Title: New Identifications and Multiwavelength Properties of Extragalactic Fermi Gamma-Ray Sources in the SPT-SZ Survey Field

Abstract

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.

Authors:

Zhang, Lizhong  ^[1];

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Vieira, Joaquin D.  ^[2];

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• Search DOE PAGES for ORCID "0000-0001-7192-3871"

Ajello, Marco  ^[3];

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Malkan, Matthew A.  ^[4];

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Archipley, Melanie A.  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-0517-9842"

Capota, Joseph  ^[5];

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Foster, Allen  ^[6];

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• Search DOE PAGES for ORCID "0000-0002-7145-1824"

Madejski, Greg ^[7]

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+ Show Author Affiliations

1. University of California, Santa Barbara, CA (United States); University of Illinois at Urbana-Champaign, IL (United States)
2. University of Illinois at Urbana-Champaign, IL (United States). National Center for Supercomputing Applications (NCSA)
3. Clemson University, SC (United States)
4. University of California, Los Angeles, CA (United States)
5. University of Illinois at Urbana-Champaign, IL (United States)
6. Case Western Reserve University, Cleveland, OH (United States)
7. SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford University, CA (United States)

Publication Date:

Mon Nov 14 00:00:00 EST 2022

Research Org.:

SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

Sponsoring Org.:

USDOE; National Science Foundation (NSF)

OSTI Identifier:

1991580

Grant/Contract Number:  

AC02-76SF00515; OPP-1852617; AST-1715213; AST-1716127

Resource Type:

Accepted Manuscript

Journal Name:

The Astrophysical Journal

Additional Journal Information:

Journal Volume: 939; Journal Issue: 2; Journal ID: ISSN 0004-637X

Publisher:

IOP Publishing

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; Active galactic nuclei; Blazars; Gamma-ray sources; Radio loud quasars; Relativistic jets; Submillimeter astronomy; figure set; machine-readable tables