arXiv subjects

M. Magdalena Gonzalez

Publications and source records attributed to M. Magdalena Gonzalez.

3 recordsLinked to original sources

arXiv2019

Search for very-high-energy emission with HAWC from GW170817 event

The detection of the gravitational wave GW170817 defined a breakthrough in multi-messenger astronomy. For the first time, a gravitational wave transient detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo interferometer was associated with a faint electromagnetic gamma-ray counterpart reported by the Gamma-ray Burst Monitor (GBM) aboard on the Fermi satellite. GRB 170817A was followed up by an enormous observational campaign covering a large fraction of the electromagnetic spectrum. In this work, we use the data from High Altitude Water Cherenkov (HAWC) gamma-ray observatory to search for very-high-energy (VHE) TeV photons in coincidence with the X-ray emission from GRB 170817A. Since no counts were observed up to $\sim$120 days after the trigger time, we derive and report the corresponding upper limits in the energy range from 1 to 100 TeV. In addition, we extend the analysis to GRBs with similar features proposed by A. von Kienlin.

astro-ph.HE↗

arXiv2012

SSC Emission as the Origin of the Gamma Ray Afterglow Observed in GRB 980923

GRB 980923 was one of the brightest bursts observed by the Burst and Transient Source Experiment (BATSE). Previous studies have detected two distinct components in addition to the main prompt episode, which is well described by a Band function. The first of these is a tail with a duration of approx. 400s, while the second is a high-energy component lasting approx. 2s. We summarize the observations, and argue for a unified model in which the tail can be understood as the early gamma-ray afterglow from forward shock synchrotron emission, while the high-energy component arises from synchrotron self-Comtpon (SSC) from the reverse shock. Consistency between the main assumption of thick shell emission and agreement between the observed and computed values for fluxes, break energies, starting times and spectral indices leads to a requirement that the ejecta be highly magnetized.

astro-ph.HE↗

arXiv2009

Performance of the first prototype of the HAWC Gamma Ray Observatory

The HAWC gamma ray observatory, to be constructed at Sierra Negra, Puebla in Mexico, is a large array of water Cherenkov detectors sited at an elevation of 4100 m, which has been optimized for gamma/hadron discrimination of the primary cosmic rays in the TeV energy range. It is based on the Milagro experience, but the design has been changed from a water pond to individual water tanks. In order to validate the design with large water tanks a prototype array has been constructed near the HAWC site with 3 of the largest commercial rotomolded plastic tanks available in Mexico. They have been instrumented with 20 cm hemispherical photomultiplier tubes and read out with 2 Gsample/s flash ADCs. The performance of a single tank has been measured as well as the response of the array to cosmic ray showers. In this paper we present the first measurements of the performance of the HAWC prototype array.

astro-ph.IM↗