Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-09-15
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
ApJ in press, vol 722, October 2010, 10 pages, 10 bitmapped figures
Scientific paper
We have discovered both a red and a blue subpopulation of Ultra-Compact Dwarf (UCD) galaxy candidates in the Coma galaxy cluster. We analyzed deep F475W (Sloan g) and F814W (I) Hubble Space Telescope images obtained with the Advanced Camera for Surveys Wide Field Channel as part of the Coma Cluster Treasury Survey and have fitted the light profiles of ~5000 point-like sources in the vicinity of NGC 4874, one of the two central dominant galaxies of the Coma cluster. Although almost all of these sources are globular clusters that remain unresolved, we found that 52 objects have effective radii between ~10 and 66 pc, in the range spanned by Dwarf Globular Transition Objects (DGTO) and UCDs. Of these 52 compact objects, 25 are brighter than M_V ~-11 mag, a magnitude conventionally thought to separate UCDs and globular clusters. The UCD/DGTO candidates have the same color and luminosity distribution as the most luminous globular clusters within the red and blue subpopulations of the immensely rich NGC 4874 globular cluster system. Unlike standard globular clusters, blue and red UCD/DGTO subpopulations have the same median effective radius. The spatial distribution of UCD/DGTO candidates reveal that they congregate towards NGC 4874, and are not uniformly distributed. We find a relative deficit of UCD/DGTOs compared with globular clusters in the inner 15 kpc around NGC 4874, however at larger radii UCD/DGTO and globular clusters follow the same spatial distribution.
Blakeslee John P.
Carter David
Ferguson Henry C.
Forbes Duncan A.
Goudfrooij Paul
No associations
LandOfFree
Ultra-Compact Dwarfs in the Core of the Coma Cluster does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Ultra-Compact Dwarfs in the Core of the Coma Cluster, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ultra-Compact Dwarfs in the Core of the Coma Cluster will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-26741