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57-495: HAWC may refer to: High Altitude Water Cherenkov Experiment , a gamma-ray observatory in Mexico HAWC, a far-infrared telescope aboard NASA's SOFIA project Wacca Airport , Ethiopia, ICAO code HAWC Hypersonic Air-breathing Weapon Concept , a hypersonic weapon project Heavy Armored Weapon Chassis , a combat vehicle in the 1997 video game G-Nome Topics referred to by

114-541: A celebration was held at the Whipple Observatory to celebrate ten years of VERITAS science. VERITAS has a broad science program that combines key aspects of astronomy, exploring the universe in the new waveband of VHE gamma rays, and physics, searching for new particles of phenomena beyond the standard model of particle physics. The basic questions pursued include: understanding cosmic particle acceleration in our Galaxy (with special emphasis on understanding

171-411: A few GeV to above 10 eV. As yet there is no experimental proof of the transition from Galactic to extragalactic cosmic rays, though it is believed that cosmic rays below about 10 eV are of Galactic origin. While there is a consensus that supernovae (SN) explosions accelerate cosmic rays up to energies of ~10 eV, experimental evidence has been difficult to obtain. The theoretical arguments are based upon

228-463: A high-speed photomultiplier tube camera. Multiple telescopes in an array are needed for stereoscopic observations of the Cherenkov light produced in extensive air showers. These stereoscopic observations allow precise reconstruction of the particle shower geometry, thus giving greatly improved angular and energy resolution compared to a single telescope. The angular direction of the incoming shower

285-588: A low energy threshold. Compared to the Whipple telescope, VERITAS employs larger 12 m diameter reflectors, improved optics and light collection efficiency, and a finer pixelated camera. Both the recording (using 500 MS/s custom-made Flash-ADCs) and trigger electronics (using a sophisticated three-level system) were significantly improved compared to earlier instruments. VERITAS was conceived in the 1990s, along with three other imaging atmospheric Cherenkov telescope (IACT) arrays: CANGAROO-III, H.E.S.S. and MAGIC . VERITAS

342-755: A number of other institutions. The chair of the VERITAS Science Board is the Spokesperson. There is a Deputy Spokesperson to assist in the leadership of the collaboration. A chronological list of the VERITAS Spokespersons and Deputy Spokespersons is given in the table below. Starting in 2007, the Spokesperson/Deputy Spokesperson served a two-year term and may be re-elected. As of 2019, the following agencies provide operational funding for VERITAS:

399-561: Is currently the only IACT array operating in the western hemisphere. The first proposal for VERITAS (called VHEGRA at the time) was submitted by Trevor Weekes ( Smithsonian Astrophysical Observatory (SAO)) to the Smithsonian Institution in 1995; this proposal described an array of nine 10 m diameter Cherenkov telescopes. In 1998, the first VERITAS collaboration meeting was held at the University of Chicago . In 2000,

456-401: Is determined by finding the central axis of the spread of the shower on each telescope and tracing those axes until they cross. The intersection of these axes determines the incoming direction of the primary particle (cosmic ray or gamma ray) that initiated the air shower in the upper atmosphere. It also determines the shower core position, i.e. the extrapolated position of the primary particle on

513-652: Is different from Wikidata All article disambiguation pages All disambiguation pages High Altitude Water Cherenkov Experiment HAWC is a joint collaboration between a large number of American and Mexican universities and scientific institutions, including the University of Maryland , the National Autonomous University of Mexico , the National Institute of Astrophysics, Optics and Electronics , Los Alamos National Laboratory , NASA / Goddard Space Flight Center ,

570-409: Is sensitive to primary particles that produce sufficient atmospheric Cherenkov light to be detectable at the ground. Its full range of sensitivity is from 50 GeV to 50 TeV (although the spectral reconstruction does not start until at least 100 GeV, depending on source strength). The energy and angular resolution depend on the energy of the incident gamma ray but at 1 TeV the energy resolution is ~17%, and

