Strong radio flare emission from the FSRQ PKS 1830-211 detected with the Medicina radio telescope at 8.3 GHz and 25.4 GHz
ATel #12667; M. N. Iacolina (ASI), A. Pellizzoni, E. Egron (INAF-OAC), I. Donnarumma (ASI), F. Verrecchia, C. Pittori (SSDC and INAF/OAR), S. Righini (INAF-IRA), M. Pilia (INAF-OAC), S. Vercellone (INAF-OA-Brera), A. Chen (Wits University), G. Valente (ASI), M. Tavani (INAF/IAPS and Univ. Roma Tor Vergata), S. Puccetti (ASI)
on 17 Apr 2019; 18:52 UT
Credential Certification: Elise Egron (elise.egron@inaf.it)
Subjects: Radio, AGN, Black Hole, Blazar, Transient, Gravitational Lensing
Following the detection of ongoing intense gamma-ray activity from the gravitationally lensed blazar PKS 1830-211 (Atels #12136, #12252, #12594, #12601, #12603, #12622), we started a radio monitoring campaign (PI Iacolina, Project INAF 41-19) with the 32-m Medicina Radio Telescope that will continue during the next weeks with the 64-m Sardinia Radio Telescope (https://www.radiotelescopes.inaf.it).
A first single-dish radio imaging observing session was performed on April 17, 2019 in UTC range 02:30-07:30 (MJD 58590.10-58590.31) with the K-band and X-band receivers at Medicina 32m.
We adopted single-dish imaging techniques and data analysis as described in Egron et al. (MNRAS, 471, 2703, 2017; MNRAS, 470, 1329, 2017) and Loru et al. (MNRAS, 482, 3857, 2019).
Quick-look data analysis revealed strong radio emission with detection significance above 30 sigma level. Preliminary flux density estimates provided 12+/-2 Jy at 25.4 GHz (bandwidth 680 MHz) and 16+/-2 Jy at 8.3 GHz (bandwidth 250 MHz), with both values showing a significant enhancement with respect to historical radio data (see e.g., Pramesh & Subrahmanyan 1988, MNRAS, 231, 229; Lovell et al. 1998, ApJ, 508, L51; Giommi et al. 2012, A&A 541, 160). Data calibration was performed through comparison of target images with the standard calibration sources 3C286 and 3C295. Refined analysis of flux densities and spectral parameters are on-going. If confirmed, these radio measurements are among the most intense flux ever detected form PKS 1830-211 at high radio frequencies.
