X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3
We report on the Chandra X-ray Observatory and Hubble Space Telescope (HST) observations of two low core-density globular clusters, NGC6144 and E3. By comparing the number of X-ray sources inside the half-mass radius to those outside, we found six X-ray sources within the half-mass radius of NGC6144...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | en_US |
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IOP Publishing
2015
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| Online Access: | http://hdl.handle.net/1721.1/95822 |
| _version_ | 1826211171188867072 |
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| author | Lan, Shih-Hao Kong, Albert K. H. Verbunt, Frank Lewin, Walter H. G. Bassa, Cees Anderson, Scott F. Pooley, David |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Lan, Shih-Hao Kong, Albert K. H. Verbunt, Frank Lewin, Walter H. G. Bassa, Cees Anderson, Scott F. Pooley, David |
| author_sort | Lan, Shih-Hao |
| collection | MIT |
| description | We report on the Chandra X-ray Observatory and Hubble Space Telescope (HST) observations of two low core-density globular clusters, NGC6144 and E3. By comparing the number of X-ray sources inside the half-mass radius to those outside, we found six X-ray sources within the half-mass radius of NGC6144, of which four are expected to be background sources; three X-ray sources are also found within the half-mass radius of E3, of which three are expected to be background sources. Therefore, we cannot exclude the possibility that all our sources are background sources. However, combining the results from X-ray and optical observations, we found that one to two sources in NGC6144 and one source in E3 are likely to be cataclysmic variables and that one source in NGC6144 is an active binary, based on the X-ray and optical properties. The number of faint X-ray sources in NGC6144 and E3 found with Chandra and HST is higher than a prediction based on collision frequency, but is closer to that based on mass. Our observations strongly suggest that the compact binary systems in NGC6144 and E3 are primordial in origin. |
| first_indexed | 2024-09-23T15:01:42Z |
| format | Article |
| id | mit-1721.1/95822 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:01:42Z |
| publishDate | 2015 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/958222022-09-29T12:08:49Z X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3 Lan, Shih-Hao Kong, Albert K. H. Verbunt, Frank Lewin, Walter H. G. Bassa, Cees Anderson, Scott F. Pooley, David Massachusetts Institute of Technology. Department of Physics MIT Kavli Institute for Astrophysics and Space Research Lewin, Walter H. G. We report on the Chandra X-ray Observatory and Hubble Space Telescope (HST) observations of two low core-density globular clusters, NGC6144 and E3. By comparing the number of X-ray sources inside the half-mass radius to those outside, we found six X-ray sources within the half-mass radius of NGC6144, of which four are expected to be background sources; three X-ray sources are also found within the half-mass radius of E3, of which three are expected to be background sources. Therefore, we cannot exclude the possibility that all our sources are background sources. However, combining the results from X-ray and optical observations, we found that one to two sources in NGC6144 and one source in E3 are likely to be cataclysmic variables and that one source in NGC6144 is an active binary, based on the X-ray and optical properties. The number of faint X-ray sources in NGC6144 and E3 found with Chandra and HST is higher than a prediction based on collision frequency, but is closer to that based on mass. Our observations strongly suggest that the compact binary systems in NGC6144 and E3 are primordial in origin. United States. National Aeronautics and Space Administration (Contract NAS5-26555) National Science Council (China) (Grant NSC 96-2112-M-007-037-MY3) 2015-03-04T20:09:11Z 2015-03-04T20:09:11Z 2010-03 2009-04 Article http://purl.org/eprint/type/JournalArticle 0004-637X 1538-4357 http://hdl.handle.net/1721.1/95822 Lan, Shih-Hao, Albert K. H. Kong, Frank Verbunt, Walter H. G. Lewin, Cees Bassa, Scott F. Anderson, and David Pooley. “X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3.” The Astrophysical Journal 712, no. 1 (March 2, 2010): 380–391. © 2010 The American Astronomical Society en_US http://dx.doi.org/10.1088/0004-637x/712/1/380 Astrophysical Journal Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf IOP Publishing American Astronomical Society |
| spellingShingle | Lan, Shih-Hao Kong, Albert K. H. Verbunt, Frank Lewin, Walter H. G. Bassa, Cees Anderson, Scott F. Pooley, David X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3 |
| title | X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3 |
| title_full | X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3 |
| title_fullStr | X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3 |
| title_full_unstemmed | X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3 |
| title_short | X-RAY AND OPTICAL STUDY OF LOW CORE DENSITY GLOBULAR CLUSTERS NGC6144 AND E3 |
| title_sort | x ray and optical study of low core density globular clusters ngc6144 and e3 |
| url | http://hdl.handle.net/1721.1/95822 |
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