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Related papers: Anomalous X-ray pulsars: Persistent States with Fa…

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We report the serendipitous discovery of a 7-s X-ray pulsar using data acquired with the Advanced Satellite for Cosmology and Astrophysics. The pulsar is detected as an unresolved source located towards a region of the Galactic plane (l,b ~…

Astrophysics · Physics 2009-10-30 E. V. Gotthelf , G. Vasisht

We discuss the options of the fall-back disk model of Anomalous X-Ray Pulsars (AXPs). We argue that the power-law index of the mass inflow rate during the propeller stage can be lower than those employed in earlier models. We take into…

Astrophysics · Physics 2009-11-10 K. Yavuz Ekşi , M. Ali Alpar

The population of clearly identified anomalous X-ray pulsars has recently grown to seven, however, one candidate anomalous X-ray pulsar (AXP) still eludes re-confirmation. Here, we present a set of seven Chandra ACIS-S observations of the…

Astrophysics · Physics 2008-11-26 C. R. Tam , V. M. Kaspi , B. M. Gaensler , E. V. Gotthelf

We present high-speed, multi-colour optical photometry of the anomalous X-ray pulsar 4U 0142+61, obtained with ULTRACAM on the 4.2-m William Herschel Telescope. We detect 4U 0142+61 at magnitudes of i'=23.7+-0.1, g'=27.2+-0.2 and u'>25.8,…

In 2003 a previously unpulsed Einstein and ROSAT source cataloged as soft and dim (Lx of few 10^33 ergs) thermal emitting object, namely XTE J1810-197, was identified as the first unambiguous transient Anomalous X-ray Pulsar. Two years…

We present X-ray imaging, timing, and phase resolved spectroscopy of the anomalous X-ray pulsar 4U 0142+61 using the Chandra X-ray Observatory. The spectrum is well described by a power law plus blackbody model with power law index =…

We report on long-term monitoring of anomalous X-ray pulsars (AXPs) using the Rossi X-ray Timing Explorer. Using phase-coherent timing, we find a wide variety of behaviors among the sources, ranging from high stability (in 1E 2259.1+586 and…

Astrophysics · Physics 2009-09-25 Fotis P. Gavriil , Victoria M. Kaspi , Deepto Chakrabarty

We show that the period clustering of anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), their X-ray luminosities, ages and statistics can be explained with fallback disks with large initial specific angular momentum. The…

High Energy Astrophysical Phenomena · Physics 2015-05-13 U. Ertan , K. Y. Eksi , M. H. Erkut , M. A. Alpar

We show that the irradiated accretion disk model can account for all the optical and infrared observations of the anomalous X-ray pulsars in the persistent state. Model fits do not constrain the outer disk radii, while placing an upper…

Astrophysics · Physics 2015-06-24 Unal Ertan , Sirin Caliskan

The ''Anomalous X-ray Pulsars'' (AXPs) are a small group of X-ray pulsars characterized by periods in the 5-10 s range and by the absence of massive companion stars. There are now 7 possible members of this class of objects. We review…

Astrophysics · Physics 2015-06-24 S. Mereghetti , L. Stella , G. L. Israel

We report the discovery of a 4.5 um counterpart to the anomalous X-ray pulsar (magnetar) 1E 2259+586 with the Spitzer Space Telescope. The mid-infrared flux density is 6.3+/-1.0 uJy at 4.5 um and <20 uJy (at 95% confidence) at 8 um, or…

High Energy Astrophysical Phenomena · Physics 2009-07-28 David L. Kaplan , Deepto Chakrabarty , Zhongxiang Wang , Stefanie Wachter

We report on the long-term monitoring of three anomalous X-ray pulsars using the Rossi X-ray Timing Explorer (RXTE). We present a phase-coherent timing ephemeris for 4U 0142+61, and show that it has rotated with high stability over 4.4 yr,…

Astrophysics · Physics 2015-06-24 Fotis P. Gavriil , Victoria M. Kaspi

The nature of the 5-12 s "anomalous" X-ray pulsars remains a mystery. Among the models that have been proposed to explain the properties of AXPs, the most likely ones are: (1) isolated accreting neutron stars evolved from the…

Astrophysics · Physics 2009-10-31 X. -D. Li

We report the discovery of the likely IR counterpart to the Anomalous X-ray Pulsar (AXP) 1RXS J1708-4009, based on the combination of Chandra HRC-I X-ray position, and deep optical/IR observations carried out from ESO telescopes and the…

The Anomalous X-ray Pulsar (AXP) 1E 1547.0-5408 reactivated in 2009 January with the emission of dozens of short bursts. Follow-up observations with Swift/XRT and XMM-Newton showed the presence of multiple expanding rings around the…

High Energy Astrophysical Phenomena · Physics 2015-05-14 A. Tiengo , G. Vianello , P. Esposito , S. Mereghetti

We show that the X-ray outburst light curves of four transient anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), namely XTE J1810-197, SGR 0501+4516, SGR 1627-41 and CXOU J164710.2-455216, can be produced by the fallback…

High Energy Astrophysical Phenomena · Physics 2012-10-08 Sirin Caliskan , Unal Ertan

We report on the detection of variability from the proposed IR counterpart to the Anomalous X-ray Pulsar (AXP) 1E1048.1-5937 based on Chandra and ESO optical/IR deep observations carried out in 2001-2002. Within the narrow Chandra…

We report here on X-ray and IR observations of the Anomalous X-ray Pulsar 1RXS J170849-400910. First, we report on new XMM-Newton, Swift-XRT and Chandra observations of this AXP, which confirm the intensity-hardness correlation observed in…

Astrophysics · Physics 2009-11-11 N. Rea , G. L. Israel , T. Oosterbroek , S. Campana , S. Zane , R. Turolla , V. Testa , M. Mendez , L. Stella

We have searched for persistent radio pulsations, bright single pulses, and bursts from four Southern anomalous X-ray pulsars (AXPs). Deep observations were conducted at 1.4 GHz in 1999 July and August with the Parkes 64-m telescope. For…

Astrophysics · Physics 2008-11-26 Fronefield Crawford , Jason W. T. Hessels , Victoria M. Kaspi

We examined the fall-back disk models, and in general accretion, proposed to explain the properties of anomalous X-ray pulsars (AXPs), soft gamma repeaters (SGRs), and radio pulsars (PSRs). We checked the possibility of some gas remaining…

Astrophysics · Physics 2009-11-07 S. O. Tagieva , E. Yazgan , A. Ankay