627-438: Is straight forward to construct and align. This design does cause some time spread in the arrival of Cherenkov photons at the camera, but this spread is small (~ 4 nanoseconds). The reflector consists of 350 individual mirror facets, hexagonal in shape, mounted on a rigid optical support structure. The camera on each telescope has 499 individual pixels (high-speed 26 mm-diameter photomultiplier tubes ). VERITAS, like other IACTs ,

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684-556: Is the array trigger which looks for a coincidence in the arrival time of the shower at multiple telescopes. The Cherenkov light that is produced by gamma rays in the upper atmosphere is very dim, so VERITAS observes best under clear, dark skies. Observations are not possible under cloudy or rainy skies, or when the Moon is very bright. However, observations are regularly made when the Moon is dim or moderate in brightness (typically less than 60% illumination). The total yearly observation time

741-473: Is typically around 1,200 hours (of which around 200–250 hours is during brighter moonlight with illumination between 20 and 60%). The observatory does not generally collect data in July or August due to local monsoon conditions. VERITAS was designed to explore the very high energy (VHE) gamma-ray sky above 100 GeV , following up on the success of the Whipple 10 m gamma-ray telescope. The Whipple telescope pioneered

798-544: The Fermi Gamma-ray Space Telescope (Fermi) . HAWC has the ability to detect a large ensemble of gamma-ray sources, measuring their spectra and variability to characterize TeV scale acceleration mechanisms. In a one-year survey, HAWC can perform a deep, unbiased survey of the TeV gamma-ray with a 50 mCrab sensitivity at 5 σ . HAWC will observe hard- spectrum (high photon energies) Galactic sources in

855-725: The GeV – TeV photon energy range. VERITAS uses the Imaging Atmospheric Cherenkov Telescope technique to observe gamma rays that cause particle showers in Earth's atmosphere that are known as extensive air showers . The VERITAS array is located at the Fred Lawrence Whipple Observatory , in southern Arizona , United States . The VERITAS reflector design is similar to the earlier Whipple 10-meter gamma-ray telescope, located at

912-517: The United Kingdom . Improvements and upgrades to VERITAS have been made periodically since 2007. Telescope #1 was moved in the summer of 2009 to a new location for better array geometry (and improved gamma-ray sensitivity). Between 2009 and 2011 an upgrade program was carried out that improved the alignment of the VERITAS mirror facets and replaced the level 2 trigger system. Furthermore, in

969-578: The University of California, Santa Cruz , Michigan Technological University , Michigan State University , Benemérita Universidad Autónoma de Puebla , the Universidad de Guadalajara , the University of Utah , the University of New Mexico , the University of Wisconsin–Madison and the Georgia Institute of Technology . The HAWC Gamma-ray Observatory is a wide field of view , continuously operating, TeV gamma-ray telescope that explores

1026-477: The Zooniverse platform. The project showed images taken with VERITAS and citizen volunteers had to classify the images as muon or non-muon events. The researchers then trained a machine learned algorithm that performed better than the standard analysis. In Muon Hunter 2.0 the project will try to improve the result with a different machine learning approach. The VERITAS collaboration was officially formed by

1083-449: The Earth's atmosphere. HAWC is sensitive to showers produced by primary cosmic rays with energies between 100 GeV and 50 TeV. Cherenkov radiation occurs when charged particles travel through a medium at a speed faster than the speed of light in that medium. High-energy gamma rays, upon striking the upper atmosphere, can create positron - electron pairs that move at great speeds. The residual effect of these particles traveling through

1140-471: The Large Area Telescope (LAT) of the Fermi Gamma-ray Space Telescope due to its larger collection area as well as coverage in a higher energy band. VERITAS is constructed of four 12 m diameter Imaging Atmospheric Cherenkov Telescopes with an approximate separation of 100 m (330 ft) between each adjacent telescope. Each telescope comprises a large, steerable optical reflector and

