Ultraviolet Emission Line Profiles of Flares and Active Regions

Balmer Emission Line Profiles and the Complex Properties of Broad Line Regions in Active Galactic Nuclei

In this work we analyze a sample of AGN spectra, selected from the 6 Data Release of the Sloan Digital Sky Survey, exploiting a generalized technique of line profile analysis, designed to take into account the whole profiles of their broad emission lines. We find that the line profile broadening functions result from a complex structure, but we may be able to infer some constraints about the ro...

Effect of Various Parameters on Emission Factors of Gas Flares

Single peaked CO emission line profiles from the inner regions of protoplanetary disks⋆

Context. Protoplanetary disks generally exhibit strong line emission from the CO fundamental v = 1–0 ro-vibrational band around 4.7 μm. The lines are usually interpreted as being formed in the Keplerian disk, as opposed to other kinematic components of the young stellar system. Aims. This paper investigates a set of disks that show CO emission line profiles characterized by a single, narrow pea...

Ultraviolet and optical flares on Gl 866

We present simultaneous ultraviolet and optical observations of five flares on the very late type M dwarf Gl 866 (dM5.5e). A procedure to estimate the physical parameters of the flaring plasma has been developed using a simplified model of the flare and a comparison of observed and computed Balmer decrements. With this procedure we have determined the optical thickness, electron temperature and...

The Ultraviolet-Optical Albedo of Broad Emission Line Clouds

We explore the e†ective UV-optical albedos of a variety of types of broad emission line clouds, as well as their possible e†ects on the observed spectra of active galactic nuclei (AGNs). An important albedo source in moderately ionized ionization-bounded clouds is that which is due to neutral hydrogen : Rayleigh scattering of continuum photons o† the extreme damping wings of Lya. The photons re...