GAMMA-RAY ASTRONOMY WITH THE HAWC OBSERVATORY

2014 ◽  
Vol 28 ◽  
pp. 1460185
Author(s):  
◽  
ROBERT J. LAUER
Keyword(s):  
Gamma Ray ◽  
Modular Design ◽  
Photon Emission ◽  
Smooth Transition ◽  
Wide Field ◽  
The Status ◽  
Transient Events ◽  
And Performance ◽  
Gamma Ray Detector ◽  
Water Cherenkov Detectors

The High Altitude Water Cherenkov (HAWC) Observatory is a wide field-of-view gamma-ray detector, sensitive to primary energies between 50 GeV and 100 TeV. The array is being built at an altitude of 4,100 m on the Sierra Negra volcano in Puebla, Mexico. With a duty cycle close to 100% and a daily coverage of ~ 8 sr of the sky above it, HAWC is ideally suited to detect bright transient events at TeV energies such as gamma-ray bursts or flares from active galactic nuclei. The array will provide an unbiased survey of gamma-ray sources at energies above 100 GeV and probe the origins of astrophysical photon emission at the highest energies. The modular design of HAWC made it possible to start data taking in September 2012 with a partial array. Operation continues while the number of water Cherenkov detectors is growing, which allowed a smooth transition to full scientific operation with 111 detectors in August 2013. The completion of the full array with 300 detectors is planned for the summer of 2014. In these proceedings, we will give an overview of the status and performance of the HAWC observatory and discuss observation strategies for various gamma-ray phenomena.

scholarly journals Design and performance of soft gamma-ray detector for NeXT mission

2005 ◽  
Author(s):  
H. Tajima ◽  
T. Kamae ◽  
G. Madejski ◽  
T. Mitani ◽  
K. Nakazawa ◽  
...  
Keyword(s):  
Gamma Ray ◽  
And Performance ◽  
Gamma Ray Detector

scholarly journals Design and performance of the soft gamma-ray detector for the NeXT mission

2005 ◽  
Vol 52 (6) ◽  
pp. 2749-2757 ◽  
Author(s):  
H. Tajima ◽  
T. Kamae ◽  
G. Madejski ◽  
T. Mitani ◽  
K. Nakazawa ◽  
...  
Keyword(s):  
Gamma Ray ◽  
And Performance ◽  
Gamma Ray Detector

scholarly journals First results from HAWC: monitoring the TeV gamma-ray sky

2014 ◽  
Vol 10 (S313) ◽  
pp. 70-75
Author(s):  
Robert J. Lauer ◽  
Keyword(s):  
Gamma Ray ◽  
Wide Field ◽  
Air Showers ◽  
Cherenkov Telescopes ◽  
Extragalactic Jets ◽  
First Results ◽  
Multi Wavelength ◽  
Pass Through ◽  
Gamma Ray Detector ◽  
Sierra Negra Volcano

AbstractThe High Altitude Water Cherenkov (HAWC) Observatory is a wide-field gamma-ray detector sensitive to primary energies between 100 GeV and 100 TeV. The array is being built at an altitude of 4100 m a.s.l. on the Sierra Negra volcano near Puebla, Mexico. Data taking has already started while construction continues, with the completion projected for early 2015. The design is optimized to detect extended air showers induced by gamma rays that pass through the array and to reconstruct the directions and energies of the primary photons. With a duty cycle close to 100% and a daily coverage of ~8 sr of the sky, HAWC will perform a survey of TeV emissions from many different sources. The northern active galactic nuclei will be monitored for up to 6 hours each day, providing unprecedented light curve coverage at energies comparable to those of imaging air Cherenkov telescopes. HAWC has been in scientific operation with more than 100 detector modules since August 2013. Here we present a preliminary look at the first results and discuss the efforts to integrate HAWC in multi-wavelength studies of extragalactic jets.

scholarly journals Design and performance of Soft Gamma-ray Detector onboard the Hitomi (ASTRO-H) satellite

2018 ◽  
Vol 4 (02) ◽  
pp. 1 ◽  
Author(s):  
Hiroyasu Tajima ◽  
Shin Watanabe ◽  
Yasushi Fukazawa ◽  
Roger Blandford
Keyword(s):  
Gamma Ray ◽  
And Performance ◽  
Gamma Ray Detector