1197-530: The TeV with a sensitivity similar to that of Fermi in the GeV, detect diffuse emission from regions of the Galactic plane , have sensitivity to see known TeV active galactic nuclei and the brightest known GeV gamma-ray bursts , and represents a large enough step in sensitivity to likely discover new phenomena. Because HAWC has a 2 steradian instantaneous field of view, it will observe diffuse gamma-ray emission from

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1254-847: The VERITAS collaboration consists of ~80 scientists from institutions in Canada, Germany, Ireland and the U.S. The participating institutions are: Barnard College , Columbia University , Cork Institute of Technology , DESY , Georgia Institute of Technology , Iowa State University , McGill University , National University of Ireland, Galway , Purdue University , Smithsonian Astrophysical Observatory , University College Dublin , University of California, Los Angeles , University of California, Santa Cruz , University of Chicago , University of Delaware , University of Iowa , University of Minnesota , University of Utah , and Washington University in St. Louis . There are also non-affiliated and associate members from

1311-539: The VHE range. The effective area of HAWC at 100 GeV (~100m ) is more than 100 times that of the Fermi-LAT. HAWC is a very sensitive detector for TeV cosmic rays. The large number of cosmic rays detected with HAWC forms an undesirable background in the search for gamma-ray sources, but it also permits precise measurements of small deviations from isotropy in the cosmic-ray flux. Over the last few years, cosmic-ray detectors in

1368-548: The angular resolution is 0.08 degrees (65% containment radius). The entire array has a peak effective area of 100,000 square meters above 1 TeV. A very weak astrophysical source with a gamma-ray flux only 1% of the Crab Nebula can be detected by VERITAS in under 25 hours of observation. Stronger sources can be detected in significantly less time. In order to distinguish between the background events (i.e. hadronic showers and muons ) or noise (i.e. starlight and moonlight) and

1425-515: The annihilation of dark matter particles. Most of these searches target the Galactic Center and dwarf spheroidal galaxies . Starting in 2017, the VERITAS science program was expanded to include observations in the optical waveband through high-time-resolution measurements of asteroid occultations and stellar intensity interferometry. As of 2020, VERITAS research had led to 58 Ph.D. 's and more than 100 peer-reviewed publications. As shown in

1482-400: The area of the detector will increase the sensitivity of the detector. The outriggers were predicted to increase the sensitivity and effective area of HAWC by 2 to 4 times for particles with energies above 10 TeV. The outrigger array was completed in early 2018, a year later than expected. HAWC detects electromagnetic radiation from air showers produced by high energy cosmic rays which hit

1539-451: The arrival direction distribution of cosmic rays to study the anisotropy with increased sensitivity is a major science goal for HAWC. High-energy astrophysical observations have the unique potential to explore fundamental physics. However, deriving fundamental physics from the astrophysical observations is complex and requires a deep understanding of the astrophysical sources. The astrophysics background must be understood in order to determine

1596-412: The atmosphere can result in a cascading shower of particles and photons that are aimed towards the surface at predictable angles. HAWC consists of large metal tanks, 7.3 m wide by 5 m high, containing a light-tight bladder holding 188,000 liters of water. Inside are four photomultiplier tubes (3-8" and 1-10" high QE). High-energy particles striking the water result in Cherenkov light that is detected by

1653-525: The concept of VERITAS as a seven telescope array was recommended by the 2000 Decadal Survey in Astronomy and Astrophysics as a moderate-sized project. Delays were incurred due to difficulties with two proposed sites in Arizona (Montosa Canyon at the base of Mount Hopkins and Kitt Peak ) and due to a reduction in available funding. The proposal for a four telescope array (now with 12 m diameter reflectors)

1710-555: The cosmic-ray flux and spectrum throughout the Galaxy. This information can be used to determine the regions within the Galaxy where particle acceleration has recently occurred. Over 20 Active Galactic Nuclei (AGN) have been detected in very high energy (VHE) gamma rays, and extreme flares of up to 50 times the quiescent flux have been observed. Gamma rays are produced via interactions of the high-energy electrons and/or protons with lower energy photons. There exist several models to explain

