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Long-Term Time Variability in the X-Ray Pulse Shape of the Crab Nebula PulsarThis is the final performance report for our grant 'Long-Term Time Variability in the X-Ray Pulse Shape of the Crab Nebula Pulsar.' In the first year of this grant, we received the 50,000-second ROSAT (German acronym for X-ray satellite) High Resolution Images (HRI) observation of the Crab Nebula pulsar. We used the data to create a 65-ms-resolution pulse profile and compared it to a similar pulse profile obtained in 1991. No statistically significant differences were found. These results were presented at the January 1998 meeting of the American Astronomical Society. Since then, we have performed more sensitive analyses to search for potential changes in the pulse profile shape between the two data sets. Again, no significant variability was found. In order to augment this long (six-year) baseline data set, we have analyzed archival observations of the Crab Nebula pulsar with the Rossi X-Ray Timing Explorer (RXTE). While these observations have shorter time baselines than the ROSAT data set, their higher signal-to-noise offers similar sensitivity to long-term variability. Again, no significant variations have been found, confirming our ROSAT results. This work was done in collaboration with Prof. Stephen Eikenberry, Cornell University. These analyses will be included in Cornell University graduate student Dae-Sik Moon's doctoral thesis.
Document ID
20000120414
Acquisition Source
Goddard Space Flight Center
Document Type
Contractor or Grantee Report
Authors
Fazio, Giovanni G.
(Smithsonian Astrophysical Observatory Cambridge, MA United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 2000
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: NAG5-4876
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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