Discovery of a soft X-ray 8 mHz QPO from the accreting millisecond pulsar IGR J00291+5934

Tiziana Di Salvo, Rosario Iaria, Burderi, Papitto, Ferrigno, D'Aì, Riggio, Bozzo, Pintore, Sanna

Risultato della ricerca: Article

7 Citazioni (Scopus)

Abstract

We report on the analysis of the peculiar X-ray variability displayed by the accreting millisecond X-ray pulsar IGR J00291+5934 in a 80 ks-long joint NuSTAR and XMM-Newton observation performed during the source outburst in 2015. The light curve of the source is characterized by a flaring-like behaviour, with typical rise and decay time-scales of ~120 s. The flares are accompanied by a remarkable spectral variability, with the X-ray emission being generally softer at the peak of the flares. A strong quasi-periodic oscillation (QPO) is detected at ~8 mHz in the power spectrum of the source and clearly associated with the flaring-like behaviour. This feature has the strongest power at soft X-rays (≲3 keV). We carried out a dedicated hardness-ratio-resolved spectral analysis and a QPO phase-resolved spectral analysis, together with an in-depth study of the source-timing properties, to investigate the origin of this behaviour. We suggest that the unusual variability of IGR J00291+5934 observed by XMM-Newton and NuSTAR could be produced by a heartbeat-like mechanism, similar to that observed in black hole X-ray binaries. The possibility that this variability, and the associated QPO, are triggered by phases of quasi-stable nuclear burning, as sustained in the literature for a number of other neutron star binaries displaying a similar behaviour, cannot be solidly tested in the case of IGR J00291+5934 due to the paucity of type I X-ray bursts detected from this source.
Lingua originaleEnglish
pagine (da-a)3450-3459
Numero di pagine10
RivistaMonthly Notices of the Royal Astronomical Society
Volume466
Stato di pubblicazionePublished - 2017

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pulsars
oscillation
oscillations
x rays
XMM-Newton telescope
spectral analysis
newton
flares
spectrum analysis
outburst
neutron stars
light curve
hardness
power spectra
bursts
time measurement
timescale
decay
flaring

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

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Discovery of a soft X-ray 8 mHz QPO from the accreting millisecond pulsar IGR J00291+5934. / Di Salvo, Tiziana; Iaria, Rosario; Burderi; Papitto; Ferrigno; D'Aì; Riggio; Bozzo; Pintore; Sanna.

In: Monthly Notices of the Royal Astronomical Society, Vol. 466, 2017, pag. 3450-3459.

Risultato della ricerca: Article

Di Salvo, T, Iaria, R, Burderi, Papitto, Ferrigno, D'Aì, Riggio, Bozzo, Pintore & Sanna 2017, 'Discovery of a soft X-ray 8 mHz QPO from the accreting millisecond pulsar IGR J00291+5934', Monthly Notices of the Royal Astronomical Society, vol. 466, pagg. 3450-3459.
Di Salvo, Tiziana ; Iaria, Rosario ; Burderi ; Papitto ; Ferrigno ; D'Aì ; Riggio ; Bozzo ; Pintore ; Sanna. / Discovery of a soft X-ray 8 mHz QPO from the accreting millisecond pulsar IGR J00291+5934. In: Monthly Notices of the Royal Astronomical Society. 2017 ; Vol. 466. pagg. 3450-3459.
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title = "Discovery of a soft X-ray 8 mHz QPO from the accreting millisecond pulsar IGR J00291+5934",
abstract = "We report on the analysis of the peculiar X-ray variability displayed by the accreting millisecond X-ray pulsar IGR J00291+5934 in a 80 ks-long joint NuSTAR and XMM-Newton observation performed during the source outburst in 2015. The light curve of the source is characterized by a flaring-like behaviour, with typical rise and decay time-scales of ~120 s. The flares are accompanied by a remarkable spectral variability, with the X-ray emission being generally softer at the peak of the flares. A strong quasi-periodic oscillation (QPO) is detected at ~8 mHz in the power spectrum of the source and clearly associated with the flaring-like behaviour. This feature has the strongest power at soft X-rays (≲3 keV). We carried out a dedicated hardness-ratio-resolved spectral analysis and a QPO phase-resolved spectral analysis, together with an in-depth study of the source-timing properties, to investigate the origin of this behaviour. We suggest that the unusual variability of IGR J00291+5934 observed by XMM-Newton and NuSTAR could be produced by a heartbeat-like mechanism, similar to that observed in black hole X-ray binaries. The possibility that this variability, and the associated QPO, are triggered by phases of quasi-stable nuclear burning, as sustained in the literature for a number of other neutron star binaries displaying a similar behaviour, cannot be solidly tested in the case of IGR J00291+5934 due to the paucity of type I X-ray bursts detected from this source.",
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T1 - Discovery of a soft X-ray 8 mHz QPO from the accreting millisecond pulsar IGR J00291+5934

