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Related papers: AstroSat/LAXPC view of GX 17+2: Spectral Evolution…

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AstroSat/LAXPC and SXT observed the persistent neutron star low-mass X-ray binary 4U 1820-30 between 2016 and 2022. During these observations, the hardness-intensity diagram (HID) and color-color diagram (CCD) indicated that the source was…

High Energy Astrophysical Phenomena · Physics 2026-03-27 Subhasish Das , Vivek Kumar Agrawal , Parijat Thakur , G. C. Dewangan , Raj Kumar , Pragati Sahu , Vineet Kumar Mannaday

We have used INTEGRAL & RXTE data to investigate the timing properties of the source in correlation with its spectral states as defined by different positions in the colour-colour diagram. The source shows two distinct branches in the…

Astrophysics · Physics 2009-11-11 P. Reig , S. Martinez-Nunez , V. Reglero

Results of a 2000 August 12-13 BeppoSAX observation of the 7.1 hr eclipsing, dipping, bursting, transient, low-mass X-ray binary (LMXRB) X1658-298 are presented. The spectrum outside of eclipses, dips and bursts can be modeled by the…

Astrophysics · Physics 2009-11-06 T. Oosterbroek , A. N. Parmar , L. Sidoli , J. J. M. in 't Zand , J. Heise

Our study presents a time-resolved X-ray spectral analysis of Mkn 421, using AstroSat observations taken during different epochs between 2016 and 2019. The variability of the source in X-rays is utilized to investigate the evolution of its…

High Energy Astrophysical Phenomena · Physics 2025-01-15 Sikandar Akbar , Zahir Shah , Ranjeev Misra , Naseer Iqbal , Javaid Tantry

In this study, we undertake a spectral-timing analysis of the black hole X-ray binary source GRS 1915+105 using simultaneous observations carried out by AstroSat (LAXPC and SXT) and NICER in 2017. The source showed two flux levels (high and…

High Energy Astrophysical Phenomena · Physics 2024-08-07 Ruchika Dhaka , Ranjeev Misra , JS Yadav , Pankaj Jain

We present results from the analysis of the two EXOSAT observations of the low mass X-ray binary (LMXRB) 4U1957+11. The 1-20keV spectrum of the source is best fitted by a power law model with exponential cutoff, that provides an…

Astrophysics · Physics 2007-05-23 D. Ricci , G. L. Israel , L. Stella

We report the first spectro-polarimetric investigation of the bright Z-type source GX 349+2 using simultaneous observations of \textit{IXPE}, \textit{NuSTAR} and \textit{Swift/XRT}. The source exhibited significant polarization in the 2-8…

High Energy Astrophysical Phenomena · Physics 2025-04-08 Raj Kumar , Subhasish Das

The study of fast variability properties in X-ray binaries advances our understanding of the physical processes and geometric properties of the accretion flow around the compact object. In this work, we study the evolution of the timing…

High Energy Astrophysical Phenomena · Physics 2025-08-27 Sandeep K. Rout , Federico Garcia , Mariano Mendez , Abhay Kumar , Santosh Vadawale , David M. Russell , Pei Jin

The X-ray energy spectra and Normalized Power Spectral Densities (NPSDs) of an X-ray nova, GS 2000+25, were investigated. The X-ray energy spectra of the source consist of two components: a hard component, which can be represented by a…

Astrophysics · Physics 2015-06-24 K. Terada , S. Kitamoto , H. Negoro , S. Iga

Results on timing and spectral properties of the Be/X-ray binary pulsar 3A 0726-260 (4U 0728-25) are presented. The binary was observed on 2016 May 6-7 with the Large Area X-ray Proportional Counter (LAXPC) and Soft X-ray Telescope (SXT)…

High Energy Astrophysical Phenomena · Physics 2020-09-30 Jayashree Roy , P. C. Agrawal , B. Singari , R. Misra

We analyze the X-ray spectra of the atoll 4U~1705-44 when the source undergoes the island-banana state transition. We use the Rossi X-ray Timing Explorer (RXTE) and BeppoSAX observations for this analysis. We demonstrate that the broad-band…

Solar and Stellar Astrophysics · Physics 2015-08-06 Elena Seifina , Lev Titarchuk , Chris Shrader , Nikolai Shaposhnikov

We report the first analysis of data from AstroSat/LAXPC observations of Cygnus X-1 in January 2016. LAXPC spectra reveals that the source was in the canonical hard state, represented by a prominent thermal Comptonization component having a…

We show an analysis of the spectral and timing properties of X-ray radiation from Z-source during its evolutions when the electron temperature of the Transition Layer (TL) kT_e monotonically decreases from 21 to 3 keV. We analyze episodes…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Elena Seifina , Lev Titarchuk , Filippo Frontera

We report the results of AstroSat observations of GRS 1915$+$105 obtained using 100 ks guaranteed-time (GT) during the soft state. The Color-Color Diagram (CCD) indicates a variability class of $\delta$ with the detection of High Frequency…

High Energy Astrophysical Phenomena · Physics 2020-11-18 Sreehari H. , Anuj Nandi , Santabrata Das , V. K. Agrawal , Samir Mandal , M. C. Ramadevi , Tilak Katoch

Z-sources are a particular class of neutron star low-mass X-ray binaries characterized by a wide Z-like track in their hard colorsoft color (or hardness-intensity) diagrams, with three branches: the horizontal (HB), the normal (NB), and the…

We report results of a BeppoSAX observation of the low-mass X-ray binary (LMXB) dipping source XB 1916-053. The source joins the small group of LMXB detected at energies ~100 keV. The non-dip spectrum is well fitted by an absorbed blackbody…

Black hole X-ray binaries routinely exhibit Quasi Periodic Oscillations (QPOs) in their Power density spectrum. Studies of QPOs have demonstrated immense ability to understand these dynamical systems although their unambiguous origin still…

High Energy Astrophysical Phenomena · Physics 2023-08-15 Nazma Husain , Akash Garg , Ranjeev Misra , Somasri Sen

4U 1705-44 is one of the most-studied type I X-ray burster and Atoll sources. This source represents a perfect candidate to test different models proposed to self-consistently track the physical changes occurring between different spectral…

High Energy Astrophysical Phenomena · Physics 2016-06-08 S. Piraino , A. Santangelo , B. Mueck , P. Kaaret , T. Di Salvo , A. D'Ai , R. Iaria , E. Egron

The black hole X-ray binary GX\,339-4 showed an X-ray outburst during 2021. The {\it AstroSat} captured this outburst when the source entered into the intermediate flux state while the count rate was declining. The source showed an…

High Energy Astrophysical Phenomena · Physics 2023-10-09 Santanu Mondal , Anirudh Salgundi , Debjit Chatterjee , Arghajit Jana , H. -K. Chang , Sachindra Naik

We perform broadband ($0.7-100$ keV) spectral analysis of five hard state observations of the low-mass back hole X-ray binary GX~339--4 taken by AstroSat during the rising phase of three outbursts from $2019$ to $2022$. We find that the…

High Energy Astrophysical Phenomena · Physics 2024-06-18 Swadesh Chand , Gulab C. Dewangan , Andrzej A. Zdziarski , Dipankar Bhattacharya , N. P. S. Mithun , Santosh V. Vadawale