New Identifications and Multiwavelength Properties of Extragalactic Fermi Gamma-Ray Sources in the SPT-SZ Survey Field
[1];
[2];
[3];
[4];
[2];
[5];
[6];
- University of California, Santa Barbara, CA (United States); University of Illinois at Urbana-Champaign, IL (United States)
- University of Illinois at Urbana-Champaign, IL (United States). National Center for Supercomputing Applications (NCSA)
- Clemson University, SC (United States)
- University of California, Los Angeles, CA (United States)
- University of Illinois at Urbana-Champaign, IL (United States)
- Case Western Reserve University, Cleveland, OH (United States)
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford University, CA (United States)
he fourth Fermi Large Area Telescope catalog (4FGL) contains 5064 $$\ γ$$-ray sources detected at high significance, but 26% of them still lack associations at other wavelengths. The SPT-SZ survey, conducted between 2008 and 2011 with the South Pole Telescope (SPT), covers 2500 deg2 of the southern sky in three millimeter-wavelength (mm) bands and was used to construct a catalog of nearly 5000 emissive sources. In this study, we introduce a new cross-matching scheme to search for multiwavelength counterparts of extragalactic $$\ γ$$-ray sources using a mm catalog. We apply a Poissonian probability to evaluate the rate of spurious false associations and compare the multiwavelength associations from the radio, mm, near-infrared, and X-ray with 4FGL $$\ γ$$-ray sources. In the SPT-SZ survey field, 85% of 4FGL sources are associated with mm counterparts. These mm sources include 94% of previously associated 4FGL sources and 56% of previously unassociated 4FGL sources. The latter group contains 40 4FGL sources for which SPT has provided the first identified counterparts. Nearly all of the SPT-associated 4FGL sources can be described as flat-spectrum radio quasars or blazars. We find that the mm band is the most efficient wavelength for detecting $$\ γ$$-ray blazars when considering both completeness and purity. We also demonstrate that the mm band correlates better to the $$\ γ$$-ray band than the radio or X-ray bands. With the next generation of CMB experiments, this technique can be extended to greater sensitivities and more sky area to further complete the identifications of the remaining unknown $$\ γ$$-ray blazars.
- Research Organization:
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE; National Science Foundation (NSF)
- Grant/Contract Number:
- AC02-76SF00515; OPP-1852617; AST-1715213; AST-1716127
- OSTI ID:
- 1991580
- Journal Information:
- The Astrophysical Journal, Vol. 939, Issue 2; ISSN 0004-637X
- Publisher:
- IOP PublishingCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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