Gamma-ray continuum emission from the inner Galactic region as observed with INTEGRAL/SPI

Strong, A. W.; Diehl, R.; Halloin, Hubert; Schönfelder, V.; Bouchet, L.; Mandrou, P.; Lebrun, F.; Terrier, R.

doi:10.1051/0004-6361:20053798

Cited by 117 publications

(112 citation statements)

References 39 publications

Supporting

Mentioning

101

Contrasting

Order By: Relevance

“…15). It should be noted that the observed cutoff in the GRXE spectrum above 60 keV does not agree with the unresolved hard X-ray excess reported by Strong et al (2005) and Bouchet et al (2005) in the SPI data. The reason for this discrepancy is not yet understood.…”

Section: Spectrumcontrasting

confidence: 67%

“…Lebrun et al (2004) and Terrier et al (2004) using IBIS telescope (Ubertini et al 2003) have shown that although bright point sources dominate the emission from the Galaxy at 30 keV, there is a significant unresolved component. Bouchet et al (2005) and Strong et al (2005) using SPI spectrometer (Vedrenne et al 2003) found an unresolved Galactic X-ray emission at energies higher than 50 keV.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hard X-ray emission from the Galactic ridge

Krivonos

Revnivtsev

Churazov

et al. 2006

A&A

120

144

View full text Add to dashboard Cite

We present results of a study of the Galactic ridge X-ray emission (GRXE) in hard X-rays performed with the IBIS telescope aboard INTEGRAL. The imaging capabilities of this coding aperture telescope make it possible to account for the flux from bright Galactic point sources whereas the wide field of view permits us to collect large flux from the underlying GRXE. Extensive study of the IBIS/ISGRI detector background allowed us to construct a model that predicts the detector count rate with ∼1−2% accuracy in the energy band 17-60 keV. The derived longitude and latitude profiles of the ridge emission are in good agreement with the Galactic distribution of stars obtained from infrared observations. This, along with the measured hard X-ray spectrum of the Galactic ridge emission strongly indicates its stellar origin. The derived unit stellar mass emissivity of the ridge in the energy band 17-60 keV, (0.9−1.2) × 10 27 erg s −1 M −1 (assuming a bulge mass of 1−1.3 × 10 10 M ), agrees with that of local (in the Solar neigborhood) accreting magnetic white dwarf binaries -dominant contributors to the GRXE at these energies. In addition, the shape of the obtained GRXE spectrum can be used to determine the average mass of white dwarfs in such systems in the Galaxy as ∼0.5 M . The total hard X-ray luminosity of the GRXE is L 17−60 keV = (3.7 ± 0.2) × 10 37 erg s −1 in the 17-60 keV band. At energies 70-200 keV no additional contribution to the total emission of the Galaxy apart from the detected point sources is seen.

show abstract

Section: Spectrumcontrasting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Hard X-ray emission from the Galactic ridge

Krivonos

Revnivtsev

Churazov

et al. 2006

A&A

120

144

View full text Add to dashboard Cite

show abstract

“…The 20-100 keV LC of V404 as well as the other sources in the field were obtained in bins of 400 s. Background models were built based on the pre-flaring data of a representative empty sky region, adjusting the normalization coefficient per hour (see, e.g., Strong et al 2005, for a more general description of the method).…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Correlated optical, X-ray, andγ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni

Rodríguez

Bel

Alfonso-Garzón

et al. 2015

A&A

Self Cite

103

View full text Add to dashboard Cite

After 25 years of quiescence, the microquasar V404 Cyg entered a new period of activity in June 2015. This X-ray source is known to undergo extremely bright and variable outbursts seen at all wavelengths. It is therefore an object of prime interest to understand the accretion-ejection connections. These can, however, only be probed through simultaneous observations at several wavelengths. We made use of the INTEGRAL instruments to obtain long, almost uninterrupted observations from 2015 June 20, 15:50 UTC to June 25, 4:05 UTC, from the optical V band up to the soft γ-rays. V404 Cyg was extremely variable in all bands, with the detection of 18 flares with fluxes exceeding 6 Crab (20-40 keV) within three days. The flare recurrence can be as short as ∼20 min from peak to peak. A model-independent analysis shows that the >6 Crab flares have a hard spectrum. A simple 10-400 keV spectral analysis of the off-flare and flare periods shows that the variation in intensity is likely to be only due to variations of a cut-off power-law component. The optical flares seem to be at least of two different types: one occurring in simultaneity with the X-ray flares, the other showing a delay greater than 10 min. The former could be associated with X-ray reprocessing by either an accretion disk or the companion star. We suggest that the latter are associated with plasma ejections that have also been seen in radio.

show abstract

“…This electron spectrum and distribution were chosen to approximately yield the observed synchrotron Haze. For comparison, we also show the measurements of the diffuse gamma ray spectrum from this region, as measured by EGRET [12]. Shown as dotted lines is the much smaller and negligible contribution from Bremsstrahlung radiation.…”

Section: Gamma Rays Synchrotron and Inverse Compton Photons Frommentioning

confidence: 99%

Prospects for detecting dark matter with GLAST in light of the WMAP haze

2008

View full text Add to dashboard Cite

Observations by the WMAP experiment have identified an excess of microwave emission from the center of the Milky Way. It has previously been shown that this "WMAP Haze" could be synchrotron emission from relativistic electrons and positrons produced in the annihilations of dark matter particles. In particular, the intensity, spectrum and angular distribution of the WMAP Haze is consistent with an electroweak scale dark matter particle (such as a supersymmetric neutralino or Kaluza-Klein dark matter in models with universal extra dimensions) annihilating with a cross section on the order of σv ∼ 3 × 10 −26 cm 3 /s and distributed with a cusped halo profile. No further exotic astrophysical or annihilation boost factors are required. If dark matter annihilations are in fact responsible for the observed Haze, then other annihilation products will also be produced, including gamma rays. In this article, we study the prospects for the GLAST satellite to detect gamma rays from dark matter annihilations in the Galactic Center region in this scenario. We find that by studying only the inner 0.1• around the Galactic Center, GLAST will be able to detect dark matter annihilating to heavy quarks or gauge bosons over astrophysical backgrounds with 5σ (3σ) significance if they are lighter than approximately 320-500 GeV (500-750 GeV). If the angular window is broadened to study the dark matter halo profile's angular extension (while simultaneously reducing the astrophysical backgrounds), WIMPs as heavy as several TeV can be identified by GLAST with high significance. Only if the dark matter particles annihilate mostly to electrons or muons will GLAST be unable to identify the gamma ray spectrum associated with the WMAP Haze.

show abstract

Gamma-ray continuum emission from the inner Galactic region as observed with INTEGRAL/SPI

Cited by 117 publications

References 39 publications

Hard X-ray emission from the Galactic ridge

Hard X-ray emission from the Galactic ridge

Correlated optical, X-ray, andγ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni

Prospects for detecting dark matter with GLAST in light of the WMAP haze

Contact Info

Product

Resources

About