Very old and very young compact objects : X-ray studies of galactic globular clusters and recent core-collapse supernovae

This thesis comprises the results of two distinct areas of research, namely, X-ray studies of Galactic globular clusters and X-ray studies of recent core collapse supernovae. My analyses of the Chandra X-ray Observatory observations of the globular clusters NGC 6752 and NGC 6440 revealed as many low-luminosity X-ray sources as was in the entire census of globular cluster sources with the previous best X-ray imaging instrument, Rontgensatellit. In the observation of NGC 6752, I detect 6 X-ray sources within the 10':5 core radius and 13 more within the 115" half-mass radius down to a limiting luminosity of Lx = 1030 ergs s-l for cluster sources. Based on a reanalysis of archival data from the Hubble Space Telescope and the Australia Telescope Compact Array, I make 12 optical identifications and one radio identification. Based on X-ray and optical properties of the identifications, I find 10 likely cataclysmic variables (CVs), 1-3 likely RS CVn or BY Dra systems, and 1 or 2 possible background objects. Of the 7 sources for which no optical identifications were made, one was detected in the archival radio data, and another was found to be a millisecond pulsar. Of the remaining sources, I expect that 2-4 are background objects and that the rest are either CVs or millisecond pulsars whose radio emission has not been detected. These and other Chandra results on globular clusters indicate that the dozens of CVs per cluster expected by theoretical arguments are being found. The findings to date also suggest that the ratio of CVs to other types of X-ray sources is remarkably similar in clusters of very different structural parameters.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2003

Author dc:creator

• Pooley, David Aaron, 1976-

Advisor dc:contributor.advisor

• Walter H.G. Lewin.

• Physics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/29309

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/29309