Recent radio activity of the Fermi blazar S5 0716+714
ATel #4447; I. Myserlis, E. Angelakis, L. Fuhrmann, V. Karamanavis, I. Nestoras, T. P. Krichbaum, J. A. Zensus (F-GAMMA team, MPIfR, Bonn, Germany), H. Ungerechts, A. Sievers (IRAM, Granada, Spain)
on 2 Oct 2012; 12:09 UT
Credential Certification: Emmanouil Angelakis (angelaki@mpifr-bonn.mpg.de)
Subjects: Radio, Millimeter, AGN, Blazar, Quasar
Abstract:
We report the recent activity (raising flux density) seen in the monitored blazar S5 0716+714 (J0721+7120, RA= 07:21:53, DEC=+71:20:36 in J2000) as recorded within the framework of the F-GAMMA program responding to ATel #4437 (optical).
Long term behaviour:
S5 0716+714 has been monitored since January 2007 at 11 frequencies between 2.64 and 228.39 GHz, showing frequent large amplitude events as well as smaller amplitude ones that are propagating through the program's bandpass as it can be seen in its light curves at: low, intermediate and higher radio frequencies (or all frequencies together). These events can also be seen in the temporal evolution of its spectrum which shows large variability over the course of the last five years and switches from highly inverted to very steep (S ~ nu^a).
Recent activity:
From the high frequencies light curves it can be seen that the source has recently come into a new activity phase. Between MJD 56050 and 56100 the flux density reaches a minimum before going into a currently increasing trend. For instance, at 142.33 GHz (2 mm) the flux density increased from 0.6 (MJD: 56074.542) to 2.4 Jy (MJD: 56175.663). At intermediate frequencies the behaviour is similar although it appears delayed with respect to the higher ones. At low frequencies the delay seems to be even larger with the 2.64 GHz for example being at the minimum even at MJD: 56173.811. Interestingly, the weekly-averaged public Fermi light curve (100 MeV - 300 GeV) indicates an outburst that has occurred between MJD: 56100 and 56200 coinciding with the period seen in the radio.
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: