Sigma/GRANAT soft gamma-ray observations of the X-ray nova in Musca - Discovery of positron annihilation emission line

Goldwurm, A.; Ballet, J.; Cordier, B.; Paul, Jacques; Bouchet, L.; Roques, J. P.; Barret, D.; Mandrou, P.; Sunyaev, R.; Churazov, E.; Gilfanov, M.; Dyachkov, A.; Khavenson, N.; Kovtunenko, V. M.; Kremnev, R. S.; Sukhanov, K. G.

doi:10.1086/186353

Cited by 70 publications

(37 citation statements)

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“…However, such a component was detected later in the outburst on 2003 May 28 by the PCA (Homan et al 2003) and may have been seen during the [1977][1978] Letter to the Editor outburst by HEAO 1 (R. Doxsey 1980, private communication in Cooke et al 1984, but no published spectrum can be found. A more detailed analysis of the INTEGRAL data will allow a sensitive search for this component, the signature of reflection, and for the 511 keV annihilation feature observed from the black hole candidates 1E 1740.7−2942 (Bouchet et al 1991) and GRS 1124−684 (Goldwurm et al 1992).…”

Section: Discussionmentioning

confidence: 99%

INTEGRAL observations of the black hole candidate H 1743-322 in outburst

Parmar

Kuulkers

Oosterbroek

et al. 2003

A&A

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Section: Discussionmentioning

confidence: 99%

INTEGRAL observations of the black hole candidate H 1743-322 in outburst

Parmar

Kuulkers

Oosterbroek

et al. 2003

A&A

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“…However, this event takes place in a short interval of time (minutes to hours). It is possible that the transient annihilation line detected from GS 1124-68, which was seen only over an interval of ∼12 hours, was indeed associated to such a transition, since the observation took place well within the Very-High State of the source, corresponding to HIMS/SIMS [35]. However, no evidence for such a spectral feature was found in the INTEGRAL data of the 2004 transition of GX 339-4.…”

Section: Energy Spectramentioning

confidence: 95%

States and Transitions in Black Hole Binaries

Belloni

2009

Lecture Notes in Physics

317

217

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Summary. With the availability of the large database of black-hole transients from the Rossi X-Ray Timing Explorer, the observed phenomenology has become very complex. The original classification of the properties of these systems in a series of static states sorted by mass accretion rate proved not to be able to encompass the new picture. I outline here a summary of the current situation and show that a coherent picture emerges when simple properties such as X-ray spectral hardness and fractional variability are considered. In particular, fast transition in the properties of the fast time variability appear to be crucial to describe the evolution of black-hole transients. Based on this picture, I present a state-classification which takes into account the observed transitions. I show that, in addition to transients systems, other black-hole binaries and Active Galactic Nuclei can be interpreted within this framework. The association between these states and the physics of the accretion flow around black holes will be possible only through modeling of the full time evolution of galactic transient systems.

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“…Bouchet et al 1991;Goldwurm et al 1992) were apparently associated with a hard X-ray source, 1E1740.7-2942, near the centre of the galaxy, that was consequently termed the "Great Annihilator". Neither contemporaneous (Jung et al 1995;Smith et al 1996b) nor long-term monitoring of the source (Sunyaev et al 1991;Harris et al 1994;Smith et al 1996a;Cheng et al 1998) provided confirmation of such activity.…”

Section: Introductionmentioning

confidence: 99%

Gamma-ray spectroscopy of positron annihilation in the Milky Way

Siegert

Diehl

Khachatryan

et al. 2016

A&A

148

246

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Context. The annihilation of positrons in the Galaxy's interstellar medium produces characteristic gamma-rays with a line at 511 keV. This gamma-ray emission has been observed with the spectrometer SPI on ESA's INTEGRAL observatory, confirming a puzzling morphology with bright emission from an extended bulge-like region, while emission from the disk is faint. Most known or plausible sources of positrons are, however, believed to be distributed throughout the disk of the Milky Way. Aims. We aim to constrain characteristic spectral shapes for different spatial components in the disk and bulge using data with an exposure that has doubled since earlier reports. Methods. We exploit high-resolution gamma-ray spectroscopy with SPI on INTEGRAL based on a new instrumental background method and detailed multi-component sky model fitting. Results. We confirm the detection of the main extended components of characteristic annihilation gamma-ray signatures, altogether at 58σ significance in the 511 keV line. The total Galactic 511 keV line intensity amounts to (2.74 ± 0.25) × 10 −3 ph cm −2 s −1 for our assumed model of the spatial distribution. We derive spectra for the bulge and disk, and a central source modelled as pointlike and at the position of Sgr A*, and discuss spectral differences. The bulge (56σ) shows a 511 keV line intensity of (0.96 ± 0.07) × 10 −3 ph cm −2 s −1 together with ortho-positronium continuum equivalent to a positronium fraction of (1.080 ± 0.029). The twodimensional Gaussian that represents the disk emission (12σ) has an extent of 60 +10 −5 degrees in longitude and a rather large latitudinal extent of 10.5 +2.5 −1.5 degrees; the line intensity is (1.66 ± 0.35)×10 −3 ph cm −2 s −1 with a marginal detection of the annihilation continuum and an overall diffuse Galactic continuum of (5.85 ± 1.05) × 10 −5 ph cm −2 s −1 keV −1 at 511 keV. The disk shows no flux asymmetry between positive and negative longitudes, although spectral details differ. The flux ratio between bulge and disk is (0.58 ± 0.13). The central source (5σ) has an intensity of (0.80 ± 0.19) × 10 −4 ph cm −2 s −1 .

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Sigma/GRANAT soft gamma-ray observations of the X-ray nova in Musca - Discovery of positron annihilation emission line

Cited by 70 publications

References 0 publications

INTEGRAL observations of the black hole candidate H 1743-322 in outburst

INTEGRAL observations of the black hole candidate H 1743-322 in outburst

States and Transitions in Black Hole Binaries

Gamma-ray spectroscopy of positron annihilation in the Milky Way

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