StellarICS: Inverse Compton Emission from the Quiet Sun and Stars from keV to TeV

Abstract

The study of the quiet Sun in gamma rays started over a decade ago, and rapidly gained a wide interest. Gamma rays from the quiet Sun are produced by Cosmic Rays (CRs) interacting with its surface (disk component) and with its photon field (spatially extended inverse-Compton component, IC). The latter component is maximum close to the Sun and it is above the background even at large angular distances, extending over the whole sky. First detected with EGRET, it is studied now with Fermi-LAT with high statistical significance. Observations of the IC component allow us to obtain information on CR electrons and positrons close to the Sun and in the heliosphere for the various periods of solar activity and polarity. They allow to learn about CR interactions and propagation close to stars, in the heliosphere and on the solar surface, and to understand the Sun itself, its environment, and its activity. Analyses of solar observations are usually model-driven. Hence advances in model calculations and constraints from precise CR measurements are timely and needed. Here we present our StellarICS code to compute the gamma-ray IC emission from the Sun and also from single stars. The code is publicly available and it is extensively used by the scientific community to analyze Fermi-LAT data. It has been used by the Fermi-LAT collaboration to produce the solar models released with the FSSC Fermi Tools. Our modeling provides the basis for analyzing and interpreting high-energy data of the Sun and of stars. After presenting examples of updated solar IC models in the Fermi-LAT energy range that account for the various CR measurements, we extend the models to keV, MeV, and TeV energies for predictions for future possible telescopes such as AMEGO, GECCO, e-ASTROGAM, HAWC, LHAASO, SWGO, and present X-ray telescopes. We also present predictions for some of the closest and most luminous stars.

Updated to reflect the published version. 17 pages, 9 figures

References in corpus (14)

• Observation of an anomalous positron abundance in the cosmic radiation
• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons
• Detection of large-scale X-ray bubbles in the Milky Way halo
• Fermi-LAT Observations of Two Gamma-Ray Emission Components from the Quiescent Sun
• TeV gamma-rays and the largest masses and annihilation cross sections of neutralino dark matter
• Gamma-ray emission from the solar halo and disk: a study with EGRET data
• Gamma-rays from halos around stars and the Sun
• Neutrinos and gamma rays from long-lived mediator decays in the Sun
• Search for dark matter signatures in the gamma-ray emission towards the Sun with the Fermi Large Area Telescope
• Cosmic-ray interactions with the Sun using the FLUKA code
• Cosmic-ray propagation around the Sun: investigating the influence of the solar magnetic field on the cosmic-ray Sun shadow
• Search for gamma-ray emission from the Sun during solar minimum with the ARGO-YBJ experiment
• Connecting direct and indirect detection with a dark spike in the cosmic-ray electron spectrum

Cited by in corpus (15)

• Simulating the Galactic Multi-messenger Emissions with HERMES
• The TeV Sun Rises: Discovery of Gamma rays from the Quiescent Sun with HAWC
• Galactic Cosmic-Ray Propagation in the Inner Heliosphere: Improved Force-Field Model
• A New Component from the Quiet Sun: Synchrotron Radiation from Galactic Cosmic-Ray Electrons
• Small-Scale Magnetic Fields are Critical to Shaping Solar Gamma-Ray Emission
• Yet Another Sunshine Mystery: Unexpected Asymmetry in GeV Emission from the Solar Disk
• Transport of Cosmic ray electrons from 1 AU to the Sun
• Role of magnetic arcades in explaining the puzzle of the gamma-ray emission from the solar disk
• Long-Lived Particles and the Quiet Sun
• High energy radiation from luminous and magnetized stars
• Anisotropic Photon and Electron Scattering without Ultrarelativistic Approximation
• Puzzling Variation of Gamma Rays from the Sun over the Solar Cycle Revealed with Fermi-LAT
• First Observations of Solar Halo Gamma Rays Over a Full Solar Cycle
• Solar gamma ray probe of local cosmic ray electrons
• A 3D Monte Carlo calculation of the inverse Compton emission from the Sun and stars in presence of magnetic and electric fields