ALPACA project to observe sub-PeV gamma-ray sky in the southern hemisphere
T. Sako*,
M. Anzorena,
E. de la Fuente,
K. Fujita,
R. Garcia,
K. Goto,
Y. Hayashi, K. Hibino, N. Hotta, G. Imaizumi, A. Jimenez-Meza, Y. Katayose, C. Kato, S. Kato, T. Kawashima, K. Kawata, T. Koi, H. Kojima, T. Makishima, Y. Masuda, S. Matsuhashi, M. Matsumoto, R. Mayta, P. Miranda, A. Mizuno, K. Munakata, Y. Nakamura, M. Nishizawa, Y. Noguchi, S. Ogio, M. Ohnishi, S. Okukawa, A. Oshima, M. Raljevich, H. Rivera, T. Saito, T.K. Sako, T. Shibasaki, S. Shibata, A. Shiomi, M. Subieta, F. Sugimoto, N. Tajima, W. Takano, M. Takita, Y. Tameda, K. Tanaka, R. Ticona, I. Toledano-Juarez, H. Tsuchiya, Y. Tsunesada, S. Udo, R. Usui, G. Yamagishi, K. Yamazaki and Y. Yokoeet al. (click to show)*: corresponding author
Pre-published on:
March 21, 2025
Published on:
—
Abstract
Though the maximum energy of the charged cosmic ray observations exceeds 100 EeV, the energy frontier of the gamma-ray observations is PeV. In the past years, Tibet AS𝛾, HAWC and LHAASO opened a new window of astronomy in the sub-PeV to PeV range, which is important to unveil yet unknown PeV cosmic accelerators in our galaxy. As these 3 experiments are all located in the northern hemisphere, observations in the southern hemisphere have been awaited. Andes Large area PArticle detector for Cosmic ray physics and Astronomy (ALPACA) is a new air shower array experiment under construction in the Bolivian Andes to explore the southern gamma-ray sky for the first time in this energy range. In this paper, we will provide an overview of the ALPACA project, including the initial observational results from a quarter-sized array named ALPAQUITA, which has been operating since 2023. A successful detection of the shadow of the moon, for example, validates the designed performance of the array. We will also outline the plan for the full-scale construction of ALPACA.
DOI: https://doi.org/10.22323/1.484.0112
How to cite
Metadata are provided both in
article format (very
similar to INSPIRE)
as this helps creating very compact bibliographies which
can be beneficial to authors and readers, and in
proceeding format which
is more detailed and complete.