Particle acceleration in the superwinds of starburst galaxies

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F18%3A00539870" target="_blank" >RIV/68378271:_____/18:00539870 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1051/0004-6361/201832666" target="_blank" >https://doi.org/10.1051/0004-6361/201832666</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/201832666" target="_blank" >10.1051/0004-6361/201832666</a>

Result language

angličtina

Original language name

Particle acceleration in the superwinds of starburst galaxies

Original language description

Context. Starbursts are galaxies undergoing massive episodes of star formation. The combined effect of stellar winds from hot stars and supernova explosions creates a high-temperature cavity in the nuclear region of these objects. The very hot gas expands adiabatically and escapes from the galaxy creating a superwind which sweeps matter from the galactic disk. The superwind region in the halo is filled with a multi-phase gas with hot, warm, cool, and relativistic components.nAims. The shocks associated with the superwind of starbursts and the turbulent gas region of the bubble inflated by them might accelerate cosmic rays up to high energies. In this work we calculate the cosmic ray production associated with the superwind using parameters that correspond to the nearby southern starburst galaxy NGC 253, which has been suggested as a potential accelerator of ultra-high-energy cosmic rays. nMethods. We evaluate the efficiency of both diffusive shock acceleration (DSA) and stochastic diffusive acceleration (SDA) in the superwind of NGC 253. We estimate the distribution of both hadrons and leptons and calculate the corresponding spectral energy distributions of photons. The electromagnetic radiation can help to discriminate between the different scenarios analyzed. nResults. We find that the strong mass load of the superwind, recently determined through ALMA observations, strongly attenuates the efficiency of DSA in NGC 253, whereas SDA is constrained by the age of the starburst. nConclusions. We conclude that NGC 253 and similar starbursts can only accelerate iron nuclei beyond similar to 10(18) eV under very special conditions. If the central region of the galaxy harbors a starved supermassive black hole of similar to 10(6) M-circle dot, as suggested by some recent observations, a contribution in the range 10(18)-10(19) eV can be present for accretion rates <(m)over dot> similar to 10(-3) in Eddington units. Shock energies of the order of 100 EeV might only be possible if very strong magnetic field amplification occurs close to the superwind.n

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10303 - Particles and field physics

Project

—

Continuities

—

Publication year

2018

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

—

Volume of the periodical

616

Issue of the periodical within the volume

Aug

Country of publishing house

FR - FRANCE

Number of pages

13

Pages from-to

1-13

UT code for WoS article

000441818700004

EID of the result in the Scopus database

2-s2.0-85051956687