[Les galaxies à flambées d'étoiles détectées par les télescopes γ]
Les galaxies à flambées d'étoiles se caractérisent par un taux de formation d'étoiles beaucoup plus élevé que ceux des galaxies ordinaires. Les vents stellaires supersoniques et les explosions de supernovæ qui s'y produisent injectent dans le milieu interstellaire une énergie cinétique considérable. De plus, alors que les vestiges de supernovæ sont considérés comme les sources principales de rayons cosmiques, ces derniers augmentent de manière significative la pression et la densité d'énergie du milieu, au point d'influencer fortement le processus de formation d'étoiles. L'observation de galaxies à flambées d'étoiles en astronomie gamma est un moyen unique pour étudier les phénomènes non thermiques dus à des protons et noyaux cosmiques, et leur rôle dans le processus de formation d'étoiles. Cet article passe en revue les observations récentes de galaxies à flambées d'étoiles avec des télescopes à rayons gamma dans l'espace et à partir du sol. Il discute aussi les interprétations théoriques actuelles de l'émission gamma observée. Enfin, un accent particulier est mis sur l'impact des télescopes à effet Tcherenkov atmosphérique de la prochaine génération sur l'étude des galaxies à flambée d'étoiles en particulier et, plus généralement, sur la formation d'étoiles dans les galaxies.
Starburst galaxies have a highly increased star-formation rate compared to regular galaxies and inject huge amounts of kinetic power into the interstellar medium via supersonic stellar winds, and supernova explosions. Supernova remnants, which are considered to be the main source of cosmic rays (CRs), form an additional, significant energy and pressure component and might influence the star-formation process in a major way. Observations of starburst galaxies at γ-ray energies give us the unique opportunity to study non-thermal phenomena associated with hadronic CRs and their relation to the star-formation process. In this work, recent observations of starburst galaxies with space and ground-based γ-ray telescopes are being reviewed, and the current state of theoretical work on the γ-ray emission is discussed. A special emphasis is put on the prospects of the next-generation Cherenkov Telescope Array for the study of starburst galaxies in particular and star-forming galaxies in general.
Mot clés : Rayons cosmiques, Rayons gamma, Amas d'étoiles, Galaxies à flambée d'étoiles, Galaxies infrarouges ultralumineuses
@article{CRPHYS_2016__17_6_585_0,
author = {Stefan Ohm},
title = {Starburst galaxies as seen by gamma-ray telescopes},
journal = {Comptes Rendus. Physique},
pages = {585--593},
publisher = {Elsevier},
volume = {17},
number = {6},
year = {2016},
doi = {10.1016/j.crhy.2016.04.003},
language = {en},
}
Stefan Ohm. Starburst galaxies as seen by gamma-ray telescopes. Comptes Rendus. Physique, Volume 17 (2016) no. 6, pp. 585-593. doi : 10.1016/j.crhy.2016.04.003. https://comptes-rendus.academie-sciences.fr/physique/articles/10.1016/j.crhy.2016.04.003/
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