text:
\section{Introduction}

The outskirts of galaxy clusters mark the transition from the cosmic
web to the intracluster medium (ICM), where cosmic filaments feed into
the gravitational potential well of the galaxy cluster.  Measurements
of gas properties in cluster outskirts directly probe the formation of
these structures and physical mechanisms that affect the ICM.  A
thorough understanding of these mechanisms at all radii will further
enable cluster cosmology.

The use of clusters as cosmological probes hinges on our ability to
tightly constrain the evolution of the galaxy cluster mass function,
which is sensitive to cosmological parameters \citep[see][for a
  review]{allen_etal11}.  We can exploit self-similar properties of
galaxy clusters to establish relationships between directly observable
properties and the galaxy cluster mass \citep[see][for a
  review]{voit_05,kravtsovandborgani_12}.

The ICM radial profiles of self-similar galaxy clusters resemble one
another when rescaled with respect to mass and redshift dependent
quantities.  When radially integrated, profile quantities can serve as
a proxy of cluster mass.  The self-similar model of galaxy clusters is
based on simplifying assumptions. In reality these assumptions are
broken in our universe's cosmology and through non-gravitational
baryonic processes, such as radiative cooling and star formation.  The
only way to directly probe and exploit self-similar relations is to
self-consistently model galaxy cluster formation and calibrate
observable-mass relations used by observations. To mitigate
complications from baryonic physics that dominate the cluster cores,
observations have pushed to cluster outskirts to potentially recapture
self-similar behavior.  Evidence, however, points to the contrary.

First, X-ray measurements show that the ICM entropy profiles break
from the self-similar power-law scaling with radius at large radii
\citep[e.g.][]{george_etal09,bautz_etal09,reiprich_etal09,hoshino_etal10,
  kawaharada_etal10,akamatsu_etal11,okabe_etal14} contradicting
theoretical predictions \citep{tozziandnorman_01, voit_etal05}.  Next,
the observational analysis of \citet{mcdonald_etal14} presents
evidence of a non-self-similar evolution of ICM properties at radii
larger than ${R}_{500c}$.  With {\em Chandra} data of 80 galaxy
clusters selected from the {\em South Pole Telescope} (SPT) survey,
they found that the outskirts of high redshift clusters have cooler
scaled temperatures than low redshift clusters.  The origin of the
observed temperature evolution is well not understood.

To address the first finding, detailed X-ray observations with {\em
  Suzaku} \citep{simionescu_etal11,walker_etal13,urban_etal14} and
{\em ROSAT} \citep{eckert_etal12,eckert_etal13} provided evidence that
density inhomogeneities in the ICM likely break self-similar entropy
profiles \citep[but see][for a different
  explanation]{okabe_etal14}. In support of observational evidence,
cosmological simulations showed that gas in cluster outskirts are
highly clumpy \citep{nagaiandlau_11,roncarelli_etal13, vazza_etal13}.
This clumpiness boosts the X-ray surface brightness, leading to
overestimates in gas densities and underestimates in entropy
\citep{avestruz_etal14}.  Such ICM inhomogeneities are associated with
overdense infalling substructures such as subhalos and penetrating
filaments \citep{battaglia_etal15, lau_etal15}.

To extend clumping effects to the second finding,
\citet{mcdonald_etal14} proposed that the presence of more accreting
group size halos at higher redshifts drives the evolution of the
scaled outskirt temperatures, an effect called ``superclumping''.
This interpretation is based on the fact that mass accretion rates and
merger frequencies increase with redshift
\citep[e.g.,][]{wechsler_etal02,fakhouriandma_09,tillson_etal11}, and
that group size halos substructures have lower virial temperatures
than host cluster ICM.  At high redshift, these substructures are
usually too dim for X-ray observations to identify and mask out.

On the other hand, a significant fraction of outskirt gas does not
reside in these dense substructures.  Rather, much of the outskirt gas
exists in the form of low density, diffuse gas
\citep[e.g.,][]{zhuravleva_etal13}.  In the outskirts, accretion
shocks convert kinetic energy of infalling gas to thermal energy.
However, not all of the kinetic energy is thermalized by the shocks.
The residual gas motions slowly thermalize through turbulent
dissipation at the dynamical timescale \citep{shiandkomatsu_14}.  As a
result, clusters that experience more recent gas accretion have less
time to thermalize and tend to have a higher fraction of energy in the
form of non-thermal gas motions
\citep{lau_etal09,vazza_etal11,nelson_etal12, shi_etal15}.  Therefore,
the ICM temperature evolution can also depend on the rate at which
these gas motions thermalize.

The aim of this work is to understand the physical mechanisms that
contribute to the observed non-self-similar evolution of temperature
profiles in cluster outskirts from the X-ray observations of the {\em
  Chandra}-SPT cluster sample by \citet{mcdonald_etal14}.  We use a
mass-limited sample of galaxy clusters from a cosmological
hydrodynamical simulation.  Our sample is comparable in mass and
redshift range to the observed cluster sample.  We demonstrate that
non-thermal gas motions in clusters is the dominant contributor to the
observed temperature evolution in cluster outskirts.  Substructure
evolution plays a subdominant role, in contrast to the original
interpretation by \citet{mcdonald_etal14}.

Our paper is organized as follows.  We overview the notions of
self-similarity in Section~\ref{sec:self-similarity} and define ICM
quantities of interest in Section~\ref{sec:pressure}. In
Section~\ref{sec:methods} we briefly describe the simulation and the
radial profile averaging.  We present our results in
Section~\ref{sec:results}, and our summary and discussions in
Section~\ref{sec:conclusions}.

\section{Theoretical Framework}

\subsection{Self-similar model}
\label{sec:self-similarity}

The standard self-similar model by \citet{kaiser_86} describes the
properties of galaxy clusters based on their mass and redshifts.  This
Kaiser model is based on several simplifying assumptions about the
formation of galaxy clusters.  First, galaxy clusters form from
scale-free gravitational collapse of the initial density perturbations
in an $\Omega_m=1$ universe.  Second, the amplitude of initial density
fluctuation is scale-free; i.e., the matter power spectrum is a power
law with $P(k)\propto k^n$.  Finally, there are no additional physical
processes that introduce any scale dependence.  The scale-free setup
of this problem defines a self-similar model where halo properties
depend only on the slope and normalization of the initial density
field at collapse.

Assuming further that the cluster gas is spherically symmetric and is
in hydrostatic equilibrium with the cluster's gravitational potential
well, we can define a characteristic temperature $T_\Delta$, which
relates to the cluster mass as,
\begin{eqnarray}\label{eqn:TM_relation}
  {T_\Delta}\propto
  \frac{GM_\Delta}{R_\Delta}\propto(\Delta\rho_r)^{1/3}M_\Delta^{2/3}.
\end{eqnarray}
Here, $M_\Delta$ is the mass enclosed within a sphere of radius,
$R_\Delta$, both defined with respect to some reference density
$\rho_{\rm r}$ such that,
\begin{eqnarray}\label{eqn:mass_def}
  M_\Delta = \frac{4\pi}{3}R_\Delta^3 \Delta \rho_{\rm r}(z) ,
\end{eqnarray}
and $\Delta$ is the mean overdensity contrast with respect to a
reference density, $\rho_r(z)$, at a given redshift $z$. The
characteristic temperature is then a function of cluster mass and redshift
$T_\Delta \equiv T_\Delta (M_\Delta,z)$.

The temperature profile can be then scaled with respect to this
characteristic temperature as,
\begin{eqnarray}\label{eqn:Tparam}
\tilde{T}\left(r/{R_\Delta}\right)&\equiv& \frac{T\left(r/R_\Delta
  \right)}{T_\Delta(M_\Delta,z)}.
\end{eqnarray}
If galaxy clusters were perfectly self-similar under this scaling, the
shape and normalization of $\tilde{T}(r/R_\Delta)$ would be
independent of the cluster mass and redshift.

It is important to note that a mass-limited sample of real galaxy
clusters do not satisfy {\it any} of the assumptions of the Kaiser
model, but have nonetheless empirically exhibited near self-similar
behavior.  We therefore explore physical effects that lead to observed
deviations from self-similar scaling in a similarly representative
sample.

