H.E.S.S. detection of the PSR J0855-4644 nebula
Abstract
HESS J0852-463 is a TeV {\gamma}-ray source located in the Galactic plane. The region consists of a supernova remnant (SNR, RX J0852.0-4622) with a shell-like morphology, commonly referred to as Vela Junior, and a pulsar denoted PSR J0855-4644. Pulsars are among the most efficient leptonic accelerators in our Galaxy, making this region particularly interesting to study. We utilise the most recent data taken by the High Energy Stereoscopic System (H.E.S.S.), to investigate any {\gamma}-ray emission associated with the pulsar in this region, PSR J0855-4644. We applied a full forward folding method on the H.E.S.S. data. Utilising 3D modelling techniques, we evaluated the TeV {\gamma}-ray emission towards the various components of this complex system. The distinct energy-dependent morphology observed in our data motivates further investigation of this source. We resolved the emission in the Vela Junior region into various components, several of which correspond to the SNR itself. In particular, we find a new extended component which is coincident with the position of PSR J0855-4644. The spectrum follows a power-law distribution with a best-fit index of {\Gamma}E = 1.81 \pm 0.07stat which differs from the properties of the surrounding {\gamma}-ray emission of the Vela Junior SNR. A one-zone leptonic joint fit between the X-rays (from XMM-Newton) and {\gamma}-rays (from H.E.S.S.) leads to a lower limit on the magnetic field of 1.6{\mu}G and a spectral index of {\alpha} = 1.88 \pm 0.01, in line with expectations of pulsar wind nebulae (PWNe). In this paper, we report the first detection of the PWN of PSR J0855-4644 at TeV energies with the H.E.S.S. experiment at a significance of 12.2{\sigma}. This is attributed to the advanced techniques of the 3D analysis. Based on the pulsar's characteristics, its PWN is consistent with the known TeV PWNe population in the Galaxy.
Cite
@article{arxiv.2602.14640,
title = {H.E.S.S. detection of the PSR J0855-4644 nebula},
author = {F. Aharonian and H. Ashkar and M. Backes and R. Batzofin and Y. Becherini and D. Berge and K. Bernlöhr and M. Böttcher and C. Boisson and J. Bolmont and F. Brun and B. Bruno and C. Burger-Scheidlin and T. Bylund and S. Casanova and D. Cecchin Momesso and J. Celic and M. Cerruti and A. Chen and M. Chernyakova and J. O. Chibueze and O. Chibueze and B. Cornejo and G. Cotter and G. Cozzolongo and J. de Assis Scarpin and M. de Bony de Lavergne and M. de Naurois and E. de Oña Wilhelmi and A. G. Delgado Giler and J. Devin and A. Dmytriiev and K. Egberts and K. Egg and J. -P. Ernenwein and C. Escañuela Nieves and P. Fauverge and K. Feijen and M. D. Filipovic and G. Fontaine and S. Funk and S. Gabici and Y. A. Gallant and M. Genaro and J. F. Glicenstein and J. Glombitza and P. Goswami and M. -H. Grondin and L. Heckmann and B. Heß and W. Hofmann and T. L. Holch and M. Holler and D. Horns and M. Jamrozy and F. Jankowsky and A. Jardin-Blicq and I. Jaroschewski and D. Jimeno and I. Jung-Richardt and E. Kasai and K. Katarzyński and D. Kerszberg and B. Khélifi and W. Kluźniak and N. Komin and K. Kosack and D. Kostunin and R. G. Lang and S. Lazarević and A. Lemière and M. Lemoine-Goumard and J. -P. Lenain and P. Liniewicz and A. Luashvili and J. Mackey and D. Malyshev and D. Malyshev and V. Marandon and M. G. F. Mayer and A. Mehta and A. M. W. Mitchell and R. Moderski and L. Mohrmann and E. Moulin and J. Niemiec and P. O'Brien and L. Olivera-Nieto and M. O. Moghadam and S. Panny and M. Panter and R. D. Parsons and P. Pichard and T. Preis and G. Pühlhofer and M. Punch and A. Quirrenbach and A. Reimer and O. Reimer and I. Reis and Q. Remy and H. X. Ren and B. Reville and F. Rieger and G. Rowell and B. Rudak and K. Sabri and V. Sahakian and M. Sasaki and F. Schüssler and J. N. S. Shapopi and W. Si Said and Ł. Stawarz and R. Steenkamp and S. Steinmassl and T. Tanaka and A. M. Taylor and G. L. Taylor and R. Terrier and Y. Tian and M. Tsirou and T. Unbehaunz and C. van Eldik and M. Vecchi and C. Venter and J. Vink and V. Voitsekhovskyi and T. Wach and S. J. Wagner and A. Wierzcholska and M. Zacharias and A. Zech and W. Zhong and F. Acero and L. Giunti},
journal= {arXiv preprint arXiv:2602.14640},
year = {2026}
}
Comments
10 pages, 7 figures. Accepted to A&A; Corresponding authors: K. Feijen, B. Kh\'elifi, R. Terrier, K. Kosack