TY - JOUR
T1 - Gamma-Ray-emitting Narrow-line Seyfert 1 Galaxies in the Sloan Digital Sky Survey
AU - Paliya, Vaidehi S.
AU - Ajello, M.
AU - Rakshit, S.
AU - Mandal, Amit Kumar
AU - Stalin, C. S.
AU - Kaur, A.
AU - Hartmann, D.
N1 - Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved..
PY - 2018/1/20
Y1 - 2018/1/20
N2 - The detection of significant γ-ray emission from radio-loud narrow-line Seyfert 1 (NLSy1s) galaxies enables us to study jets in environments different than those in blazars. However, due to the small number of known γ-ray-emitting NLSy1 (γ-NLSy1) galaxies, a comprehensive study could not be performed. Here, we report the first detection of significant γ-ray emission from four active galactic nuclei (AGNs), recently classified as NLSy1 from their Sloan Digital Sky Survey (SDSS) optical spectrum. Three flat-spectrum radio quasars (FSRQs) present in the third Large Area Telescope AGN catalog (3LAC) are also found as γ-NLSy1 galaxies. Comparing the γ-ray properties of these objects with 3LAC blazars reveals their spectral shapes to be similar to FSRQs, however, with low γ-ray luminosity (≲1046-47 erg s-1). In the Wide-field Infrared Survey Explorer color-color diagram, these objects occupy a region mainly populated by FSRQs. Using the Hβ emission line parameters, we find that on average γ-NLSy1 have smaller black hole masses than FSRQs at similar redshifts. In the low-resolution SDSS image of one of the γ-NLSy1 source, we find the evidence of an extended structure. We conclude by noting that overall many observational properties of γ-NLSy1 sources are similar to FSRQs, and therefore these objects could be their low black hole mass counterparts, as predicted in the literature.
AB - The detection of significant γ-ray emission from radio-loud narrow-line Seyfert 1 (NLSy1s) galaxies enables us to study jets in environments different than those in blazars. However, due to the small number of known γ-ray-emitting NLSy1 (γ-NLSy1) galaxies, a comprehensive study could not be performed. Here, we report the first detection of significant γ-ray emission from four active galactic nuclei (AGNs), recently classified as NLSy1 from their Sloan Digital Sky Survey (SDSS) optical spectrum. Three flat-spectrum radio quasars (FSRQs) present in the third Large Area Telescope AGN catalog (3LAC) are also found as γ-NLSy1 galaxies. Comparing the γ-ray properties of these objects with 3LAC blazars reveals their spectral shapes to be similar to FSRQs, however, with low γ-ray luminosity (≲1046-47 erg s-1). In the Wide-field Infrared Survey Explorer color-color diagram, these objects occupy a region mainly populated by FSRQs. Using the Hβ emission line parameters, we find that on average γ-NLSy1 have smaller black hole masses than FSRQs at similar redshifts. In the low-resolution SDSS image of one of the γ-NLSy1 source, we find the evidence of an extended structure. We conclude by noting that overall many observational properties of γ-NLSy1 sources are similar to FSRQs, and therefore these objects could be their low black hole mass counterparts, as predicted in the literature.
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U2 - 10.3847/2041-8213/aaa5ab
DO - 10.3847/2041-8213/aaa5ab
M3 - Article
AN - SCOPUS:85041215419
SN - 2041-8205
VL - 853
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L2
ER -