XL-Calibur measurements of polarised hard X-ray emission from the Crab
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866916903862140928 |
|---|---|
| author | Awaki, Hisamitsu Baring, Matthew G. Bose, Richard Braun, Dana Casey, Jacob Chun, Sohee Galchenko, Pavel Gau, Ephraim Goya, Kazuho Hakamata, Tomohiro Hayashi, Takayuki Heatwole, Scott Hu, Kun Imazawa, Ryo Ishi, Daiki Ishida, Manabu Kislat, Fabian Kiss, Mózsi Klepper, Kassi Krawczynski, Henric Kuramoto, Haruki Lanzi, R. James Lisalda, Lindsey Maeda, Yoshitomo Malmborg, Filip af Matsumoto, Hironori Menon, Shravan Vengalil Miyamoto, Aiko Miyamoto, Asca Miyazawa, Takuya Murakami, Kaito Nagao, Azuki Okajima, Takashi Pearce, Mark Rauch, Brian F. Cavero, Nicole Rodriguez Shima, Kohei Shirahama, Kentaro Snow, Carlton M. Spooner, Sean Takahashi, Hiromitsu Takatsuka, Sayana Tamura, Keisuke Tanaka, Kojiro Uchida, Yuusuke West, Andrew Thomas Wulf, Eric A. Yokota, Masato Yoshimoto, Marina |
| author_facet | Awaki, Hisamitsu Baring, Matthew G. Bose, Richard Braun, Dana Casey, Jacob Chun, Sohee Galchenko, Pavel Gau, Ephraim Goya, Kazuho Hakamata, Tomohiro Hayashi, Takayuki Heatwole, Scott Hu, Kun Imazawa, Ryo Ishi, Daiki Ishida, Manabu Kislat, Fabian Kiss, Mózsi Klepper, Kassi Krawczynski, Henric Kuramoto, Haruki Lanzi, R. James Lisalda, Lindsey Maeda, Yoshitomo Malmborg, Filip af Matsumoto, Hironori Menon, Shravan Vengalil Miyamoto, Aiko Miyamoto, Asca Miyazawa, Takuya Murakami, Kaito Nagao, Azuki Okajima, Takashi Pearce, Mark Rauch, Brian F. Cavero, Nicole Rodriguez Shima, Kohei Shirahama, Kentaro Snow, Carlton M. Spooner, Sean Takahashi, Hiromitsu Takatsuka, Sayana Tamura, Keisuke Tanaka, Kojiro Uchida, Yuusuke West, Andrew Thomas Wulf, Eric A. Yokota, Masato Yoshimoto, Marina |
| contents | We report measurements of the linear polarisation degree (PD) and angle (PA) for hard X-ray emission from the Crab pulsar and wind nebula. Measurements were made with the XL-Calibur ($\sim$15-80 keV) balloon-borne Compton-scattering polarimeter in July 2024. The polarisation parameters are determined using a Bayesian analysis of Stokes parameters obtained from X-ray scattering angles. Well-constrained ($\sim$8.5$σ$) results are obtained for the polarisation of the $\sim$19-64 keV signal integrated over all pulsar phases: PD=(25.1$\pm$2.9)% and PA=(129.8$\pm$3.2)$^\circ$. In the off-pulse (nebula-dominated) phase range, the PD is constrained at $\sim$4.5$σ$ and is compatible with the phase-integrated result. The PA of the nebular hard X-ray emission aligns with that measured by IXPE in the 2-8 keV band for the toroidal inner region of the pulsar wind nebula, where the hard X-rays predominantly originate. For the main pulsar peak, PD=(32.8$^{+18.2}_{-28.5}$)% and PA=(156.0 $\pm$ 21.7)$^\circ$, while for the second peak (inter-pulse), PD=(0.0$^{+33.6}_{-0.0}$)% and PA=(154.5 $\pm$ 34.5)$^\circ$. A low level of polarisation in the pulsar peaks likely does not favour emission originating from the inner regions of the pulsar magnetosphere. Discriminating between Crab pulsar emission models will require deeper observations, e.g. with a satellite-borne hard X-ray polarimeter. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_14307 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | XL-Calibur measurements of polarised hard X-ray emission from the Crab Awaki, Hisamitsu Baring, Matthew G. Bose, Richard Braun, Dana Casey, Jacob Chun, Sohee Galchenko, Pavel Gau, Ephraim Goya, Kazuho Hakamata, Tomohiro Hayashi, Takayuki Heatwole, Scott Hu, Kun Imazawa, Ryo Ishi, Daiki Ishida, Manabu Kislat, Fabian Kiss, Mózsi Klepper, Kassi Krawczynski, Henric Kuramoto, Haruki Lanzi, R. James Lisalda, Lindsey Maeda, Yoshitomo Malmborg, Filip af Matsumoto, Hironori Menon, Shravan Vengalil Miyamoto, Aiko Miyamoto, Asca Miyazawa, Takuya Murakami, Kaito Nagao, Azuki Okajima, Takashi Pearce, Mark Rauch, Brian F. Cavero, Nicole Rodriguez Shima, Kohei Shirahama, Kentaro Snow, Carlton M. Spooner, Sean Takahashi, Hiromitsu Takatsuka, Sayana Tamura, Keisuke Tanaka, Kojiro Uchida, Yuusuke West, Andrew Thomas Wulf, Eric A. Yokota, Masato Yoshimoto, Marina High Energy Astrophysical Phenomena Instrumentation and Methods for Astrophysics We report measurements of the linear polarisation degree (PD) and angle (PA) for hard X-ray emission from the Crab pulsar and wind nebula. Measurements were made with the XL-Calibur ($\sim$15-80 keV) balloon-borne Compton-scattering polarimeter in July 2024. The polarisation parameters are determined using a Bayesian analysis of Stokes parameters obtained from X-ray scattering angles. Well-constrained ($\sim$8.5$σ$) results are obtained for the polarisation of the $\sim$19-64 keV signal integrated over all pulsar phases: PD=(25.1$\pm$2.9)% and PA=(129.8$\pm$3.2)$^\circ$. In the off-pulse (nebula-dominated) phase range, the PD is constrained at $\sim$4.5$σ$ and is compatible with the phase-integrated result. The PA of the nebular hard X-ray emission aligns with that measured by IXPE in the 2-8 keV band for the toroidal inner region of the pulsar wind nebula, where the hard X-rays predominantly originate. For the main pulsar peak, PD=(32.8$^{+18.2}_{-28.5}$)% and PA=(156.0 $\pm$ 21.7)$^\circ$, while for the second peak (inter-pulse), PD=(0.0$^{+33.6}_{-0.0}$)% and PA=(154.5 $\pm$ 34.5)$^\circ$. A low level of polarisation in the pulsar peaks likely does not favour emission originating from the inner regions of the pulsar magnetosphere. Discriminating between Crab pulsar emission models will require deeper observations, e.g. with a satellite-borne hard X-ray polarimeter. |
| title | XL-Calibur measurements of polarised hard X-ray emission from the Crab |
| topic | High Energy Astrophysical Phenomena Instrumentation and Methods for Astrophysics |
| url | https://arxiv.org/abs/2503.14307 |