TY - JOUR

T1 - Account of the baryonic feedback effect in γ -ray measurements of intergalactic magnetic fields

AU - Bondarenko, K.

AU - Boyarsky, A.

AU - Korochkin, A.

AU - Neronov, A.

AU - Semikoz, D.

AU - Sokolenko, A.

N1 - Funding Information: Acknowledgements. Work of D.S. and A.N. has been supported in part by the French National Research Agency (ANR) grant ANR-19-CE31-0020, work of A.K. was supported in part by Russian Science Foundation grant 20-42-09010. A.K.’s stay in the APC laboratory was provided by the “Vernadsky” scholarship of the French embassy in Russia. K.B. and A.B. are supported by the European ResearchCouncil (ERC) Advanced Grant “NuBSM” (694896). A.S. is supported by the FWF Research Group grant FG1. Publisher Copyright: ©

PY - 2022/4/1

Y1 - 2022/4/1

N2 - Aims. Intergalactic magnetic fields in the voids of the large-scale structure can be probed via measurements of secondary γ-ray emission from γ-ray interactions with extragalactic background light. Lower bounds on the magnetic field in the voids were derived from the nondetection of this emission. It is not clear a priori what kind of magnetic field is responsible for the suppression of the secondary γ-ray flux: a cosmological magnetic field that might be filling the voids, or the field spread by galactic winds driven by star formation and active galactic nuclei. Methods. We used IllustrisTNG cosmological simulations to study the effect of magnetized galactic wind bubbles on the secondary γ-ray flux. Results. We show that within the IllustrisTNG model of baryonic feedback, galactic wind bubbles typically provide energy-independent secondary flux suppression at a level of about 10%. The observed flux suppression effect has to be due to the cosmological magnetic field in the voids. This might not be the case for the special case when the primary γ-ray source has a hard intrinsic γ-ray spectrum that peaks in the energy range above 50 TeV. In this case, the observational data may be strongly affected by the magnetized bubble that is blown by the source host galaxy.

AB - Aims. Intergalactic magnetic fields in the voids of the large-scale structure can be probed via measurements of secondary γ-ray emission from γ-ray interactions with extragalactic background light. Lower bounds on the magnetic field in the voids were derived from the nondetection of this emission. It is not clear a priori what kind of magnetic field is responsible for the suppression of the secondary γ-ray flux: a cosmological magnetic field that might be filling the voids, or the field spread by galactic winds driven by star formation and active galactic nuclei. Methods. We used IllustrisTNG cosmological simulations to study the effect of magnetized galactic wind bubbles on the secondary γ-ray flux. Results. We show that within the IllustrisTNG model of baryonic feedback, galactic wind bubbles typically provide energy-independent secondary flux suppression at a level of about 10%. The observed flux suppression effect has to be due to the cosmological magnetic field in the voids. This might not be the case for the special case when the primary γ-ray source has a hard intrinsic γ-ray spectrum that peaks in the energy range above 50 TeV. In this case, the observational data may be strongly affected by the magnetized bubble that is blown by the source host galaxy.

KW - Gamma rays: general

KW - Intergalactic medium

KW - ISM: jets and outflows

KW - Magnetic fields

KW - Magnetohydrodynamics (MHD)

UR - http://www.scopus.com/inward/record.url?scp=85128473993&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/202141595

DO - 10.1051/0004-6361/202141595

M3 - Article

AN - SCOPUS:85128473993

VL - 660

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - A80

ER -