1767-465: The deviations from this background due to new physics. In some cases, astronomers can help with the understanding of the astrophysical background, such as using supernovae as standard candles to measure dark energy. However, high-energy physicists will have to detect and explain high energy astrophysical phenomena in order to derive the fundamental physics. The HAWC deep survey of the TeV gamma-ray sky will provide an unbiased picture necessary to characterize

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1824-547: The energy released in SN being sufficient to maintain the observed cosmic rays in the Galaxy, and the creation of strong shocks by SN enabling first order Fermi acceleration. Thus the tasks for future experiments are to confirm that supernovae are sites of the acceleration of hadronic cosmic rays up to the knee, and to determine the sources of the Galactic cosmic rays above 10 eV. The diffuse gamma radiation from our Galaxy also probes

1881-562: The enigmatic gamma-ray source at the Galactic Center . Extragalactic sources include active galactic nuclei , starburst galaxies , and gamma-ray bursts . An important component of VERITAS observations is that associated with multi-wavelength and multi-messenger follow up, including fast radio burst (FRB), high energy neutrino , and gravitational wave events. VERITAS has an extensive dark matter program, in which indirect searches are conducted to find VHE gamma rays resulting from

1938-459: The figure, VERITAS has detected 63 astrophysical sources of very high energy gamma rays (as of January 2020). The first VERITAS source catalog had only six sources. Some of the scientific highlights of VERITAS include: VERITAS researchers have also pioneered the use of an IACT to carry out Citizen Science . To improve the detection of muon events, the Muon Hunter project was created on

1995-507: The first measurement of the cosmic-ray spectrum, and new results on the observed positron excess of antimatter . In 2023 HAWC reported the first detection of gamma rays at TeV energies coming from the sun, produced by the interaction of cosmic rays with gas in the solar atmosphere. VERITAS VERITAS ( Very Energetic Radiation Imaging Telescope Array System ) is a major ground-based gamma-ray observatory with an array of four 12 meter optical reflectors for gamma-ray astronomy in

2052-409: The ground had it not interacted. The energy of the primary particle is determined from the total amount of Cherenkov light measured in each telescope, along with the distance of that telescope from the shower core. Each of the individual telescopes has a 12 m diameter aperture and a 3.5 degree field of view. The telescopes are built on a Davies-Cotton optical design, which uses a spherical reflector and

2109-437: The most extreme variability and probe the highest energy particles. HAWC will have the sensitivity to detect strong flares, such as those that have been observed from Markarian 421 , at greater than 10σ in under 30 minutes. The Fermi satellite has now observed both long and short gamma-ray bursts that emit multi-GeV gamma rays. No high energy cut off is observed in any of these GRBs, and the highest energy gamma ray observed in

2166-431: The most intense GeV emission occurs promptly, and also extends longer than the emission at lower energies. A wide field of view, high duty factor observatory, such as HAWC, is required to observe this prompt emission and determine its extent at high energies especially for a burst such as 090510, in which the prompt emission was less than half a second in duration. HAWC has the sensitivity to continue these observations into

2223-403: The northern and southern hemisphere have found anisotropy in the arrival direction distribution of TeV cosmic rays at the per-mille level. Since we expect the arrival directions of charged particles at these energies to be completely scrambled by Galactic magnetic fields, these deviations are surprising and imply that the propagation of cosmic rays from their sources to us is not understood. Mapping

2280-437: The origin of cosmic rays ) and beyond our Galaxy, probing extreme environments near compact objects such as neutron stars and black holes , the nature of dark matter and the intergalactic magnetic field, and whether the speed of light is constant at these extreme gamma-ray energies. The VERITAS observational program includes Galactic sources such as supernova remnants , pulsars , pulsar wind nebulae , binary systems and

