X-RAY BURSTS FROM THE TERZAN 5 TRANSIENT IGR J17480-2446: NUCLEAR RATHER THAN GRAVITATIONAL

Journal Article · Fri Apr 01 04:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/730/2/L23· OSTI ID:21560418

Bhattacharyya, Sudip ^[1]

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1. Tata Institute of Fundamental Research, Mumbai-400005 (India)

The 2010 outburst of the transient neutron star low-mass X-ray binary IGR J17480-2446 has exhibited a series of unique X-ray bursts as well as millihertz (mHz) quasi-periodic oscillations (QPOs) related to these bursts. It has been recently proposed that these are type-II bursts, powered by the gravitational energy. This implies that the current nuclear-burning-based model of mHz QPOs is not correct, and this timing feature cannot be used as a tool to measure the neutron star parameters. We report the analysis of the Rossi X-Ray Timing Explorer data of IGR J17480-2446 to show that the burst properties of this source are quite different from the properties of the type-II bursts observed from the rapid burster and GRO J1744-28. For example, the inferred ratio ({approx}50-90) of the non-burst fluence to burst fluence is consistent with the thermonuclear origin of IGR J17480-2446 bursts and is significantly different from this ratio ({approx}<4) for type-II bursts. Our results suggest that the bursts and the mHz QPOs from IGR J17480-2446 are powered by the nuclear energy.

• OSTI ID: 21560418
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 730; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCRETION DISKS
BINARY STARS
COSMIC RADIATION
COSMIC RAY SOURCES
COSMIC X-RAY BURSTS
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
NEUTRON STARS
PRIMARY COSMIC RADIATION
RADIATIONS
STARS
X RADIATION