NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124

Colleen A. Wilson-Hodge, Christian Malacaria, Peter A. Jenke, Gaurava K. Jaisawal, Matthew Kerr, Michael T. Wolff, Zaven Arzoumanian, Deepto Chakrabarty, John P. Doty, Keith C. Gendreau, Sebastien Guillot, Wynn C.G. Ho, Beverly Lamarr, Craig B. Markwardt, Feryal Ozel, Gregory Y. Prigozhin, Paul S. Ray, Mercedes Ramos-Lerate, Ronald A. Remillard, Tod E. StrohmayerMichael L. Vezie, Kent S. Wood

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Swift J0243.6+6124 is a newly discovered Galactic Be/X-ray binary, revealed in late 2017 September in a giant outburst with a peak luminosity of 2 × 1039(d/7 kpc)2 erg s-1 (0.1-10 keV), with no formerly reported activity. At this luminosity, Swift J0243.6+6124 is the first known galactic ultraluminous X-ray pulsar. We describe Neutron star Interior Composition Explorer (NICER) and Fermi Gamma-ray Burst Monitor (GBM) timing and spectral analyses for this source. A new orbital ephemeris is obtained for the binary system using spin frequencies measured with GBM and 15-50 keV fluxes measured with the Neil Gehrels Swift Observatory Burst Alert Telescope to model the system's intrinsic spin-up. Power spectra measured with NICER show considerable evolution with luminosity, including a quasi-periodic oscillation near 50 mHz that is omnipresent at low luminosity and has an evolving central frequency. Pulse profiles measured over the combined 0.2-100 keV range show complex evolution that is both luminosity and energy dependent. Near the critical luminosity of L ∼ 1038 erg s-1, the pulse profiles transition from single peaked to double peaked, the pulsed fraction reaches a minimum in all energy bands, and the hardness ratios in both NICER and GBM show a turnover to softening as the intensity increases. This behavior repeats as the outburst rises and fades, indicating two distinct accretion regimes. These two regimes are suggestive of the accretion structure on the neutron star surface transitioning from a Coulomb collisional stopping mechanism at lower luminosities to a radiation-dominated stopping mechanism at higher luminosities. This is the highest observed (to date) value of the critical luminosity, suggesting a magnetic field of B ∼ 1013 G.

Original languageEnglish (US)
Article number9
JournalAstrophysical Journal
Volume863
Issue number1
DOIs
StatePublished - Aug 10 2018

Fingerprint

gamma ray bursts
pulsars
neutron stars
monitors
luminosity
x rays
stopping
outburst
erg
Swift observatory
accretion
profiles
pulses
softening
hardness
energy bands
energy
power spectra
bursts
turnover

Keywords

  • accretion, accretion disks
  • pulsars: individual (SWIFT J0243.6+6124)
  • X-rays: binaries

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Wilson-Hodge, C. A., Malacaria, C., Jenke, P. A., Jaisawal, G. K., Kerr, M., Wolff, M. T., ... Wood, K. S. (2018). NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124. Astrophysical Journal, 863(1), [9]. https://doi.org/10.3847/1538-4357/aace60

NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124. / Wilson-Hodge, Colleen A.; Malacaria, Christian; Jenke, Peter A.; Jaisawal, Gaurava K.; Kerr, Matthew; Wolff, Michael T.; Arzoumanian, Zaven; Chakrabarty, Deepto; Doty, John P.; Gendreau, Keith C.; Guillot, Sebastien; Ho, Wynn C.G.; Lamarr, Beverly; Markwardt, Craig B.; Ozel, Feryal; Prigozhin, Gregory Y.; Ray, Paul S.; Ramos-Lerate, Mercedes; Remillard, Ronald A.; Strohmayer, Tod E.; Vezie, Michael L.; Wood, Kent S.

In: Astrophysical Journal, Vol. 863, No. 1, 9, 10.08.2018.

