SPT-210903 - South Pole Telescope Reports Detection of a Millimeter-Band Flaring Source
ATel #14891; Sam Guns, Allen Foster, SPT-3G Collaboration
on 3 Sep 2021; 23:00 UT
Credential Certification: Sam Guns (sguns@berkeley.edu)
Subjects: Millimeter, AGN, Transient
The South Pole Telescope Collaboration reports:
The 3rd-generation receiver on the South Pole Telescope (SPT-3G) detects a flaring millimeter point source at RA = 355.21397d, DEC = -43.11194d (estimated positional uncertainty of 15 arcseconds). Detectable emission began in the week of July 26 2021, rising steadily and reaching a peak of 14.7 ± 3.4 mJy at 95 GHz, 12.8 ± 4.0 mJy at 150 GHz, and 37.5 ± 15.9 mJy at 220GHz on August 26. SPT-3G will continue to monitor this source at hour- to day-long intervals.
Average quiescent flux at this position in 2020 measured via SPT-3G is 0.9 ± 0.5 mJy (95 GHz), 1.0 ± 0.6 mJy (150 GHz) and 4.9 ± 2.1 mJy (220GHz) suggesting a factor of >10 increase in millimeter-band luminosity. The source is 8 arcseconds away from WISEA J234051.04-430634.5.
All flux calibrations quoted here are preliminary and are believed to be accurate to 20%. Further information including lightcurves and an updated catalog of SPT transient detections can be found at https://pole.uchicago.edu/public/data/transients/.
The South Pole Telescope is a 10-meter telescope designed for observations of the cosmic microwave background located at Amundsen-Scott South Pole Station and supported by the National Science Foundation and the US Dept. of Energy. The SPT online transient program providing data in this telegram is supported by NSF grants AST-1716965 and OPP 1852617, and observes 1500 square degrees of the southern sky at 95, 150, and 220 GHz with an average revisit cadence of 12 hours. For more details on the SPT transient program and survey strategy, please see https://arxiv.org/abs/2103.06166.