Note that the self-similar model depends on which overdensity is used
to define cluster mass and radius in Equation~(\ref{eqn:mass_def}).  A
commonly used density contrast in cluster measurements is $\Delta =
500c$, where $c$ denotes the overdensity defined with respect to the
critical density of the universe.  We additionally consider several
different characteristic overdensities $\Delta=200c, 500c, 1600c$ and
$\Delta = 200m, 500m, 1600m$, where $m$ denotes the overdensity
defined with respect to the mean mass density of the universe. Note
that these overdensities are redshift dependent; e.g., $\Delta=1600m$
approximately corresponds to $\Delta=500c$ at $z=0$.

\begin{figure*}[t]
\begin{center}
\includegraphics[scale=0.55]{f1.pdf}
\includegraphics[scale=0.55]{f2.pdf}
\includegraphics[scale=0.55]{f3.pdf}
\caption
{Projected mass-weighted temperature $T_\text{mw}$ maps of one of the
  $z=0$ clusters selected from the sample. From {\em left} to {\em
    right}: map of the total gas, substructures (clump and filaments),
  and ``bulk'' gas (i.e., without substructures). The dimension for
  each panel is $15.6\,h^{-1}{\rm Mpc}\times15.6\,h^{-1}{\rm Mpc}$,
  with depth of $1.9\,h^{-1}{\rm Mpc}$. The circle in dashed line
  shows $3R_{500c} = 2.6\,h^{-1}{\rm Mpc}$ of the
  cluster. The color bars show the temperature scales in Kelvin. }
\label{fig:cluster_map}
\end{center}
\end{figure*}

\subsection{Thermal, Non-thermal and Total Energy Contents of the ICM}\label{sec:pressure}

Energy content of the ICM consists of thermal and non-thermal
components, where the latter arises primarily from random gas motions
generated by mergers and accretion events.  We can define the
``total'' temperature as the sum of specific kinetic and internal
energies of the gas, as it incorporates both thermal and non-thermal
motions of the gas,
\begin{eqnarray}
T_{\text{tot}}&\equiv&T_{\text{mw}}+T_{\text{nt}},
\end{eqnarray}
where $T_{\text{mw}}$ is the mass-weighted temperature and
$T_{\text{nt}}$ is the ``non-thermal temperature'' defined as,
\begin{eqnarray}\label{eqn:tnt}
k_bT_\text{nt}&\equiv&\frac{1}{3}\mu m_p \langle
v^2_{\text{gas}}\rangle_{\rm mw},
\end{eqnarray}
where $k_b$ is the Boltzmann constant, $\mu=0.59$ is the mean
molecular weight of the ionized ICM, $m_p$ is the proton mass, and
$\sqrt{\langle v^2_{\text{gas}}\rangle_{\rm mw}}$ is the 3-dimensional
mass-weighted root-mean-square velocity of the gas.  Physically, this
``non-thermal temperature'' $k_bT_\text{nt}$ represents the specific
kinetic energy associated with gas motions in the ICM.

The total temperature for a virialized gas is analogous to the
velocity dispersion of a halo, which is in local Jeans equilibrium
with the gravitational potential of the halo \citep{diemer_etal13}.
The circular velocity profile, a proxy for the potential, evolves
self-similarly when scaled with respect to the critical density of the
universe \citep{diemerandkravtsov_14, lau_etal15}.  This follows from
the fact that gravitational potential wells of galaxy clusters are set
early in their history \citep[e.g.,][]{vandenbosch_etal14} and evolve
slowly.  Therefore, the total temperature profile within near
virialized regions should exhibit the same scaling as the circular
velocity profile.  Note that the thermal temperature would only
exhibit this scaling if the cluster were in perfect hydrostatic
equilibrium.

\section{Methodology}
\label{sec:methods}

\subsection{Cosmological Simulation}

We use galaxy clusters extracted from the {\em Omega500} simulation
\citep{nelson_etal14}.  The {\em Omega500} simulation is a
cosmological hydrodynamical simulation performed with the Adaptive
Refinement Tree code \citep{kravtsov_99, kravtsov_etal02,
  rudd_etal08}. The simulation box has a comoving length of
500~$h^{-1}\, {\rm Mpc}$, resolved using a uniform $512^3$ root grid
and 8 levels of mesh refinement, with maximum comoving spatial
resolution of 3.8~$h^{-1}\, {\rm kpc}$.

We analyze a mass-limited sample of 65 galaxy clusters with $M_{\rm
  500c}\geq 3\times10^{14}h^{-1}M_{\odot}$ at $z=0.0$ and their
progenitors at $z=0.3$, $0.5$, and $0.7$ to match the {\em
  Chandra}-SPT sample of \citet{mcdonald_etal14}.  We then measure the
average evolution of thermodynamic profiles in our sample.

Initial cluster identification uses a spherical overdensity halo
finder described in \citet{nelson_etal14}.  The final cluster sample
is from a re-simulated box with higher resolution dark matter
particles in regions of the identified clusters.  This ``zoom-in''
technique results in an effective mass resolution of $2048^{3}$,
corresponding to a dark matter particle mass of $9\times10^{8}\,
h^{-1} M_{\odot}$ inside a spherical region with cluster-centric
radius of three times the virial radius for each cluster.  Further
details of the simulation can be found in \citet{nelson_etal14}.

Since cluster core physics are not expected to significantly affect
cluster outskirts, we present our main results using the {\em
  Omega500} simulation with non-radiative (NR) gas physics.  In order
to assess the effects of baryonic physics, we also analyze the outputs
of the {\em Omega500} re-simulation with radiative cooling, star
formation, and supernova feedback based on the same sub-grid model of
galaxy formation described in \citet{nagai_etal07a}.

\subsection{Averaged Radial Profiles}\label{sec:meth:avg_rad}

We compute average radial profiles by dividing the gas volume of a
galaxy cluster halo into 99 concentric spherical shell bins centered
around the minimum of the gravitational potential.  Throughout this
work, we use the equally spaced logarithmic spacing in the comoving
radial distance from $10\,h^{-1}$~kpc to $10\,h^{-1}$~Mpc.

We compute average temperature profile of each simulated galaxy
cluster as,
\begin{equation}
T_{w} (r_i)=\frac{\sum_j w_{ij} T_{ij}\Delta V_j}{\sum_j w_{ij}\Delta V_{ij}},
\end{equation}
where $\Delta V_{ij}$ is the volume occupied by the hydro cell $j$ in
the radial bin $i$, $T_{ij}$ is the temperature of the gas cell, and
$w_{ij}$ is the ``weight'' for the averaging.

We adopt two different weighting schemes. First,  we compute mass-weighted
temperature profile $T_{\text{mw}}$, with the weight set to the gas mass density
of the hydro cell $w_{ij} = \rho_{g,ij}$. Physically, the mass-weighted temperature
corresponds to the specific internal energy of the cluster gas.

Second, we compute the spectral-temperature $T_\text{sp}$, which is
the average temperature using X-ray emission as weights:
\begin{equation}\label{eqn:emission}
w_{ij} =  \rho_{g,ij} ^2 \Lambda_{\rm eff}(T_{ij},Z_{ij}=0.3Z_\odot)
\end{equation}
where $\Lambda_{\rm eff}$ is the effective cooling function in the
$0.5-2.0$~keV energy band using the MEKAL \citep{liedahl_etal95}
plasma code, weighted by the effective area of the {\em ACIS-I} CCD on
{\em Chandra} X-ray telescope.  Since the X-ray emission in the
$0.5-2.0$~keV energy range is not very sensitive to the adopted
metallicity, we assume constant abundance of $Z=0.3$ solar throughout.

Finally, using the self-similar scaling defined by
Equation~(\ref{eqn:Tparam}), we normalize each galaxy cluster profile,
\begin{eqnarray}
\tilde{T}(r/R_{500c})&=&\frac{T(r/R_{500c})}{T_{500c}},
\end{eqnarray}
where $T_{500c}\equiv GM_{500c}/(2R_{500c})$.  We then calculate the
average $\tilde{T}$ in each redshift in order to assess the departure
of the {\em average normalized temperature profile} from self-similar
evolution.

\begin{figure}
  \centering
  \mbox{
  \includegraphics[width=3.5in]{f4.pdf}
  }
  \vspace{-5mm}
  \caption{Top panel: Ratio of the average density profile of all gas
    to that of the bulk component (without substructures), $\Delta
    \rho \equiv \rho_{\rm all}/\rho_{\rm bulk}$, at different
    redshifts as a function of the cluster-centric radius for
    simulated clusters at $z=0.0, 0.3, 0.5, 0.7$.  The shaded region
    corresponds to the $1\sigma$ spread about the mean profile at
    $z=0$. The bottom panel shows the fractional difference between
    the profile at each redshift to the profile at $z=0$.}
  \label{fig:clumping_redshift}
\end{figure}

\subsection{Decomposition of Diffuse and Clumpy Components}\label{sec:meth:clumping}

To assess the effects of gas clumping on the X-ray emissions, we
decompose the ICM into the diffuse and clumpy components using the
method described in \citet{zhuravleva_etal13}.  The probability
distribution function (PDF) of the density in each shell follows a
log-normal distribution with a high density tail.  We exclude small
scale gas clumps, infalling subhalos, and penetrating filaments by
removing gas that have density higher than $2\sigma$ from the median
of the density PDF in each radial bin.

We denote the profiles calculated with or without denser substructures
using the subscripts, ``all'' or ``bulk'', respectively.  The
mass-weighted temperature profile with (or without) substructures is
labeled by $T_{\text{mw,all}}$ (or $T_{\text{mw,bulk}}$).
Figure~\ref{fig:cluster_map} illustrates the mass-weighted temperature
maps for one of the simulated clusters including all gas,
substructures, and bulk diffuse components \citep[see Figure~1 in][for
  the corresponding projected gas density maps]{lau_etal15}.

