H.E.S.S. detection of the PSR J0855−4644 nebula

F. Aharonian; H. Ashkar; M. Backes; R. Batzofin; Y. Becherini; D. Berge; K. Bernlöhr; M. Böttcher; C. Boisson; J. Bolmont; F. Brun; B. Bruno; C. Burger-Scheidlin; T. Bylund; S. Casanova; D. Cecchin Momesso; J. Celic; M. Cerruti; A. Chen; M. Chernyakova; J. O. Chibueze; O. Chibueze; B. Cornejo; G. Cotter; G. Cozzolongo; J. de Assis Scarpin; M. de Bony de Lavergne; M. de Naurois; E. de Oña Wilhelmi; A. G. Delgado Giler; J. Devin; A. Dmytriiev; K. Egberts; K. Egg; J. P. Ernenwein; C. Escañuela Nieves; P. Fauverge; K. Feijen; M. D. Filipovic; G. Fontaine; S. Funk; S. Gabici; Y. A. Gallant; M. Genaro; J. F. Glicenstein; J. Glombitza; P. Goswami; M. H. Grondin; L. Heckmann; B. Heß; H.E.S.S. Collaboration; et al.

doi:10.1051/0004-6361/202558346

H.E.S.S. detection of the PSR J0855−4644 nebula

F. Aharonian
, H. Ashkar
, M. Backes
, R. Batzofin
, Y. Becherini
, D. Berge
, K. Bernlöhr
, M. Böttcher
, C. Boisson
, J. Bolmont
, F. Brun
, B. Bruno
, C. Burger-Scheidlin
, T. Bylund
, S. Casanova
, D. Cecchin Momesso
, J. Celic
, M. Cerruti
, A. Chen
, M. Chernyakova

J. O. Chibueze, O. Chibueze, B. Cornejo, G. Cotter, G. Cozzolongo, J. de Assis Scarpin, M. de Bony de Lavergne, M. de Naurois, E. de Oña Wilhelmi, A. G. Delgado Giler, J. Devin, A. Dmytriiev, K. Egberts, K. Egg, J. P. Ernenwein, C. Escañuela Nieves, P. Fauverge, K. Feijen, M. D. Filipovic, G. Fontaine, S. Funk, S. Gabici, Y. A. Gallant, M. Genaro, J. F. Glicenstein, J. Glombitza, P. Goswami, M. H. Grondin, L. Heckmann, B. Heß, H.E.S.S. Collaboration, et al.

School of Science

Yerevan State University
Max Planck Institute for Nuclear Physics
Dublin Institute for Advanced Studies
Laboratoire Leprince-Ringuet
University of Namibia
North West University
University of Potsdam
Université Paris Cité
German Electron Synchrotron
Humboldt University of Berlin
Observatoire de Paris
Sorbonne Université
Université Paris-Saclay
Friedrich-Alexander University Erlangen-Nürnberg
Instytut Fizyki Jacadrowej PAN
University of the Witwatersrand
Dublin City University
University of Oxford
CPPM
Laboratoire Univers et Particules de Montpellier
Université de Bordeaux
Heidelberg University
University of Tübingen

Research output: Contribution to journal › Article › peer-review

1 Citation (Scopus)

Abstract

Context. HESS J0852−463 is a TeV γ-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 named PSR J0855−4644. Pulsars are among the most efficient leptonic accelerators in our Galaxy, making this region particularly interesting to study. Aims. We utilise the most recent data taken by the High Energy Stereoscopic System (H.E.S.S.) to investigate any γ-ray emission associated with the pulsar in this region, PSR J0855−4644. Methods. We applied a full forward-folding method on the H.E.S.S. data. Utilising 3D modelling techniques, we evaluated the TeV γ-ray emission towards the various components of this complex system. Results. 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 coincident with the position of PSR J0855−4644. The spectrum follows a power-law distribution with a best-fit index of Γ_E = 1.81 ± 0.07_stat, which differs from the properties of the surrounding γ-ray emission of the Vela Junior SNR. A one-zone leptonic joint fit between the X-rays (from XMM-Newton) and γ-rays (from H.E.S.S.) leads to a lower limit on the magnetic field of 1.6 μG and a spectral index of α = 1.88 ± 0.01, in line with expectations of pulsar wind nebulae (PWNe). Conclusions. 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 12.2σ. 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.

