Not Available

We present a sample of 33 damped Lyman α systems (DLAs) discovered in the Sloan Digital Sky Survey (SDSS) whose absorption redshifts (zabs) are within 6000 km s-1 of the quasi-stellar object's (QSO) systemic redshift (zsys). Our sample is based on 731 2.5 zsys 4.5 non-broad absorption line (non-BAL) QSOs from Data Release 3 (DR3) of the SDSS. We

This is a theoretical investigation on the formation of the linearly polarized line spectrum of ionized cerium in the sun. We calculate the scattering line polarization pattern emergent from a plane-parallel layer of Ce ii atoms illuminated from below by the photospheric radiation field, taking into account the differential pumping induced in the

We have developed a new technique to decouple the spectra of the host and the nucleus of type I AGNs using integral field spectroscopy (IFS) data. The technique is a simple extension of methods widely tested in 2D imaging. We present here the results from applying the technique to data taken with INTEGRAL at the 4.2m WHT telescope on the Seyfert 1

The exceptionally high luminosities of gamma-ray bursts (GRBs), gradually emerging as extremely useful probes of star formation, make them promising tools for exploration of the high-redshift Universe. Here we present a carefully selected sample of Swift GRBs, intended to estimate in an unbiased way the GRB mean redshift (z_mean), constraints on

We report on the properties of a 99.3-d periodic modulation in the X-ray transient XTEJ1716-389. We associate this source with the transient KSJ1716-389, first detected by the Mir/Kvant module in 1994. The spectral characteristics of XTEJ1716-389, a high intrinsic absorption column, strong emission features and a power-law spectrum, make it very