\section{Results}
\label{sec:results}

In this work, we investigate physical mechanisms that contribute to
the evolution of scaled thermal temperature profiles in the outskirts
of galaxy clusters. These mechanisms include the evolution of
overdense gas substructures, non-thermal gas motions, growth of the
cluster halo with respect to the defined reference overdensity,
non-equilibrium physics, and baryonic cooling and star formation.
With a mass-limited simulated cluster sample, we assess the relative
importance of factors that influence temperature profiles in galaxy
cluster outskirts.

\subsection{Evolution of Substructures}
\label{sec:substructures}

We first examine the contribution of substructures on the evolution of
the gas density profiles.  The top panel of
Figure~\ref{fig:clumping_redshift} shows the ratio of the average
density profile of all gas to that of the bulk component (without
substructures), $\Delta \rho \equiv \rho_{\rm all}/\rho_{\rm bulk}$,
at different redshifts. We normalize the radial range of all profiles
using $R_{500c}$ of each cluster before computing the average profiles
of the cluster sample at each redshift. The lower panel shows the
fractional deviation of the gas density ratio at high redshifts
relative to $z=0$.

At all redshifts, we find that the bulk component comprises more than
$90\%$ of the gas at $r\lesssim R_{500c}$, while the contribution of
substructures increases with radius at $r\gtrsim R_{500c}$. The
contribution of gaseous subhalos and filaments are more prominent in
the outskirts of galaxy clusters. We also find that the contribution
of dense substructures increases with redshift. For example, the
substructures comprise $\approx50\%$ of the total gas density at
$r/R_{500c}=2$ at $z=0.7$, while their contribution is only $\approx
20\%$ at $z=0$. High redshift clusters contain an enhanced level of
substructures compared to the low redshift counterparts.

\subsection{Evolution of ICM Temperatures}
\label{sec:non-thermal}

\begin{figure}
  \centering
  \mbox{
  \subfigure{\includegraphics[width=3.5in]{f5.pdf}}
  }
  \vspace{-5mm}
  \caption{Top panel: Solid lines correspond to the average normalized
    mass weighted gas temperature profile, $\tilde{T}_{\rm mw}$, at
    $z=0.0, 0.3, 0.5, 0.7$.  The shaded region shows the $1\sigma$
    spread for the $z=0$ sample.  The dotted lines correspond to the
    average normalized non-thermal temperature, $\tilde{T}_{\rm nt}$,
    defined in Equation~\ref{eqn:tnt}.  The dashed lines correspond to
    the sum of the two temperatures at each redshift,
    $\tilde{T}_{\text{tot}}=\tilde{T}_{\text{mw}}+\tilde{T}_{\text{nt}}$. Bottom
    panel: Solid (dashed or dotted) lines show the difference in the
    ratios for between each thermal (total on non-thermal) average
    temperature profile to the $z=0$ average profile.  The normalized
    $\tilde{T}_{\text{mw}}$ profiles have a clear systematic evolution
    outside of $r/R_{500c}\gtrsim 0.5$ that breaks self-similarity.
    High redshift clusters have cooler outskirts.  The trend is
    reversed for $\tilde{T}_{\text{nt}}$.  The total temperature,
    however, maintains a self-similar behavior at all radii with no
    indication of a systematic evolution.  The thermal temperature
    evolution is due to the fact that clusters at higher redshifts are
    dynamically younger with gas that has not fully
    thermalized.}\label{fig:Tmw_nt_tot}
\end{figure}
\begin{figure*}[t]
  \centering \mbox{
    \subfigure{\includegraphics[width=3.5in]{f6.pdf}}\quad
    \subfigure{\includegraphics[width=3.5in]{f7.pdf}}
  }
  \vspace{-5mm}
  \caption{Same as the lower panel in Figure~\ref{fig:Tmw_nt_tot} but
    for different overdensities.  From top to bottom: $\Delta = 200$,
    $500$, and $1600$.  The left column corresponds to overdensities
    with respect to the mean density of the universe, denoted with
    $m$, and the right with respect to the critical density of the
    universe, denoted with $c$.  The radial scales are chosen such
    that each overdensity probes approximately the same radial range
    $0.1\leq r/R_{500c} \leq 2.7$ at $z=0$.  The scaling with respect
    to $\Delta=200m$ best captures the evolution in thermalization
    state of the gas in the outskirts; the mass-weighted temperature
    exhibits the most self-similar evolution with this choice of
    $\Delta$.}\label{fig:Tmw_nt_tot_overdensities}
\end{figure*}

Next, we examine the role of the non-thermal gas motions on the
evolution of temperature profiles.  The solid lines in the top panel
of Figure~\ref{fig:Tmw_nt_tot} show the average radial profile of the
normalized mass-weighted temperature, $\tilde{T}_\text{mw}$, at
$z=0.0, 0.3, 0.5$, and $0.7$.  The solid lines in the bottom panel of
Figure~\ref{fig:Tmw_nt_tot} show the difference between
$\tilde{T}_\text{mw}$ at each redshift to that of $z=0$: $\Delta
\tilde{T}_\text{mw} \equiv
\tilde{T}_\text{mw}(z)/\tilde{T}_\text{mw}(z=0)-1$.  Note that $\Delta
\tilde{T}_\text{mw} \approx 0$ would indicate that the cluster sample
exhibits self-similar evolution with this scaling.

The magnitude of $\Delta \tilde{T}_\text{mw}$ systematically increases
with redshift in cluster outskirts.  For example, $\Delta
\tilde{T}_\text{mw}$ at $r/R_{500c} \gtrsim 1.5$ is $\sim 30\%$
between $z=0.0$ to $z=0.7$, and $\sim 10\%$ between $z=0.0$ to
$z=0.5$. These evolutionary trends are consistent with the results of
the recent {\em Chandra} measurements \citep{mcdonald_etal14}.

The dotted lines in Figure~\ref{fig:Tmw_nt_tot} show the average
normalized profiles of the non-thermal temperature,
$\tilde{T}_\text{nt}$, at each redshift.  At all redshifts,
$\tilde{T}_\text{nt}$ increases with radius and exceeds
$\tilde{T}_\text{mw}$ at $2 \lesssim r/R_{500c} \lesssim 4$.  The
crossover occurs at smaller cluster-centric radii for higher redshift
clusters, when the potential well also extends to a smaller radius.
This result is consistent with a physical picture that gas motions
generated by mergers and accretion events are gradually converted into
the kinetic energy through shocks and turbulent dissipation at smaller
radii. Since the timescale of turbulent dissipation is shorter in the
dense, inner regions of galaxy clusters \citep{shiandkomatsu_14}, a
larger fraction of the merger or accretion driven gas motions have
thermalized \citep{yu_etal15}.  The timescale difference leads to
monotonically increasing (decreasing) thermal (non-thermal)
temperature profiles.

Furthermore, we find a significant redshift evolution in
$\tilde{T}_\text{nt}$.  At $r/R_{500c}\approx1.5$,
$\tilde{T}_{\text{nt}}$ increases by $40\%$ between $z=0.0$ and
$z=0.7$. High redshift clusters have a higher level of the normalized
non-thermal temperature than low redshift clusters, because high
redshift clusters are dynamically younger with more active gas
accretion events \citep{nelson_etal14b}.

The dashed lines in the top panel of Figure~\ref{fig:Tmw_nt_tot} show
the average total temperature profiles in each redshift bin, which
exhibit a remarkable degree of self-similar evolution at large radii,
unlike the non-thermal and thermal temperature profiles.

We conclude that the evolution in the scaled thermal temperature
profile is driven primarily by the thermalization process of the
cluster gas where merger and accretion induced gas motions gradually
convert into the thermal energy component of the ICM.

\subsection{Dependence on Halo Overdensity Definition}
\label{sec:halo_def}

In this section, we highlight that the departure from the
self-similarity depends on the definition of halo mass and
radius. Figure~\ref{fig:Tmw_nt_tot_overdensities} shows the normalized
mass-weighted, non-thermal, and total temperature profiles, $\Delta
\tilde{T} \equiv \tilde{T}(z)/\tilde{T}(z=0)-1$, for different
overdensity values: $\Delta = 1600, 500$, and $200$ defined with
respect to the mean density (left panels) and the critical density of
the universe (right panels). The range of the $x$-axis in each panel
shows the same physical radii corresponding to the radial range of
$0.1<R/R_{500c}<2.7$ at $z=0$.

The left panel of Figure~\ref{fig:Tmw_nt_tot_overdensities} shows that
the different choices of reference densities with respect to the mean
density results in varying degree of self-similar evolution in the
ICM. Specifically, we find that the departure from the self-similar
model diminishes for the smaller values of $\Delta_{\rm mean}$. For
example, the largest departure from the self-similar model is found
for the largest mean overdensity of $\Delta = 1600m$, where the
difference in the temperature at $R_{1600m}$ (which roughly
corresponds to $R_{500c}$ at $z=0$) is about $30\%$.  At $r/R_{\rm
  500m}=0.6$ in the second panel, the normalized temperature decreases
by $\sim 10\%$ from $z=0.7$ to $z=0$. At $r/R_{\rm 200m}=0.4$ in the
third panel, the evolution is even smaller (at the level of $\sim
5\%$).  Our results suggest that the overdensity of $\Delta=200m$
works best, because $R_{200m}$ tracks the average evolution of the
radial location of the accretion shock \citep{lau_etal15, shi16b},
where the bulk of thermalization process of the ICM occurs.

