A&A 370, L26-L30 (2001)
DOI: 10.1051/0004-6361:20010333

Deep H I observations of the compact high-velocity cloud HVC 125+41-207

C. Brüns^{1, 2}, J. Kerp¹ and A. Pagels<sup>1

1</sup>  Radioastronomisches Institut der Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
²  The Australia Telescope National Facility, CSIRO, PO Box 76, Epping NSW 1710, Australia

(Received 14 December 2000 / Accepted 7 March 2001 )

Abstract
We present deep HI observations of the compact high-velocity cloud HVC 125+41-207 using the 100-m Effelsberg telescope. Our goal was in particular to study the warm neutral medium (WNM) in detail. The Effelsberg data reveals a two phase core/halo structure -one component with a velocity width of km s^-1 (Westerbork data show km s^-1, Braun & Burton 2000) and one with km s^-1. The column density distribution of the warmer component is highly asymmetric and shows a head-tail structure. We performed a Gaussian decomposition of the cloud and found that 52% of the HI mass of the cloud is in the WNM. 24% of the WNM is located in the tail. The overall structure and the systematic variation of the observational parameters radial velocity, velocity dispersion and column density indicate that this cloud is currently interacting with the ambient medium. The Westerbork HI data of this HVC (Braun & Burton 2000) reveals an interesting dense condensation. Assuming that this condensation is virialized and in pressure equilibrium with the ambient medium, we derive a distance of 130 kpc for HVC 125+41-207. Following these considerations, it is possible to constrain the parameters cm^-3 and K of the intergalactic medium of the Local Group.

Key words: ISM: clouds, kinematics and dynamics -- Galaxy: halo -- galaxies: intergalactic medium

Offprint request: C. Brüns, cbruens@astro.uni-bonn.de

SIMBAD Objects

© ESO 2001

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

• If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
• You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
• You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.