Beitrag in einer Fachzeitschrift

Details zur Publikation

Autorinnen und Autoren: Furst F, Grinberg V, Tomsick JA, Bachetti M, Boggs SE, Brightman M, Christensen FE, Craig WW, Gandhi P, Grefenstette B, Hailey CJ, Harrison FA, Madsen KK, Parker ML, Pottschmidt K, Stern D, Walton DJ, Wilms J, Zhang WW
Zeitschrift: Astrophysical Journal
Verlag: Institute of Physics Publishing
Jahr der Veröffentlichung: 2016
Band: 828
Heftnummer: 1
ISSN: 0004-637X
eISSN: 1538-4357


We present an analysis of Nuclear Spectroscopic Telescope Array observations of a hard intermediate state of the transient black hole GX 339-4 taken in 2015 January. With the source softening significantly over the course of the 1.3 day long observation we split the data into 21 sub-sets and find that the spectrum of all of them can be well described by a power-law continuum with an additional relativistically blurred reflection component. The photon index increases from ∼1.69 to ∼1.77 over the course of the observation. The accretion disk is truncated at around nine gravitational radii in all spectra. We also perform timing analysis on the same 21 individual data sets, and find a strong type-C quasi-periodic oscillation (QPO), which increases in frequency from ∼0.68 to ∼1.05 Hz with time. The frequency change is well correlated with the softening of the spectrum. We discuss possible scenarios for the production of the QPO and calculate predicted inner radii in the relativistic precession model as well as the global disk mode oscillations model. We find discrepancies with respect to the observed values in both models unless we allow for a black hole mass of ∼100 , which is highly unlikely. We discuss possible systematic uncertainties, in particular with the measurement of the inner accretion disk radius in the relativistic reflection model. We conclude that the combination of observed QPO frequencies and inner accretion disk radii, as obtained from spectral fitting, is difficult to reconcile with current models.

FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Wilms, Jörn Prof. Dr.
Professur für Astronomie und Astrophysik

Einrichtungen weiterer Autorinnen und Autoren

California Institute of Technology (Caltech)
Columbia University
Massachusetts Institute of Technology (MIT)
National Aeronautics and Space Administration (NASA)
National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF)
Technical University of Denmark / Danmarks Tekniske Universitet (DTU)
University of California, Berkeley
University of Cambridge
University of Maryland, Baltimore County
University of Southampton


Furst, F., Grinberg, V., Tomsick, J.A., Bachetti, M., Boggs, S.E., Brightman, M.,... Zhang, W.W. (2016). SPECTRO-TIMING STUDY of GX 339-4 in A HARD INTERMEDIATE STATE. Astrophysical Journal, 828(1). https://dx.doi.org/10.3847/0004-637X/828/1/34

Furst, F., et al. "SPECTRO-TIMING STUDY of GX 339-4 in A HARD INTERMEDIATE STATE." Astrophysical Journal 828.1 (2016).


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