Searching for Gamma-ray Narrow-line Seyfert 1 Galaxies'

Narrow-line Seyfert 1 (NLS1) galaxies are presumably an early evolutionary stage of AGN, as they have relatively low supermassive black hole (SMBH) masses. Despite this, they have high Eddington ratios and possibly super-Eddington accretion rates. They are characterized by their emission lines: FWHM(Hβ) < 2000km/s, S([O III])/S(Hβ) < 3, and strong Fe II lines. These confirm the lower SMBH mass and the fact that their more central broad-line region is in view. It was previously believed that only AGNs with the most massive SMBHs would be powerful enough to launch relativistic jets. This idea was proven false when gamma rays were detected from NLS1s, which could only be launched from relativistic jets. Since then, gamma ray detection replaced radioloudness as a proxy for whether an AGN is jetted. Since the first gamma-ray NLS1 was detected 15 years ago, about a dozen more have been detected, each with their own dedicated work. One of these, published in 2018, reduced the Fermi GST data of 7 NLS1s and detected gamma-rays from one. It highlighted, however, 3 candidates that gamma rays could be detected from, if given more data. I aim to reduce the data collected since then to confirm or deny the presence of gamma-rays in these NLS1s.