NuSTAR detection of a cyclotron line in the supergiant fast X-ray transient IGR J17544-2619

Varun Bhalerao, Patrizia Romano, John Tomsick, Lorenzo Natalucci, David M. Smith, Eric Bellm, Steven E. Boggs, Deepto Chakrabarty, Finn Erland Christensen, William W. Craig, Felix Fuerst

Research output: Contribution to journalJournal articleResearchpeer-review

400 Downloads (Pure)

Abstract

We present NuSTAR spectral and timing studies of the supergiant fast X-ray transient (SFXT) IGR J17544-2619. The spectrum is well described by an  ∼ 1 keV blackbody and a hard continuum component, as expected from an accreting X-ray pulsar. We detect a cyclotron line at 17 keV, confirming that the compact object in IGR J17544-2619 is indeed a neutron star. This is the first measurement of the magnetic field in an SFXT. The inferred magnetic field strength, B = (1.45 +/- 0.03) x 1012 G (1 + z) is typical of neutron stars in X-ray binaries, and rules out a magnetar nature for the compact object. We do not find any significant pulsations in the source on time-scales of 1-2000 s.
Original languageEnglish
JournalMonthly Notices of the Royal Astronomical Society
Volume447
Issue number3
Pages (from-to)2274-2281
ISSN0035-8711
DOIs
Publication statusPublished - 2015

Keywords

  • X-rays: binaries
  • X-rays: individual: IGR J17544-2619

Cite this

Bhalerao, V., Romano, P., Tomsick, J., Natalucci, L., Smith, D. M., Bellm, E., Boggs, S. E., Chakrabarty, D., Christensen, F. E., Craig, W. W., & Fuerst, F. (2015). NuSTAR detection of a cyclotron line in the supergiant fast X-ray transient IGR J17544-2619. Monthly Notices of the Royal Astronomical Society, 447(3), 2274-2281. https://doi.org/10.1093/mnras/stu2495