Nonthermal emission from the Arches cluster (G0.121+0.017) and the origin of γ-ray emission from 3EG J1746-2851

F. Yusef-Zadeh; M. Nord; M. Wardle; C. Law; C. Lang; T. J.W. Lazio

doi:10.1086/376854

Nonthermal emission from the Arches cluster (G0.121+0.017) and the origin of γ-ray emission from 3EG J1746-2851

F. Yusef-Zadeh^*, M. Nord, M. Wardle, C. Law, C. Lang, T. J.W. Lazio

^*Corresponding author for this work

Physics and Astronomy

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

24 Scopus citations

Abstract

High-resolution Very Large Array observations of the Arches cluster near the Galactic center show evidence of continuum emission at λ = 3.6, 6, 20, and 90 cm. The continuum emission at λ = 90 cm is particularly striking because thermal sources generally become optically thick at longer wavelengths and fall off in brightness, whereas nonthermal sources increase in brightness. It is argued that the radio emission from this unique source has compact and diffuse components produced by thermal and nonthermal processes, respectively. Compact sources within the cluster arise from stellar winds of mass-losing stars, whereas diffuse emission is likely to be due to colliding wind shocks of the cluster flow that generate relativistic particles that are due to diffuse shock acceleration. We also discuss the possibility that γ-ray emission from 3EG J1746-2851, located within 3′.3 of the Arches cluster, results from the inverse Compton scattering of the radiation field of the cluster.

Original language	English (US)
Pages (from-to)	L103-L106
Journal	Astrophysical Journal
Volume	590
Issue number	2 II
DOIs	https://doi.org/10.1086/376854
State	Published - Jun 20 2003

Keywords

Cosmic rays
Galaxy: center
ISM: abundances
X-rays: ISM

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1086/376854

Cite this

@article{add2b42239c4467ca88c5ea967fb474d,

title = "Nonthermal emission from the Arches cluster (G0.121+0.017) and the origin of γ-ray emission from 3EG J1746-2851",

abstract = "High-resolution Very Large Array observations of the Arches cluster near the Galactic center show evidence of continuum emission at λ = 3.6, 6, 20, and 90 cm. The continuum emission at λ = 90 cm is particularly striking because thermal sources generally become optically thick at longer wavelengths and fall off in brightness, whereas nonthermal sources increase in brightness. It is argued that the radio emission from this unique source has compact and diffuse components produced by thermal and nonthermal processes, respectively. Compact sources within the cluster arise from stellar winds of mass-losing stars, whereas diffuse emission is likely to be due to colliding wind shocks of the cluster flow that generate relativistic particles that are due to diffuse shock acceleration. We also discuss the possibility that γ-ray emission from 3EG J1746-2851, located within 3′.3 of the Arches cluster, results from the inverse Compton scattering of the radiation field of the cluster.",

keywords = "Cosmic rays, Galaxy: center, ISM: abundances, X-rays: ISM",

author = "F. Yusef-Zadeh and M. Nord and M. Wardle and C. Law and C. Lang and Lazio, {T. J.W.}",

note = "Funding Information: 1 Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208; zadeh@northwestern.edu, claw@northwestern.edu. 2Naval Research Laboratory, Space Sciences Division, 4555 Overlook Avenue, SW, Code 7600A, Washington, DC 20375-5351; michael.nord@nrl.navy .mil, joseph.lazio@nrl.navy.mil. 3Department of Physics, Macquarie University, NSW 2109, Australia; wardle@physics.mq.edu.au. 4 Department of Physics and Astronomy, University of Iowa, 203 Van Allen Hall, Iowa City, IA 52245; cornelia-lang@uiowa.edu. 5The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under a cooperative agreement by Associated Universities, Inc.",

year = "2003",

month = jun,

day = "20",

doi = "10.1086/376854",

language = "English (US)",

volume = "590",

pages = "L103--L106",

journal = "Astrophysical Journal",

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TY - JOUR

T1 - Nonthermal emission from the Arches cluster (G0.121+0.017) and the origin of γ-ray emission from 3EG J1746-2851

AU - Yusef-Zadeh, F.

AU - Nord, M.

AU - Wardle, M.

AU - Law, C.

AU - Lang, C.

AU - Lazio, T. J.W.

N1 - Funding Information: 1 Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208; zadeh@northwestern.edu, claw@northwestern.edu. 2Naval Research Laboratory, Space Sciences Division, 4555 Overlook Avenue, SW, Code 7600A, Washington, DC 20375-5351; michael.nord@nrl.navy .mil, joseph.lazio@nrl.navy.mil. 3Department of Physics, Macquarie University, NSW 2109, Australia; wardle@physics.mq.edu.au. 4 Department of Physics and Astronomy, University of Iowa, 203 Van Allen Hall, Iowa City, IA 52245; cornelia-lang@uiowa.edu. 5The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under a cooperative agreement by Associated Universities, Inc.

PY - 2003/6/20

Y1 - 2003/6/20

N2 - High-resolution Very Large Array observations of the Arches cluster near the Galactic center show evidence of continuum emission at λ = 3.6, 6, 20, and 90 cm. The continuum emission at λ = 90 cm is particularly striking because thermal sources generally become optically thick at longer wavelengths and fall off in brightness, whereas nonthermal sources increase in brightness. It is argued that the radio emission from this unique source has compact and diffuse components produced by thermal and nonthermal processes, respectively. Compact sources within the cluster arise from stellar winds of mass-losing stars, whereas diffuse emission is likely to be due to colliding wind shocks of the cluster flow that generate relativistic particles that are due to diffuse shock acceleration. We also discuss the possibility that γ-ray emission from 3EG J1746-2851, located within 3′.3 of the Arches cluster, results from the inverse Compton scattering of the radiation field of the cluster.

AB - High-resolution Very Large Array observations of the Arches cluster near the Galactic center show evidence of continuum emission at λ = 3.6, 6, 20, and 90 cm. The continuum emission at λ = 90 cm is particularly striking because thermal sources generally become optically thick at longer wavelengths and fall off in brightness, whereas nonthermal sources increase in brightness. It is argued that the radio emission from this unique source has compact and diffuse components produced by thermal and nonthermal processes, respectively. Compact sources within the cluster arise from stellar winds of mass-losing stars, whereas diffuse emission is likely to be due to colliding wind shocks of the cluster flow that generate relativistic particles that are due to diffuse shock acceleration. We also discuss the possibility that γ-ray emission from 3EG J1746-2851, located within 3′.3 of the Arches cluster, results from the inverse Compton scattering of the radiation field of the cluster.

KW - Cosmic rays

KW - Galaxy: center

KW - ISM: abundances

KW - X-rays: ISM

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JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2 II

ER -

Nonthermal emission from the Arches cluster (G0.121+0.017) and the origin of γ-ray emission from 3EG J1746-2851

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