Detection of Sub-TeV Gamma Rays from the Galactic Center Direction by CANGAROO-II

Abstract

We have detected sub-TeV gamma-ray emission from the direction of the Galactic center (GC) using the CANGAROO-II Imaging Atmospheric Cerenkov Telescope. We detected a statistically significant excess at energies greater than 250 GeV. The flux was 1 order of magnitude lower than that of the Crab Nebula at 1 TeV with a soft spectrum proportional to . The signal centroid is consistent with the GC direction, and the Ϫ4.6‫5.0ע‬E observed profile is consistent with a pointlike source. Our data suggest that the GeV source 3EG J1746Ϫ2851 is identical to this TeV source, and we study the combined spectra to determine the possible origin of the gammaray emission. We also obtain an upper limit on the cold dark matter density in the Galactic halo.

Discovery of very-high-energy γ-rays from the Galactic Centre ridge

“…Early H.E.S.S. observations of the GC region led to the detection of a point-like source of VHE γ-rays at the gravitational centre of the Galaxy (HESS J1745−290) [6], compatible with the positions of the supermassive black hole Sagittarius A ⋆ , the supernova remnant (SNR) Sgr A East, and a GC source reported by other groups [7,8]. A more sensitive exposure of the region in 2004 revealed a second source: the supernova remnant/pulsar wind nebula G 0.9+0.1 [9].…”

Hidden fermion as milli-charged dark matter in StueckelbergZ′ model

“…In the Galactic center region, excesses of γ-rays were also reported by VERITAS [25] in the range above 2.8 TeV and by CANGAROO collaborations [26] in the range of 250 GeV to 1 TeV. Such excesses are also hard to be explained by conventional dark matter candidates.…”

Черенковские Гамма-Телескопы: Прошлое, Настоящее, Будущее. Проект ALEGRO

“…Помимо упомянутых выше в 1980-х г. было осу-ществлено еще несколько проектов черенковских гамма-телескопов, таких как CAT (Франция [27]), CANGAROO (Япония, Австралия [28]), его значительно более эф-фективная модификация CANGAROO II (см., напри-мер, [29]), TACTIC (Индия [30]), серия телескопов Mark 1−6 (Великобритания, с размещением в США, Ав-стралии и на Канарских островах, см., например, [31,32] и ссылки там же), ШАЛОН (Россия [33]) и др. Все эти инструменты, которые принято также относить ко второ-му поколению черенковских гамма-телескопов, работали в тераэлектроновольтном диапазоне энергий первичных частиц.…”