ASKAP observations of blazars possibly associated with neutrino events IC190730A and IC190704A
ATel #12981; Dougal Dobie (University of Sydney/CSIRO), David L. Kaplan (University of Wisconsin, Milwaukee), Adam Stewart (University of Sydney), Tara Murphy (University of Sydney), Emil Lenc (CSIRO), David McConnell (CSIRO), Aidan Hotan (CSIRO), Julie Banfield (CSIRO), Wasim Raja (CSIRO), Matthew Whiting (CSIRO)
on 2 Aug 2019; 07:23 UT
Credential Certification: Dougal Dobie (ddob1600@uni.sydney.edu.au)
Subjects: Radio, Neutrinos, Blazar
GCN #24981 reports the detection of a high-energy astrophysical neutrino candidate, IC190704A, spatially coincident with the known blazar 1WHSP J104516.2+275133.
ATel #12967 reports the detection of a high-energy astrophysical neutrino candidate, IC190730A, spatially coincident with the known blazar PKS 1502+106.
We have obtained observations of both blazars prior to the detection of the corresponding neutrino candidates with the Australian Square Kilometre Array Pathfinder (ASKAP) as part of the Rapid ASKAP Continuum Survey (RACS). Observations were carried out at 888 MHz with a bandwidth of 288 MHz.
The field containing PKS 1502+106 was observed on 2019-04-24 and we find a flux density of ~1.68 Jy, which is consistent with archival measurements. Historically this source appears to exhibit minimal radio variability.
Two fields containing 1WHSP J104516.2+275133 were observed on 2019-04-21 and we find a flux density of ~4.5 mJy in each. This is broadly consistent with observations with the VLA on 2019-07-09 (ATel #12926) and archival data from FIRST. Comparing the RACS measurement to the observation as part of the VLA Sky Survey on 2019-06-08 suggests the blazar had a much steeper spectrum prior to the neutrino event and is exhibiting significant variability.
This work was done as part of the ASKAP Variables and Slow Transients (VAST) collaboration (Murphy et al. 2013, PASA, 30, 6).
The Rapid ASKAP Continuum Survey
