Bibcode
DOI
Gutiérrez, C. M.; López-Corredoira, M.; Prada, F.; Eliche, M. C.
Bibliographical reference
The Astrophysical Journal, Volume 579, Issue 2, pp. 592-599.
Advertised on:
11
2002
Journal
Citations
14
Refereed citations
11
Description
We present deep broadband R and narrowband Hα images of Stephan's
Quintet. The observations in the R band show that the diffuse halo of
Stephan's Quintet is larger than previously thought and extends out to
NGC 7320C. However, we have not found emission connecting NGC 7331 and
NGC 7320 to R~26.7 mag arcsec-2 (at more than a 3 σ
level), so there is no direct evidence up to this limiting magnitude of
a relation between the peculiar kinematical structure found in NGC 7331
and an ongoing or past interaction between this galaxy and NGC 7320. The
Hα emission at high velocity (6000-7000 km s-1) is
distributed in a diffuse structure running north-south between NGC 7319
and NGC 7318B and in some other more concentrated features. Some of
these are located in the tidal tails produced by the interaction between
the galaxies of the group. With the Hα images we have made a
two-dimensional velocity map that helps to identify the origin of each
structure detected. This map does not show features at intermediate
velocities between the high- and low-redshift members of the group. This
is in agreement with the standard scenario in which the apparent
proximity of NGC 7320 to the rest of the galaxies of the Quintet is
merely a projection effect. The only point that is unclear in this
interpretation is an Hα filament that is seen extending throughout
NGC 7320 with velocity at 6500 km s-1 instead of the 800 km
s-1 expected for this galaxy. Accepted in final form 20002
July 12.