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Broad Band X-ray Spectra of Atoll Source 4U 1636-536: NuSTAR and Swift Results

Agrawal, Vivek Kumar and Hasan, Mohammad (2016) Broad Band X-ray Spectra of Atoll Source 4U 1636-536: NuSTAR and Swift Results. . (Submitted)

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In this work we investigate broad band (1-79 keV) spectral nature of the atoll source 4U 1636-536 using the combined Nu-STAR and SWIFT-XRT data. The spectra are complex and have emission components from the disc, boundary-layer and corona. In addition to that a broad iron line is also observed. A relativistic line model assuming Schwarzchild metric fits this feature. The total flux varies from 1.4 × 10^(−9) to 4.36× 10^(−9)ergs/s/cm^2. At the highest flux level the source was found in the soft state. In this state the Comptonized component has temperature kT_e ∼ 3 keV and optical depth τ ∼ 16. We also detect a non-thermal tail with index ∼ 2.4, contributing ∼ 10 % of the total flux in the soft state. We also find that the inner disc radius, electron temperature and optical depth vary with the total 0.1-100 keV unabsorbed flux. We discuss the implication of the results in this paper.

Item Type:Report or Paper (Discussion Paper)
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Additional Information:This research has made use of data and/or software provided by High Energy Astrophysics Science Archive Research Center (HEASARC). We thank Dr. Anil Agarwal, GD, SAG, Mr. Subramanya Udupa. DD, CDA and Dr. M. Annadurai, Director, ISAC for encouragement and continuous support to carry out this research.
Record Number:CaltechAUTHORS:20161129-092739528
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:72370
Deposited By: Joy Painter
Deposited On:29 Nov 2016 17:37
Last Modified:02 Jun 2023 00:27

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