Baldini L, Ballet J, Bastieri D, Becerra Gonzalez J, Bellazzini R, Berretta A, Bissaldi E, Blandford RD, Bloom ED, Bonino R, Bottacini E, Bruel P, Buson S, Cameron RA, Caraveo PA, Cavazzuti E, Chen S, Chiaro G, Ciangottini D, Cibario N, Ciprini S, Cristarella Orestano P, Crnogorcevic M, Cutini S, D'Ammando F, De La Torre Luque P, De Palma F, Digel SW, Di Lalla N, Dirirsa F, Di Venere L, Dominguez A, Fiori A, Fleischhack H, Franckowiak A, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Germani S, Giglietto N, Giordano F, Giroletti M, Green D, Grenier IA, Griffin S, Guiriec S, Gustafsson M, Hewitt JW, Horan D, Imazawa R, Johannesson G, Kerr M, Kocevski D, Kuss M, Larsson S, Latronico L, Li J, Liodakis I, Longo F, Loparco F, Lovellette MN, Lubrano P, Maldera S, Manfreda A, Martí-Devesa G, Matake H, Mazziotta MN, Mereu I, Meyer M, Mirabal N, Mitthumsiri W, Mizuno T, Monzani ME, Morselli A, Moskalenko IV, Nagasawa S, Negro M, Ojha R, Orienti M, Orlando E, Palatiello M, Paliya V, Paneque D, Pei Z, Persic M, Pesce-Rollins M, Petrosian V, Poon H, Porter TA, Principe G, Racusin JL, Raino S, Rando R, Rani B, Razzano M, Razzaque S, Reimer A, Reimer O, Saz Parkinson PM, Scotton L, Serini D, Sgro C, Siskind EJ, Spandre G, Spinelli P, Suson DJ, Tajima H, Tak D, Torres DF, Tosti G, Troja E, Wood K, Yassine M, Zaharijas G (2021)
Publication Type: Journal article
Publication year: 2021
Book Volume: 256
Journal Issue: 1
We present the first Fermi Large Area Telescope (LAT) catalog of long-term gamma-ray transient sources (1FLT). This comprises sources that were detected on monthly time intervals during the first decade of Fermi-LAT operations. The monthly timescale allows us to identify transient and variable sources that were not yet reported in other Fermi-LAT catalogs. The monthly data sets were analyzed using a wavelet-based source detection algorithm that provided the candidate new transient sources. The search was limited to the extragalactic regions of the sky to avoid the dominance of the Galactic diffuse emission at low Galactic latitudes. The transient candidates were then analyzed using the standard Fermi-LAT maximum likelihood analysis method. All sources detected with a statistical significance above 4 sigma in at least one monthly bin were listed in the final catalog. The 1FLT catalog contains 142 transient gamma-ray sources that are not included in the 4FGL-DR2 catalog. Many of these sources (102) have been confidently associated with active galactic nuclei (AGNs): 24 are associated with flat-spectrum radio quasars, 1 with a BL Lac object, 70 with blazars of uncertain type, 3 with radio galaxies, 1 with a compact steep-spectrum radio source, 1 with a steep-spectrum radio quasar, and 2 with AGNs of other types. The remaining 40 sources have no candidate counterparts at other wavelengths. The median gamma-ray spectral index of the 1FLT-AGN sources is softer than that reported in the latest Fermi-LAT AGN general catalog. This result is consistent with the hypothesis that detection of the softest gamma-ray emitters is less efficient when the data are integrated over year-long intervals.
APA:
Baldini, L., Ballet, J., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Berretta, A.,... Zaharijas, G. (2021). Catalog of Long-term Transient Sources in the First 10 yr of Fermi-LAT Data. Astrophysical Journal Supplement Series, 256(1). https://doi.org/10.3847/1538-4365/ac072a
MLA:
Baldini, Luca, et al. "Catalog of Long-term Transient Sources in the First 10 yr of Fermi-LAT Data." Astrophysical Journal Supplement Series 256.1 (2021).
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