GRO J1744-28: An intermediate B-field pulsar in a low-mass X-ray binary

Rosario Iaria, Marco Matranga, Carmela Galiano, Tiziana Di Salvo, D'Aì, Riggio, Dauser, Bozzo, Pintore, Sanna, Matranga, Galiano, Robba, Burderi, García, Iaria, Di Salvo

Risultato della ricerca: Article

16 Citazioni (Scopus)

Abstract

The bursting pulsar, GRO J1744-28, went again in outburst after ~18 yr of quiescence in 2014 mid-January. We studied the broad-band, persistent, X-ray spectrum using X-ray data from a XMM-Newton observation, performed almost at the peak of the outburst, and from a close INTEGRAL observation, performed 3 d later, thus covering the 1.3-70.0 keV band. The spectrum shows a complex continuum shape that cannot be modelled with standard high-mass X-ray pulsar models, nor by two-components models. We observe broad-band and peaked residuals from 4 to 15 keV, and we propose a self-consistent interpretation of these residuals, assuming they are produced by cyclotron absorption features and by a moderately smeared, highly ionized, reflection component. We identify the cyclotron fundamental at ~4.7 keV, with hints for two possible harmonics at ~10.4 and ~15.8 keV. The position of the cyclotron fundamental allows an estimate for the pulsar magnetic field of (5.27 ± 0.06) × 10<sup>11</sup> G, if the feature is produced at its surface. From the dynamical and relativistic smearing of the disc reflected component, we obtain a lower limit estimate for the truncated accretion disc inner radius (≳100 R<inf>g</inf>) and for the inclination angle (18°-48°). We also detect the presence of a softer thermal component that we associate with the emission from an accretion disc truncated at a distance from the pulsar of 50-115 R<inf>g</inf>. From these estimates,we derive the magnetospheric radius for disc accretion to be ~0.2 times the classical Alfvén radius for radial accretion.
Lingua originaleEnglish
pagine (da-a)4288-4303
Numero di pagine16
RivistaMonthly Notices of the Royal Astronomical Society
Volume449
Stato di pubblicazionePublished - 2015

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pulsars
accretion
accretion disks
cyclotrons
outburst
radii
x rays
estimates
broadband
XMM-Newton telescope
newton
inclination
coverings
continuums
magnetic field
harmonics
magnetic fields

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

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GRO J1744-28: An intermediate B-field pulsar in a low-mass X-ray binary. / Iaria, Rosario; Matranga, Marco; Galiano, Carmela; Di Salvo, Tiziana; D'Aì; Riggio; Dauser; Bozzo; Pintore; Sanna; Matranga; Galiano; Robba; Burderi; García; Iaria; Di Salvo.

In: Monthly Notices of the Royal Astronomical Society, Vol. 449, 2015, pag. 4288-4303.

Risultato della ricerca: Article

Iaria, R, Matranga, M, Galiano, C, Di Salvo, T, D'Aì, Riggio, Dauser, Bozzo, Pintore, Sanna, Matranga, Galiano, Robba, Burderi, García, Iaria & Di Salvo 2015, 'GRO J1744-28: An intermediate B-field pulsar in a low-mass X-ray binary', Monthly Notices of the Royal Astronomical Society, vol. 449, pagg. 4288-4303.
Iaria, Rosario ; Matranga, Marco ; Galiano, Carmela ; Di Salvo, Tiziana ; D'Aì ; Riggio ; Dauser ; Bozzo ; Pintore ; Sanna ; Matranga ; Galiano ; Robba ; Burderi ; García ; Iaria ; Di Salvo. / GRO J1744-28: An intermediate B-field pulsar in a low-mass X-ray binary. In: Monthly Notices of the Royal Astronomical Society. 2015 ; Vol. 449. pagg. 4288-4303.
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title = "GRO J1744-28: An intermediate B-field pulsar in a low-mass X-ray binary",
abstract = "The bursting pulsar, GRO J1744-28, went again in outburst after ~18 yr of quiescence in 2014 mid-January. We studied the broad-band, persistent, X-ray spectrum using X-ray data from a XMM-Newton observation, performed almost at the peak of the outburst, and from a close INTEGRAL observation, performed 3 d later, thus covering the 1.3-70.0 keV band. The spectrum shows a complex continuum shape that cannot be modelled with standard high-mass X-ray pulsar models, nor by two-components models. We observe broad-band and peaked residuals from 4 to 15 keV, and we propose a self-consistent interpretation of these residuals, assuming they are produced by cyclotron absorption features and by a moderately smeared, highly ionized, reflection component. We identify the cyclotron fundamental at ~4.7 keV, with hints for two possible harmonics at ~10.4 and ~15.8 keV. The position of the cyclotron fundamental allows an estimate for the pulsar magnetic field of (5.27 ± 0.06) × 1011 G, if the feature is produced at its surface. From the dynamical and relativistic smearing of the disc reflected component, we obtain a lower limit estimate for the truncated accretion disc inner radius (≳100 Rg) and for the inclination angle (18°-48°). We also detect the presence of a softer thermal component that we associate with the emission from an accretion disc truncated at a distance from the pulsar of 50-115 Rg. From these estimates,we derive the magnetospheric radius for disc accretion to be ~0.2 times the classical Alfv{\'e}n radius for radial accretion.",
author = "Rosario Iaria and Marco Matranga and Carmela Galiano and {Di Salvo}, Tiziana and D'A{\`i} and Riggio and Dauser and Bozzo and Pintore and Sanna and Matranga and Galiano and Robba and Burderi and Garc{\'i}a and Iaria and {Di Salvo}",
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pages = "4288--4303",
journal = "Monthly Notices of the Royal Astronomical Society",
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TY - JOUR

