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Outburst of gx304-1 monitored with integral: positive correlation between the cyclotron line energy and flux
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Rothschild, R. E. Doroshenko, V. Pilhlhofer, G. Ferrigno, C. Kreykenbohm, I. Klochkov, D. Staubert, R. Caballero, I. Santangelo, A. Pottschmidt, I. Kretschmar, P. Wilms, J. |
| Copyright Year | 2012 |
| Description | Context. X-ray spectra of many accreting pulsars exhibit significant variations as a function of flux and thus of mass accretion rate. In some of these pulsars, the centroid energy of the cyclotron line(s), which characterizes the magnetic field strength at the site of the X-ray emission, has been found to vary systematically with flux. Aims. GX304-1 is a recently established cyclotron line source with a line energy around 50 keV. Since 2009, the pulsar shows regular outbursts with the peak flux exceeding one Crab. We analyze the INTEGRAL observations of the source during its outburst in January-February 2012. Methods. The observations covered almost the entire outburst, allowing us to measure the source's broad-band X-my spectrum at different flux levels. We report on the variations in the spectral parameters with luminosity and focus on the variations in the cyclotron line. Results. The centroid energy of the line is found to be positively correlated with the luminosity. We interpret this result as a manifestation of the local sub-Eddington (sub-critical) accretion regime operating in the source. |
| File Size | 1731220 |
| Page Count | 5 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20120016353 |
| Archival Resource Key | ark:/13960/t4jm78616 |
| Language | English |
| Publisher Date | 2012-05-25 |
| Access Restriction | Open |
| Subject Keyword | Astronomy Magnetic Flux Cyclotron Radiation Neutron Stars X Ray Binaries Pulsars Centroids X Ray Spectra X Ray Astronomy Magnetic Fields Accretion Disks Stellar Luminosity Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
