Gamma Rays from Fast Black-hole Winds
: Ajello M, Baldini L, Ballet J, Barbiellini G, Bastieri D, Bellazzini R, Berretta A, Bissaldi E, Blandford RD, Bloom ED, Bonino R, Bruel P, Buson S, Cameron RA, Caprioli D, Caputo R, Cavazzuti E, Chartas G, Chen S, Cheung CC, Chiaro G, Costantin D, Cutini S, D'Ammando F, Luque PD, de Palma F, Desai A, Diesing R, Di Lalla N, Dirirsa F, Di Venere L, Dominguez A, Fegan SJ, Franckowiak A, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Giglietto N, Giordano F, Giroletti M, Green D, Grenier IA, Guiriec S, Hartmann D, Horan D, Johannesson G, Karwin C, Kerr M, Kovacevic M, Kuss M, Larsson S, Latronico L, Lemoine-Goumard M, Li J, Liodakis I, Longo F, Loparco F, Lovellette MN, Lubrano P, Maldera S, Manfreda A, Marchesi S, Marcotulli L, Marti-Devesa G, Mazziotta MN, Mereu I, Michelson PF, Mizuno T, Monzani ME, Morselli A, Moskalenko IV, Negro M, Omodei N, Orienti M, Orlando E, Paliya V, Paneque D, Pei Z, Persic M, Pesce-Rollins M, Porter TA, Principe G, Racusin JL, Raino S, Rando R, Rani B, Razzano M, Reimer A, Reimer O, Parkinson PMS, Serini D, Sgro C, Siskind EJ, Spandre G, Spinelli P, Suson DJ, Tak D, Torres DF, Troja E, Wood K, Zaharijas G, Zrake J
Publisher: IOP Publishing Ltd
: 2021
Astrophysical Journal
: ASTROPHYSICAL JOURNAL
: ASTROPHYS J
: ARTN 144
: 921
: 2
: 14
: 0004-637X
DOI: https://doi.org/10.3847/1538-4357/ac1bb2
: https://research.utu.fi/converis/portal/detail/Publication/68488768
Massive black holes at the centers of galaxies can launch powerful wide-angle winds that, if sustained over time, can unbind the gas from the stellar bulges of galaxies. These winds may be responsible for the observed scaling relation between the masses of the central black holes and the velocity dispersion of stars in galactic bulges. Propagating through the galaxy, the wind should interact with the interstellar medium creating a strong shock, similar to those observed in supernovae explosions, which is able to accelerate charged particles to high energies. In this work we use data from the Fermi Large Area Telescope to search for the gamma-ray emission from galaxies with an ultrafast outflow (UFO): a fast (v similar to 0.1 c), highly ionized outflow, detected in absorption at hard X-rays in several nearby active galactic nuclei (AGN). Adopting a sensitive stacking analysis we are able to detect the average gamma-ray emission from these galaxies and exclude that it is due to processes other than UFOs. Moreover, our analysis shows that the gamma-ray luminosity scales with the AGN bolometric luminosity and that these outflows transfer similar to 0.04% of their mechanical power to gamma-rays. Interpreting the observed gamma-ray emission as produced by cosmic rays (CRs) accelerated at the shock front, we find that the gamma-ray emission may attest to the onset of the wind-host interaction and that these outflows can energize charged particles up to the transition region between galactic and extragalactic CRs.
