2015/10/19 by Neng-Hui Liao, Yun-Feng Liang, Liao, Neng-Hui +9
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · pdf · doi:10.48550/arxiv.1510.05584
openalex publication_date 2015/10/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Narrow line Seyfert 1 galaxies (NLS1s) usually do not host relativistic jets\nand the detection of their \γ-ray emissions is rarely reported. Evidences\nfor strong relativistic beaming effect have been found in all \γ-ray\nNLS1s to date and hence their jets are believed to be closely aligned. In this\nwork we perform a systematic analysis of 7-year it Fermi Large Area\nTelescope (LAT) data of 18 steep radio spectrum NLS1s (S-NLS1s) and report the\n it first two detections of \γ-ray emissions in this class, increasing\nthe total number of known \γ-ray NLS1s to 9. A strong and stable\n\γ-ray signal (over 8\σ) is produced by SDSS J144318.56+472556.7,\nand a significant \γ-ray emission (4.5\σ) of SDSS\nJ130522.74+511640.2 has been detected in a monthly flare in November 2013. A\nthorough investigation of their multiwavelength properties from radio to X rays\nhas been performed, finding no significant variability. Along with their\nspectral energy distributions and the radio morphology, these facts strongly\nsuggest that these two sources harbor mis-aligned and possibly underdeveloped\nrelativistic jets, which provides valuable targets to reveal the formation and\nevolution of relativistic jets under extreme circumstances.\n