New measurements of the cyclotron line energy in Cen X-3
Autor: | Biswajit Paul, Gunjan Tomar, Pragati Pradhan |
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Rok vydání: | 2020 |
Předmět: |
Physics
High Energy Astrophysical Phenomena (astro-ph.HE) Range (particle radiation) 010308 nuclear & particles physics Cyclotron FOS: Physical sciences Astronomy and Astrophysics Astrophysics 01 natural sciences Spectral line Luminosity law.invention Pulsar Space and Planetary Science law 0103 physical sciences Emission spectrum Astrophysics - High Energy Astrophysical Phenomena 010303 astronomy & astrophysics Energy (signal processing) Line (formation) |
DOI: | 10.48550/arxiv.2011.05534 |
Popis: | We report results from the analysis of data from two observations of the accreting binary X-ray pulsar Cen X-3 carried out with the broadband X-ray observatories Suzaku and NuSTAR. The pulse profile is dominated by a broad single peak and show some energy dependence with two additional weak pulse peaks at energies below 15 and 25 keV respectively. The broadband X-ray spectrum for 0.8-60.0 keV for Suzaku and 3.0-60.0 keV for NuSTAR is fitted well with high energy cut-off power-law model along with soft-excess, multiple iron emission lines and a cyclotron absorption. The cyclotron line energy is found to be $30.29^{+0.68}_{-0.61}$ keV and $29.22^{+0.28}_{-0.27}$ keV respectively in the Suzaku and NuSTAR spectra. We make a comparison of these two measurements with four previous measurements of CRSF in Cen X-3 obtained with Ginga, BeppoSAX and RXTE. We find no evidence for a dependence of the CRSF on luminosity. Except for one CRSF measurement with BeppoSAX, the remaining measurements are consistent with a CRSF energy in the range of 29.5 - 30.0 keV over a luminosity range of 1.1-5.4 $\times 10^{37}$ ergs s$^{-1}$ different from several other sources that show considerable CRSF variation in the same luminosity range. Comment: 8 pages, 5 figures, accepted for publication in MNRAS |
Databáze: | OpenAIRE |
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