2013/10/03 by Gaurava K. Jaisawal, Sachindra Naik, Biswajit Paul · 2 citations
Earth and Planetary Sciences · Physics and Astronomy · #Absorption (acoustics) #Astrophysical Phenomena and Observations #Binary pulsar #Crab Pulsar #Cutoff #Cyclotron resonance #Earth Systems and Cosmic Evolution #Pulsar #Pulsars and Gravitational Waves Research #Scattering #Spectral line #Spectral shape analysis #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.1088/0004-637x/779/1/54
published as The Astrophysical Journal, 2013, 779, 54 · 7 Pages, 7 Figures, Accepted for publication in The Astrophysical Journal
arxiv created 2013/10/03 · openalex publication_date 2013/11/25 · arxiv updated 2016/02/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present timing and broad band spectral studies of the high-mass X-ray binary pulsar 4U 1909+07 using data from Suzaku observations during 2010 November 2–3. The pulse period of the pulsar is estimated to be 604.11 ± 0.14 s. Pulsations are seen in the X-ray light curve up to ∼70 keV. The pulse profile is found to be strongly energy-dependent: a complex, multi-peaked structure at low energy becomes a simple single peak at higher energy. We found that the 1–70 keV pulse-averaged continuum can be fit by the sum of a blackbody and a partial covering Negative and Positive power law with Exponential cutoff model. A weak iron fluorescence emission line at 6.4 keV was detected in the spectrum. An absorption-like feature at ∼44 keV was clearly seen in the residuals of the spectral fitting, independent of the continuum model adopted. To check the possible presence of a cyclotron resonance scattering feature (CRSF) in the spectrum, we normalized the pulsar spectrum with the spectrum of the Crab Nebula. The resulting Crab ratio also showed a clear dip centered at ∼44 keV. We performed statistical tests on the residuals of the spectral fitting and also on the Crab spectral ratio to determine the significance of the absorption-like feature and identified it as a CRSF of the pulsar. We estimated the corresponding surface magnetic field of the pulsar to be 3.8 × 10 12 G.