Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T04:18:53.326Z Has data issue: false hasContentIssue false
  • English
  • Français

HI 21cm absorption studies of damped Lyman-$\alpha$ systems

Published online by Cambridge University Press:  06 October 2005

Nissim Kanekar  and
Jayaram N. Chengalur
Nissim Kanekar
Affiliation:
National Radio Astronomy Observatory, Socorro, USA email: [email protected]
Jayaram N. Chengalur
Affiliation:
National Centre for Radio Astrophysics (TIFR), Pune, India email: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

HI 21cm absorption spectroscopy provides an independent probe of the nature of damped Lyman-$\alpha$ systems (DLAs), yielding information on their ISM conditions, kinematics, and spatial extent. We find that the majority of DLAs have significantly higher spin temperatures than seen in the Milky Way and local spirals, indicating larger fractions of the warm phase of HI, especially at high redshifts. Present data suggests that the spin temperature might be used as a secondary indicator of the nature of the absorbing galaxy. We have succeeded in spatially resolving the 21cm absorption in two $z\sim 0.4$ DLAs, thus obtaining lower limits on the transverse extent of these absorbers.

Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 1 , Colloquium C199: Probing Galaxies through Quasar Absorption Lines , March 2005 , pp. 156 - 161
Copyright
© 2005 International Astronomical Union