The right panel of Figure~\ref{fig:Tmw_nt_tot_overdensities}, on the
other hand, illustrates that the choice of different overdensities
with respect to the critical density does not significantly affect the
evolutionary trends in the inner regions, $r\lsim{R}_{500c}$, because
the critical density evolves slowly after $z\lsim1$ and tracks the
evolution of the gravitational potential in the inner regions.  The
gas beyond this radial range is less thermalized especially at high
redshifts due to the enhanced mass accretion, evidenced by the higher
normalization of the non-thermal temperature profiles (indicated by
dotted lines).  The total temperature (indicated by dashed lines), on
the other hand, remains self-similar with the difference of order
$10\%$ between $z=0.7$ and $z=0$.

\subsection{Effects of Substructures}
\label{sec:substructures2}

\begin{figure}
  \centering
  \includegraphics[width=3.5in]{f8.pdf}
  \vspace{-5mm}
  \caption{Top: Solid lines show the ratio of the mass-weighted
    temperatures $T_{\rm mw}$ of all gas to that of the substructure
    excluded ``bulk'' gas component at $z=0.0, 0.3, 0.5, 0.7$.  The
    dashed lines show the same ratio for the spectral-weighted
    temperature $T_{\rm sp}$. Bottom: Difference in the ratios of the
    temperature profiles with $z=0$.}\label{fig:ratios_bulk_mean}
\end{figure}

We quantify the effects of substructures on the temperature evolution
by comparing the average temperature profile, normalized to
$T_{500c}$, with and without excluding high density gas in infalling
subhalos and filaments.

The solid lines in Figure~\ref{fig:ratios_bulk_mean} correspond to the
ratios of $T_{\rm mw, all}$, the normalized mass-weighted temperature
of all gas, and $T_{\rm mw, bulk}$, the normalized mass-weighted
temperature of the substructure-excluded bulk component.  Each line
color corresponds to the average profile at $z=0.0, 0.3, 0.5$, and
$0.7$ for our simulated cluster sample.  The ratio $\Delta T_{\rm
  mw}=T_{\rm mw, all}/T_{\rm mw, bulk}$, is less than unity at all
radii and all redshifts because the dense gas associated with
substructures is typically cooler than the diffuse gas.  At
$r/R_{500c}=2$, $\Delta T_{\rm mw}$ is $92\%$ at $z=0$.  $\Delta
T_{\rm mw}$ decreases with redshift, reaching $70\%$ at $z=0.7$.

The dashed lines in the top panel of Figure~\ref{fig:ratios_bulk_mean}
show the ratio $\Delta T_{\rm spec}=T_{\rm spec, all}/T_{\rm spec,
  bulk}$, the spectral-weighted temperature ratios at $z=0.0, 0.3,
0.5$, and $0.7$.  Within $r/R_{500c}<1.5 $, $\Delta T_{\rm sp}$ are
nearly identical to those of $\Delta T_{\rm mw}$ at all redshifts. At
larger radii, $\Delta T_{\rm sp}$ is larger and evolves less than
$\Delta T_{\rm mw}$.

The $\Delta T_{\rm sp}$ profiles indicate that spectral weighting
leads to the average of all of the gas to be more similar to the bulk
component.  Spectral weighting has both a temperature and density
dependence, whereas the mass weighting simply gives more weight to
cells that contain more gas mass.  The change in weighting places
slightly relatively more weight on the warmer bulk component of the
gas at large radii, decreasing the difference between $T_{\rm sp, all}$
and $T_{\rm sp, bulk}$.

In summary, substructures lead to a change in the average normalized
temperature profile at most $10\%$ at $r/R_{500c}=1.5$ from $z=0.7$ to
$z=0$, regardless of the weighting schemes.

\subsection{Effects of Non-Equilibrium Electrons}
\label{sec:ep}
\begin{figure}
  \centering
  \mbox{
  \subfigure{\includegraphics[width=3.5in]{f9.pdf}}
  }
  \vspace{-5mm}
  \caption{Top panel: Average ratio of the mass-weighted electron
    temperature, $T_e$, to the mass-weighted mean gas temperature,
    $T_{\rm mw}$, as a function of the cluster-centric radius at
    different redshifts: $z=0.0, 0.3, 0.5, 0.7$.  The shaded region
    indicates $1\sigma$ scatter in the $z=0$ profile.  Bottom panel:
    the fractional evolution in $T_e/T_{\rm mw}$ at high redshifts
    relative to $z=0$. }\label{fig:ep}
\end{figure}

The X-ray temperature is sensitive to the thermal energy of electrons
in the ICM plasma. However, since the equilibration time of electrons
and ions can be comparable to the Hubble time in the low-density
regions in the outskirts of galaxy clusters
\citep{spitzer_62,ruddandnagai_09}, the ICM temperature derived using
X-ray observation could be biased low.

The temperature bias from non-equilibrium electrons also depends on
the mass accretion rate and the mass of cluster
\citep{avestruz_etal15}.  On average, high redshift clusters have
higher mass accretion rates, which magnifies the bias.  However, high
redshift clusters have lower average masses.  The shorter Coulomb
equilibration timescale of the lower temperature gas in less massive
clusters therefore counteracts the effect of higher mass accretion
rates in high redshift clusters.  Figure~\ref{fig:ep} illustrates the
net effect, where we show profile of the ratio of the electron
temperature and the total gas temperature.  We thus conclude that the
evolution between $z=0$ and $z=0.7$ is less than $5\%$ up to
$r/R_{500c}\approx 1.5$.

\subsection{Effects of Baryonic Physics}
\label{sec:baryons}

\begin{figure}
  \centering
  \mbox{
  \subfigure{\includegraphics[width=3.5in]{f10.pdf}}
  }
  \vspace{-5mm}
  \caption{Similar to Figure~\ref{fig:Tmw_nt_tot}, showing the
    evolution of the temperature profiles for the simulated clusters
    with radiative cooling, star formation, and supernova feedback.
    See the figure caption of Figure~\ref{fig:Tmw_nt_tot} for the
    descriptions of panels and line types.
    }\label{fig:Tmw_nt_tot_CSF}
\end{figure}

Although the effects of baryonic heating and cooling processes are
expected to be small in the outskirts of galaxy clusters, dissipative
processes can potentially introduce additional physical scales that
can lead to breaking of self-similarity in the ICM properties.  To
assess these effects, we analyze a re-simulation of the {\em Omega
  500} box that includes radiative cooling, star formation, and
supernova feedback (CSF).  Since our CSF simulation does not include
feedback from active galactic nuclei, this simulation suffers from the
well-known ``overcooling'' problem.  Due to overcooling, too many
stars form in the cluster core, compared with observations, and the
simulation overestimates the impact of baryonic effects. The results
from our CSF simulations should therefore provide an {\em upper} limit
to the role of cooling and star formation.

Figure~\ref{fig:Tmw_nt_tot_CSF} shows the evolution of the ICM
temperature profiles in the CSF simulation. The normalized
mass-weighted temperature, $\tilde{T}_{\rm mw}$, at $r/R_{500c}\gtrsim
0.1$ evolves by about $20\%$ over the redshift range of $0\leq z \leq
0.7$, which is roughly consistent with the evolutionary trend seen in
the NR run. The non-thermal temperature profiles, $\tilde{T}_{\rm
  nt}$, in the CSF run (dotted lines in the upper panel of
Figure~\ref{fig:Tmw_nt_tot_CSF}) show a higher normalization in the
inner regions compared to their NR counterparts, due to rotational gas
motions induced by strong gas cooling in the CSF run \citep[see
  e.g.,][]{lau_etal11}. Despite the effects of baryonic physics on the
ICM temperature profiles, the total temperature profile in the CSF run
remains self-similar in the regions $0.2 \leq r/R_{500c}\leq 2.5$.

\begin{figure}
  \centering
  \includegraphics[width=3.5in]{f11.pdf}
  \vspace{-5mm}
  \caption{Same as Figure~\ref{fig:ratios_bulk_mean} for the CSF
    simulation.}\label{fig:ratios_bulk_mean_CSF}
  \vspace{5mm}
\end{figure}

Figure~\ref{fig:ratios_bulk_mean_CSF} shows the temperature ratio
$\Delta T\equiv {T}_{\rm all}/{T}_{\rm bulk}$ in the CSF simulation.
Similar to the results for the NR case in
Figure~\ref{fig:ratios_bulk_mean}, this ratio shows little evolution
for $r/R_{500c}\lesssim 1.5$ for both mass-weighted (solid lines) and
X-ray spectral-weighted temperatures (dashed lines). In fact, this
effect is smaller in the CSF run than in the NR run, with
only $\lesssim 15\%$ change between $0\leq z\leq 0.7$.

