UNVEILING THE NATURE OF THE UNIDENTIFIED GAMMA-RAY SOURCES. V. ANALYSIS OF THE RADIO CANDIDATES WITH THE KERNEL DENSITY ESTIMATION

Massaro F, D'Abrusco R, Paggi A, Masetti N, Giroletti M, Tosti G, Smith HA, Funk S (2013)

Publication Type: Journal article

Publication year: 2013

Journal

Astrophysical Journal Supplement Series American Astronomical Society

Book Volume: 209

Journal Issue: 1

DOI: 10.1088/0067-0049/209/1/10

Abstract

Nearly one-third of the gamma-ray sources detected by Fermi are still unidentified, despite significant recent progress in this area. However, all of the gamma-ray extragalactic sources associated in the second Fermi-LAT catalog have a radio counterpart. Motivated by this observational evidence, we investigate all the radio sources of the major radio surveys that lie within the positional uncertainty region of the unidentified gamma-ray sources (UGSs) at a 95% level of confidence. First, we search for their infrared counterparts in the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) and then we analyze their IR colors in comparison with those of the known gamma-ray blazars. We propose a new approach, on the basis of a two-dimensional kernel density estimation technique in the single [3.4] - [4.6] - [12] mu m WISE color-color plot, replacing the constraint imposed in our previous investigations on the detection at 22 mu m of each potential IR counterpart of the UGSs with associated radio emission. The main goal of this analysis is to find distant gamma-ray blazar candidates that, being too faint at 22 mu m, are not detected by WISE and thus are not selected by our purely IR-based methods. We find 55 UGSs that likely correspond to radio sources with blazar-like IR signatures. An additional 11 UGSs that have blazar-like IR colors have been found within the sample of sources found with deep recent Australia Telescope Compact Array observations.

Authors with CRIS profile

Stefan Funk

Involved external institutions

Stanford National Accelerator Laboratory (SLAC) US United States (USA) (US) Harvard University US United States (USA) (US) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) IT Italy (IT) Università degli Studi di Perugia IT Italy (IT)

How to cite

APA:

Massaro, F., D'Abrusco, R., Paggi, A., Masetti, N., Giroletti, M., Tosti, G.,... Funk, S. (2013). UNVEILING THE NATURE OF THE UNIDENTIFIED GAMMA-RAY SOURCES. V. ANALYSIS OF THE RADIO CANDIDATES WITH THE KERNEL DENSITY ESTIMATION. Astrophysical Journal Supplement Series, 209(1). https://doi.org/10.1088/0067-0049/209/1/10

MLA:

Massaro, Francesco, et al. "UNVEILING THE NATURE OF THE UNIDENTIFIED GAMMA-RAY SOURCES. V. ANALYSIS OF THE RADIO CANDIDATES WITH THE KERNEL DENSITY ESTIMATION." Astrophysical Journal Supplement Series 209.1 (2013).

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