The IXPE View of GRB 221009A

0573059 - ASÚ 2024 RIV US eng J - Článek v odborném periodiku
Negro, M. - Di Lalla, N. - Omodei, N. - Dovčiak, Michal - Karas, Vladimír … celkem 112 autorů
The IXPE View of GRB 221009A.
Astrophysical Journal Letters. Roč. 946, č. 1 (2023), č. článku L21. ISSN 2041-8205. E-ISSN 2041-8213
Institucionální podpora: RVO:67985815
Klíčová slova: gamma-ray bursts * polarimetry * X-ray astronomy
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 7.9, rok: 2022
Způsob publikování: Open access

We present the IXPE observation of GRB 221009A, which includes upper limits on the linear polarization degree of both prompt and afterglow emission in the soft X-ray energy band. GRB 221009A is an exceptionally bright gamma-ray burst (GRB) that reached Earth on 2022 October 9 after traveling through the dust of the Milky Way. The Imaging X-ray Polarimetry Explorer (IXPE) pointed at GRB 221009A on October 11 to observe, for the first time, the 2-8 keV X-ray polarization of a GRB afterglow. We set an upper limit to the polarization degree of the afterglow emission of 13.8% at a 99% confidence level. This result provides constraints on the jet opening angle and the viewing angle of the GRB, or alternatively, other properties of the emission region. Additionally, IXPE captured halo-rings of dust-scattered photons that are echoes of the GRB prompt emission. The 99% confidence level upper limit to the prompt polarization degree depends on the background model assumption, and it ranges between similar to 55% and similar to 82%. This single IXPE pointing provides both the first assessment of X-ray polarization of a GRB afterglow and the first GRB study with polarization observations of both the prompt and afterglow phases.
Trvalý link: https://hdl.handle.net/11104/0343828