Pathways ahead for New Zealand hill country farming

2016 ◽  
Vol 78 ◽  
pp. 73-82 ◽  
Author(s):  
F.G. Scrimgeour
Keyword(s):  
New Zealand ◽  
Rural Communities ◽  
New Technologies ◽  
Service Providers ◽  
Farming Systems ◽  
Hill Country ◽  
The Status ◽  
And Performance ◽  
Hill Farming ◽  
The Hill

This paper provides a stocktake of the status of hill country farming in New Zealand and addresses the challenges which will determine its future state and performance. It arises out of the Hill Country Symposium, held in Rotorua, New Zealand, 12-13 April 2016. This paper surveys people, policy, business and change, farming systems for hill country, soil nutrients and the environment, plants for hill country, animals, animal feeding and productivity, and strategies for achieving sustainable outcomes in the hill country. This paper concludes by identifying approaches to: support current and future hill country farmers and service providers, to effectively and efficiently deal with change; link hill farming businesses to effective value chains and new markets to achieve sufficient and stable profitability; reward farmers for the careful management of natural resources on their farm; ensure that new technologies which improve the efficient use of input resources are developed; and strategies to achieve vibrant rural communities which strengthen hill country farming businesses and their service providers. Keywords: farming systems, hill country, people, policy, productivity, profitability, sustainability

Study on Common Ground Testing Platform Technology for Telemetry Core Equipment

2012 ◽  
Vol 220-223 ◽  
pp. 1472-1475
Author(s):  
Qiu Lin Tan ◽  
Xiang Dong Pei ◽  
Si Min Zhu ◽  
Ji Jun Xiong
Keyword(s):  
Data Exchange ◽  
Common Ground ◽  
Digital Signal ◽  
Test System ◽  
Automatic Test System ◽  
Module Design ◽  
The Status ◽  
Output Module ◽  
And Performance ◽  
Hardware Circuit

On the basis of automatic test system of the status in domestic and foreign, by analysis of the various functions and performance of the integrated test system, a design of the integrated test system is proposed, FPGA as the core logic controller of the hardware circuit. The system of the hardware design include: digital signal source output modules, analog output module and PCM codec module. Design of hardware circuit are mainly described. In addition, a detailed analysis of some key technologies in the design process was given. Overall, its data exchange with host computer is through the PCI card, data link and bandwidth can be expanded in accordance with the actual needs. The entire system designed in the modular principle, which has a strong scalability.

scholarly journals Spin-one dark matter and gamma ray signals from the galactic center

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
H. Hernández-Arellano ◽  
M. Napsuciale ◽  
S. Rodríguez
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Gamma Ray ◽  
Galactic Center ◽  
Photon Emission ◽  
Scalar Coupling ◽  
Initial State ◽  
Internal Bremsstrahlung ◽  
Resonance Effects ◽  
State Radiation

Abstract In this work we study the possibility that the gamma ray excess (GRE) at the Milky Way galactic center come from the annihilation of dark matter with a (1, 0) ⊕ (0, 1) space-time structure (spin-one dark matter, SODM). We calculate the production of prompt photons from initial state radiation, internal bremsstrahlung, final state radiation including the emission from the decay products of the μ, τ or hadronization of quarks. Next we study the delayed photon emission from the inverse Compton scattering (ICS) of electrons (produced directly or in the prompt decay of μ, τ leptons or in the hadronization of quarks produced in the annihilation of SODM) with the cosmic microwave background or starlight. All these mechanisms yield significant contributions only for Higgs resonant exchange, i.e. for M ≈ MH /2, and the results depend on the Higgs scalar coupling to SODM, gs. The dominant mechanism at the GRE bump is the prompt photon production in the hadronization of b quarks produced in $$ \overline{D}D\to \overline{b}b $$ D ¯ D → b ¯ b , whereas the delayed photon emission from the ICS of electrons coming from the hadronization of b quarks produced in the same reaction dominates at low energies (ω < 0.3 GeV ) and prompt photons from c and τ , as well as from internal bremsstrahlung, yield competitive contributions at the end point of the spectrum (ω ≥ 30 GeV ). Taking into account all these contributions, our results for photons produced in the annihilation of SODM are in good agreement with the GRE data for gs ∈ [0.98, 1.01] × 10−3 and M ∈ [62.470, 62.505] GeV . We study the consistency of the corresponding results for the dark matter relic density, the spin-independent dark matter-nucleon cross-section σp and the cross section for the annihilation of dark matter into $$ \overline{b}b $$ b ¯ b , τ+τ−, μ+μ− and γγ, taking into account the Higgs resonance effects, finding consistent results in all cases.

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