Issue |
A&A
Volume 401, Number 1, April I 2003
|
|
---|---|---|
Page(s) | 173 - 183 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361:20030108 | |
Published online | 17 March 2003 |
Stephan's Quintet: The X-ray anatomy of a multiple galaxy collision
1
INAF-Osservatorio Astronomico di Brera, via Brera 28, 20121 Milano Italy
2
Physics & Astronomy, University of Alabama, USA
3
Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85740 Garching, Germany
Corresponding author: G. Trinchieri, ginevra@brera.mi.astro.it
Received:
10
October
2002
Accepted:
17
January
2003
Chandra observations of the compact galaxy group known as
Stephan's Quintet (SQ) are presented. The major morphological features
that were discovered with the ROSAT HRI are now imaged with higher
resolution and S/N. The large scale shock (15, ~40 kpc if at
85 Mpc) is resolved into a narrow NS feature embedded in more extended
diffuse emission (
). The NS structure is somewhat clumpy,
more sharply bounded on the W side and prominent only in the soft band
(energies below ~2 keV). Its observational properties are best
explained as a shock produced by a high velocity encounter between
NGC 7318b, a “new intruder”, and the intergalactic medium in SQ. The
shock conditions near the high speed intruder suggest that a bow shock
is propagating into a pre-existing H i cloud and heating the gas to a
temperature of
keV. The low temperature in the shock is a
problem unless we postulate an oblique shock.
One member, NGC 7319, hosts a Seyfert 2
nucleus, with an intrinsic luminosity
erg s-1,
embedded in a region of more diffuse emission with 10'' radius
extent. The nuclear spectrum can be modeled with a strongly absorbed
power-law typical of this class of sources. Several additional compact
sources are detected including three in foreground NGC 7320. Some of
these sources are very luminous and could be related to the
ultraluminous X-ray sources found in nearby galaxies.
Key words: ISM: general / X-rays: galaxies: clusters / galaxies: ISM / X-rays: ISM
© ESO, 2003
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.