Magnetic field properties inside the jet of Mrk 421

0582090 - ASÚ 2025 RIV FR eng J - Článek v odborném periodiku
Kim, D. E. - Di Gesu, L. - Liodakis, I. - Dovčiak, Michal - Karas, Vladimír … celkem 136 autorů
Magnetic field properties inside the jet of Mrk 421.
Astronomy & Astrophysics. Roč. 681, January (2024), č. článku A12. ISSN 0004-6361. E-ISSN 1432-0746
Institucionální podpora: RVO:67985815
Klíčová slova: x-ray-polarization * gas pixel detector * parsec-scale jets
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 6.5, rok: 2022
Způsob publikování: Open access

We aim to probe the magnetic field geometry and particle acceleration mechanism in the relativistic jets of supermassive black holes.Methods. We conducted a polarimetry campaign from radio to X-ray wavelengths of the high-synchrotron-peak (HSP) blazar Mrk 421, including Imaging X-ray Polarimetry Explorer (IXPE) measurements from 2022 December 6-8. During the IXPE observation, we also monitored Mrk 421 using Swift-XRT and obtained a single observation with XMM-Newton to improve the X-ray spectral analysis. The time-averaged X-ray polarization was determined consistently using the event-by-event Stokes parameter analysis, spectropolarimetric fit, and maximum likelihood methods. We examined the polarization variability over both time and energy, the former via analysis of IXPE data obtained over a time span of 7 months.Results. We detected X-ray polarization of Mrk 421 with a degree of Pi(X) = 14 +/- 1% and an electric-vector position angle psi(X) = 107 +/- 3 degrees in the 2-8 keV band. From the time variability analysis, we find a significant episodic variation in psi(X). During the 7 months from the first IXPE pointing of Mrk 421 in 2022 May, psi(X) varied in the range 0 degrees to 180 degrees, while Pi(X) remained relatively constant within similar to 10-15%. Furthermore, a swing in psi(X) in 2022 June was accompanied by simultaneous spectral variations.
Trvalý link: https://hdl.handle.net/11104/0353268