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Title: HESS J1640–465 AND HESS J1641–463: TWO INTRIGUING TeV SOURCES IN LIGHT OF NEW FERMI -LAT OBSERVATIONS

Abstract

We report on γ-ray analysis of the region containing the bright TeV source HESS J1640-465 and the closeby TeV source HESS J1641-463 using 64 months of observationswith the Fermi Large Area Telescope (LAT). Previously only one GeV source was reported in this region and was associated with HESS J1640-465. With an increased dataset and the improved sensitivity afforded by the reprocessed data (P7REP) of the LAT, we now report the detection, morphological study and spectral analysis of two distinct sources above 100 MeV. The softest emission in this region comes from the TeV source HESS J1641-463 which is well fitted with a power law of index Γ = 2.47 ± 0.05 ± 0.06 and presents no significant γ-ray signal above 10 GeV, which contrasts with its hard spectrum at TeV energies. The Fermi-LAT spectrum of the second TeV source, HESS J1640-465 is well described by a power-law shape of index Γ = 1.99 ± 0.04 ± 0.07 that links up naturally with the spectral data points obtained by the High Energy Stereoscopic System (H.E.S.S.). These new results provide new constraints concerning the identification of these two puzzling γ-ray sources.

Authors:
ORCiD logo [1];  [1];  [2]; ORCiD logo [2];  [1];  [1]
  1. Univ. Bordeaux (France)
  2. Univ. Paris Diderot (France)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1356449
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
The Astrophysical Journal. Letters
Additional Journal Information:
Journal Volume: 794; Journal Issue: 1; Journal ID: ISSN 2041-8213
Publisher:
Institute of Physics (IOP)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS

Citation Formats

Lemoine-Goumard, M., Grondin, M. -H., Acero, F., Ballet, J., Laffon, H., and Reposeur, T.. HESS J1640–465 AND HESS J1641–463: TWO INTRIGUING TeV SOURCES IN LIGHT OF NEW FERMI -LAT OBSERVATIONS. United States: N. p., 2014. Web. doi:10.1088/2041-8205/794/1/L16.
Lemoine-Goumard, M., Grondin, M. -H., Acero, F., Ballet, J., Laffon, H., & Reposeur, T.. HESS J1640–465 AND HESS J1641–463: TWO INTRIGUING TeV SOURCES IN LIGHT OF NEW FERMI -LAT OBSERVATIONS. United States. https://doi.org/10.1088/2041-8205/794/1/L16
Lemoine-Goumard, M., Grondin, M. -H., Acero, F., Ballet, J., Laffon, H., and Reposeur, T.. Tue . "HESS J1640–465 AND HESS J1641–463: TWO INTRIGUING TeV SOURCES IN LIGHT OF NEW FERMI -LAT OBSERVATIONS". United States. https://doi.org/10.1088/2041-8205/794/1/L16. https://www.osti.gov/servlets/purl/1356449.
@article{osti_1356449,
title = {HESS J1640–465 AND HESS J1641–463: TWO INTRIGUING TeV SOURCES IN LIGHT OF NEW FERMI -LAT OBSERVATIONS},
author = {Lemoine-Goumard, M. and Grondin, M. -H. and Acero, F. and Ballet, J. and Laffon, H. and Reposeur, T.},
abstractNote = {We report on γ-ray analysis of the region containing the bright TeV source HESS J1640-465 and the closeby TeV source HESS J1641-463 using 64 months of observationswith the Fermi Large Area Telescope (LAT). Previously only one GeV source was reported in this region and was associated with HESS J1640-465. With an increased dataset and the improved sensitivity afforded by the reprocessed data (P7REP) of the LAT, we now report the detection, morphological study and spectral analysis of two distinct sources above 100 MeV. The softest emission in this region comes from the TeV source HESS J1641-463 which is well fitted with a power law of index Γ = 2.47 ± 0.05 ± 0.06 and presents no significant γ-ray signal above 10 GeV, which contrasts with its hard spectrum at TeV energies. The Fermi-LAT spectrum of the second TeV source, HESS J1640-465 is well described by a power-law shape of index Γ = 1.99 ± 0.04 ± 0.07 that links up naturally with the spectral data points obtained by the High Energy Stereoscopic System (H.E.S.S.). These new results provide new constraints concerning the identification of these two puzzling γ-ray sources.},
doi = {10.1088/2041-8205/794/1/L16},
url = {https://www.osti.gov/biblio/1356449}, journal = {The Astrophysical Journal. Letters},
issn = {2041-8213},
number = 1,
volume = 794,
place = {United States},
year = {2014},
month = {9}
}

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Cited by: 7 works
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Works referenced in this record:

FERMI LAT DISCOVERY OF EXTENDED GAMMA-RAY EMISSION IN THE DIRECTION OF SUPERNOVA REMNANT W51C
journal, October 2009


OBSERVATION OF SUPERNOVA REMNANT IC 443 WITH THE FERMI LARGE AREA TELESCOPE
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Discovery of the source HESS J1356-645 associated with the young and energetic PSR J1357-6429
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HESS J1640-465 - an exceptionally luminous TeV  -ray supernova remnant
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Discovery of the hard Spectrum vhe γ-Ray Source hess J1641–463
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THE LARGE AREA TELESCOPE ON THE FERMI GAMMA-RAY SPACE TELESCOPE MISSION
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XMM‐Newton Observations Reveal the X‐Ray Counterpart of the Very High Energy Gamma‐Ray Source HESS J1640−465
journal, June 2007


NuSTAR DISCOVERY OF A YOUNG, ENERGETIC PULSAR ASSOCIATED WITH THE LUMINOUS GAMMA-RAY SOURCE HESS J1640–465
journal, June 2014


Long-Term Monitoring of the High-Energy γ-Ray Emission from ls i +61°303 and ls 5039
journal, March 2012


The distance and neutral environment of the massive stellar cluster Westerlund 1
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SEARCH FOR SPATIALLY EXTENDED FERMI LARGE AREA TELESCOPE SOURCES USING TWO YEARS OF DATA
journal, August 2012


High-Resolution X-Ray Observations of the Pulsar wind Nebula Associated with the Gamma-Ray Source hess J1640–465
journal, November 2009


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journal, August 2010


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    Works referencing / citing this record:

    Interstellar gas towards the TeV γ-ray sources HESS J1640−465 and HESS J1641−463
    journal, October 2016


    Interstellar gas towards the TeV γ-ray sources HESS J1640−465 and HESS J1641−463
    text, January 2017