Millimeter radio event emerging in the gamma-ray flaring blazar PKS 0528+134
E. Angelakis, L. Fuhrmann, I. Nestoras, R. Schmidt, J. A. Zensus, T. P. Krichbaum (F-GAMMA team, MPIfR, Bonn, Germany), H. Ungerechts, A. Sievers, D. Riquelme (IRAM, Granada, Spain)
Responding to the ATel #3412 reporting the recent activity of PKS 0528+134 at gamma-rays, we here report its behavior in the cm-to-mm radio bands as observed by the F-GAMMA program.

Recent activity: Observations performed with the Effelsberg 100-m and the IRAM 30-m telescope since January 2007 show that the source is following monotonously decaying long term trend. Frequencies lower than 14.60 GHz continue to decrease till today (last measurements June 5, 2011). However, the flux density at 86 and 142.3 GHz are inverting their behavior showing a slowly increasing trend already since 2010.4. The most recent measurements were done on June 5, 2011 (identical to the date reported in ATel #3412) and resulted a flux density of 2.75+/-0.15 Jy at 86 GHz and of 2.15+/-0.15 Jy at 142.3 GHz as compared to 0.92+/-0.12 Jy and 0.40+/-0.06 Jy on May 31, 2010, respectively. Hence, a flaring event is "building up" at the highest radio frequencies in our band-pass overlapping with the event in gamma-rays reported by ATel #3412. The radio light curves can be accessed separately at low, intermediate and high. Alternatively, also the evolution of its spectrum as a function of time can be accessed.

The source will be continuously monitored and possible future activity will be reported through the current platform.

F-GAMMA program: F-GAMMA (Fermi-GST AGN Multi-frequency Monitoring Alliance) program is the coordinated effort of several observatories and research teams to probe AGN physics through the multi-frequency monitoring approach. The core program relies on monthly observations with the Effelsberg 100-m radio telescope (operating at 8 frequencies between 2.6 and 43 GHz), the IRAM 30-m telescope (observing at 86 and 142 GHz) and additional measurements with the APEX 12-m telescope (operating at 345 GHz). The core sample consists of roughly 60 Fermi-GST/LAT monitored blazars. The data are taken simultaneously within 40 minutes for Effelsberg and 10 minutes for the IRAM telescope while the cross-station coherency is of order of 10 days. Data products are publicly accessible here. For more details, visit:
radio,millimeter,gamma ray,agn,black hole,blazar,quasar,variables