The profiles of both $\Delta T_{\rm mw}$ and $\Delta T_{\rm sp}$ have
lower normalizations in the CSF clusters than in the NR clusters,
since gas cooling in dense, gaseous substructures leads to lower
temperatures in the CSF run.  Unlike the NR profiles, $\Delta T_{\rm
  sp}$ at $r/R_{500c}\lesssim 1.5$ in the CSF run has a significantly
lower normalization than the profiles of $\Delta T_{\rm mw}$ at each
redshift, particularly in the inner radii.  Here, the spectroscopic
weighting gives more weights to substructures in the ICM that are
cooler and denser in the CSF run.  Nevertheless, the contribution of
substructures introduces little additional evolution in the ICM
temperature.

Thus, even in the presence of baryonic physics, the thermal
temperature evolution is mainly driven by the redshift-dependent
non-thermal gas motions, not by the increased amount of gaseous
substructures.

\section{Summary and Discussions}
\label{sec:conclusions}

We have investigated the origins of the evolution in the ICM
temperature profiles in the outskirts of galaxy clusters using a
mass-limited sample of 65 galaxy clusters extracted from the {\em
  Omega500} NR and CSF hydrodynamical cosmological simulations. Our
key findings are summarized below:

\begin{itemize}

\item The non-thermal pressure due to gas motions is the primary
  mechanism for driving the evolution of the ICM temperature profiles
  in the outskirts of galaxy clusters, producing a change in the ICM
  temperature by $30\%$ at $R_{500c}$ relative to the prediction of
  the self-similar model.

\item Gaseous substructures associated with infalling satellites and
  penetrating filaments contribute to the evolution of the temperature
  profiles by $\lesssim 10\%$ at $R_{500c}$, and it is subdominant to
  the evolution due to thermalization of gas motions.

\item The effects of spectral-weighted temperature, and the effects of
  non-equilibrium electrons, contribute to less than $10\%$ in the
  evolution of the ICM temperature.  Baryonic physics do not alter
  these conclusions.

\end{itemize}

These results suggest that the recently observed temperature evolution
in the outskirts of galaxy clusters by \citet{mcdonald_etal14} is
primarily due to the evolution of the non-thermal pressure profiles in
the ICM, in contrary to their original interpretation of
``superclumping''.

Our work further suggests that it may be possible to mitigate and
control the departure from the self-similar evolution.  First, we find
that an appropriate choice of cluster mass and radius can mitigate
departures from self-similarity in the temperature profile. The
reference density that scales with accretion in the outskirts, 200
times the mean background density, best captures self-similar
evolution in the temperature profile in the outskirts.  Other
reference densities with respect to the mean density, e.g.,
$\rho_{1600m}$ and $\rho_{500m}$, do {\em not} scale as well. Second,
we find that the ``total'' temperature, which is the sum of thermal
and non-thermal gas energies, exhibits a remarkable degree of
self-similar evolution when scaled with respect to the critical
density.

In practice, while the thermal component of the ICM can be directly
imaged using X-ray and SZ observations, emerging high-angular
resolution X-ray and SZ imaging observations can measure fluctuations
in the ICM properties, which are sensitive to the level of non-thermal
pressure due to gas motions \citep[e.g.,][]{schuecker_etal04,
  khatri_gaspari16}. Future X-ray observatories, such as {\em
  Athena+}, also promise to provide direct measurements of gas motions
in the ICM through Doppler broadening of Fe lines.

Note that our simulations do not include other scale-dependent plasma
physics, such as thermal conduction and magnetic fields. However, we
expect these to have subdominant effects.  Thermal conduction in the
cluster outskirts is believed to be ineffective due to the long
conduction timescales of the diffuse low temperature outskirt gas
\citep[e.g.,][]{mccourt_etal13}.  While magnetic fields can drive gas
turbulence through magnetothermal instability (MTI)
\citep{parrish_etal12}, \citet{mccourt_etal13} shows MTI-driven
turbulence to be subdominant to the gas motions driven by mergers and
accretion for realistic cluster mass accretion histories. Therefore,
neither thermal conduction nor magnetic fields are likely to play
significant roles in the evolution of temperature profiles in cluster
outskirts.  Other effects, such as pressure provided by cosmic rays,
can in principle alter ICM properties in cluster outskirts.  We leave
the study of the effects of these plasma physics for future work.

To advance our understanding of ICM properties and their evolution in
cluster outskirts, future work should focus on (1) improving
theoretical modeling of both thermal and non-thermal components
including turbulence, cosmic rays, magnetic fields, and their
interactions; (2) deriving observational constraints on the
non-thermal temperature/pressure in the ICM based on pressure
fluctuations as well as direct measurements with the upcoming X-ray
missions; and (3) developing techniques to control the still poorly
understood astrophysical uncertainties and their impact on
cluster-based cosmological inferences.

\acknowledgments This work is supported by NSF grant AST-1412768, NASA
ATP grant NNX11AE07G, NASA Chandra Theory grant GO213004B, the
Research Corporation, and by the facilities and staff of the Yale
Center for Research Computing. CA acknowledges support from the
Fisk-Vanderbilt Dissertation Completion Award, the Kavli Institute of
Cosmological Physics, the Enrico Fermi Institute at the University of
Chicago, and the University of Chicago Provost's Office.
\lastpagefootnotes

redpajama_set_name: RedPajamaArXiv


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text:
Audit: Oregon Education Department fails on promise to help alternative schools
A new report shows the Oregon Department of Education hasn't made changes they agreed to implement by 2018 to improve alternative and online schools.
Audit: Oregon Education Department fails on promise to help alternative schools A new report shows the Oregon Department of Education hasn't made changes they agreed to implement by 2018 to improve alternative and online schools. Check out this story on statesmanjournal.com: https://www.statesmanjournal.com/story/news/education/2019/03/20/oregon-education-department-fails-plan-help-alternative-schools/3224132002/
Natalie Pate, Salem Statesman Journal Published 11:36 a.m. PT March 20, 2019 | Updated 1:23 p.m. PT March 20, 2019
In December 2017, state officials released an audit showing the Oregon Department of Education needed to do more to help at-risk students in alternative and online schools.
But less than two years later, Acting Secretary of State Leslie Cummings released a follow-up report Wednesday showing the department has made little progress implementing the changes.
The initial audit — titled "Stronger Accountability, Oversight, and Support Would Improve Results for Academically At-Risk Students in Alternative and Online Education" — outlined 15 recommendations for the agency.
Changes included developing a more meaningful accountability system, establishing and monitoring standards for crucial practices such as annual evaluations, and strengthening the attendance and funding standards for online schools.
A teacher works with students in a virtual classroom during a demonstration for the Oregon Connections Academy at the Oregon State Capitol in Salem on Wednesday, Feb. 24, 2016. Oregon Connections Academy is a state-wide, online public school. (Photo: ANNA REED / Statesman Journal)
Get more education news: Stay on top of educational trends, news and get alerts by becoming a Statesman Journal subscriber today for less than $1 a month.
Education department officials agreed to all of the recommendations and anticipated most of the work would be completed in 2018.
However, only three of the promises have been kept so far.
"We are disappointed ODE has made little progress implementing the audit recommendations," Acting Secretary Cummings said. "Fully implementing the remaining recommendations is critical to improving the education of Oregon students in alternative education and online schools."
Read the original story: Auditors seek accountability, oversight of Oregon's alternative and online schools
Students, communities affected
Traditional high schools, operated by districts, serve about 90 percent of public high school students in Oregon, according to the original 2017 audit. Alternative schools and programs and online schools account for the remaining 10 percent.
Alternative schools are stand-alone schools, enrolling thousands of students statewide.
Many of these schools are designed to serve teens who are at risk of not graduating, known as "academically at-risk students." In fact, these "at-risk" students account for nearly half of the high school students who drop out.
This matters for the future of the students, as well as the communities in which they live.
Auditors have found earning a high school diploma expands livelihood and career opportunities, whether a graduate enters the workforce or continues with higher education.
In contrast, research used in the graduate rate audit also released in 2017 showed not graduating leads to higher unemployment, lower incomes, poorer health and higher incarceration rates.
And students aren't the only ones who face consequences.
"Society also faces financial impacts such as higher social service and incarceration costs, and lower tax revenues from non-graduates," according to the graduation audit. "This cost is estimated at $260,000 to $292,500 for each student without a high school diploma."
Whale watching: Here's where on the Oregon Coast to spot migrating Gray whales
Promises made, unfulfilled
According to this week's report, the Oregon Department of Education has partially implemented three of the 15 recommendations.
They have developed a clearer definition of alternative schools and programs to use in future data collection, held work sessions with stakeholders to discuss ways to strengthen attendance and funding standards for virtual schools, and increased its alternative education program staff in 2019.
But state officials said the department still needs to conduct "significant work" to fully implement the remaining 12 recommendations.
Colt Gill serves as the director and deputy superintendent of public instruction for Oregon. At the time of the initial audit, Gill was serving as acting deputy superintendent for the state and wrote his response to the recommendations in a letter included in the audit.
"Much of this work has begun," he wrote in 2017.
The department claimed they were in the final stages of developing an alternative education definition and they planned to convene a group to review and make recommendations for reporting and accountability in the following spring.
The department agreed to develop publicly reported measures of these schools and their staff, as well as various state standards and best practices.
The department also agreed to work with the Oregon Legislature to require upgrades to accountability and oversight for alternative programs.
Measles outbreak: Oregon Health Authority confirms second case in Salem
The agency planned to have 11 recommendations fully implemented by fall 2018, with the other four recommendations to be fully implemented by summer 2019.
In the report Wednesday, department officials cited requirements under the Every Student Succeeds Act and staffing in the alternative education program as challenges to fully implementing the recommendations.
Gill gave a comment to the Statesman Journal, saying the department agrees with the recommendations and intends to implement them.
He said the department's preparation and roll-out of Oregon's plan under the Every Student Succeeds Act "pulled limited staff resources away from implementing these recommendations within the timeline," but that the department is now able to refocus on these efforts.
Additionally, he said they have filled a key vacancy in the alternative education team and increased the amount of staff assigned to alternative education.
"These recommendations remain important and we plan to move forward," Gill said in his statement. "Now that we have full staffing we believe we can make more progress."
Read the full report at https://sos.oregon.gov/audits/Documents/2019-12.pdf.
For more information, contact the Oregon Department of Education at 503-947-5600 or the state's audit division at 503-986-2255.
Contact reporter Natalie Pate at npate@StatesmanJournal.com, 503-399-6745 or follow her on Twitter @Nataliempate or Facebook at www.Facebook.com/nataliepatejournalist.
Support local journalism: Stay on top of educational trends and news in our area. Become a Statesman Journal subscriber today and get unlimited digital access to stories that matter.
Read or Share this story: https://www.statesmanjournal.com/story/news/education/2019/03/20/oregon-education-department-fails-plan-help-alternative-schools/3224132002/
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Deputies looking for 'aggressive driver' on Hwy 22

