J. Cotzomi

Dark Matter Limits from Dwarf Spheroidal Galaxies with the HAWC Gamma-Ray Observatory

The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field of view observatory sensitive to 500 GeV - 100 TeV gamma rays and cosmic rays. It can also perform diverse indirect searches for dark matter (DM) annihilation and decay. Among the most promising targets for the indirect detection of dark matter are dwarf spheroidal galaxies. These objects are expected to have few astrophysical sources of gamma rays but high dark matter content, making them ideal candidates for an indirect dark matter detection with gamma rays. Here we present individual limits on the annihilation cross section and decay lifetime for 15 dwarf spheroidal galaxies within the HAWC field-of-view, as well as their combined limit. These are the first limits on the annihilation cross section and decay lifetime using data collected with HAWC.

Results from the Puebla extensive air shower detector array

Abstract We describe the design and operation of the first stage of the EAS-UAP extensive air shower array, as a detector of very high energy cosmic rays ( E o > 10 14 eV ). The array is located at the Campus of Puebla University and consists of 18 liquid scintillator detectors, with an active surface of 1 m 2 each and a detector spacing of 20 m in a square grid. In this report we discuss the stability and the calibration of the detector array, as derived from the 10 detectors in operation in the first stage. The main characteristics of the array allow us also to use it as an educational and training facility. First distributions of the arrival direction and the lateral shower srpead are also given.

Extensive Air Shower Array at the University of Puebla (EAS‐BUAP)

We describe the design and operation of the first stage of the EAS‐UAP extensive air shower array, as a detector of very high energy cosmic rays (1016 > Eo > 1014eV). The array is located at the Campus of Puebla University. It consist of 18 liquid scintillator detectors, with an active surface of 1 m2 each and a detector spacing of 20 m in a square grid. One Auger Water Cherenkov detector is also included as part of the array. In this report we discuss the stability, the calibration, the arrival direction and lateral distribution function reconstruction capabilities of the detector array, as derived from the 10 detectors in operation in the first stage. Our results shows that the angular accuracy in arrival direction is less than 5.5° in the range from 20° to 60°. The measurements in the Water Cherenkov Detector show us the possibility to separete electromagnetic and muon component. The main characteristics of the array allow us also to use it as educational and training facility.

Signal Temporal Profile of a Water Cherenkov Detector

The suggested existence of temporal structure in the signals of extensive air showers (EAS) for energies greater than 1017 eV at core distances of about 500 m, and its correlation with important parameters of EASs has stimulated us to study this structure for showers with lower energies in an Auger water Cherenkov detector(WCD). Preliminary analysis of experimental data on the widths of signals in a WCD and their correlation with other parameters of the signal are presented. The detector was triggered by the EAS‐BUAP array which operates in the region of 1014 – 1016 eV. The distance of the WCD to the EAS core is larger than 30 m.

Extensive Air Shower Detector Array at the Universidad Autonoma de Puebla

We describe the operation of an Extensive Air Shower Array located at the campus of the FCFM‐BUAP. The array consists of 8 liquid scintillation detectors with a surface of 1 m2 each and a detector spacing of 20 m in a square grid. The array was designed to measure the energy and arrival direction of primary particles that generate extensive air showers (EAS) in the region of 1013 eV – 1016 eV. The angular distribution measured with this array, Cos8(Θ)×Sin(Θ), agrees very well with the literature. We also present the measured energies of a number of vertical showers in the range of 5×1012 eV to 5×1013 eV.