Issue |
A&A
Volume 373, Number 1, July I 2001
|
|
---|---|---|
Page(s) | 24 - 37 | |
Section | Cosmology (including clusters of galaxies) | |
DOI | https://doi.org/10.1051/0004-6361:20010555 | |
Published online | 15 July 2001 |
Environment status of blue compact galaxies and trigger of star formation *
1
Special Astrophysical Observatory RAS, Nizhnij Arkhyz, 369167, Karachai-Circassia, Russia
2
Isaac Newton Institute of Chile, SAO Branch
Corresponding author: S. Pustilnik, sap@sao.ru
Received:
26
December
2000
Accepted:
26
March
2001
The work studies
of the environment of low-mass galaxies with
active star formation (SF) and a possible trigger of SF bursts due to
gravitational interaction. Following the study by Taylor et al. (1995), we
extend the search for possible disturbing galaxies of various masses
to a much larger sample of 86 BCGs from the sky region of the Second Byurakan
survey (SBS). The BCG magnitudes and radial velocities are revised and
up-dated. The sample under study is separated by the criteria:
EW([Oiii] Åand
km s-1and should be representative of all low-mass galaxies which
experience SF bursts. We argue that the moderate tidal disturbers should be
taken into account, and incorporate the respective range of distances in the
search for disturbing neighbours. The majority of the neighbours in the
vicinity of the studied BCGs are found through the study of their
environment among UZC (Falco et al. [CITE]) galaxies, and the
follow-up careful search of the fainter galaxies in the
NED database. For the remaining BCGs, the neighbouring galaxies are found
based on the results of the SAO 6 m telescope spectroscopy.
By studing
the data on the radial velocities of galaxies in the vicinity of BCGs we
found: 1) 33 of the studied BCGs (
) are associated with
significantly brighter galaxies (
1.5m);
2) 23 BCGs (
) have neighbours either of comparable or significantly
lower brightness; 3) 14 of the studied BCGs (16% ) with no evident
associated galaxy are either certain, or probable, mergers.
Summarizing, we conclude that in
(or more) BCGs from the studied
sample, the SF bursts are triggered either by tidal action of various
strengths
from other galaxies, or due to mergers of low-mass galaxies. We briefly
discuss the implications of our main conclusion for evolutionary
links of BCGs to other types of low-mass galaxies.
Part of our sample falls into the volume belonging to the Local
Supercluster.
Therefore we formulate the results separately on the "Local Supercluster
volume" and "general field region" .
The total fractions of BCGs likely triggered by interaction with other
galaxy are respectively,
and 80% for the nearby volume and for
the general field.
The fractions of BCGs with significantly brighter disturbers in these
two groups are seemingly different (
vs.
,
respectively).
Among the so called "isolated" BCGs (that is, without a bright
neighbouring galaxy) in both the Local Supercluster volume and in general
field,
are probably disturbed by dwarf galaxies and
have a merger morphology.
In the Appendix we present the results of the spectroscopy with the
SAO 6 m
telescope of 27 galaxies
in an attempt to find possible disturbing galaxies in the
vicinity of some of the sample BCGs.
Key words: galaxies: dwarf / galaxies: interaction / galaxies: evolution / galaxies: starburst
© ESO, 2001
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.