderness. Check your dignity at the door, and you may find yourself laughing in spite of yourself, sinking into the blissful world of Stupid Cinema, a no-brains-no-headache subdivision of the comedy omniverse. No, the film does not fit into the lucrative "Land of Apatow"-the hormonal/misogynistic capers seen in box office smashes Knocked Up and Superbad-although the cast does include Superbad's Jonah Hill. Strange Wilderness is lower than that niche, or at least off to the left of it.
Basically, it's a mindless satirical take on a ripe target, which surprisingly has remained fairly satire-free throughout the years: the phenom of the wildlife television program. Partymeister Steve Zahn is at the center of the claptrap, as the son of a pioneering wildlife showman with much more skill and dedication than his son has. But hey, it's a gig, and an excuse to cavort with the animals-including a dubious, dope-loving crew. In the narrative yarn of this film, the crew is headed south, in more ways than one, to pursue Bigfoot's rumored hangout in the Andes.
Among the more old-school show-biz types lured into the fray, Ernest Borgnine and Joe Don Baker play bit roles, and Waddy Wachtel cooks up a classic-rocking musical score. Some of the best lines are tucked into the scripts of the episodes, as when Zahn says in his best slacker-stoner voice, "Monkeys make up 80 percent of the world's monkey population," or "sharks are the assholes of the sea." Yes, the humor comes to us directly from the more feckless side of frat comedic sensibilities, but it's also splashed with the liberating stuff of post-Dada absurdity.
You know you're in shallow cultural waters when you find yourself in convulsive laughter while Zahn does a goofy impression of a bucktoothed shark, but you may not want to admit it in public. Oops, I think I just did.
https://www.independent.com/2008/02/07/strange-wilderness/
Josef Woodard
Dying Well 'At Heaven's Door'