Simultaneous Millimeter-wave, Gamma-Ray, and Optical Monitoring of the Blazar PKS 2326-502 during a Flaring State

Journal Article · Fri Mar 10 00:00:00 EST 2023 · The Astrophysical Journal. Letters

DOI:https://doi.org/10.3847/2041-8213/acbf45· OSTI ID:1960275

Hood II, J. C.; Simpson, A.; McDaniel, A.; Foster, A.; Ade, P. R.; Ajello, M.; Anderson, A. J.; Austermann, J. E.; Beall, J. A.; Bender, A. N.; Benson, B. A.; Bianchini, F.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Chaubal, P.; Chiang, H. C.; Chou, T-L; Citron, R.; Moran, C. Corbett ; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Everett, W.; Gallicchio, J.; George, E. M.; Gupta, N.; Halverson, N. W.; Hilton, G. C.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Huang, N.; Hubmayr, J.; Irwin, K. D.; Knox, L.; Lee, A. T.; Li, D.; Lowitz, A.; Madejski, G.; Malkan, M.; McMahon, J. J.; Meyer, S. S.; Montgomery, J.; Natoli, T.; Nibarger, J. P.; Noble, G.; Novosad, V.; Omori, Y.; Padin, S.; Patil, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Saliwanchik, B. R.; Schaffer, K. K.; Sievers, C.; Smecher, G.; Stark, A. A.; Tucker, C.; Veach, T.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Wu, W. K.; Yefremenko, V.; Zebrowski, J. A.; Zhang, L.

Including millimeter-wave data in multiwavelength studies of the variability of active galactic nuclei (AGN) can provide insights into AGN physics that are not easily accessible at other wavelengths. We demonstrate in this work the potential of cosmic microwave background (CMB) telescopes to provide long-term, high-cadence millimeter-wave AGN monitoring over large fractions of sky. We report on a pilot study using data from the SPTpol instrument on the South Pole Telescope (SPT), which was designed to observe the CMB at arcminute and larger angular scales. Between 2013 and 2016, SPTpol was used primarily to observe a single 500 deg2 field, covering the entire field several times per day with detectors sensitive to radiation in bands centered at 95 and 150 GHz. We use SPT 150 GHz observations to create AGN light curves, and we compare these millimeter-wave light curves to those at other wavelengths, in particular γ-ray and optical. In this Letter, we focus on a single source, PKS 2326-502, which has extensive, day-timescale monitoring data in gamma-ray, optical, and now millimeter-wave between 2013 and 2016. We find PKS 2326-502 to be in a flaring state in the first 2 yr of this monitoring, and we present a search for evidence of correlated variability between millimeter-wave, optical R-band, and γ-ray observations. This pilot study is paving the way for AGN monitoring with current and upcoming CMB experiments such as SPT-3G, Simons Observatory, and CMB-S4, including multiwavelength studies with facilities such as Vera C. Rubin Observatories Large Synoptic Survey Telescope.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science; USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: SPT
• Grant/Contract Number: AC02-06CH11357; AC02-07CH11359
• OSTI ID: 1960275
• Alternate ID(s): OSTI ID: 1969358
• Report Number(s): FERMILAB-PUB-23-100-PPD; arXiv:2302.14749; oai:inspirehep.net:2637377
• Journal Information: The Astrophysical Journal. Letters, Journal Name: The Astrophysical Journal. Letters Journal Issue: 2 Vol. 945; ISSN 2041-8205
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AGN
Active galactic nuclei
Blazars
Gamma-ray astronomy
Gamma-ray source
Millimeter astronomy