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Related papers: The variable super-orbital modulation of Cygnus X-…

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The examination of two 2010 Chandra ACIS exposures of the Circinus galaxy resulted in the discovery of two pulsators: CXO J141430.1-651621 and CXOU J141332.9-651756. We also detected 26-ks pulsations in CG X-1, consistently with previous…

High Energy Astrophysical Phenomena · Physics 2016-08-08 P. Esposito , G. L. Israel , D. Milisavljevic , M. Mapelli , L. Zampieri , L. Sidoli , G. Fabbiano , G. A. Rodríguez Castillo

We present X-ray and infrared observations of the X-ray source CXOGC J174536.1-285638. Previous observations suggest that this source may be an accreting binary with a high-mass donor (HMXB) or a colliding wind binary (CWB). Based on the…

V407 Vul (RXJ1914.4+2456) and HM Cnc (RXJ0806.3+1527) are X-ray emitting stars with X-ray light curves that are 100% modulated on periods of 569 and 321 seconds respectively. These periods are thought possibly to represent the orbital…

A homogeneous set of UBV photometry (354 data points obtained between 1983 and 1998) for the Be/X-ray binary A0535+26 = V725Tau is analysed, aiming to look for possible periodic component(s). After subtraction of the long-term variation it…

Astrophysics · Physics 2009-11-07 V. Larionov , V. M. Lyuty , G. V. Zaitseva

We address the problem where the X-ray emission lines are formed and investigate orbital dynamics using Chandra HETG observations, photoionizing calculations and numerical wind-particle simulations.The observed Si XIV (6.185 A) and S XVI…

High Energy Astrophysical Phenomena · Physics 2015-05-13 O. Vilhu , P. Hakala , D. C. Hannikainen , M. McCollough , K. Koljonen

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 present almost-simultaneous detections of Cygnus X-1 in the radio and mm regimes, obtained during the low/hard X-ray state. The source displays a flat spectrum between 2 and 220 GHz, with a spectral index flatter than 0.15 (3sigma).…

Astrophysics · Physics 2009-10-31 R. P. Fender , G. G. Pooley , P. Durouchoux , R. P. J. Tilanus , C. Brocksopp

We present preliminary results of long-term monitoring of the peculiar cataclysmic variable FS Aurigae conducted during the 2010-2011 observational season. The multicolor observations revealed, for the first time in photometric data, the…

Solar and Stellar Astrophysics · Physics 2011-11-29 V. Neustroev , G. Tovmassian , S. Zharikov , G. Sjoberg , T. Arranz Heras , P. B. Lake , D. Lane , G. Lubcke , A. A. Henden

Cygnus X-3 is a unique microquasar which shows X-ray state changes, strong radio emission, and relativistic jets. It is also an unusual X-ray binary with the mass-donating companion being a high mass star Wolf-Rayet but the orbital…

High Energy Astrophysical Phenomena · Physics 2010-12-21 Michael McCollough , Karri Koljonen , Diana Hannikainen , Guy Pooley , Sergei A. Trushkin , Danny Steeghs , Marco Tavani , Robert Droulans

We model the currently available $\gamma$-ray data from the Fermi Large Area Telescope on Cyg X-3. Thanks to its very strong $\gamma$-ray activity during 2018--2021, the data quality has significantly improved. We study the strong orbital…

High Energy Astrophysical Phenomena · Physics 2024-07-17 Anton Dmytriiev , Andrzej A. Zdziarski , Denys Malyshev , Valenti Bosch-Ramon , Maria Chernyakova

We report on NuSTAR, XMM-Newton and Swift observations of the gamma-ray binary 1FGL J1018.6-5856. We measure the orbital period to be 16.544+/-0.008 days using Swift data spanning 1900 days. The orbital period is different from the 2011…

The high-mass X-ray binary SMC X-1 is an eclipsing binary with an orbital period of 3.89 d. This system exhibits a superorbital modulation with a period varying between ~40 d and ~65 d. The instantaneous frequency and the corresponding…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Chin-Ping Hu , Yi Chou , Ting-Chang Yang , Yi-Hao Su

The Burst Alert Telescope (BAT) on board Swift has accumulated extensive light curves for 265 sources (not including GRBs) in the energy range 14 to 200 keV. We present here a summary of searches for periodic modulation in the flux from…

We present results from the first radio observations of a complete orbit (~ 17 days) of the neutron star X-ray binary Circinus X-1 using the Australia Telescope Compact Array Broadband Backend, taken while the system was in an historically…

High Energy Astrophysical Phenomena · Physics 2015-05-30 D. E. Calvelo , R. P. Fender , A. K. Tzioumis , N. Kawai , J. W. Broderick , M. E. Bell

We present a broad-band X-ray timing study of the variations in pulse behavior with superorbital cycle in the low-mass X-ray binary Her X-1. This source shows a 35-day superorbital modulation in X-ray flux that is likely caused by…

Precessing relativistic jets launched by compact objects are rarely directly measured, and present an invaluable opportunity to better understand many features of astrophysical jets. In this Letter we present MeerKAT radio observations of…

We study orbital modulation of X-rays from Cyg X-3, using data from Swift, INTEGRAL and RXTE. Using the wealth of the presently available data and an improved averaging method, we obtain energy-dependent folded and averaged light curves…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Andrzej A. Zdziarski , Chandreyee Maitra , Adam Frankowski , Gerald K. Skinner , Ranjeev Misra

The neutron star X-ray binary (NSXRB) Cygnus X-2 was observed by the Swift satellite 51 times over a 4 month period in 2008 with the XRT, UVOT, and BAT instruments. During this campaign, we observed Cyg X-2 in all three branches of the Z…

High Energy Astrophysical Phenomena · Physics 2014-11-20 E. S. Rykoff , E. M. Cackett , J. M. Miller

We present the first X-ray observations with the XMM-Newton and INTEGRAL satellites of the recently discovered cataclysmic variable 1RXSJ173021.5-055933, together with simultaneous UV and coordinated optical photometry aiming at…

Variability of the spin period of the white dwarf in the V405 Aur (RX J0558.0+5353) system using our observations and previously published maxima timings is analyzed. As the phase light curve contains two nearly equal photometric waves, one…

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