相关论文: A torque reversal of 4U 1907+09

X-ray observations of the accreting X-ray pulsar 4U~1907+09, obtained during February 1996 with the Proportional Counter Array on the Rossi X-ray Timing Experiment (RXTE), have enabled the first measurement of the intrinsic pulse period…

We present timing and spectral analysis of RXTE-PCA observations of the accretion powered pulsar 4U 1907+09 between June 2007 and August 2008. 4U 1907+09 had been in a spin-down episode with a spin-down rate of $-3.54\times10^{-14}$ Hz…

Using X-ray data from the Rossi X-Ray Timing Explorer (RXTE), we report the pulse timing results of the accretion powered high mass X-ray binary (HMXRB) pulsar 4U 1907+09 covering a time span of almost two years. We measured three new pulse…

In this paper we present our recent timing and spectral analysis of the X-ray pulsar 4U 1907+09. Our X-ray data consist of an extended set of RXTE & INTEGRAL observations that were analyzed before ({\c{S}}ahiner et al. 2012). From the X-ray…

We analyse \emph{INTEGRAL} (between 2005 October and 2007 November) and \emph{RXTE} (between 2007 June and 2011 March) observations of the accretion powered pulsar 4U 1907+09. From \emph{INTEGRAL} IBIS-ISGRI and \emph{RXTE}-PCA…

We analyzed RXTE archival observations of 4U 1907+09 between 17 February 1996 and 6 March 2002. The pulse timing analysis showed that the source stayed at almost {\bf{constant}} period around August 1998 and then started to spin-down at a…

We present a spectral and timing analysis of INTEGRAL observations of two high mass X-ray binaries, 4U 1538-522 and 4U 1907+09. Our timing measurements for 4U 1538-522 find the pulse period to have exhibited a spin-up trend until…

We review the pulse profile evolution of the unique accretion powered X-ray pulsar 4U 1626-67 over the last 40 years since its discovery. This pulsar showed two distinct eras of steady spin-up separated by a steady spin-down episode for…

We present the results obtained from the analysis of high mass X-ray binary pulsar 4U 1909+07 using NuSTAR and Astrosat observations in 2015 and 2017 July, respectively. X-ray pulsations at $\approx$604 s are clearly detected in our study.…

We present an analysis of the spectral shape and pulse profile of the accretion-powered pulsar 4U 1626-67 observed with Suzaku and NuSTAR during a spin-up state. The pulsar, which experienced a torque reversal to spin-up in 2008, has a spin…

We present observations of the accretion-powered X-ray pulsar (XRP) 4U 1907+09, conducted with the Imaging X-ray Polarimetry Explorer (IXPE) that delivers the first high-quality polarization measurements of this source. 4U 1907+09 was…

The observed abrupt torque reversals in X-ray pulsars, 4U 1626-67, GX 1+4, and OAO 1657-415, can be explained by transition in accretion flow rotation from Keplerian to sub-Keplerian, which takes place at a critical accretion rate, $\sim…

We present timing and broad-band spectral studies of the high mass X-ray binary pulsar 4U 1909+07 using data from Suzaku observation during 2010 November 2-3. The pulse period of the pulsar is estimated to be 604.11+/-0.14 s. Pulsations are…

We use the In data collected during the 2019 outburst from X-ray pulsar 4U 1901+03 to complement the orbital parameters reported by Fermi/GBM. Using the Insight-HXMT, we examine the correlation between the derivative of the intrinsic spin…

After about 18 years of steadily spinning down, the accretion-powered pulsar 4U 1626-67, experienced a torque reversal at the beginning of 2008. For the present study we have used all available Fermi/GBM data since its launch in 2008 June…

X-ray timing studies of the persistent, Galactic, accretion-powered pulsar 4U 1626$-$67 reveal torque reversals, during which the pulse frequency $\nu(t)$ alternates between multiyear episodes of secular acceleration and deceleration,…

The accretion-powered, X-ray pulsar 4U 1626-67 has recently shown an abrupt torque reversal accompanied by a dramatic spectral transition and a relatively small luminosity change. The time-averaged X-ray spectrum during spin-down is…

We report on 10 yr of monitoring of the 8.7-s Anomalous X-ray Pulsar 4U 0142+61 using the Rossi X-Ray Timing Explorer (RXTE). This pulsar exhibited stable rotation from 2000 until February 2006: the RMS phase residual for a spin-down model…

We present the first detailed spectral and timing analysis of the High Mass X-ray Binary (HMXB) 4U 1909+07 with INTEGRAL and RXTE. 4U 1909+07 is detected with an average of 2.4cps in ISGRI, but shows flares up to ~50cps. The system shows a…

We report X-ray observations of the High Mass X-ray Binary (HMXB) pulsar 4U 1907+09. Spectral and Timing analysis of the source has been performed using NuSTAR observation. Timing analysis of the photon events revealed the coherent X-ray…