Fermi-LAT Observation of Quiescent Solar Emission
نویسنده
چکیده
The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray Space Telescope is a pair-conversion detector designed to study the gamma-ray sky in the energy range 30 MeV to 300 GeV. Fermi has detected high-energy gamma rays from the quiet Sun produced by interactions of cosmic-ray nucleons with the solar surface, and cosmic-ray electrons with solar photons in the heliosphere. While the Sun was detected by EGRET on CGRO with low statistics, Fermi provides highquality detections on a daily basis allowing variability to be addressed. Such observations will provide a probe of the extreme conditions near the solar surface and a monitor the modulation of cosmic rays over the inner heliosphere. We discuss the study of the quiescent solar emission including spectral analysis of its two components, disk and inverse Compton.
منابع مشابه
Fermi Observations of GRB 090902 B : A Distinct Spectral Component in the Prompt and Delayed Emission
We report on the observation of the bright, long gamma-ray burst, GRB 090902B, by the Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) instruments on-board the Fermi observatory. This was one of the brightest GRBs to have been observed by the LAT, which detected several hundred photons during the prompt phase. With a redshift of z = 1.822, this burst is among the most luminous detec...
متن کاملGamma-ray Burst Theory in the Fermi Era
The Large Area Telescope (LAT) on-board the Fermi satellite detected emission above 20 MeV only in a small fraction of the long gamma-ray bursts (GRBs) detected by the Fermi Gamma-ray Burst Monitor (GBM) at 8 keV-40 MeV. Those bursts that were detected by the LAT were among the brightest GBM bursts. The emission detected by LAT seerms to be delayed respect to the one detected by the GBM. In thi...
متن کاملFermi observations of Cassiopeia and Cepheus: gamma-ray diffuse emission in the outer Galaxy
We have used measurements by the Fermi Large Area Telescope (LAT) to study the interstellar gamma-ray emission in a region of the second Galactic quadrant, at 100◦ < l < 145◦ and −15◦ < b < 30. This region encompasses the prominent Gould-Belt clouds of Cassiopeia, Cepheus, and the Polaris flare, as well as large atomic and molecular complexes at larger distances in several spiral arms. The good...
متن کاملDiffuse Cosmic Rays Shining in the Galactic Center: A Novel Interpretation of H.E.S.S. and Fermi-LAT γ-Ray Data.
We present a novel interpretation of the γ-ray diffuse emission measured by Fermi-LAT and H.E.S.S. in the Galactic center (GC) region and the Galactic ridge (GR). In the first part we perform a data-driven analysis based on PASS8 Fermi-LAT data: We extend down to a few GeV the spectra measured by H.E.S.S. and infer the primary cosmic-ray (CR) radial distribution between 0.1 and 3 TeV. In the se...
متن کاملInverse Compton gamma - rays from Markarian 421 - A study of GeV and TeV emission from Mrk 421 based on Fermi - LAT and H . E . S . S . data
This thesis summarizes a senior project on the Active Galactic Nucleus (AGN) Markarian 421 (Mrk 421). An AGN is thought to be the site of acceleration where gamma-rays are generated in energy jets at kpc-Mpc scales. From this mechanism, an intense flux of GeV and TeV photons is created by means of non-thermal processes, e.g. synchrotron radiation and inverse Compton. Mrk 421 is one of the most ...
متن کامل