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Related papers: The magnetar candidate AX J1818.8-1559

200 papers

We present spectra for 34 accretion-powered X-ray and one millisecond pulsars that were within the field of view of the INTEGRAL observatory over two years (December 2002 - January 2005) of its in-orbit operation and that were detected by…

Astrophysics · Physics 2009-11-13 E. V. Filippova , S. S. Tsygankov , A. A. Lutovinov , R. A. Sunyaev

The broad-band 1-300 keV Suzaku spectrum of IGR J17497-2821, the X-ray transient discovered by INTEGRAL in September 2006, is presented. Suzaku observed IGR J17497-2821 on September 25, eight days after its discovery, for a net exposure of…

Several observations obtained in the last few years indicate that Soft Gamma-ray Repeaters (SGRs) and Anomalous X-ray Pulsars (AXPs) are basically a single class of isolated neutron stars. Their properties are well explained by the magnetar…

High Energy Astrophysical Phenomena · Physics 2009-05-01 Sandro Mereghetti

At the end of March 2004, the blazar S5 0716+714 underwent an optical outburst that prompted for quasi-simultaneous target-of-opportunity observations with the INTEGRAL and XMM-Newton satellites. In this paper, we report the results of the…

Studies were made of the 1-70 keV persistent spectra of fifteen magnetars as a complete sample observed with Suzaku from 2006 to 2013. Combined with early NuSTAR observations of four hard X-ray emitters, nine objects showed a hard power-law…

We report the ASCA discovery of a new X-ray pulsar, AX J0049-732, in the Small Magellanic Cloud (SMC). The pulse shape is sinusoidal with a barycentric period of 9.1320 +/- 0.0004 s. The X-ray spectrum was fitted by an absorbed power-law…

Astrophysics · Physics 2015-06-24 Masaru Ueno , Jun Yokogawa , Kensuke Imanishi , Katsuji Koyama

We report on the results of a deep 1.6 Ms INTEGRAL observation of the Cassiopeia region performed from December 2003 to February 2004. Eleven sources were detected with the imager IBIS-ISGRI at energies above 20 keV, including three new…

Astrophysics · Physics 2009-11-11 P. R. den Hartog , W. Hermsen , L. Kuiper , J. Vink , J. J. M. in 't Zand , W. Collmar

Aims: Hete J1900.1-2455 is the seventh known X-ray transient accreting millisecond pulsar and has been in outburst for more than one year. We compared the data on Hete J1900.1-2455 with other similar objects and made an attempt at deriving…

We present and interpret several new X-ray features of the X-ray pulsar PSR J1838-0655. The X-ray data are obtained from the archival data of CHANDRA, RXTE}, and SUZAKU. We combine all these X-ray data and fit the spectra with different…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Lupin Chun-Che Lin , Jumpei Takata , Chorng-Yuan Hwang , Jau-Shian Liang

We report the first detection of radio emission from any anomalous X-ray pulsar (AXP). Data from the Very Large Array (VLA) MAGPIS survey with angular resolution 6" reveals a point-source of flux density 4.5 +/- 0.5 mJy at 1.4 GHz at the…

Astrophysics · Physics 2009-11-13 J. P. Halpern , E. V. Gotthelf , R. H. Becker , D. J. Helfand , R. L. White

The source IGR J17200-3116 was discovered in the hard X-ray band by INTEGRAL. A periodic X-ray modulation at ~326 s was detected in its Swift light curves by our group (and subsequently confirmed by a Swift campaign). In this paper, we…

High Energy Astrophysical Phenomena · Physics 2014-06-06 P. Esposito , G. L. Israel , L. Sidoli , A. Tiengo , S. Campana , A. Moretti

The anomalous X-ray pulsars (AXPs) represent a growing class of neutron stars discovered at X-ray energies. While the nature of their multi-wavelength emission mechanism is still under debate, evidence has been recently accumulating in…

Astrophysics · Physics 2009-11-10 Samar Safi-Harb , Jennifer West

We present the transient nature of INTEGRAL source IGR J17285-2922, identified from a single period of activity during an IBIS/ISGRI Galactic Centre Deep Exposure in September 2003. The source has a maximum detection significance of 14…

MAXI J1816-195 is a newly discovered accreting millisecond pulsar with prolific thermonuclear bursts, detected during its outburst in 2022 June by Insight-HXMT and NICER. During the outburst, Insight-HXMT detected 73 bursts in its peak and…

High Energy Astrophysical Phenomena · Physics 2025-02-24 Yu-Peng Chen , Shu Zhang , Long Ji , Shuang-Nan Zhang , Peng-Ju Wang , Ling-Da Kong , Zhi Chang , Jing-Qiang Peng , Qing-Cang Shui , Jian Li , Lian Tao , Ming-Yu Ge , Jin-Lu Qu

We report on the first NuSTAR observation of the gamma-ray emitting millisecond pulsar binary PSR J1723-2837. X-ray radiation up to 79 keV is clearly detected and the simultaneous NuSTAR and Swift spectrum is well described by an absorbed…

High Energy Astrophysical Phenomena · Physics 2017-05-03 A. K. H. Kong , C. Y. Hui , J. Takata , K. L. Li , P. H. T. Tam

We present X-ray observations of the new transient magnetar Swift J1834.9-0846, discovered with Swift BAT on 2011 August 7. The data were obtained with Swift, RXTE, CXO, and XMM-Newton both before and after the outburst. Timing analysis…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Oleg Kargaltsev , Chryssa Kouveliotou , George G. Pavlov , Ersin Gogus , Lin Lin , Stefanie Wachter , Roger L. Griffith , Yuki Kaneko , George Younes

We discuss the X-ray, optical and radio properties of AX J0843+2942, a high luminosity Type 2 AGN found in the ASCA Hard Serendipitous Survey. The X-ray spectrum is best described by an absorbed power-law model with photon index of Gamma =…

We have observed the 5.54s anomalous X-ray pulsar XTE J1810-197 at radio, millimeter, and infrared (IR) wavelengths, with the aim of learning about its broad-band spectrum. At the IRAM 30m telescope, we have detected the magnetar at 88 and…

We present the analysis of six XMM-Newton observations of the Anomalous X-ray Pulsar CXOU J010043.1-721134, the magnetar candidate characterized by the lowest interstellar absorption. In contrast with all the other magnetar candidates, its…

Astrophysics · Physics 2009-11-13 A. Tiengo , P. Esposito , S. Mereghetti

We have detected significant X-ray emission from the direction of the young radio pulsar PSR J1105-6107 using the ASCA Observatory. The 11 sigma detection includes 460 background-subtracted source counts derived using data from all four…

Astrophysics · Physics 2009-10-30 E. V. Gotthelf , V. M. Kaspi