Research output: Contribution to journalArticle

Wilson-Hodge, CA, Malacaria, C, Jenke, PA, Jaisawal, GK, Kerr, M, Wolff, MT, Arzoumanian, Z, Chakrabarty, D, Doty, JP, Gendreau, KC, Guillot, S, Ho, WCG, Lamarr, B, Markwardt, CB, Ozel, F, Prigozhin, GY, Ray, PS, Ramos-Lerate, M, Remillard, RA, Strohmayer, TE, Vezie, ML & Wood, KS 2018, 'NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124', Astrophysical Journal, vol. 863, no. 1, 9. https://doi.org/10.3847/1538-4357/aace60
Wilson-Hodge, Colleen A. ; Malacaria, Christian ; Jenke, Peter A. ; Jaisawal, Gaurava K. ; Kerr, Matthew ; Wolff, Michael T. ; Arzoumanian, Zaven ; Chakrabarty, Deepto ; Doty, John P. ; Gendreau, Keith C. ; Guillot, Sebastien ; Ho, Wynn C.G. ; Lamarr, Beverly ; Markwardt, Craig B. ; Ozel, Feryal ; Prigozhin, Gregory Y. ; Ray, Paul S. ; Ramos-Lerate, Mercedes ; Remillard, Ronald A. ; Strohmayer, Tod E. ; Vezie, Michael L. ; Wood, Kent S. / NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124. In: Astrophysical Journal. 2018 ; Vol. 863, No. 1.
@article{c917afbd15ef4278a3747522605d7e9c,
title = "NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124",
abstract = "Swift J0243.6+6124 is a newly discovered Galactic Be/X-ray binary, revealed in late 2017 September in a giant outburst with a peak luminosity of 2 × 1039(d/7 kpc)2 erg s-1 (0.1-10 keV), with no formerly reported activity. At this luminosity, Swift J0243.6+6124 is the first known galactic ultraluminous X-ray pulsar. We describe Neutron star Interior Composition Explorer (NICER) and Fermi Gamma-ray Burst Monitor (GBM) timing and spectral analyses for this source. A new orbital ephemeris is obtained for the binary system using spin frequencies measured with GBM and 15-50 keV fluxes measured with the Neil Gehrels Swift Observatory Burst Alert Telescope to model the system's intrinsic spin-up. Power spectra measured with NICER show considerable evolution with luminosity, including a quasi-periodic oscillation near 50 mHz that is omnipresent at low luminosity and has an evolving central frequency. Pulse profiles measured over the combined 0.2-100 keV range show complex evolution that is both luminosity and energy dependent. Near the critical luminosity of L ∼ 1038 erg s-1, the pulse profiles transition from single peaked to double peaked, the pulsed fraction reaches a minimum in all energy bands, and the hardness ratios in both NICER and GBM show a turnover to softening as the intensity increases. This behavior repeats as the outburst rises and fades, indicating two distinct accretion regimes. These two regimes are suggestive of the accretion structure on the neutron star surface transitioning from a Coulomb collisional stopping mechanism at lower luminosities to a radiation-dominated stopping mechanism at higher luminosities. This is the highest observed (to date) value of the critical luminosity, suggesting a magnetic field of B ∼ 1013 G.",
keywords = "accretion, accretion disks, pulsars: individual (SWIFT J0243.6+6124), X-rays: binaries",
author = "Wilson-Hodge, {Colleen A.} and Christian Malacaria and Jenke, {Peter A.} and Jaisawal, {Gaurava K.} and Matthew Kerr and Wolff, {Michael T.} and Zaven Arzoumanian and Deepto Chakrabarty and Doty, {John P.} and Gendreau, {Keith C.} and Sebastien Guillot and Ho, {Wynn C.G.} and Beverly Lamarr and Markwardt, {Craig B.} and Feryal Ozel and Prigozhin, {Gregory Y.} and Ray, {Paul S.} and Mercedes Ramos-Lerate and Remillard, {Ronald A.} and Strohmayer, {Tod E.} and Vezie, {Michael L.} and Wood, {Kent S.}",
year = "2018",
month = "8",
day = "10",
doi = "10.3847/1538-4357/aace60",
language = "English (US)",
volume = "863",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - NICER and Fermi GBM Observations of the First Galactic Ultraluminous X-Ray Pulsar Swift J0243.6+6124

AU - Wilson-Hodge, Colleen A.

AU - Malacaria, Christian

AU - Jenke, Peter A.

AU - Jaisawal, Gaurava K.

AU - Kerr, Matthew

AU - Wolff, Michael T.

AU - Arzoumanian, Zaven

AU - Chakrabarty, Deepto

AU - Doty, John P.

AU - Gendreau, Keith C.

