Very high energy gamma rays from the direction of Sagittarius A

Aharonian, F
Akhperjanian, AG
Aye, KM
Bazer-Bachi, AR
Beilicke, M
Benbow, W
Berge, D
Berghaus, P
Bernlohr, K
Bolz, O
Boisson, C
Borgmeier, C
Breitling, F
Brown, AM
Gordo, JB
Chadwick, PM
Chitnis, VR
Chounet, LM
Cornils, R
Costamante, L
Degrange, B
Djannati-Atai, A
Drury, LO
Ergin, Tülün
Espigat, P
Feinstein, F
Fleury, P
Fontaine, G
Funk, S
Gallant, Y
Giebels, B
Gillessen, S
Goret, P
Guy, J
Hadjichristidis, C
Hauser, M
Heinzelmann, G
Henri, G
Hermann, G
Hinton, JA
Hofmann, W
Holleran, M
Horns, D
de Jager, OC
Jung, I
Khelifi, B
Komin, N
Konopelko, A
Latham, IJ
Le Gallou, R
Lemoine, M
Lemiere, A
Leroy, N
Lohse, T
Marcowith, A
Masterson, C
McComb, TJL
de Naurois, M
Nolan, SJ
Noutsos, A
Orford, KJ
Osborne, JL
Ouchrif, M
Panter, M
Pelletier, G
Pita, S
Pohl, M
Puhlhofer, G
Punch, M
Raubenheimer, BC
Raue, M
Raux, J
Rayner, SM
Redondo, I
Reimer, A
Reimer, O
Ripken, J
Rivoal, M
Rob, L
Rolland, L
Rowell, G
Sahakian, V
Sauge, L
Schlenker, S
Schlickeiser, R
Schuster, C
Schwanke, U
Siewert, M
Sol, H
Steenkamp, R
Stegmann, C
Tavernet, JP
Theoret, CG
Tluczykont, M
van der Walt, DJ
Vasileiadis, G
Vincent, P
Visser, B
Volk, HJ
Wagner, SJ
We report the detection of a point-like source of very high energy (VHE) gamma-rays coincident within 1' of Sgr A* obtained with the HESS array of Cherenkov telescopes. The gamma-rays exhibit a power-law energy spectrum with a spectral index of -2.2+/-0.09+/-0.15 and a flux above the 165 GeV threshold of (1.82+/-0.22)x10(-7) m(-2) s(-1). The measured flux and spectrum differ substantially from recent results reported in particular by the CANGAROO collaboration.


HESS observations of PKS 2155-304
Aharonian, F; et. al. (2005-02-01)
The high-frequency peaked BL Lac PKS 2155-304 at redshift z=0.117 has been detected with high significance (similar to45sigma) at energies greater than 160 GeV, using the H.E.S.S. stereoscopic array of imaging air-Cherenkov telescopes in Namibia. A strong signal is found in each of the data sets corresponding to the dark periods of July and October, 2002, and June-September, 2003. The observed flux of VHE gamma rays shows variability on time scales of months, days, and hours. The monthly-averaged integral f...
Very high energy gamma rays from the composite SNR G0.9+0.1
Aharonian, F; et. al. (EDP Sciences, 2005-03-01)
Very high energy (> 100 GeV) gamma-ray emission has been detected for the first time from the composite supernova remnant G0.9+ 0.1 using the HESS instrument. The source is detected with a significance of approximate to 13sigma, and a photon flux above 200 GeV of ( 5.7 +/- 0.7(stat) +/- 1.2(sys)) x 10(-12) cm(-2) s(-1), making it one of the weakest sources ever detected at TeV energies. The photon spectrum is compatible with a power law ( dN/dE proportional to E-Gamma) with photon index Gamma = 2.40 +/- 0.1...
VERITAS discovery of > 200 GeV gamma-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae
Acciari, V. A.; et. al. (IOP Publishing, 2008-09-10)
We report the detection of very high energy gamma- ray emission from the intermediate- frequency- peaked BL Lacertae object W Comae (z = 0.102) by VERITAS. The source was observed between 2008 January and April. A strong outburst of gamma-ray emission was measured in the middle of March, lasting for only 4 days. The energy spectrum measured during the two highest flare nights is fit by a power law and is found to be very steep, with a differential photon spectral index of Gamma = 3.81 +/- 0.35(stat) +/- 0.3...
Strange particle production in pp collisions at root s=0.9 and 7 TeV
Khachatryan, V.; et. al. (Springer Science and Business Media LLC, 2011-05-01)
The spectra of strange hadrons are measured in proton-proton collisions, recorded by the CMS experiment at the CERN LHC, at centre-of-mass energies of 0.9 and 7TeV. The K-S(0), A, and Xi(-) particles and their antiparticles are reconstructed from their decay topologies and the production rates are measured as functions of rapidity and transverse momentum, p(T). The results are compared to other experiments and to predictions of the PYTHIA Monte Carlo program. The p(T) distributions are found to differ subst...
Investigating the region of 3C 397 in High Energy Gamma rays
Bhattacharjee, Pooja; Majumdar, Pratik; Ergin, Tülün; Saha, Lab; Joarder, Partha S. (2017-02-24)
We investigate the supernova remnant (SNR) 3C 397 and its neighboring pulsar PSR J1906+0722 in high energy gamma rays by using nearly six years of archival data of Large Area Telescope on board Fermi Gamma Ray Space Telescope (Fermi-LAT). The off-pulse analysis of gamma-ray flux from the location of PSR J1906+0722 reveals an excess emission which is found to be very close to the radio location of 3C 397. Here, we present the preliminary results of this gamma-ray analysis of 3C 397 and PSR J1906+0722.
Citation Formats
F. Aharonian et al., “Very high energy gamma rays from the direction of Sagittarius A,” ASTRONOMY & ASTROPHYSICS, pp. 0–0, 2004, Accessed: 00, 2020. [Online]. Available: