The first cyclotron harmonic of 4U 1538–52

Roca, José Joaquín Rodes; Torrejón, J. M.; Kreykenbohm, I.; Martínez-Núñez, Silvia; Camero-Arranz, A.; Bernabeu, Guillermo

doi:10.1051/0004-6361/200912815

Cited by 38 publications

(35 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Variability of the absorption at eclipse egress allows to measure the stellar wind parameters (Clark et al, 1994). The X-ray spectrum (Robba et al, 1992) displays two cyclotron absorption features (Clark et al, 1990;Robba et al, 2001;Rodes-Roca et al, 2009). Emission lines from an extended ionised region have been detected during eclipses (Rodes-Roca et al, 2011).…”

Section: Discussionmentioning

confidence: 99%

High-mass X-ray binaries in the Milky Way

Walter

Lutovinov

Bozzo

et al. 2015

Astron Astrophys Rev

228

234

View full text Add to dashboard Cite

High-mass X-ray binaries are fundamental in the study of stellar evolution, nucleosynthesis, structure and evolution of galaxies and accretion processes. Hard X-rays observations by INTEGRAL and Swift have broadened significantly our understanding in particular for the super-giant systems in the Milky Way, which number has increased by almost a factor of three. INTEGRAL played a crucial role in the discovery, study and understanding of heavily obscured systems and of fast X-ray transients. Most super-giant systems can now be classified in three categories: classical/obscured, eccentric and fast transient.The classical systems feature low eccentricity and variability factor of ∼ 10 3 , mostly driven by hydrodynamic phenomena occurring on scales larger than the accretion radius. Among them, systems with short orbital periods and close to Roche-Lobe overflow or with slow winds, appear highly obscured. In eccentric systems, the variability amplitude can reach even higher factors, because of the contrast of the wind density along the orbit. Four super-giant systems, featuring fast outbursts, very short orbital periods and anomalously low accretion rates, are not yet understood.Simulations of the accretion processes on relatively large scales have progressed and reproduce parts of the observations. The combined effects of wind

show abstract

Section: Discussionmentioning

confidence: 99%

High-mass X-ray binaries in the Milky Way

Walter

Lutovinov

Bozzo

et al. 2015

Astron Astrophys Rev

228

234

View full text Add to dashboard Cite

show abstract

“…1). Therefore, we included the CRSF in our models and fixed its parameters with the values obtained by Rodes-Roca et al (2009). We use the absorption cross sections from Verner et al (1996), and the abundances are set to those of Wilms et al (2000).…”

Section: Orbital Phase Averaged Spectrummentioning

confidence: 99%

“…Previous works in this direction have been carried out for only one or two orbits (Makishima et al 1987;Robba et al 2001;Mukherjee et al 2006;Rodes-Roca 2007) or for a shorter orbital phase (Rodes-Roca et al 2011). We obtained orbital phaseresolved spectra of the HMXB pulsar 4U 1538−52, accumulating the 60 s duration scans into six ∼0.5 day orbital phase bins outside of eclipse (Nakahira et al 2012;Doroshenko et al 2013;Islam & Paul 2014).…”

Section: Orbital Phase-resolved Spectramentioning

confidence: 99%

Orbital phase-resolved spectroscopy of 4U 1538−52 with MAXI

Roca

Mihara

Nakahira

et al. 2015

A&A

Self Cite

View full text Add to dashboard Cite

Context. 4U 1538−52, an absorbed high mass X-ray binary with an orbital period of ∼3.73 days, shows moderate orbital intensity modulations with a low level of counts during the eclipse. Several models have been proposed to explain the accretion at different orbital phases by a spherically symmetric stellar wind from the companion. Aims. The aim of this work is to study both the light curve and orbital phase spectroscopy of this source in the long term. In particular, we study the folded light curve and the changes in the spectral parameters with orbital phase to analyse the stellar wind of QV Nor, the mass donor of this binary system. Methods. We used all the observations made from the Gas Slit Camera on board MAXI of 4U 1538−52 covering many orbits continuously. We obtained the good interval times for all orbital phase ranges, which were the input for extracting our data. We estimated the orbital period of the system and then folded the light curves, and we fitted the X-ray spectra with the same model for every orbital phase spectrum. We also extracted the averaged spectrum of all the MAXI data available. Results. The MAXI spectra in the 2-20 keV energy range were fitted with an absorbed Comptonisation of cool photons on hot electrons. We found a strong orbital dependence of the absorption column density but neither the fluorescence iron emission line nor low energy excess were needed to fit the MAXI spectra. The variation in the spectral parameters over the binary orbit were used to examine the mode of accretion onto the neutron star in 4U 1538−52. We deduce a best value ofṀ/v ∞ = 0.65 × 10 −9 M yr −1 /(km s −1 ) for QV Nor.

show abstract

“…In previous works based on a wider energy range (Tenma, 1.5−35 keV, Makishima et al 1987; BeppoSAX, 0.1−100 keV, Robba et al 2001;RXTE, 3−100 keV, Coburn et al 2002;Rodes 2007;INTEGRAL, 3−100 keV, Rodes-Roca et al 2009), the X-ray continuum of 4U 1538−52 was described by different absorbed power-law relations, modified by a high-energy cutoff plus a Gaussian emission line at ∼6.4 keV, whenever present. Moreover, these models have also been modified by absorption cyclotron resonant scattering features at ∼21 keV (Clark et al 1990;Robba et al 2001) and at ∼47 keV (Rodes-Roca et al 2009). …”

Section: Spectral Analysismentioning

confidence: 99%

Detecting emission lines withXMM-Newtonin 4U 1538–52

Roca

Page

Torrejón

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

Context. The properties of the X-ray emission lines are a fundamental tool for studying the nature of the matter surrounding the neutron star and the phenomena that produce these lines. Aims. The aim of this work is to analyse the X-ray spectrum of 4U 1538−52 obtained by the XMM-Newton observatory and to look for the presence of diagnostic lines in the energy range 0.3−11.5 keV. Methods. We used a 54 ks PN & MOS/XMM-Newton observation of the high-mass X-ray binary 4U 1538−52 covering the orbital phase between 0.75 to 1.00 (the eclipse ingress). We modelled the 0.3−11.5 keV continuum emission with three absorbed power laws and looked for the emission lines. Results. We found previously unreported recombination lines in this system at ∼2.4 keV, ∼1.9 keV, and ∼1.3 keV, which is consistent with the presence of highly ionized states of S XV Heα, Si XIII Heα, and either Mg Kα or Mg XI Heα. On the other hand, in spectra that are both out of eclipse and in eclipse, we detect a fluorescence iron emission line at 6.4 keV, which is resolved into two components: a narrow (σ ≤ 10 eV) fluorescence Fe Kα line plus one hot line from highly photoionized Fe XXV. Conclusions. The detection of new recombination lines during eclipse ingress in 4U 1538−52 indicates that there is an extended ionized region surrounding the neutron star.

show abstract

The first cyclotron harmonic of 4U 1538–52

Cited by 38 publications

References 18 publications

High-mass X-ray binaries in the Milky Way

High-mass X-ray binaries in the Milky Way

Orbital phase-resolved spectroscopy of 4U 1538−52 with MAXI

Detecting emission lines withXMM-Newtonin 4U 1538–52

Contact Info

Product

Resources

About