EDP Sciences Journals List
Advanced Search
Subscriber Authentication Point
Home All issues Volume 483/1 Article
Free access article

Issue A&A
Volume 483, Number 1, May III 2008
Page(s) 89 - 106
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20078139
Published online 04 February 2008



A&A 483, 89-106 (2008)
DOI: 10.1051/0004-6361:20078139

Pre-peak ram pressure stripping in the Virgo cluster spiral galaxy NGC 4501

B. Vollmer1, M. Soida2, A. Chung3, J. H. van Gorkom4, K. Otmianowska-Mazur2, R. Beck5, M. Urbanik2, and J. D. P. Kenney6

1  CDS, Observatoire astronomique de Strasbourg, 11, rue de l'université, 67000 Strasbourg, France
    e-mail: bvollmer@astro.u-strasbg.fr
2  Astronomical Observatory, Jagiellonian University, Orla 171, 30-244 Kraków, Poland
3  NRAO Jansky fellow at University of Massachusetts, Amherst, MA 01003, USA
4  Department of Astronomy, Columbia University, 538 West 120th Street, New York, NY 10027, USA
5  Max-Planck-Insitut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
6  Yale University Astronomy Department, PO Box 208101, New Haven, CT 06520-8101, USA

(Received 22 June 2007 / Accepted 25 January 2008)

Abstract
VIVA HI observations of the Virgo spiral galaxy NGC 4501 are presented. The HI disk is sharply truncated to the southwest, well within the stellar disk. A region of low surface-density gas, which is more extended than the main HI disk, is discovered northeast of the galaxy center. These data are compared to existing 6 cm polarized radio continuum emission, H$\alpha$, and optical broad band images. We observe a coincidence between the western HI and polarized emission edges, on the one hand, and a faint H$\alpha$ emission ridge, on the other. The polarized emission maxima are located within the gaps between the spiral arms and the faint H$\alpha$ ridge. Based on the comparison of these observations with a sample of dynamical simulations with different values for maximum ram pressure and different inclination angles between the disk and the orbital plane, we conclude that ram pressure stripping can account for the main observed characteristics. NGC 4501 is stripped nearly edge-on, is heading southwest, and is ~200-300 Myr before peak ram pressure, i.e. its closest approach to M 87. The southwestern ridge of enhanced gas surface density and enhanced polarized radio-continuum emission is due to ram pressure compression. It is argued that the faint western H$\alpha$ emission ridge is induced by nearly edge-on ram pressure stripping. NGC 4501 represents an especially clear example of early stage ram pressure stripping of a large cluster-spiral galaxy.


Key words: galaxies: individual: NGC 4501 -- galaxies: interactions -- galaxies: ISM -- galaxies: kinematics and dynamics



© ESO 2008


What is OpenURL?

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.