Suzaku View of the Neutron Star in the Dipping Source 4U 1822$-$37

Abstract

The dipping X-ray source 4U 1822$-$37 was observed by Suzaku on 2006 Octrober 20 for a net exposure of 37 ks. The source was detected with the XIS at a 1-10 keV flux of 5.5$\times 10^{-10}$ erg cm${}^{-2}$ s${}^{-1}$, and with the HXD (HXD-PIN) at a 10-50 keV flux of 8.9$\times 10^{-10}$ erg cm${}^{-2}$ s${}^{-1}$. With HXD-PIN, the pulsation was detected at a barycentric period of 0.592437 s, and its change rate was reconfirmed as $-2.43\times$10${}^{-12}$ s s${}^{-1}$. The 1-50 keV spectra of 4U 1822-37 were found to be very similar to those of Her X-1 in the slopes, cutoff and iron lines. Three iron lines (Fe K$\alpha$, Fe XXV, and Fe XXVI) were detected, on top of a 1-50 keV continuum that is described by an NPEX model plus a soft blackbody. In addition, a cyclotron resonance scattering feature was detected significantly ($>99\%$ confidence), at an energy of 33$\pm$2 keV with a depth of 0.4${}_{-0.3}^{+0.6}$. Therefore, the neutron star in this source is concluded to have a strong magnetic field of 2.8$\times 10^{12}$ G. Further assuming that the source has a relatively high intrinsic luminosity of several times 10${}^{37}$ erg s${}^{-1}$, its spectral and timing properties are consistently explained.

References in corpus (10)

• Evaluating Spectral Models and the X-ray States of Neutron-Star X-ray Transients
• Relativistic iron emission lines in neutron star low-mass X-ray binaries as probes of neutron star radii
• X-ray Spectroscopy of the High Mass X-ray Binary Pulsar Centaurus X-3 over its Binary Orbit
• New ephemeris of the ADC source 2A 1822-371: a stable orbital-period derivative over 30 years
• Data-oriented Diagnostics of Pileup Effects on the Suzaku XIS
• Timing and Spectral properties of Be/X-ray pulsar EXO 2030+375 during a Type I outburst
• Accretion Geometry of the Low-Mass X-ray Binary Aquila X-1 in the Soft and Hard States
• X-ray spectroscopy of the ADC source X1822-371 with Chandra and XMM-Newton
• The Photoionized Accretion Disk in Her X-1
• Detailed study of the X-ray and Optical/UV orbital ephemeris of X1822-371

Cited by in corpus (13)

• Cyclotron lines in highly magnetized neutron stars
• Spectral and Timing Nature of the Symbiotic X-ray Binary 4U 1954+319: The Slowest Rotating Neutron Star in an X-ray Binary System
• A possible cyclotron resonance scattering feature near 0.7 keV in X1822-371
• Formation of Binary Millisecond Pulsars by Accretion-Induced Collapse of White Dwarfs under Wind-Driven Evolution
• Formation of Mass-gap Black Holes from Neutron Star X-ray Binaries with Super-Eddington Accretion
• EXTraS discovery of an 1.2-s X-ray pulsar in M 31
• Suzaku Observation of the High-Inclination Binary EXO 0748-676 in the Hard State
• New Constraints on the Geometry and Kinematics of Matter Surrounding the Accretion Flow in X-ray Binaries from $Chandra$ HETG X-ray Spectroscopy
• The X-ray Pulsar 2A 1822-371 as a Super Eddington source
• Comprehensive broadband study of accreting neutron stars with Suzaku: Is there a bi-modality in the X-ray spectrum?
• Probing the Mysteries of the X-Ray Binary 4U 1210-64 with ASM, PCA, MAXI, BAT and Suzaku
• On the rapid orbital expansion in the compact low-mass X-ray binary 2A 1822$-$371
• Accretion disc winds in X-ray binaries