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A cutoff in the x-ray fluctuation power density spectrum of the seyfert 1 galaxy ngc 3516
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Edelson, Rick Nandra, Kirpal |
| Copyright Year | 1999 |
| Description | During 1997 March-July, RXTE observed the bright, strongly variable Seyfert 1 galaxy NGC 3516 once every approx. 12.8 hr for 4.5 months and nearly continuously (with interruptions due to SAA passage but not Earth occultation) for a 4.2 day period in the middle. These were followed by ongoing monitoring once every approx. 4.3 days. These data are used to construct the first well-determined X-ray fluctuation power density spectrum (PDS) of an active galaxy to span more than 4 decades of usable temporal frequency. The PDS shows no signs of any strict or quasi-periodicity, but does show a progressive flattening of the power-low slope from -1.74 at short time scales to -0.73 at longer time scales. This is the clearest observation to date of the long-predicted cutoff in the PDS. The characteristic variability time scale corresponding to this cutoff temporal frequency is approx. 1 month. Although it is unclear how this time scale may be interpreted in terms of a physical size or process, there are several promising candidate models. The PDS appears similar to those seen for Galactic black hole candidates such as Cyg X-1, suggesting that these two classes of objects with very different luminosities and putative black hole masses (differing by more than a factor of 10(exp 5)) may have similar X-ray generation processes and structures. |
| File Size | 1050166 |
| Page Count | 22 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19990064013 |
| Archival Resource Key | ark:/13960/t53f9pt8w |
| Language | English |
| Publisher Date | 1999-05-01 |
| Access Restriction | Open |
| Subject Keyword | Space Radiation Cygnus Constellation Slopes Interruption Galaxies Variability Luminosity Frequencies Periodic Variations Seyfert Galaxies X Rays Flattening X Ray Timing Explorer Occultation Black Holes Astronomy Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
