IMPLICATIONS OF BURST OSCILLATIONS FROM THE SLOWLY ROTATING ACCRETING PULSAR IGR J17480-2446 IN THE GLOBULAR CLUSTER TERZAN 5

Journal Article · Mon Oct 10 00:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/740/1/L8· OSTI ID:21565406

Cavecchi, Y; Patruno, A; Haskell, B; Watts, A L; Altamirano, D; Wijnands, R; Van der Klis, M ^[1]; Levin, Y ^[2]; Linares, M ^[3]

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1. Astronomical Institute 'Anton Pannekoek', University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands)
2. Sterrewacht Leiden, University of Leiden, Niels Bohrweg 2, NL-2333 CA Leiden (Netherlands)
3. MIT Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States)

The recently discovered accreting X-ray pulsar IGR J17480-2446 spins at a frequency of {approx}11 Hz. We show that Type I X-ray bursts from this source display oscillations at the same frequency as the stellar spin. IGR J17480-2446 is the first secure case of a slowly rotating neutron star (NS) which shows Type I burst oscillations (BOs), all other sources featuring such oscillations spin at hundreds of Hertz. This means that we can test BO models in a completely different regime. We explore the origin of Type I BOs in IGR J17480-2446 and conclude that they are not caused by global modes in the NS ocean. We also show that the Coriolis force is not able to confine an oscillation-producing hot spot on the stellar surface. The most likely scenario is that the BOs are produced by a hot spot confined by hydromagnetic stresses.

• OSTI ID: 21565406
• Journal Information: Astrophysical Journal Letters, Vol. 740, Issue 1; Other Information: DOI: 10.1088/2041-8205/740/1/L8; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COSMIC X-RAY BURSTS
NEUTRON STARS
OSCILLATIONS
PULSARS
SPIN
X RADIATION
ANGULAR MOMENTUM
COSMIC RADIATION
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
PARTICLE PROPERTIES
PRIMARY COSMIC RADIATION
RADIATIONS
STARS