redpajama_set_name: RedPajamaCommonCrawl


To illustrate the impact these mistakes tend to have for Data Warehouse projects, let me compare it to a team of medics in a hospital and imagine the project is you who is about to receive a costly and critical treatment. I am sure you do not want to hear staff exchanging conversation mentioned below before you doze off at the operating table.
Most of the Data Warehouse projects start with a lot of enthusiasm but fail at the end because they just did not meet the business objectives. Very well designed Data Warehouses will fail if the content doesn't help to solve any business needs. Even if you see yourself as a technician first or are in a position without contact to users of the final product, never forget that whatever you produce, it is the customer that must be satisfied.
"Anyone feels like this treatment is successful so far? Can we find out? No ideas?" (silence).
Even if you are aware of your business objectives, success is not guaranteed by this alone. Every clear business objective is measurable. If you can't quantify, you will have a tough time commenting on your expenses, and you will show up on top of the blacklist as soon as the next restructuring takes place. The latter usually revolve in cycles of about 3 to 5 years in length.
Overspecialization became a huge problem in today's Data Warehouse projects. Industries with a longer history are well aware of the adverse effects of the extreme division of labor (look up "Taylorism"). Think of the Kaizen idea that became famous in the 80s and 90s – , it seems to be the case that Data Warehousing is about to repeat history. Any environment where each project member has to contribute to a very narrow range of skills, lacks understanding of the big picture or is not expected to develop such, is predestined for failure. It is very fashionable these days to create ever more exact roles with the sole purpose of cutting costs – at least at the beginning of a project. From my experience, this never actually pays off. It just moves the costs from the beginning to the end of the project while they multiply along the way and it is the time when you have to hire real data warehouse experts to get back on track again. Be wary of so-called experts without real-world, hands-on experience.
While it seems tempting, from a cost perspective, to pick up the source data and provide it without any costly transformations to the customer – even developers with no or only a little knowledge about data warehousing can be employed to do this, once again this is the recipe for failure. I cannot overemphasize how important the implementation of a theoretically sound data model is. Don't even think about leaving out surrogate keys, taking over the source system specific naming conventions or trying to solve the issues caused by the mentioned ODS approach at a next place, like in the data marts or reports.
Data Warehouse Architect, Data Modeler, Performance Specialists or any other kind of system-specific technical experts (Teradata experts).
The typical project team consists of some highly specialized database developers missing the big picture and a project manager without academic and hands-on experience in Data Warehousing, one shortage often accompanied by a lack of good relations with business departments or even fundamental project management skills. Without the support of a technical lead (Teradata expert) which is capable of taking over the roles of the architect and the general modeling of the solution, project delays and failure are most likely.
We should never forget, that data warehousing is, at the end of the day, a very technical topic. The technical component si all too often considered a low-prestige subsidiary location.
Solid education of people involved is required at many levels, in-depth knowledge and fluency are needed in the fields of Teradata, ETL-Tools (Data Stage, Informatica, Ab Initio) and Reporting Tools (Cognos, Business Objects, Microstrategy).
Too often, the interaction of these different technical components is not getting enough attention and performance is almost always ignored completely at the beginning of the project. Often, omitted clarification of professional interaction and compatibility of various software can't be handled anymore at a later time. One ends up in a minefield of workarounds upon workarounds and never-ending issues around new releases that soon start to lead a life of its own.
The first mile on the highway to disaster always looks perfect. It appears to be brand-new, there is no speed limit, all traffic lights are on green, and you seem to drive a racing car. This part of the journey ends after the first turn.
First, if you start a project with amounts, assumptions or milestones that are illusionary or grossly out of touch with the average experience of professionals, it does not matter if, but only when you will see yourself in unpleasant meetings, bending over backward to cautiously add reality to the plan.
Second, if the company shows a distaste for straightforwardness, clarity, transparency and decisiveness, not only will the real problems multiply, but, alongside them, the bureaucratic dissimulation tactics will take over more and more of the remaining resources.
Your best project members are usually the first to exit this race to the bottom for better opportunities.


