IATE   20350
INSTITUTO DE ASTRONOMIA TEORICA Y EXPERIMENTAL
Unidad Ejecutora - UE
artículos
Título:
GEMINI SPECTROSCOPY OF ULTRACOMPACT DWARFS IN THE FOSSIL GROUP NGC 1132
Autor/es:
MADRID, J.; DONZELLI, C.J.
Revista:
ASTROPHYSICAL JOURNAL
Editorial:
IOP PUBLISHING LTD
Referencias:
Lugar: Londres; Año: 2013 vol. 770 p. 158 - 164
ISSN:
0004-637X
Resumen:
A spectroscopic follow-up of ultracompact dwarf (UCD) candidates in the
fossil group NGC 1132 is undertaken with the Gemini Multi Object
Spectrograph. These new Gemini spectra prove the presence of six UCDs in
the fossil group NGC 1132 at a distance of D ~ 100 Mpc and a recessional
velocity of vr = 6935 ± 11 km s-1.
The brightest and largest member of the UCD population is an M32 analog
with a size of 77.1 pc and a magnitude of MV = -14.8
mag with the characteristics in between those of the brightest UCDs and
compact elliptical galaxies. The ensemble of UCDs have an average radial
velocity of langvr rang = 6966 ± 208 km
s-1 and a velocity dispersion of σ v
= 169 ± 18 km s-1 similar to the one of poor
galaxy groups. This work shows that UCDs can be used as test particles
to determine the dynamical properties of galaxy groups. The presence of
UCDs in the fossil group environment is confirmed and thus the fact that
UCDs can form across diverse evolutionary conditions.