Inverse Compton Origin of the Hard X-Ray and Soft Gamma-Ray Emission from the Galactic Ridge

By Troy A. Porter, Igor V. Moskalenko, A. Strong, E. Orlando, L. Bouchet. 2008

214 citations recorded by the source corpus.

A recent redetermination of the nonthermal component of the hard X-ray to soft γ-ray emission from the Galactic ridge, using the SPI instrument on the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), is shown to be well reproduced as inverse Compton emission from the interstellar medium. Both cosmic-ray primary electrons and secondary electrons and positrons contribute to the emission. The prediction uses the GALPROP model and includes a new calculation of the interstellar radiation field. This may solve a long-standing mystery of the origin of this emission, and potentially opens a new window on Galactic cosmic rays.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/e7b2865b2da62588605d98d828448d21718542ea

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

Galactic electrons and positrons at the Earth: new estimate of the primary and secondary fluxes (2010, methodology): “2, we report the ISRF data that we extracted from the analysis of Porter et al. (2008), and averaged in cylinders of radius and half-height of 500 pc (model 2, M2) and 2 kpc (model 1, M1) about the Earth, on top of which we show that a sum of black-body distributions can provide a reasonable fit.”
FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE SUPERNOVA REMNANT W28 (G6.4−0.1) (2010, methodology): “The infrared and optical components are taken from the interstellar radiation field at the location of W28 in the GALPROP code (Porter et al. 2008).”
Galactic secondary positron flux at the Earth (2008, result): “The positron flux, by itself, does not exhibit unusual features and is in basic agreement with the results of Moskalenko & Strong (1998) and Porter et al. (2008).”
Background model systematics for the Fermi GeV excess (2014, background): “[110] for a description on how it is constructed).”
DEVELOPMENT OF THE MODEL OF GALACTIC INTERSTELLAR EMISSION FOR STANDARD POINT-SOURCE ANALYSIS OF FERMI LARGE AREA TELESCOPE DATA (2016, methodology): “We have decomposed the total SEDs into contributions originating from the interstellar gas (atomic, molecular, and DNM), from an axisymmetric Galactic ISRF for the IC radiation, and from the EEE.”
FERMI LAT DISCOVERY OF EXTENDED GAMMA-RAY EMISSION IN THE DIRECTION OF SUPERNOVA REMNANT W51C (2009, methodology): “The infrared and optical components are adjusted to reproduce the interstellar radiation ﬁeld in the GALPROP code (Porter et al. 2008).”
FERMI/LARGE AREA TELESCOPE BRIGHT GAMMA-RAY SOURCE LIST (2009, methodology): “For this work, the GALPROP package has been updated to include recent H I and CO surveys, more accurate decomposition into Galactocentric rings, as well as a new calculation of the interstellar radiation field for inverse Compton emission (Porter et al. 2008).”
The Fermi Galactic Center GeV Excess and Implications for Dark Matter (2017, methodology): “…we will model Galactic interstellar emission from the large-scale CR populations in the Galaxy starting from predictions obtained through the GALPROP code71 (Moskalenko & Strong 1998; Strong et al. 2000, 2004; Ptuskin et al. 2006; Strong et al. 2007; Porter et al. 2008; Vladimirov et al. 2011).”
THE SPECTRUM OF ISOTROPIC DIFFUSE GAMMA-RAY EMISSION BETWEEN 100 MeV AND 820 GeV (2014, methodology): “We use the ISRF model introduced in Porter et al. (2008), which is available within GALPROP.”
FERMI-LAT OBSERVATIONS OF HIGH-ENERGY γ-RAY EMISSION TOWARD THE GALACTIC CENTER (2015, methodology): “Another possible explanation is a higher intensity for the radiation field energy density in the inner Galaxy than used in the standard ISRF model of Porter et al. (2008); these possibilities are not tested here because they require detailed investigations that are beyond the scope of the current…”
Dark Matter Searches with Astroparticle Data (2011, methodology): “The IC templates are obtained from runs of the GALPROP code (http://galprop.stanford.edu) using a model for the ISRF that has uncertainties, particularly in the inner Galaxy, that have not been completely quantified (Porter & Strong, 2005; Porter et al., 2008).”
Galactic synchrotron emission with cosmic ray propagation models (2013, methodology): “Gas maps and ISRF are provided and updated to the most recent observations (Porter et al. 2008; Ackermann et al. 2012).”
The interstellar cosmic-ray electron spectrum from synchrotron radiation and direct measurements. (2011, methodology): “A description of the GALPROP3 model can be found in Strong et al. (2007) and references therein; in particular see Strong & Moskalenko (1998), Strong et al. (2004a) and Porter et al. (2008), and the GALPROP Explanatory Supplement available from the GALPROP website.”
THE FIRST FERMI LAT SUPERNOVA REMNANT CATALOG (2015, methodology): “The IC map is obtained using GALPROP to reproduce the direct CR measurements with a realistic model of the Galactic interstellar radiation field (ISRF), as was done in Porter et al. (2008).”
THE LARGE AREA TELESCOPE ON THE FERMI GAMMA-RAY SPACE TELESCOPE MISSION (2009, background): “…EGRET data have concluded that the EGRET sensitivity above 1 GeV has been overestimated (Stecker et al. 2008) or underestimated (Baughman et al. 2007) or imply different cosmic-ray energy spectra in other parts of the Galaxy compared to the local values (Strong et al. 2004a; Porter et al. 2008).”
CONSTRAINTS ON COSMIC-RAY PROPAGATION MODELS FROM A GLOBAL BAYESIAN ANALYSIS (2010, methodology): “The γ-rays are calculated using the propagated CR distributions, including a contribution from secondary particles such as positrons and electrons from inelastic processes in the ISM that increases the γ-ray flux at MeV energies (Strong et al. 2004; Porter et al. 2008).”