Bibcode
Freudling, W.; Prieto, M. Almudena
Referencia bibliográfica
Astronomy and Astrophysics, v.306, p.39
Fecha de publicación:
2
1996
Revista
Número de citas
5
Número de citas referidas
5
Descripción
The relatively large neutral hydrogen contents and enhanced density of
companion galaxies around Seyfert 2 galaxies suggests that tidal
interaction could play a major role in the evolution of Seyfert 2
galaxies. Recent observations of the distribution of neutral hydrogen in
the active S0 galaxy NGC5252 have shown a disturbed morphology which
suggests that the HI in this galaxy could have been acquired through
interaction with neighboring galaxies (Prieto & Freudling 1993 and
1995). We have searched for other HI rich galaxies within a radius of 25
arcmin and a redshift range of +/-600km/s around the center location and
redshift of NGC5252. A total of five galaxies were found, four of them
are cataloged galaxies with no previous redshifts available. These five
galaxies were mapped with the VLA in order to search for signs of recent
tidal interactions. The maps and derived HI parameters are presented and
compared to the one of NGC5252, the sixth member of the group. Two of
the galaxies (UGC 8635) are an interacting pair. No signs of other
recent interactions were found. Using the Arecibo telescope, we also
searched for intergalactic neutral hydrogen between the group members as
another potential source of gas for NGC5252. Upper limits on intergroup
gas are given for three positions. The lack of evidence for interaction
among the galaxies could be interpreted in two different ways. Either
interaction occurred in the distant past and triggered activity in this
galaxy over a long period of time. Alternatively, factors other than the
gas supply might be responsible for the observation that Seyfert 2
galaxies tend to be surrounded by a region of enhanced galaxy density.