T1 - GRO J1744-28: An intermediate B-field pulsar in a low-mass X-ray binary

AU - Iaria, Rosario

AU - Matranga, Marco

AU - Galiano, Carmela

AU - Di Salvo, Tiziana

AU - D'Aì, null

AU - Riggio, null

AU - Dauser, null

AU - Bozzo, null

AU - Pintore, null

AU - Sanna, null

AU - Matranga, null

AU - Galiano, null

AU - Robba, null

AU - Burderi, null

AU - García, null

AU - Iaria, null

AU - Di Salvo, null

PY - 2015

Y1 - 2015

N2 - The bursting pulsar, GRO J1744-28, went again in outburst after ~18 yr of quiescence in 2014 mid-January. We studied the broad-band, persistent, X-ray spectrum using X-ray data from a XMM-Newton observation, performed almost at the peak of the outburst, and from a close INTEGRAL observation, performed 3 d later, thus covering the 1.3-70.0 keV band. The spectrum shows a complex continuum shape that cannot be modelled with standard high-mass X-ray pulsar models, nor by two-components models. We observe broad-band and peaked residuals from 4 to 15 keV, and we propose a self-consistent interpretation of these residuals, assuming they are produced by cyclotron absorption features and by a moderately smeared, highly ionized, reflection component. We identify the cyclotron fundamental at ~4.7 keV, with hints for two possible harmonics at ~10.4 and ~15.8 keV. The position of the cyclotron fundamental allows an estimate for the pulsar magnetic field of (5.27 ± 0.06) × 1011 G, if the feature is produced at its surface. From the dynamical and relativistic smearing of the disc reflected component, we obtain a lower limit estimate for the truncated accretion disc inner radius (≳100 Rg) and for the inclination angle (18°-48°). We also detect the presence of a softer thermal component that we associate with the emission from an accretion disc truncated at a distance from the pulsar of 50-115 Rg. From these estimates,we derive the magnetospheric radius for disc accretion to be ~0.2 times the classical Alfvén radius for radial accretion.

AB - The bursting pulsar, GRO J1744-28, went again in outburst after ~18 yr of quiescence in 2014 mid-January. We studied the broad-band, persistent, X-ray spectrum using X-ray data from a XMM-Newton observation, performed almost at the peak of the outburst, and from a close INTEGRAL observation, performed 3 d later, thus covering the 1.3-70.0 keV band. The spectrum shows a complex continuum shape that cannot be modelled with standard high-mass X-ray pulsar models, nor by two-components models. We observe broad-band and peaked residuals from 4 to 15 keV, and we propose a self-consistent interpretation of these residuals, assuming they are produced by cyclotron absorption features and by a moderately smeared, highly ionized, reflection component. We identify the cyclotron fundamental at ~4.7 keV, with hints for two possible harmonics at ~10.4 and ~15.8 keV. The position of the cyclotron fundamental allows an estimate for the pulsar magnetic field of (5.27 ± 0.06) × 1011 G, if the feature is produced at its surface. From the dynamical and relativistic smearing of the disc reflected component, we obtain a lower limit estimate for the truncated accretion disc inner radius (≳100 Rg) and for the inclination angle (18°-48°). We also detect the presence of a softer thermal component that we associate with the emission from an accretion disc truncated at a distance from the pulsar of 50-115 Rg. From these estimates,we derive the magnetospheric radius for disc accretion to be ~0.2 times the classical Alfvén radius for radial accretion.

UR - http://hdl.handle.net/10447/154303

UR - http://mnras.oxfordjournals.org/

M3 - Article

VL - 449

SP - 4288

EP - 4303

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

ER -