ATCA finds a long-term radio flare of PKS0215+015 coincident with IceCube-220225A
ATel #15245; Matthias Kadler (JMU Wuerzburg), Jamie Stevens (CSIRO Astronomy and Space Science), Roopesh Ojha (NASA HQ), and Philip G. Edwards (CSIRO Astronomy and Space Science)
on 27 Feb 2022; 07:30 UT
Credential Certification: Matthias Kadler (matthias.kadler@astro.uni-wuerzburg.de)
Subjects: Radio, Gamma Ray, Neutrinos, Request for Observations, AGN, Blazar, Quasar
We report on contemporary radio observations of PKS0215+015, a radio and gamma-bright AGN possibly associated with the recently detected high-energy neutrino IceCube-220225A (GCN#31650) on Feb 22, 2022, and the flaring gamma-ray source 4FGL J0217.8+0144 (ATel#15243).
ATCA has monitored PKS0215+015 at multiple frequencies ranging from
2.1GHz to 50GHz since 2004. The observations showed a long relatively low emission state with flux densities around 0.8Jy to 1.3Jy between 2014 and February 2021. Since May 2021, the data show a strong long-term increase of the source flux density at all wavelengths. On May 22, 2021, flux densities of 1.703+-0.025Jy and 1.667+-0.025Jy were measured at 33GHz and 35GHz, respectively. On Oct 31, 2021, substantially higher flux densities of 3.243+-0.032Jy and 3.081+-0.032Jy were measured at 16.8GHz and 21.2GHz, respectively. The most recent fully calibrated measurements were made at the lower frequencies of 5.5GHz and 8.5GHz on Nov 18, 2021, and showed 2.418+-0.021Jy and 2.967+-0.021Jy, respectively. Additional observations made in February 2022, which are currently being calibrated and tested, show a persisting long-term radio flaring activity. Primary flux density calibration was performed against similar scans on PKS 1934-638 at all frequencies and epochs.
We acknowledge that other long-term radio programs have also registered the radio flare of PKS0215+015 (priv. com.) preceding the neutrino detection and we encourage more observations to better constrain the correlation with the gamma-ray emission.
The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Australian Government for operation as a National Facility managed by CSIRO.