text:
Home Opinion NO FRILLS
12:00 AM, October 02, 2018 / LAST MODIFIED: 12:45 PM, October 02, 2018
Cyber security readiness in banks
Syed Mansur Hashim
A recent survey titled "IT security of banks in Bangladesh: threats and preparedness" carried out by the Bangladesh Institute of Bank Management (BIBM) paints a rather dismal picture of certain banks and their ability to combat cyber threats. We are informed that nearly a third of banks (28 percent) have taken no effective steps to thwart a large-scale cyber-attack. The good news is that 38 percent are fully-equipped for such an attack, but then 34 percent are partially-prepared. The presenter of the research paper Professor Mahbubur Rahman Alam outlined the areas that need a lot more attention.
We learn that system vendors who provide software to the banking sector are largely dependent on foreign software. More alarming is that 27 percent of these vendors have been found to have breached safety arrangements—what that translates into is anyone's guess. With the exponential growth of paperless transactions, i.e. the use of plastic cards, consumers are now facing a whole new range of threats that include fraud at ATMs and mobile financial transactions are increasingly falling prey to cyber frauds.
There is a general lack of IT security awareness prevalent amongst bank employees themselves. The survey has found that 18 percent scored "poor", 12 percent "very poor", while 29 percent scored "moderate"; and the senior management of the banking industry considers spending money on IT infrastructure and qualified IT personnel to be a wasteful exercise. Indeed, of the Tk 2,035 crore spent on IT systems in 2017, the bulk was spent on procurement of hardware and software and a measly 3 percent was allotted to training. What all this boils down to is that the banking sector has left itself wide open to sophisticated hacking operations and we do not need to be reminded of what happened when the central bank was attacked where hackers made off with millions in hard currency!
To quote from the report, "in the last year, 68 percent of the banks have experienced at least one attack, most commonly in the form of malware, subsequently followed by spam Phising attacks...of these, 24 percent have had their network intruded in some way of at a significant cost to the business." And it is not only financial loss that banks are counting; access to sensitive information—be it the bank's or clients' information, can and does fetch a pretty sum on the black market for stolen information. Any incident like this is bad for business because it directly affects the image and reputation of a financial institution.
It is incomprehensible that bank managements view development of human resources for IT a waste of time. The study is damning when we consider that the rate of frauds involving mobile financial services (MFS), ATM machine and plastic card transactions are higher than all other categories combined, precisely what could explain this lethargy in investing in personnel who could effectively combat cyber threats? From what is discussed in the study, building up a safety net against this online onslaught of hackers requires investment in three areas: hardware, software, IT personnel and all three go hand-in-hand.
Last year, a similar study was shared by BIBM titled "An Exploration of the Digital Banking Revolution in Bangladesh" by the same author. In the cyber security readiness section, the author had exposed some unfortunate truths about the sector as a whole. There we found that IT governance was broken into three segments, where technology constituted a mere 6 percent while process was 10 percent, but the biggest segment was people who made up 84 percent of how IT would play in the banking sector! It appears that the sector's senior management has not taken this advice to heart.
To put things into perspective, we simply have to look at cybercrime data globally. As pointed out in the study from last year, we get some sobering facts: The global cost of cybercrime will reach USD 2 billion by 2019 (https://www.juniperresearch.com/press/press-releases/cybercrime-cost-bus...), a threefold increase from the 2015 estimate of USD 500 billion. According to the Identity Theft Resource Center's (ITRC) Data Breach Report (https://www.idtheftcenter.org/new-facebook-security-breach-compromises-5...), more than 29 million records were exposed. Furthermore, Ponemon Institute's "2016 Cost of Data Breach Study: Global Analysis", which queried 383 organisations that suffered at least one breach in 2016, the average cost per breach was USD 4 million. That figure rose to USD 7 million in the US.
As we move closer to home, the BIBM study in 2017 found that 6 out of 10 (60 percent) employees use the "exact same password for everything they access. Meanwhile, 63 percent of confirmed data breaches leverage a weak, default or stolen password." Who exactly are we trying to fool here? The above statement shows a massive lack of awareness of very basic security concerns that any IT expert will point out is a major breach of standard operating practices in any cyber environment!
BIBM rightly points out that the central bank has a major role to play here. Bangladesh Bank can organise professional certification courses, like a Masters in E-banking and Certified E-Banker. It can enlist the help of other central banks in the region for such efforts. What we find in the latest study (which echoes and builds on concerns voiced during last year's study) is that we are woefully unprepared for digital security threats in the banking sector. There has been some progress made, but as we go increasingly "online" with our transactions, lagging behind in IT security because spending resources on IT human resources is considered "wasteful" is something no bank can afford, under any circumstances, in today's "connected" world.
Syed Mansur Hashim is Assistant Editor, The Daily Star.
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Don't share anything on internet without verification: PM
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text:
'Watchmen': Will Damon Lindelof Return For A Second Season? "Probably Not"
Posted February 3rd, 2020 by Stuart Conover
Kathy Hutchins / Shutterstock.com</em.
In what could likely be the final nail in the coffin of HBO's 'Watchmen' when recently asked about returning for a second season, showrunner of the first season Damon Lindelof said he would "probably not" be back. While HBO's programming executive Casey Bloys previously shared that they likely wouldn't create a second season without Lindelof's involvement, the showrunner does offer hope for fans as to how it can continue without him.
The question was poised to the creator by Variety at the Writers Guild Awards last Saturday. While the focus of the interview concerned the ending of 'The Good Place,' it, of course, turned to his return to 'Watchmen.'
"I understand that the culture writ large wants a firm answer. Is there going to be more, isn't there going to be more. And unfortunately, the answer is, 'probably not.' I've been pretty consistent about that since we premiered the show at Comic-Con."
RELATED: The Future Of 'Watchmen' Just Got Even Darker As HBO Won't Proceed Without Damon Lindeloff
Now, that isn't to say we'll never get another outing in the 'Watchmen' universe by HBO. Lindelof's idea makes it quite feasible to return if HBO is willing to work with another showrunner:
"When I first pitched the show to HBO, where I looked at it as, in the model of 'Fargo' and 'True Detective,' I think there's a very high likelihood that there will be more 'Watchmen.' I think the likelihood of me being involved as showrunner starts to drop off. I would love to see more, and I think I'd love to see television shows like 'True Detective' or 'Fargo' where other visionaries can come in and take their run at it. I didn't create 'Watchmen,' so I think it's hypocritical for me to say I'm the only one who can do it. But I also want to leave space for, if three or four or five years from now, I have that 'eureka' moment that we could do another one."
While the first season of 'Watchmen' gave us a complete story, there is room for more in this world. Hopefully, HBO will only go this route if another showrunner can deliver a compelling story that would also be a stand-alone piece.
Do you hope that 'Watchmen' ends up returning for a second season? Is Damon Lindelof needed for a sequel, or would the network be able to tap another showrunner? Share your thoughts in the comments below!
damon lindelof
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HomeSermonsAt The MoviesAt the Movies: Black Panther
At the Movies: Black Panther
Heather King
Black Panther: My Brother's Keeper
Scripture: Genesis 4: 1 – 10 and Psalm 133
Even though Wonder Woman is a DC character and Black Panther is by Marvel, it dawned on me last week during Jill's sermon that they have very similar signature moves. (demonstrate). They have also accomplished similar record-breaking feats as cinematic successes, moving from ensemble movies to incredibly successful solo films, both a "first" in their category.
So besides learning that audiences will flock to see majority black films, what do we learn from Black Panther? Since I'm fresh off of teaching a May Term course at the University of Redlands on race and comics, allow me a bit of history before jumping into the movie itself.
Black Panther debuted in 1966 (July, in fact; the Black Panther Party was founded in October of the same year). He was introduced in the popular Fantastic Four series. He was the brainchild of the inimitable Stan Lee and Jack Kirby. In his debut issue, he lures the foursome to Wakanda as a final test for himself: if he could defeat them, he was ready to take on his nemesis, Klaw. As otherworldly as Wakanda looked to us on the big screen, one member of the Fantastic Four felt that he was familiar with the story – an interesting commentary about the pre-scripted narratives of the genre and how they shape our expectations. (Picture) The effect is to undercut the Black Panther, even though other characters chastise The Thing for his brash remarks. Lee and Kirby were evidently willing to be ground breakers, but perhaps wanted to remind readers that they weren't doing anything that new. Of course, Black Panther and the Fantastic Four end up working together and defeating Klaw; once that's accomplished, T'Challa isn't sure what to do next. Luckily, his new white friends have the answer: share his powers with the down-trodden everywhere. That's just what he does, bouncing back and forth between The Avengers and The Fantastic Four, falling in love with a black female musician from Harlem, and spending a lot of time in New York. The writers seemed to lose interest in Wakanda for a decade or so.
The world presented in Ryan Coogler's movie is more fully realized as a composite African country, and the question of what it means to have power resonates all the more strongly. This time, however, the pros and cons of involvement outside of Wakanda are voiced by other Wakandans, both those close to T'Challa, and those who challenge him.
First, Nakia, his exgirlfriend.
His friend and advisor Wakabi has another view on relationships with outsiders.
Finally, the most challenging position comes from his antagonist, Killmonger (born N'Jadaka). Some of Killmonger's background is important to understand – as you'll remember, his father, N'Jobu, was brother to the previous ruler of Wakanda, King T'Chaka. He was sent to Oakland, California, as a spy; what he witnessed there radicalized him, and he plotted to take violent action to seize power in the community by using vibranium, Wakanda's secret magical mineral. T'Chaka is so determined to keep Wakanda under wraps that he kills his own brother for risking exposure, leaving his nephew, N'Jadaka, behind. The Cain and Abel narrative is brought forcibly to mind in this confrontation between brothers. This begins the path of violence that Killmonger has been walking since.
Killmonger was an incredibly powerful figure in the film, especially since it is hard to disagree with his criticism of Wakanda, even if you disavow his violent methods. When CIA agent Everett Ross labels Killmonger "one of ours" the criticism of American race relations is poignant. Since Killmonger has passed his childhood in Oakland, being "one of ours" resonated for me as a Californian as well. (and I'd be happy to talk more with anyone interested in this character – there is a lot being written about him). He was not always quite so engaging (picture), but the film's presentation of the character really drives home the question of what it means to be your brother's keeper, the question Cain raises in angry self-defense. When Jill asked me to talk about Black Panther, this was the first theme that occurred to me; imagine my relief when doing some research in preparation for today I discovered that the director, Ryan Coogler, considers the question of what it means to be your brother's keeper one of the core messages of the film as well. Whew!
T'Challa's development over the course of the movie helps us see that we must not only think about what it means to designate someone our "brother" or not, but also what it means to "keep" them. He reaches the conclusion that Killmonger has been let down by his father's country, as have by extension all of those who were torn from Africa. He comes to believe that the wealthy and powerful have a responsibility to those without power, even if they are not responsible for the disparity. He confronts his father's spirit, but his anger is not just at his father for neglecting N'Jadaka (aka Killmonger) but at all of the former rulers of Wakanda for isolating themselves from blacks suffering around the world.
You were wrong
But the solution is not "to rule over them in the right way" as Killmonger's father suggests to T'Challa's father. In fact, Black Panther engaged with more global racial concerns very early in his history (picture), but what he could accomplish by this path of violence was very limited, and he gave only the strength of his arm, not the power of his country. In the film, in no small part because of Nakia's example, T'Challa has learned the importance of nurturing and supporting those he would help, not just stopping those he opposes. This is the work that T'Challa takes up at the end of the film.
UN speech
This strikes me as significant for a couple of reasons; first, because unlike his initial appearance in the comic book, T'Challa is deciding his own actions, not being told what to do by white westerners; that's an important representation of African autonomy on the individual and national level. In fact, T'Challa is helping not in his role as the rugged individual hero Black Panther, but from his position as a leader of people. He doesn't show up ready to fight drug dealers and corrupt cops; he shows up with educational resources and community outreach programs, delegating day-to-day operations to Nakia and his sister, Shuri. Some critics view the contrast between Killmonger and T'Challa as a reflection on the different stages of the Black Panther Party itself, with Killmonger representing the more militant phase, and T'Challa symbolizing the more peaceful, grassroots activist phase; the increased importance of women in that phase is echoed by Nakia and Shuri's roles in T'Challa's schemes.
Secondly, while we, the viewers, may not be royalty, there is certainly something for everyone watching this to learn about who our brothers are, and the kind of keeping we can offer. Those that T'Challa seeks to help are grouped by skin color, but their number will include descendants of many nations on the African continent and from the islands, and will include those of mixed heritage as well. His sense of his "brothers and sisters" has gotten widely inclusive by the end of the film, a model to which we would do well to aspire. And the science fiction plot crutch of vibranium is not without its symbolism for us to ponder; this metal has made Wakanda's fortune, insured its independence, and is a central part of the national identity. Given that one of its chief properties is the ability to absorb shocks and vibrations, I would suggest we can see it as a sci-fi representation of privilege. If you strike it, it absorbs the blow rather than breaking; if it is dropped, it absorbs the sound. It keeps things quiet, the ultimate "smooth ride." How many of us have had smoother rides, even if not luxurious, because our grandparents were able to own property where they pleased? How many of us, from a happy accident of birth, grew up in a community that helped absorb the shocks of life – a neighborhood that had clean water, good schools, well-stocked, accessible grocery stores, safe places for children to play? Or equal political rights for all, administered fairly? If you are born with resources that insulate you from the bumps and jostles of life, what is your responsibility to those born without such protection, without vibranium or inherited wealth or cultural capital or social standing? Can we, like T'Challa, learn to recognize our brothers and sisters from different walks of life and different national origin, and to understand what it means to "keep" them? I believe we can, and I believe we must. The power to dwell in unity, as the psalmist celebrates, is within all of our reach.
Series: At the Movies
At the Movies: Wonder…
At the Movies: Won't You…


