| Title: |
Search for Synchrotron Emission from Secondary Electrons of Proton–Proton Interactions in Galactic PeVatron Candidate HESS J1641–463 |
| Authors: |
Naomi Tsuji, Takaaki Tanaka, Samar Safi-Harb, Felix Aharonian, Sabrina Casanova, Roland Kothes, Emmanuel Moulin, Hiroyuki Uchida, Yasunobu Uchiyama |
| Source: |
The Astrophysical Journal, Vol 967, Iss 2, p 138 (2024) |
| Publisher Information: |
IOP Publishing, 2024. |
| Publication Year: |
2024 |
| Collection: |
LCC:Astrophysics |
| Subject Terms: |
Galactic cosmic rays, Diffuse radiation, Gamma-rays, Gamma-ray sources, Astrophysics, QB460-466 |
| More Details: |
HESS J1641−463 is an unidentified gamma-ray source with a hard TeV gamma-ray spectrum, and thus it has been proposed to be a possible candidate for a cosmic-ray (CR) accelerator up to PeV energies (a PeVatron candidate). The source spatially coincides with the radio supernova remnant G338.5+0.1 but has not yet been fully explored in the X-ray band. We analyzed newly taken NuSTAR data, pointing at HESS J1641−463, with 82 ks effective exposure time. There is no apparent X-ray counterpart of HESS J1641−463, while nearby stellar cluster, Mercer 81, and stray-light X-rays are detected. Combined with the archival Chandra data, partially covering the source, we derived an upper limit of ∼6 × 10 ^−13 erg cm ^−2 s ^−1 in 2–10 keV (∼3 × 10 ^−13 erg cm ^−2 s ^−1 in 10–20 keV). If the gamma-ray emission is originated from the decay of π ^0 mesons produced in interactions between CR protons and ambient materials, secondary electrons in the proton–proton interactions can potentially emit synchrotron photons in the X-ray band, which can be tested by our X-ray observations. Although the obtained X-ray upper limits cannot place a constraint on the primary proton spectrum, it will be possible with a future hard X-ray mission. |
| Document Type: |
article |
| File Description: |
electronic resource |
| Language: |
English |
| ISSN: |
1538-4357 |
| Relation: |
https://doaj.org/toc/1538-4357 |
| DOI: |
10.3847/1538-4357/ad3fb1 |
| Access URL: |
https://doaj.org/article/6e74ee0e5909425683241aa517f3f90d |
| Accession Number: |
edsdoj.6e74ee0e5909425683241aa517f3f90d |
| Database: |
Directory of Open Access Journals |
