Understanding the spectral and timing behavior of a newly discovered transient X-ray pulsar Swift J0243.6+6124

Abstract

We present the results obtained from timing and spectral studies of the newly discovered accreting X-ray binary pulsar Swift J0243.6+6124 using a NuSTAR observation in 2017 October at a flux level of ~280 mCrab. Pulsations at 9.85423(5) s were detected in the X-ray light curves of the pulsar. Pulse profiles of the pulsar were found to be strongly energy dependent. A broad profile at lower energies was found to evolve into a double peaked profile in $\ge$30keV. The 3-79 keV continuum spectrum of the pulsar was well described with a negative and positive exponential cutoff or high energy cutoff power law models modified with a hot blackbody at $\sim$3 keV. An iron emission line was also detected at 6.4 keV in the source spectrum. We did not find any signature of cyclotron absorption line in our study. Results obtained from phase-resolved and time-resolved spectroscopy are discussed in the paper.

arXiv comment7 pages, 6 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Society Journal

References in corpus (13)

• The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission
• Be/X-ray binaries
• Thermal and Bulk Comptonization in Accretion-Powered X-Ray Pulsars
• Spectral Formation in Accreting X-Ray Pulsars: Bimodal Variation of the Cyclotron Energy with Luminosity
• Orbit and intrinsic spin-up of the newly discovered transient X-ray pulsar Swift J0243.6+6124
• Discovery and Modeling of a Flattening of the Positive Cyclotron Line/Luminosity Relation in GX 304-1 with RXTE
• Suzaku view of Be/X-ray binary pulsar GX 304-1 during Type I X-ray outbursts
• RX J0440.9+4431: a persistent Be/X-ray binary in outburst
• Decade long RXTE monitoring observations of Be/X-ray binary pulsar EXO 2030+375
• Suzaku Observations of Hercules X-1 : Measurements of the Two Cyclotron Harmonics
• Suzaku observation of the transient X-ray pulsar GRO J1008-57
• Broad band X-ray spectroscopy of A0535+262 with SUZAKU
• A Suzaku View of Accretion Powered X-ray Pulsar GX 1+4

Cited by in corpus (18)

• NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-ray Pulsar Swift J0243.6+6124
• On the magnetic field of the first Galactic ultraluminous X-ray pulsar Swift J0243.6+6124
• Hot disk of the Swift J0243.6+6124 revealed by Insight-HXMT
• Super-Eddington accretion onto the Galactic ultraluminous X-ray pulsar Swift J0243.6+6124
• An evolving broad iron line from the first Galactic ultraluminous X-ray pulsar Swift J0243.6+6124
• Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst
• NuSTAR observations of the Transient Galactic Black Hole Binary Candidate Swift J1858.6-0814: A New Sibling of V404 Cyg and V4641 Sgr?
• AstroSat Observations of the first Galactic ULX Pulsar Swift J0243.6+6124
• Revisiting the spectral and timing properties of 4U 1909+07 with NuSTAR and Astrosat
• Searching for the Donor Stars of ULX Pulsars
• Insight-HXMT observations of Swift J0243.6+6124: the evolution of RMS pulse fractions at super-Eddington luminosity
• ULX pulsar Swift J0243.6+6124 observations with NuSTAR -- dominance of reflected emission in the super-Eddington state
• The Transient Ultra-luminous X-ray Source, ULX-4, in M51
• AstroSat detection of a mHz QPO and cyclotron line in IGR J19294+1816 during the 2019 outburst
• X-ray emission evolution of the Galactic ultra-luminous X-ray pulsar Swift J0243.6+6124 during the 2017-2018 outburst observed by the MAXI GSC
• Detection of X-ray pulsations at the lowest observed luminosity of Be/X-ray binary pulsar EXO 2030+375 with AstroSat
• Timing analysis of Swift J0243.6+6124 with NICER and Fermi/GBM during the decay phase of the 2017-2018 outburst
• An X-ray view of the 2021 outburst of SXP 15.6: constraints on the binary orbit and magnetic field of the Neutron Star