A Catalogue of Damped Lyman Alpha Absorption Systems and Radio Flux Densities of the Background Quasars

Steve Curran


This website is the author produced HTML version of S. J. Curran, J. K. Webb, M. T. Murphy, R. Bandiera, E. Corbelli and V. V. Flambaum, 2002, "A Catalogue of Damped Lyman Alpha Absorption Systems and Radio Flux Densities of the Background Quasars" (Publications of the Astronomical Society of Australia 19, 455-474). By having this catalogue on-line it is my hope that it can be continually updated so that it retains its usefulness to the astronomical community. In order to concentrate on the actual list of objects, the reader is referred to the paper (linked above) for full details (such as scientific motivation, etc). To use this catalogue, however, it is necessary to note the following:

Column 1 This is the name, as obtained from NED, of the background quasar, illuminating the damped Lyman alpha absorber (DLA). Note that those in red are not part of the original published list (see the note in column 6).

Columns 2 & 3 The J2000 coordinates. Unfortunately, some of these may be erroneous (see Sect. 2.1 of the paper). Therefore, before observing these objects, it is strongly recommended that the coordinates are checked, for example on the Digitized Sky, APM and COSMOS Surveys (the coordinates in green have already been checked). I would be very grateful if you could notify me of any such errors (and any new DLAs) and I shall update this list accordingly.

Column 4 The redshift of the background quasar.

Column 5 The redshift of the DLA. As per Section 3 of the paper, this field links to any other absorption features of interest, e.g. the 21 cm hyperfine transition of neutral atomic hydrogen in the DLA.

Column 6 The base 10 logarithm of the column density of the DLA in cm-2. The superscript denotes the reference to the DLA, as given in the published paper, and each of these is a hyper-link to the ADS abstract. In the case of new DLAs no superscripts are allocated but the reference can still be reached via this column. Also not published in the original paper are inferred DLAs. Although, not yet observed in the Lyman alpha line, each is believed, from other (e.g. metal or 21 cm) absorption lines, to possess the column density of neutral atomic hydrogen (N HI>1020   cm-2 ) characteristic of a DLA. Since we were not initially interested in these sources for our work, the catalogue at this stage by no means constitutes an exhaustive list of these (note also, in some cases the original references have yet to be published).
Finally, note that ``*'' denotes a candidate DLA which has yet to be confirmed using higher resolution spectroscopy (``**'' designates that this absorber has subsequently been found not to be damped.)

Column 7 The visual magnitude, obtained either from the original reference (previous column), the Véron catalogue of Quasars and Active Galactic Nuclei (10th Ed.) or the NASA/IPAC Extragalactic Database (NED).

``Radio flux densities'' These are the radio flux densities of the background quasars in Janskys for 0.4, 1.4, 2.7, 5.0 and "higher" (frequency given in parenthesis) GHz. ``X'' denotes no measured radio flux at the survey's detection limit (0.25 Jy for the Texas Survey at 365 MHz over -35.5o≤ δ &le 71.5o). As in column 5, the superscripts denote the references to the radio properties and link to the ADS abstract or straight to the (CDS) catalogue (the CDS version of this catalogue can be accessed here).


Quasar                       Coordinates (J2000)      zem       zabs      log N HI                  V                  Radio flux densities (Jy)
                         h   m   s d   '   ''                S0.4                   S1.4             S2.7          S5.0                                  Shigher