High-redshift Narrow-line Seyfert 1 Galaxies: A Candidate Sample
Abstract
The study of narrow-line Seyfert 1 galaxies (NLS1s) is now mostly limited to low redshift (z<0.8) because their definition requires the presence of the Hβ emission line, which is redshifted out of the spectral coverage of major ground-based spectroscopic surveys at z>0.8. We studied the correlation between the properties of Hβ and Mg II lines of a large sample of SDSS DR14 quasars to find high-z NLS1 candidates. Based on the strong correlation of FWHM(MgII)=(0.880 0.005) × FWHM(Hβ)+ (0.4380.018), we present a sample of high-z NLS1 candidates having FWHM of Mg II < 2000 km s-1. The high-z sample contains 2684 NLS1s with redshift z=0.8-2.5 with a median logarithmic bolometric luminosity of 46.160.42 erg s-1, logarithmic black hole mass of 8.010.35 M, and logarithmic Eddington ratio of 0.020.27. The fraction of radio-detected high-z NLS1s is similar to that of the low-z NLS1s and SDSS DR14 quasars at a similar redshift range, and their radio luminosity is found to be strongly correlated with their black hole mass.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.