2003/10/21 by Anca Constantin, Joseph C. Shields, Constantin, Anca +1
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0310623
4 pages. To appear in "AGN Physics with the Sloan Digital Sky Survey", ed. G.T. Richards & P.B. Hall (ASP Conference Series)
arxiv created 2003/10/21 · arxiv updated 2009/12/01
The emission and absorption attributes of the UV-blue nuclear spectra of the Narrow-Line Seyfert 1 (NLS1) galaxies are analyzed based on high quality archival HST observations. Measurements from composite spectra as well as from individual sources reveal differences from the more general AGN samples: NLS1s have steeper (redder) UV-blue continua. Objects with UV line absorption show redder spectra, suggesting that internal dust is important in modifying the continuum shapes. A strong relationship is found between the slopes of the power-laws that best fit the UV-blue continua and the luminosities: the more luminous sources have bluer SEDs. This trend is possibly attributed to a luminosity-dependent inner geometry of the obscuring (dusty) material.