A Point-Source Excess in Abell 1185: Intergalactic Globular Clusters?
| Autor: | Andrés Jordán, Michael J. West, Patrick Côté, Ronald O. Marzke |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Physics
education.field_of_study 010308 nuclear & particles physics Point source Hubble Deep Field Astrophysics::High Energy Astrophysical Phenomena Astrophysics (astro-ph) Population FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences Advanced Camera for Surveys Galaxy Space and Planetary Science Globular cluster 0103 physical sciences Magnitude (astronomy) Astrophysics::Solar and Stellar Astrophysics Intergalactic travel education 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics |
| Zdroj: | The Astronomical Journal. 125:1642-1648 |
| ISSN: | 1538-3881 0004-6256 |
| Popis: | Deep imaging with WFPC2 and the Hubble Space Telescope has been used to search for a population of intergalactic globular clusters (GCs) belonging to Abell 1185, a richness I cluster at cz = 9800 km/s. The field is noteworthy in that it contains no bright galaxies and yet is centered on the peak of the cluster's X-ray surface brightess distribution. We detect a total of 99 point sources in this field to a limiting magnitude I_F814W ~ 26. An identical analysis of the Hubble Deep Field North, which serves as our control field, reveals a total of 12 objects in the same magnitude range. We discuss possible explanations for this discrepancy, and conclude that the point source excess is likely due to the presence of GCs within A1185. The number and spatial distribution of these GCs are consistent with their being intergalactic in nature, although we cannot rule out the possibility that some of the GCs may be associated with neighboring bright galaxies. Deeper imaging with the Advanced Camera for Surveys may resolve this ambiguity. 6 pages, 3 postscript figures. Accepted for publication in AJ |
| Databáze: | OpenAIRE |
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