Original language	English
Article number	A6
Number of pages	9
Journal	Astronomy and Astrophysics
Volume	708
DOIs	https://doi.org/10.1051/0004-6361/202558346
Publication status	Published - Apr 2026

Keywords

astroparticle physics
gamma rays: general
ISM: supernova remnants
pulsars: individual: PSR J0855−4644
radiation mechanisms: non-thermal

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10.1051/0004-6361/202558346Licence: CC BY

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Cite this

Aharonian, F., Ashkar, H., Backes, M., Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., Brun, F., Bruno, B., Burger-Scheidlin, C., Bylund, T., Casanova, S., Cecchin Momesso, D., Celic, J., Cerruti, M., Chen, A., ... al., E. (2026). H.E.S.S. detection of the PSR J0855−4644 nebula. Astronomy and Astrophysics, 708, Article A6. https://doi.org/10.1051/0004-6361/202558346

@article{e245e766e87243479e0fda4a3db162e5,

title = "H.E.S.S. detection of the PSR J0855−4644 nebula",

abstract = "Context. HESS J0852−463 is a TeV γ-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 named PSR J0855−4644. Pulsars are among the most efficient leptonic accelerators in our Galaxy, making this region particularly interesting to study. Aims. We utilise the most recent data taken by the High Energy Stereoscopic System (H.E.S.S.) to investigate any γ-ray emission associated with the pulsar in this region, PSR J0855−4644. Methods. We applied a full forward-folding method on the H.E.S.S. data. Utilising 3D modelling techniques, we evaluated the TeV γ-ray emission towards the various components of this complex system. Results. 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 coincident with the position of PSR J0855−4644. The spectrum follows a power-law distribution with a best-fit index of ΓE = 1.81 ± 0.07stat, which differs from the properties of the surrounding γ-ray emission of the Vela Junior SNR. A one-zone leptonic joint fit between the X-rays (from XMM-Newton) and γ-rays (from H.E.S.S.) leads to a lower limit on the magnetic field of 1.6 μG and a spectral index of α = 1.88 ± 0.01, in line with expectations of pulsar wind nebulae (PWNe). Conclusions. 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 12.2σ. This is attributed to the advanced techniques of the 3D analysis. Based on the pulsar{\textquoteright}s characteristics, its PWN is consistent with the known TeV PWNe population in the Galaxy.",

keywords = "astroparticle physics, gamma rays: general, ISM: supernova remnants, pulsars: individual: PSR J0855−4644, radiation mechanisms: non-thermal",

author = "F. Aharonian and H. Ashkar and M. Backes and R. Batzofin and Y. Becherini and D. Berge and K. Bernl{\"o}hr and M. B{\"o}ttcher and C. Boisson and J. Bolmont and F. Brun and B. Bruno and C. Burger-Scheidlin and T. Bylund and S. Casanova and \{Cecchin Momesso\}, D. and J. Celic and M. Cerruti and A. Chen and M. Chernyakova and Chibueze, \{J. O.\} and O. Chibueze and B. Cornejo and G. Cotter and G. Cozzolongo and \{de Assis Scarpin\}, J. and \{de Bony de Lavergne\}, M. and \{de Naurois\}, M. and \{de O{\~n}a Wilhelmi\}, E. and \{Delgado Giler\}, \{A. G.\} and J. Devin and A. Dmytriiev and K. Egberts and K. Egg and Ernenwein, \{J. P.\} and \{Esca{\~n}uela Nieves\}, C. and P. Fauverge and K. Feijen and Filipovic, \{M. D.\} and G. Fontaine and S. Funk and S. Gabici and Gallant, \{Y. A.\} and M. Genaro and Glicenstein, \{J. F.\} and J. Glombitza and P. Goswami and Grondin, \{M. H.\} and L. Heckmann and B. He{\ss} and \{H.E.S.S. Collaboration\} and et al.",

year = "2026",

month = apr,

doi = "10.1051/0004-6361/202558346",

language = "English",

volume = "708",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

}

Aharonian, F, Ashkar, H, Backes, M, Batzofin, R, Becherini, Y, Berge, D, Bernlöhr, K, Böttcher, M, Boisson, C, Bolmont, J, Brun, F, Bruno, B, Burger-Scheidlin, C, Bylund, T, Casanova, S, Cecchin Momesso, D, Celic, J, Cerruti, M, Chen, A, Chernyakova, M, Chibueze, JO, Chibueze, O, Cornejo, B, Cotter, G, Cozzolongo, G, de Assis Scarpin, J, de Bony de Lavergne, M, de Naurois, M, de Oña Wilhelmi, E, Delgado Giler, AG, Devin, J, Dmytriiev, A, Egberts, K, Egg, K, Ernenwein, JP, Escañuela Nieves, C, Fauverge, P, Feijen, K, Filipovic, MD, Fontaine, G, Funk, S, Gabici, S, Gallant, YA, Genaro, M, Glicenstein, JF, Glombitza, J, Goswami, P, Grondin, MH, Heckmann, L, Heß, B, H.E.S.S. Collaboration & al., E 2026, 'H.E.S.S. detection of the PSR J0855−4644 nebula', Astronomy and Astrophysics, vol. 708, A6. https://doi.org/10.1051/0004-6361/202558346

TY - JOUR

T1 - H.E.S.S. detection of the PSR J0855−4644 nebula

AU - Aharonian, F.