AU - Di Salvo, Tiziana

AU - Iaria, Rosario

AU - Burderi, null

AU - Papitto, null

AU - Ferrigno, null

AU - D'Aì, null

AU - Riggio, null

AU - Bozzo, null

AU - Pintore, null

AU - Sanna, null

PY - 2017

Y1 - 2017

N2 - We report on the analysis of the peculiar X-ray variability displayed by the accreting millisecond X-ray pulsar IGR J00291+5934 in a 80 ks-long joint NuSTAR and XMM-Newton observation performed during the source outburst in 2015. The light curve of the source is characterized by a flaring-like behaviour, with typical rise and decay time-scales of ~120 s. The flares are accompanied by a remarkable spectral variability, with the X-ray emission being generally softer at the peak of the flares. A strong quasi-periodic oscillation (QPO) is detected at ~8 mHz in the power spectrum of the source and clearly associated with the flaring-like behaviour. This feature has the strongest power at soft X-rays (≲3 keV). We carried out a dedicated hardness-ratio-resolved spectral analysis and a QPO phase-resolved spectral analysis, together with an in-depth study of the source-timing properties, to investigate the origin of this behaviour. We suggest that the unusual variability of IGR J00291+5934 observed by XMM-Newton and NuSTAR could be produced by a heartbeat-like mechanism, similar to that observed in black hole X-ray binaries. The possibility that this variability, and the associated QPO, are triggered by phases of quasi-stable nuclear burning, as sustained in the literature for a number of other neutron star binaries displaying a similar behaviour, cannot be solidly tested in the case of IGR J00291+5934 due to the paucity of type I X-ray bursts detected from this source.

AB - We report on the analysis of the peculiar X-ray variability displayed by the accreting millisecond X-ray pulsar IGR J00291+5934 in a 80 ks-long joint NuSTAR and XMM-Newton observation performed during the source outburst in 2015. The light curve of the source is characterized by a flaring-like behaviour, with typical rise and decay time-scales of ~120 s. The flares are accompanied by a remarkable spectral variability, with the X-ray emission being generally softer at the peak of the flares. A strong quasi-periodic oscillation (QPO) is detected at ~8 mHz in the power spectrum of the source and clearly associated with the flaring-like behaviour. This feature has the strongest power at soft X-rays (≲3 keV). We carried out a dedicated hardness-ratio-resolved spectral analysis and a QPO phase-resolved spectral analysis, together with an in-depth study of the source-timing properties, to investigate the origin of this behaviour. We suggest that the unusual variability of IGR J00291+5934 observed by XMM-Newton and NuSTAR could be produced by a heartbeat-like mechanism, similar to that observed in black hole X-ray binaries. The possibility that this variability, and the associated QPO, are triggered by phases of quasi-stable nuclear burning, as sustained in the literature for a number of other neutron star binaries displaying a similar behaviour, cannot be solidly tested in the case of IGR J00291+5934 due to the paucity of type I X-ray bursts detected from this source.

KW - Pulsars: individual: IGR J00291+5934; Stars: neutron; X-rays: binaries; Astronomy and Astrophysics; Space and Planetary Science

UR - http://hdl.handle.net/10447/228373

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

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SN - 0035-8711

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