OBSERVATION OF TeV GAMMA RAYS FROM THE UNIDENTIFIED SOURCE HESS J1841-055 WITH THE ARGO-YBJ EXPERIMENT

Journal Article · Sat Apr 20 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/767/2/99· OSTI ID:22126947

Bartoli, B.; Catalanotti, S. ^[1]; Bernardini, P.; D'Amone, A. ^[2]; Bi, X. J.; Cao, Z.; Chen, S. Z.; Chen, Y. ^[3]; Bolognino, I. ^[4]; Branchini, P.; Budano, A. ^[5]; Calabrese Melcarne, A. K. ^[6]; Camarri, P. ^[7]; Cardarelli, R. ^[8]; Cattaneo, C. ^[9]; Chen, T. L. ^[10]; Creti, P. ^[11]; Cui, S. W. ^[12]; Dai, B. Z. ^[13]; others, and

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1. Dipartimento di Fisica dell'Universita di Napoli ''Federico II'', Complesso Universitario di Monte Sant'Angelo, via Cinthia, I-80126 Napoli (Italy)
2. Dipartimento Matematica e Fisica ''Ennio De Giorgi'', Universita del Salento, via per Arnesano, I-73100 Lecce (Italy)
3. Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918, 100049 Beijing (China)
4. Dipartimento di Fisica dell'Universita di Pavia, via Bassi 6, I-27100 Pavia (Italy)
5. Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy)
6. Istituto Nazionale di Fisica Nucleare-CNAF, Viale Berti-Pichat 6/2, I-40127 Bologna (Italy)
7. Dipartimento di Fisica dell'Universita di Roma ''Tor Vergata'', via della Ricerca Scientifica 1, I-00133 Roma (Italy)
8. Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tor Vergata, via della Ricerca Scientifica 1, I-00133 Roma (Italy)
9. Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, via Bassi 6, I-27100 Pavia (Italy)
10. Tibet University, 850000 Lhasa, Xizang (China)
11. Istituto Nazionale di Fisica Nucleare, Sezione di Lecce, via per Arnesano, I-73100 Lecce (Italy)
12. Hebei Normal University, Shijiazhuang 050016, Hebei (China)
13. Yunnan University, 2 North Cuihu Road, 650091 Kunming, Yunnan (China)

We report the observation of a very high energy {gamma}-ray source whose position is coincident with HESS J1841-055. This source has been observed for 4.5 years by the ARGO-YBJ experiment from 2007 November to 2012 July. Its emission is detected with a statistical significance of 5.3 standard deviations. Parameterizing the source shape with a two-dimensional Gaussian function, we estimate an extension {sigma}=(0.40{sup +0.32}{sub -0.22}){sup o}, which is consistent with the HESS measurement. The observed energy spectrum is dN/dE = (9.0 {+-} 1.6) Multiplication-Sign 10{sup -13}(E/5 TeV){sup -2.32{+-}0.23} photons cm{sup -2} s{sup -1} TeV{sup -1}, in the energy range 0.9-50 TeV. The integral {gamma}-ray flux above 1 TeV is 1.3 {+-} 0.4 Crab, which is 3.2 {+-} 1.0 times the flux derived by HESS. The differences in the flux determination between HESS and ARGO-YBJ and possible counterparts at other wavelengths are discussed.

• OSTI ID: 22126947
• Journal Information: Astrophysical Journal, Vol. 767, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
EMISSION
ENERGY SPECTRA
GAMMA RADIATION
GAUSS FUNCTION
INTEGRALS
PHOTONS
STANDARDS
TEV RANGE
TWO-DIMENSIONAL CALCULATIONS
WAVELENGTHS