Title:	Kinematics of diffuse interstellar clouds: recent GMRT results
Authors:	Dwarakanath, K.S.
Keywords:	ISM: clouds kinematics and dynamics Radio lines ISM
Issue Date:	Sep-2004
Publisher:	The Astronomical Society of India
Citation:	Bulletin of the Astronomical Society of India, 2004, Vol.32, p215-221
Abstract:	A high latitude HI 21 cm-line absorption survey towards extragalactic sources was recently completed using the Giant Meterwave Radio Telescope (GMRT). A total of 104 sources with |b|>15o and with a 21 cm ¤ux density greater than 1 Jy were observed for ~120 hours. With an optical depth detection limit of ~ 0.01 this is the most sensitive high-latitude survey as yet. Most of the detected HI 21 cm-line absorption features belong to a population with a velocity dispersion of ~7.6 km s-1. These are the standard HI clouds and have been well-studied for decades. However, we also detect a second population of absorbing clouds with a velocity dispersion of ~ 21 km s-1. About 20% of the total population of absorbing clouds belong to this population. This new population of fast clouds can be identified with a similar velocity dispersion Ca II absorbing clouds and with the Halo clouds recently detected in HI emission from Green Bank.
URI:	http://hdl.handle.net/2289/1354
ISSN:	0304-9523
Alternative Location:	http://adsabs.harvard.edu/cgi-bin/bib_query?2004BASI...32..215D
Copyright:	(2004) by the Astronomical Society of India.
Appears in Collections:	Research Papers (A&A)

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