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Bent Walad DZ est une série télévisée algérienne qui est diffusée en simultané du  à 2015. Elle suit le quotidien d'un nouveau couple marié, sur un ton humoristique et critique de la société algérienne, sur le modèle d'Un gars, une fille. Elle est suivie par Bibiche et Bibicha.

La première saison est diffusée durant l'année 2014 sur Echorouk TV, la deuxième est diffusée sur Télévision Algérienne et sur Canal Algérie pour les rediffusions.

Distribution

Acteurs principaux
 Merouane Guerouabi : Bibiche
 Souhila Mallem : Bibicha

Invités

 Fayçal Erraoui
 Kamal Zerrara
 Wassila Aridj
 Salim Zerrouk
 Zoubir Belhour
 Boukhalfa Sahli
 Manel Djaafar
 Farah Louzouaz

Fiche technique
 Titre original :
 Titre en français : Bent Walad DZ
 Réalisation : Samy Faour
 Scénario : Aïssa Sharit
 Photographie : Ikbal Arrafa
 Sociétés de production : Not Found Prod et Wellcom Advertising
 Société(s) de distribution : Echorouk TV, Télévision Algérienne
 Pays d'origine :
 Langue originale : arabe
 Format : couleur - HDTV - son stéréo
 Genre : Comédie
 Durée : 25 minutes

Chaine Youtube
 Bibiche et Bibicha

Références

Série télévisée créée en 2014
Série télévisée algérienne
Série télévisée en arabe
Série télévisée de l'Établissement public de télévision

redpajama_set_name: RedPajamaWikipedia


text:
Scopula sybillaria is a moth of the family Geometridae first described by Charles Swinhoe in 1902. It is found in western China, Hong Kong and possibly Borneo.

Adults are greyish fawn in colour.

References

Moths described in 1902
sybillaria
Moths of Asia


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One of Glasgow's most unique cafes is up for sale just one year after opening
The former toilet block was given a new lease of life in 2017 - but now needs new owners
Gillian LoneySenior editor
(Image: Chaiwallah/Facebook)
Get all the latest food and drink news sent straight to your inbox
A former Victorian toilet block given a new lease of life as a cafe for park goers is on the market - just one year after it opened.
Chaiwallah in the west end of Glasgow opened in 2017, converting an old and derelict brick building into a coffee shop, lunchtime cafe and event space.
The place proved popular on social media thanks to its unusual location - and with students from nearby Glasgow University and Kelvingrove park goers alike.
The 25 most talked-about Glasgow restaurants of 2017
But an advert for the Chaiwallah leasehold has appeared online for an asking price of £100,000 to £200,000, including furniture, fixtures and stock.
It reads: "The building is a former Victorian public convenience which has been fully renovated and fitted out to establish a cafe and community venue, retaining many of the original architectural features with original period fittings and fixtures added.
There's a free vegan cookout taking place in Glasgow next month - and you're all invited to get involved
"The business has potential to expand in many ways with permission granted within lease terms to operate cycle hire, community/private events within Kelvingrove Park, also table licence.
"Premises rarely come onto the market within the location. Since opening, the business has attracted some social media attention."
The place shut up for winter in December, but had announced no plans to reopen this year - and the Chaiwallah Facebook page is marked 'permanently closed'.
It may be sad news for fans, as the cafe changing hands might mean a new brand moving in.
A weekend in Glasgow? Here's the best way to spend it
Last year, BeanYet Ltd promised a "community hub offering a range of services, including the start of a free mobility scooter hire fleet for the disabled".
Still, for the right business, this place could prove to be a winner - especially with its prime west end location and unique history.
You can find the for sale listing here.
Glasgow University
Kelvingrove Park


Hemp bags and shawls -- once all the rage -- are now passé; the new "in," manufactured by local Kumaonis, are stoles made from the stinging nettle. The plant is converted into fiber, and the resulting hand-woven stoles are stylish, soft, and ultra-luxurious; and no, they don't itch. Initiated by a women's cooperative, you can take a fascinating tour of the Panchachuli factory (Pataldevi Industrial Area; tel. 05962/23-6817; www.panchachuli.com) which also has a shop attached. Or, if time is of essence, then head for the outlet in Almora market (Mall road; tel. 05962/23-0968; from Rs 2,000).
En route from Naukuchiatal to Bhowali, make sure you stop at Fruitage, which sells apple chutney, apricot halves, and a refreshing rhododendron squash. Some species of rhododendron are believed to have medicinal qualities that cool you down (ideal on a hot day). In addition, the plant's extracts (or honey produced from its nectar) are thought to alleviate cardiac problems, high blood pressure, and asthma. Connoisseurs of honey should also stop at the sleepy state-run apiary in Jeolikot, 17km (11 miles) from Nainital, famous for its pure wildflower honey. Sample unique, naturally occurring honey varieties like mustard, litchi, and eucalyptus.


text:
Ekeby distrikt är ett distrikt i Bjuvs kommun och Skåne län.

Området ligger söder om Bjuv.

Tidigare administrativ tillhörighet
Distriktet inrättades 2016 och utgörs av socknen Ekeby i Bjuvs kommun.

Området motsvarar den omfattning Ekeby församling hade 1999/2000.

Referenser

Noter

Indelningar i Bjuvs kommun
Distrikt i Skåne län


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Q: meteor connection to an other mongodb (not the local one) I have launched a localhost:207017 mongod 3.0.5 which is a completely separate mongodb than meteor's
I want to connect to it from meteor (which has a local mongodb).
I have seen in How do I use an existing MongoDB in a Meteor project? that we can use: export MONGO_URL=mongodb://localhost:27017/your_db to link "something" to my mongo server.
Question:

*

*where is this mongo_url env variable stored ie locally in my meteor appli ? Is it specifically for the meteor appli I am dealing with or for all meteor.

*how do I come back to the local mongodb of my appli

*with the following code, no collection is created in your_db BUT I have a new collection (empty) called meteor_accounts_loginServiceConfiguration.

In meteor, I am using todo example from meteor doc site
.js file
Tasks = new Mongo.Collection("tasks");

if (Meteor.isClient) {
  // This code only runs on the client
  Template.body.helpers({
    tasks: function () {
      return Tasks.find({});
    }
  });
}

.html file

Todo List

      {{#each tasks}}
        {{> task}}
      {{/each}}

<template name="task">

{{text}}

</template>

Anybody has a clew how all this is setup and working and how to fix it?
Best,
G

A: Environment variables can be set on the command line as you launch the application, so you do not need to set this in your overall shell environment. Doing that would mean either it is global for that shell or global for all shell sessions depending if you set that permanently.
But a simple migration for me is just a few steps:

*

*Start meteor application in one window

*In another window connect to it's local MongoDB by the running port. ( in this case on 3001 ), just to check:
mongo --port 3001

*After reporting connected and exiting the shell, then I run a mongoexport and mongoimport to copy the desired collection:
mongoexport --port 3001 -d meteor -c cards | mongoimport -d meteor -c cards

I am just piping the output from the export to the import which is simple. Also I am choosing to keep the same database name, but you can change if you want. Repeat exports for each collection you want.

*Stop the meteor application which stops the local server, and then resart with the environment setting issued before the meteor command. Again, I put everyhting in the "meteor" database, so that is what I am connecting to:
MONGO_URL="mongodb://localhost:27017/meteor" meteor

When the app is started up, it hapilly reads the data from the migrated collection and displays perfectly.
For the paranoid, if you did not notice the output in the meteor startup which did not report a local MongoDB starting, then you can check the running processes and see that only your "global" MongoDB is the only instance running.
Or of course if you pointed to another machine, then there is no MongoDB running on the application server.

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