The brightest radio state of PKS 1830-21
ATel #12739; S. A. Trushkin, N. A. Nizhelskij, P. G. Tsybulev, N. N. Bursov (SAO RAS, Russia)
on 9 May 2019; 09:01 UT
Credential Certification: Sergei Trushkin (satr@sao.ru)
Subjects: Radio, Millimeter, X-ray, Gamma Ray, AGN
Gravitationally lensed quasar PKS 1830-211 (J1833-2103) is one of most often observed bright radio sources with the RATAN-600 radio telescope. After detection of the renewed GeV gamma-ray activity by Fermi LAT and the record gamma-ray flux by AGILE (ATels #12136, #12252, #12594, #12601, #12603, #12622, #12685) we have measured the multi-frequency fluxes from the relatively recent RATAN observations since 2005. Using our CATS data base (http://cats.sao.ru) we collected about 600 flux points from published data, adding the recent data from ATel #12667. Then we have observed PKS1830-21 in April 2019. Indeed the fluxes were extremely high: 14.6 +/- 0.25, 13.3 +/- 0.15, 18.0 +/- 0.10, 18.8 +/- 0.10, 17.1 +/- 0.15, 10.3 +/- 0.15, 8.5 +/- 0.20 at 1.24, 2.3, 4.7, 8.2, 11.2, 21.7 and 30 GHz respectively. These values are strongly higher previous measurements in October 2018 and the lowest fluxes measured in September 2005. Thus we propose that now PKS 1830-21 is in the most bright phase of the radio emission since beginning of its regular radio observations. PKS1830-21 with the last spectrum having the maximum around 8 GHz looks like the Gigahertz-Peaked Spectrum sources, belonged to wide class of active galactic nuclei. Obviously the nature of the active state connected with internal jet activity of the source and new VLBI-mapping could be very relevant.
The RATAN-600 radio spectra of PKS 1830-21 in different epochs with compiled data
