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تسجيل مستخدم جديدA catalogue of damped Lyman alpha absorption systems and radio flux densities of the background quasars
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تأليف
S. J. Curran
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We present a catalogue of the 322 damped Lyman alpha absorbers taken from the literature. All damped Lyman alpha absorbers are included, with no selection on redshift or quasar magnitude. Of these, 123 are candidates and await confirmation using high resolution spectroscopy. For all 322 objects we catalogue the radio properties of the background quasars, where known. Around 60 quasars have radio flux densities above 0.1 Jy and approximately half of these have optical magnitudes brighter than V = 18. This compilation should prove useful in several areas of extragalactic/cosmological research.
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We present the results from the optical component of a survey for damped Lyman-alpha systems (DLAs) towards radio-loud quasars. Our quasar sample is drawn from the Texas radio survey with the following primary selection criteria: z_em > 2.4, optical
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systems. We have surveyed an additional 10 QSOs with the Lick 120 and the Anglo-Australian Telescope. We have combined these with previous data resulting in a statistical sample of 646 QSOs and 85 damped Ly-alpha absorbers with column densities N(HI) >= 2 x 10^20 atoms/cm^2 covering the redshift range 0.008 <= z <= 4.694. To make the data in our statistical sample more readily available for comparison with scenarios from various cosmological models, we provide tables that includes all 646 QSOs from our new survey and previously published surveys. They list the minimum and maximum redshift defining the redshift path along each line of sight, the QSO emission redshift, and when an absorber is detected, the absorption redshift and measured HI column density. [see the paper for the complete abstract]
We image 19 quasars with 22 damped Lyman alpha (DLA) systems using the F160W filter and the Near-Infrared Camera and Multiobject Spectrograph aboard the Hubble Space Telescope, in both direct and coronagraphic modes. We reach 5 sigma detection limits
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