Hard X-ray imaging of the Galactic black hole candidate GX 339 - 4

Covault, C. E.; Grindlay, J. E.; Manandhar, R. P.

doi:10.1086/186331

Cited by 9 publications

(2 citation statements)

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“…Source-background rocking of the two clusters provides a direct measurement of the HEXTE background with measured long term systematic uncertainties of < 1% (Rothschild et al 1998). Although no other strong sources in the field around GX 339−4 are known (Covault, Grindlay & Manandhar 1992;Bouchet et al 1993;Trudolyubov et al 1998), we extracted individual background spectra for both HEXTE cluster background positions to check for contamination of the spectrum from weak background sources. In all cases the background spectra differed by ∼ < 1 cps.…”

Section: Rxte Data Extractionmentioning

confidence: 99%

Low‐Luminosity States of the Black Hole Candidate GX 339−4. I.ASCAand Simultaneous Radio/RXTEObservations

Wilms

Nowak

Dove

et al. 1999

ApJ

100

148

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We discuss a series of observations of the black hole candidate GX 339−4 in low luminosity, spectrally hard states. We present spectral analysis of three separate archival Advanced Satellite for Cosmology and Astrophysics (ASCA) data sets and eight separate Rossi X-ray Timing Explorer (RXTE) data sets. Three of the RXTE observations were strictly simultaneous with 843 MHz and 8.3-9.1 GHz radio observations. All of these observations have (3-9 keV) flux < ∼ 10 −9 ergs s −1 cm −2 . The ASCA data show evidence for an ≈ 6.4 keV Fe line with equivalent width ≈ 40 eV, as well as evidence for a soft excess that is well-modeled by a power law plus a multicolor blackbody spectrum with peak temperature ≈ 150-200 eV. The RXTE data sets also show evidence of an Fe line with equivalent widths ≈ 20-140 eV. Reflection models show a hardening of the RXTE spectra with decreasing X-ray flux; however, these models do not exhibit evidence of a correlation between the photon index of the incident power law flux and the solid angle subtended by the reflector. 'Sphere+disk' Comptonization models and Advection Dominated Accretion Flow (ADAF) models also provide reasonable descriptions of the RXTE data. The former models yield coronal temperatures in the range 20-50 keV and optical depths of τ ≈ 3. The model fits to the X-ray data, however, do not simultaneously explain the observed radio properties. The most likely source of the radio flux is synchrotron emission from an extended outflow of size greater than O(10 7 GM/c 2 ). Subject headings: accretion -black hole physics -Stars: binaries -X-rays: Stars A bpl : Power law normalization (photons keV −1 cm −2 s −1 at 1 keV). E l : line energy. A l : Line normalization (photons cm −2 s −1 in the line). EW: line equivalent width. Uncertainties are at the 90% confidence level for one interesting parameter (∆χ 2 = 2.71). FIG. 1.-GX 339−4 ASCA observation of 1994 August 24 with energy bins rebinned by a factor of 25 for clarity. Model and associated residuals (data/model) are for the best fit multicolor blackbody plus broken power law without a Gaussian line component. For clarity, only the SIS0 (circles) and GIS2 (triangles) data are shown.

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Section: Rxte Data Extractionmentioning

confidence: 99%

Low‐Luminosity States of the Black Hole Candidate GX 339−4. I.ASCAand Simultaneous Radio/RXTEObservations

Wilms

Nowak

Dove

et al. 1999

ApJ

100

148

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show abstract

“…Significant results include the hard X-ray detection of the Einstein source 1E1740.7-2942 with a possible second source, perhaps a transient source, about 40 arcmin West (EXS1737.9-2952) (Grindlay et al 1993), and the first imaging observation of the black hole candidate GX 339−4 at hard X-ray energies (see Fig. 11) (Covault et al 1992).…”

Section: -Exitementioning

confidence: 99%

Hard X-ray/Soft gamma-ray experiments and missions: overview and prospects

Cavallari,

Frontera

2017

Preprint

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Starting from 1960s, a great number of missions and experiments have been performed for the study of the high-energy sky. This review gives a wide vision of the most important space missions and balloon experiments that have operated in the 10-600 keV band, a crucial window for the study of the most energetic and violent phenomena in the Universe. Thus it is important to take the stock of the achievements to better establish what we have still to do with future missions in order to progress in this field, to establish which are the technologies required to solve the still open issues and to extend our knowledge of the Universe.

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Detector Development and Optimization for Space Based Astronomy from Satellites and Balloons

Sarkar

2018

Astrophysics and Space Science Proceedings

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Hard X-ray imaging of the Galactic black hole candidate GX 339 - 4

Cited by 9 publications

References 0 publications

Low‐Luminosity States of the Black Hole Candidate GX 339−4. I.ASCAand Simultaneous Radio/RXTEObservations

Low‐Luminosity States of the Black Hole Candidate GX 339−4. I.ASCAand Simultaneous Radio/RXTEObservations

Hard X-ray/Soft gamma-ray experiments and missions: overview and prospects

Detector Development and Optimization for Space Based Astronomy from Satellites and Balloons

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