High frequency quasi-periodic oscillations in the X-ray radiation of the black hole binary GRS 1915+105

GRS 1915+105 is an accreting black-hole in a binary system located in the Milky Way. It is one of the most variable X-ray sources known, and 12 variability classifications have been defined, many of which appear to be repetitive cycles of accretion instability. We study one particular variability type, the p cycle, which is selected for its high frequency quasi-periodic oscillations (HFQPOs) and recurring double-peak flare in the light curve. We investigate the primary properties of the 82 p-type observations collected by RXTE. The range in flare recurrence time () is 33.73 s < T < 122.49 s, with <> ± asample = 65.44 ± 19.83 s. The flaring fraction , defined by percent of cycle exposure > 1.2*mean count rate, ranges 12.11% < ( < 37.61%, with <> ± asample = 20.05 ± 5.33%. We find a correlation between T and ( which divides the 82 observations into three sub-classes: pi; slow with low , P2; fast with low , and P3; fast with high . The evolution between sub-classes suggests two driving mechanisms, an unknown mechanism limiting T > 33 s and a process consistent with the Eddington limit that increases (at the lower limit of ) for the p3 group.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Gazak, Jonathan Zachary

Advisor dc:contributor.advisor

• Ronald A. Remillard.

• 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/1721.1/36128

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/36128