68 research outputs found
VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory
VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l.
in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design,
construction techniques and data acquisition system of the HAWC observatory.
HAWC is an air-shower array currently under construction at the same site of
VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water
Cherenkov detectors and two different data acquisition systems. It was in
operation between October 2011 and May 2012 with an average live time of 30%.
Besides the scientific verification purposes, the eight months of data were
used to obtain the results presented in this paper: the detector response to
the Forbush decrease of March 2012, and the analysis of possible emission, at
energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages,
10 figures). Corresponding authors: A.Marinelli and D.Zaboro
Milagro limits and HAWC sensitivity for the rate-density of evaporating Primordial Black Holes
postprin
A Contribution of the HAWC Observatory to the TeV era in the High Energy Gamma-Ray Astrophysics: The case of the TeV-Halos
We present a short overview of the TeV-Halos objects as a discovery and a
relevant contribution of the High Altitude Water \v{C}erenkov (HAWC)
observatory to TeV astrophysics. We discuss history, discovery, knowledge, and
the next step through a new and more detailed analysis than the original study
in 2017. TeV-Halos will contribute to resolving the problem of the local
positron excess observed on the Earth. To clarify the latter, understanding the
diffusion process is mandatory.Comment: Work presented in the 21st International Symposium on Very High
Energy Cosmic Ray Interactions(ISVHECRI 2022) as part of the Ph. D. Thesis of
Ramiro Torres-Escobedo (SJTU, Shanghai, China). Accepted for publication in
SciPost Physics Proceedings (ISSN 2666-4003). 11 pages, 3 Figures. Short
overview of HAWC and TeV Halos objects until 202
The High-Altitude Water Cherenkov (HAWC) Observatory in M\'exico: The Primary Detector
The High-Altitude Water Cherenkov (HAWC) observatory is a second-generation
continuously operated, wide field-of-view, TeV gamma-ray observatory. The HAWC
observatory and its analysis techniques build on experience of the Milagro
experiment in using ground-based water Cherenkov detectors for gamma-ray
astronomy. HAWC is located on the Sierra Negra volcano in M\'exico at an
elevation of 4100 meters above sea level. The completed HAWC observatory
principal detector (HAWC) consists of 300 closely spaced water Cherenkov
detectors, each equipped with four photomultiplier tubes to provide timing and
charge information to reconstruct the extensive air shower energy and arrival
direction. The HAWC observatory has been optimized to observe transient and
steady emission from sources of gamma rays within an energy range from several
hundred GeV to several hundred TeV. However, most of the air showers detected
are initiated by cosmic rays, allowing studies of cosmic rays also to be
performed. This paper describes the characteristics of the HAWC main array and
its hardware.Comment: Accepted for publications in Nuclear Inst. and Methods in Physics
Research, A (2023) 168253 (
https://www.sciencedirect.com/science/article/abs/pii/S0168900223002437 ); 39
pages, 14 Figure
Biodiversity of Arbuscular Mycorrhizal Fungi in South America: A Review
Identification of species is crucial in understanding how diversity changes affect ecosystemic processes. Particularly, soil microbial are key factors of ecosystemic functioning .Among soil microbes, arbuscular mycorrhizal fungi (AMF, phylum Glomeromycota) are worldwide distributed and form symbiotic associations with almost 80% of the vascular plants of the earth, except for one species, Geosiphon pyriformis, which associates with the cyanobacteria Nostoc. AMF comprise around 300 morphologically defined or 350–1000 molecularly defined taxa. Since AMF associate with aboveground community, their occurrence and composition can influence ecosystemic processes either through affecting plant community composition and thus its processes rates, or soil microbial communities, which are directly involved in nutrient cycling. Soil microorganisms are considered a potentially suitable target for studying regional and local effects on diversity. The symbiosis with AMF not only increases nutrient uptake by the plant of mainly phosphorus (P) and nitrogen (N) in exchange for plant-assimilated carbon (C), but also improves the tolerance of plants to various biotic and abiotic stresses such as pathogens, salinity, and drought
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