ar X iv : a st ro - p h / 96 05 11 3 v 1 1 7 M ay 1 99 6 An Excess of C iv Absorbers in Luminous QSOs :

ar X iv : a st ro - p h / 97 09 12 6 v 1 1 3 Se p 19 97 Proximity Effect for Metal Absorption Systems

Using our photoionization code CIRRUS [1], we show that the study of proximity effect on metal elements provides a possibility of placing constraints on the spectral shape of the metagalactic UV background (MUVB). From theoretical point of view, the most optimum indicator of the spectral shape of the MUVB is the ratio O iv/O iii. Unlike previous thought, the ratio Si iv/C iv is not a good indic...

ar X iv : a st ro - p h / 95 05 14 5 v 1 3 1 M ay 1 99 5 Search for GRB counterparts

ar X iv : a st ro - p h / 97 02 07 4 v 1 7 F eb 1 99 7 The hosts of z = 2 QSOs

We present results of the hosts of four high-redshift (z ≈ 2) and high luminosity (MB ∼ −28 mag) QSOs, three radio-quiet one radio-loud, imaged in R and K bands. The extensions to the nuclear unresolved source are most likely due to the hosts galaxies of these QSOs, with luminosities at rest-frame 2300Å of at least 3−7 per cent of the QSO luminosity, and most likely around 6−18 per cent of the ...

ar X iv : a st ro - p h / 96 01 03 1 v 1 9 J an 1 99 6 Very close pairs of Quasi - Stellar Objects

It is pointed out that there are now known four very close pairs of QSOs with separations < 5 arcsec and very different redshifts. Several estimates of the probability that they are accidental configurations range between 10 −7 and 3.5×10 −3. We conclude either that this is further evidence that QSOs have significant non-cosmological redshift components, or that the pairs must be explained by g...

ar X iv : a st ro - p h / 99 05 37 6 v 1 2 8 M ay 1 99 9 A 6 . 4 - hr positive superhump period in TV