_version_ 1866915980627673088
author Paraschos, Georgios F.
Liodakis, Ioannis
Jorstad, Svetlana
Kovalev, Yuri Y.
Chakraborty, Sudip
Marin, Frederic
Ehlert, Steven R.
Traianou, Efthalia
Debbrecht, Lena C.
Agudo, Ivan
Barnouin, Thibault
Casey, Jacob J.
Di Gesu, Laura
Kaaret, Philip
Kim, Dawoon E.
Kislat, Fabian
Ratheesh, Ajay
Saade, M. Lynne
Tombesi, Francesco
Marscher, Alan
Gomez, Jose-Luis
Pushkarev, Alexander B.
Savolainen, Tuomas
Myserlis, Ioannis
Gurwell, Mark
Keating, Garrett
Rao, Ramprasad
Kang, Sincheol
Lee, Sang-Sung
Kim, Sanghyun
Cheong, Whee Yeon
Jeong, Hyeon-Woo
Song, Chanwoo
Li, Shan
Nam, Myeong-Seok
Alvarez-Ortega, Diego
Casadio, Carolina
Chen, Chien-Ting
Costa, Enrico
Churazov, Eugene
Ferrazzoli, Riccardo
Galanti, Giorgio
Khabibullin, Ildar
O'Dell, Stephen L.
Pacciani, Luigi
Roncadelli, Marco
Roberts, Oliver J.
Soffitta, Paolo
Swartz, Douglas A.
Tavecchio, Fabrizio
Weisskopf, Martin C.
Zhuravleva, Irina
author_facet Paraschos, Georgios F.
Liodakis, Ioannis
Jorstad, Svetlana
Kovalev, Yuri Y.
Chakraborty, Sudip
Marin, Frederic
Ehlert, Steven R.
Traianou, Efthalia
Debbrecht, Lena C.
Agudo, Ivan
Barnouin, Thibault
Casey, Jacob J.
Di Gesu, Laura
Kaaret, Philip
Kim, Dawoon E.
Kislat, Fabian
Ratheesh, Ajay
Saade, M. Lynne
Tombesi, Francesco
Marscher, Alan
Gomez, Jose-Luis
Pushkarev, Alexander B.
Savolainen, Tuomas
Myserlis, Ioannis
Gurwell, Mark
Keating, Garrett
Rao, Ramprasad
Kang, Sincheol
Lee, Sang-Sung
Kim, Sanghyun
Cheong, Whee Yeon
Jeong, Hyeon-Woo
Song, Chanwoo
Li, Shan
Nam, Myeong-Seok
Alvarez-Ortega, Diego
Casadio, Carolina
Chen, Chien-Ting
Costa, Enrico
Churazov, Eugene
Ferrazzoli, Riccardo
Galanti, Giorgio
Khabibullin, Ildar
O'Dell, Stephen L.
Pacciani, Luigi
Roncadelli, Marco
Roberts, Oliver J.
Soffitta, Paolo
Swartz, Douglas A.
Tavecchio, Fabrizio
Weisskopf, Martin C.
Zhuravleva, Irina
contents The location of $γ$-ray creation and emission within extra-galactic jets is a matter of active debate. One particularly well-suited source to pinpoint the location is the nearby, bright radio galaxy 3C 84, harbouring a powerful jet. Here we investigate the origin of $γ$-rays measured during a recent $γ$-ray flare, by analysing the linear polarisation signal of close-in-time very long baseline interferometry (VLBI) observations at centimetre and millimetre wavelengths. While 3C 84 is overall almost unpolarised, we find that close-in-time to the $γ$-ray flare peak regions at parsec-scale distances from the central engine shows a fractional linear polarisation increase. Under the physically well-motivated assumption of a causal relation between this polarisation enhancement and the $γ$-ray flare, and combined with insights from concurrent X-ray polarisation measurements, the $γ$-rays being created in this region is a physically motivated scenario, in a process consistent with synchrotron self-Compton.
format Preprint
id arxiv_https___arxiv_org_abs_2603_22403
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Where within the 3C 84 jet are $γ$-rays produced?
Paraschos, Georgios F.
Liodakis, Ioannis
Jorstad, Svetlana
Kovalev, Yuri Y.
Chakraborty, Sudip
Marin, Frederic
Ehlert, Steven R.
Traianou, Efthalia
Debbrecht, Lena C.
Agudo, Ivan
Barnouin, Thibault
Casey, Jacob J.
Di Gesu, Laura
Kaaret, Philip
Kim, Dawoon E.
Kislat, Fabian
Ratheesh, Ajay
Saade, M. Lynne
Tombesi, Francesco
Marscher, Alan
Gomez, Jose-Luis
Pushkarev, Alexander B.
Savolainen, Tuomas
Myserlis, Ioannis
Gurwell, Mark
Keating, Garrett
Rao, Ramprasad
Kang, Sincheol
Lee, Sang-Sung
Kim, Sanghyun
Cheong, Whee Yeon
Jeong, Hyeon-Woo
Song, Chanwoo
Li, Shan
Nam, Myeong-Seok
Alvarez-Ortega, Diego
Casadio, Carolina
Chen, Chien-Ting
Costa, Enrico
Churazov, Eugene
Ferrazzoli, Riccardo
Galanti, Giorgio
Khabibullin, Ildar
O'Dell, Stephen L.
Pacciani, Luigi
Roncadelli, Marco
Roberts, Oliver J.
Soffitta, Paolo
Swartz, Douglas A.
Tavecchio, Fabrizio
Weisskopf, Martin C.
Zhuravleva, Irina
High Energy Astrophysical Phenomena
Astrophysics of Galaxies
The location of $γ$-ray creation and emission within extra-galactic jets is a matter of active debate. One particularly well-suited source to pinpoint the location is the nearby, bright radio galaxy 3C 84, harbouring a powerful jet. Here we investigate the origin of $γ$-rays measured during a recent $γ$-ray flare, by analysing the linear polarisation signal of close-in-time very long baseline interferometry (VLBI) observations at centimetre and millimetre wavelengths. While 3C 84 is overall almost unpolarised, we find that close-in-time to the $γ$-ray flare peak regions at parsec-scale distances from the central engine shows a fractional linear polarisation increase. Under the physically well-motivated assumption of a causal relation between this polarisation enhancement and the $γ$-ray flare, and combined with insights from concurrent X-ray polarisation measurements, the $γ$-rays being created in this region is a physically motivated scenario, in a process consistent with synchrotron self-Compton.
title Where within the 3C 84 jet are $γ$-rays produced?
topic High Energy Astrophysical Phenomena
Astrophysics of Galaxies
url https://arxiv.org/abs/2603.22403