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http://hdl.handle.net/2289/3999| Title: | Flares, broadening of the pulse-frequency peak and quasi-periodic oscillations in the transient X-ray pulsar 4U 1901+03 |
| Authors: | James, Marykutty Paul, Biswajit Devasia, Jincy Indulekha, Kavila |
| Keywords: | individual: 4U 1901+03 stars: neutron pulsars: individual 4U 1901+03 X-rays binaries X-rays stars |
| Issue Date: | Jan-2011 |
| Publisher: | Wiley-Blackwell for the RAS |
| Citation: | Monthly Notices of the Royal Astronomical Society, 2010, Vol.410, p1489 |
| Abstract: | After a long quiescence of three decades, the transient X-ray pulsar 4U 1901+03 became highly active in 2003 February. From the analysis of a large number of Rossi X-ray Timing Explorer/Proportional Counter Array (RXTE/PCA) observations of this source, we report here the detection of X-ray flares, a broadening of the pulse-frequency feature and quasi-periodic oscillations (QPOs). The X-ray flares showed spectral changes, had a duration of 100-300 s, and were more frequent and stronger during the peak of the outburst. In most of the observations during the outburst we also detected a broadening of the pulse-frequency peak. We have also found intensity-dependent changes in the pulse profile at very short time-scales. This reveals a coupling between the periodic and the low-frequency aperiodic variabilities. In addition, near the end of the outburst we have detected a strong QPO feature centred at ˜0.135 Hz. The QPO feature is broad with a quality factor of 3.3 and with an rms value of 18.5 ± 3.1 per cent. Using the QPO frequency and the X-ray luminosity during the QPO detection period we estimated the magnetic field strength of the neutron star as 0.31 × 1012 G which is consistent with the value inferred earlier under the assumption of spin equilibrium. |
| Description: | Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations) |
| URI: | http://hdl.handle.net/2289/3999 |
| ISSN: | 0035-8711 1365-2966 (Online) |
| Alternative Location: | http://adsabs.harvard.edu/abs/2011MNRAS.410.1489J http://arxiv.org/abs/1008.2815 http://dx.doi.org/10.1111/j.1365-2966.2010.17543.x |
| Copyright: | 2010 The authors & the Royal Astronomical Society |
| Appears in Collections: | Research Papers (A&A) |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| 2010_MNRAS_410_1489.pdf Restricted Access | Restricted Access An open-access version is available at arXiv.org (one of the alternative locations) | 942.01 kB | Adobe PDF | View/Open Request a copy |
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