AU - Ashkar, H.

AU - Backes, M.

AU - Batzofin, R.

AU - Becherini, Y.

AU - Berge, D.

AU - Bernlöhr, K.

AU - Böttcher, M.

AU - Boisson, C.

AU - Bolmont, J.

AU - Brun, F.

AU - Bruno, B.

AU - Burger-Scheidlin, C.

AU - Bylund, T.

AU - Casanova, S.

AU - Cecchin Momesso, D.

AU - Celic, J.

AU - Cerruti, M.

AU - Chen, A.

AU - Chernyakova, M.

AU - Chibueze, J. O.

AU - Chibueze, O.

AU - Cornejo, B.

AU - Cotter, G.

AU - Cozzolongo, G.

AU - de Assis Scarpin, J.

AU - de Bony de Lavergne, M.

AU - de Naurois, M.

AU - de Oña Wilhelmi, E.

AU - Delgado Giler, A. G.

AU - Devin, J.

AU - Dmytriiev, A.

AU - Egberts, K.

AU - Egg, K.

AU - Ernenwein, J. P.

AU - Escañuela Nieves, C.

AU - Fauverge, P.

AU - Feijen, K.

AU - Filipovic, M. D.

AU - Fontaine, G.

AU - Funk, S.

AU - Gabici, S.

AU - Gallant, Y. A.

AU - Genaro, M.

AU - Glicenstein, J. F.

AU - Glombitza, J.

AU - Goswami, P.

AU - Grondin, M. H.

AU - Heckmann, L.

AU - Heß, B.

AU - H.E.S.S. Collaboration,

AU - al., et

PY - 2026/4

Y1 - 2026/4

N2 - Context. HESS J0852−463 is a TeV γ-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 named PSR J0855−4644. Pulsars are among the most efficient leptonic accelerators in our Galaxy, making this region particularly interesting to study. Aims. We utilise the most recent data taken by the High Energy Stereoscopic System (H.E.S.S.) to investigate any γ-ray emission associated with the pulsar in this region, PSR J0855−4644. Methods. We applied a full forward-folding method on the H.E.S.S. data. Utilising 3D modelling techniques, we evaluated the TeV γ-ray emission towards the various components of this complex system. Results. 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 coincident with the position of PSR J0855−4644. The spectrum follows a power-law distribution with a best-fit index of ΓE = 1.81 ± 0.07stat, which differs from the properties of the surrounding γ-ray emission of the Vela Junior SNR. A one-zone leptonic joint fit between the X-rays (from XMM-Newton) and γ-rays (from H.E.S.S.) leads to a lower limit on the magnetic field of 1.6 μG and a spectral index of α = 1.88 ± 0.01, in line with expectations of pulsar wind nebulae (PWNe). Conclusions. 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 12.2σ. 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.

AB - Context. HESS J0852−463 is a TeV γ-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 named PSR J0855−4644. Pulsars are among the most efficient leptonic accelerators in our Galaxy, making this region particularly interesting to study. Aims. We utilise the most recent data taken by the High Energy Stereoscopic System (H.E.S.S.) to investigate any γ-ray emission associated with the pulsar in this region, PSR J0855−4644. Methods. We applied a full forward-folding method on the H.E.S.S. data. Utilising 3D modelling techniques, we evaluated the TeV γ-ray emission towards the various components of this complex system. Results. 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 coincident with the position of PSR J0855−4644. The spectrum follows a power-law distribution with a best-fit index of ΓE = 1.81 ± 0.07stat, which differs from the properties of the surrounding γ-ray emission of the Vela Junior SNR. A one-zone leptonic joint fit between the X-rays (from XMM-Newton) and γ-rays (from H.E.S.S.) leads to a lower limit on the magnetic field of 1.6 μG and a spectral index of α = 1.88 ± 0.01, in line with expectations of pulsar wind nebulae (PWNe). Conclusions. 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 12.2σ. 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.

KW - astroparticle physics

KW - gamma rays: general

KW - ISM: supernova remnants

KW - pulsars: individual: PSR J0855−4644

KW - radiation mechanisms: non-thermal

UR - https://www.scopus.com/pages/publications/105043452732

U2 - 10.1051/0004-6361/202558346

DO - 10.1051/0004-6361/202558346

M3 - Article

AN - SCOPUS:105043452732

SN - 0004-6361

VL - 708

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - A6

ER -

H.E.S.S. detection of the PSR J0855−4644 nebula

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