AU - Guillot, Sebastien

AU - Ho, Wynn C.G.

AU - Lamarr, Beverly

AU - Markwardt, Craig B.

AU - Ozel, Feryal

AU - Prigozhin, Gregory Y.

AU - Ray, Paul S.

AU - Ramos-Lerate, Mercedes

AU - Remillard, Ronald A.

AU - Strohmayer, Tod E.

AU - Vezie, Michael L.

AU - Wood, Kent S.

PY - 2018/8/10

Y1 - 2018/8/10

N2 - Swift J0243.6+6124 is a newly discovered Galactic Be/X-ray binary, revealed in late 2017 September in a giant outburst with a peak luminosity of 2 × 1039(d/7 kpc)2 erg s-1 (0.1-10 keV), with no formerly reported activity. At this luminosity, Swift J0243.6+6124 is the first known galactic ultraluminous X-ray pulsar. We describe Neutron star Interior Composition Explorer (NICER) and Fermi Gamma-ray Burst Monitor (GBM) timing and spectral analyses for this source. A new orbital ephemeris is obtained for the binary system using spin frequencies measured with GBM and 15-50 keV fluxes measured with the Neil Gehrels Swift Observatory Burst Alert Telescope to model the system's intrinsic spin-up. Power spectra measured with NICER show considerable evolution with luminosity, including a quasi-periodic oscillation near 50 mHz that is omnipresent at low luminosity and has an evolving central frequency. Pulse profiles measured over the combined 0.2-100 keV range show complex evolution that is both luminosity and energy dependent. Near the critical luminosity of L ∼ 1038 erg s-1, the pulse profiles transition from single peaked to double peaked, the pulsed fraction reaches a minimum in all energy bands, and the hardness ratios in both NICER and GBM show a turnover to softening as the intensity increases. This behavior repeats as the outburst rises and fades, indicating two distinct accretion regimes. These two regimes are suggestive of the accretion structure on the neutron star surface transitioning from a Coulomb collisional stopping mechanism at lower luminosities to a radiation-dominated stopping mechanism at higher luminosities. This is the highest observed (to date) value of the critical luminosity, suggesting a magnetic field of B ∼ 1013 G.

AB - Swift J0243.6+6124 is a newly discovered Galactic Be/X-ray binary, revealed in late 2017 September in a giant outburst with a peak luminosity of 2 × 1039(d/7 kpc)2 erg s-1 (0.1-10 keV), with no formerly reported activity. At this luminosity, Swift J0243.6+6124 is the first known galactic ultraluminous X-ray pulsar. We describe Neutron star Interior Composition Explorer (NICER) and Fermi Gamma-ray Burst Monitor (GBM) timing and spectral analyses for this source. A new orbital ephemeris is obtained for the binary system using spin frequencies measured with GBM and 15-50 keV fluxes measured with the Neil Gehrels Swift Observatory Burst Alert Telescope to model the system's intrinsic spin-up. Power spectra measured with NICER show considerable evolution with luminosity, including a quasi-periodic oscillation near 50 mHz that is omnipresent at low luminosity and has an evolving central frequency. Pulse profiles measured over the combined 0.2-100 keV range show complex evolution that is both luminosity and energy dependent. Near the critical luminosity of L ∼ 1038 erg s-1, the pulse profiles transition from single peaked to double peaked, the pulsed fraction reaches a minimum in all energy bands, and the hardness ratios in both NICER and GBM show a turnover to softening as the intensity increases. This behavior repeats as the outburst rises and fades, indicating two distinct accretion regimes. These two regimes are suggestive of the accretion structure on the neutron star surface transitioning from a Coulomb collisional stopping mechanism at lower luminosities to a radiation-dominated stopping mechanism at higher luminosities. This is the highest observed (to date) value of the critical luminosity, suggesting a magnetic field of B ∼ 1013 G.

KW - accretion, accretion disks

KW - pulsars: individual (SWIFT J0243.6+6124)

KW - X-rays: binaries

UR - http://www.scopus.com/inward/record.url?scp=85051562528&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85051562528&partnerID=8YFLogxK

U2 - 10.3847/1538-4357/aace60

DO - 10.3847/1538-4357/aace60

M3 - Article

AN - SCOPUS:85051562528

VL - 863

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 9

ER -