2337-614: The origin of cosmic rays , study the acceleration of particles in extreme physical environments, and search for new TeV physics. HAWC was built at an elevation of 4100 m above sea level in Mexico by a collaboration of 15 US and 12 Mexican institutions, and it is operated with funding from the US National Science Foundation , the US Department of Energy and CONACyT (Mexico's science funding agency). HAWC

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2394-421: The origin of cosmic rays. This radiation is due to the interaction of hadronic cosmic rays with interstellar gas, and subsequent decay of neutral pions, and the interaction of high-energy electrons with gas and radiation fields (radio, microwave, infrared, optical, UV and magnetic). If the distribution of matter and radiation is known through other measurements, knowledge of the diffuse emission allows one to measure

2451-456: The photomultiplier tubes. HAWC uses the difference in arrival times of the light at different tanks to measure the direction of the primary particle. The pattern of light allows for discrimination between primary ( hadrons ) and gamma-rays. From this, scientists can map the sky using gamma-rays. HAWC will: The origin of the cosmic radiation has been a mystery since its discovery by Victor Hess in 1912. The cosmic-ray energy spectrum extends from

2508-459: The plane of the galaxy over a broad range of galactic longitudes reaching to the Galactic Center . In September 2015, a Laboratory Directed Research and Development grant was awarded to Brenda Dingus of Los Alamos National Laboratory to improve HAWC's effective area and sensitivity by adding an array of outrigger tanks, surrounding the larger central tanks. Due to the greater size of particle showers created by high energy cosmic rays, increasing

2565-620: The properties of the astrophysical sources in order to search for new fundamental physics effects. Examples of HAWC investigations include: HAWC construction and operation is funded jointly by the US National Science Foundation , the US Department of Energy Office of High-Energy Physics, and Consejo Nacional de Ciencia y Tecnología (CONACyT) in Mexico and the Laboratory Directed Research and Development (LDRD) program of Los Alamos National Laboratory. Other significant sources of funding are: In 2017, HAWC announced

2622-418: The same site, but is larger in size and has a longer focal length for better control of optical aberrations. VERITAS consists of an array of imaging telescopes deployed to view atmospheric Cherenkov showers from multiple locations to give the highest sensitivity in the 100 GeV – 10 TeV band (with sensitivity from 50 GeV to up to 50 TeV). This very high energy observatory, completed in 2007, effectively complements

2679-405: The same term [REDACTED] This disambiguation page lists articles associated with the title HAWC . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=HAWC&oldid=1048101118 " Category : Disambiguation pages Hidden categories: Short description

2736-559: The signing of a teaming agreement in 2000 between nine member institutions in three countries. The member institutions were: Iowa State University , Purdue University , Smithsonian Astrophysical Observatory , University of California, Los Angeles , University of Chicago , University of Utah , and Washington University in St. Louis in the U.S., University of Leeds in the U.K. and National University of Ireland Dublin in Ireland. A tenth member institution, McGill University in Canada,

2793-433: The source of photons including: synchrotron emission by the same population of electrons; radiation from the accretion disk ; and cosmic microwave background photons. Simultaneous observations using multiple wavelengths and multi-messenger approaches are required to distinguish among these models. Monitoring at VHE energies is an efficient mechanism to initiate such observations because the highest energy gamma rays exhibit

2850-426: The summer of 2012 all of the camera photomultiplier tubes were upgraded to high-quantum-efficiency tubes, which again increased the sensitivity, especially near the low end of the gamma-ray energy range. Compared to its initial design sensitivity, the actual achieved sensitivity of VERITAS is significantly better with the time required to detect weak gamma-ray sources reduced by more than a factor of two. In June 2017,

2907-427: The targeted data (i.e. electromagnetic showers produced by gamma rays), VERITAS uses a three-level trigger system. Level one corresponds to a level crossing on each pixel using constant fraction discriminators . Level two is a pattern selection trigger, which selects photon-like showers, which have compact shapes, and eliminates most of the background showers, which produce more random shapes in each camera. Level three

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2964-487: The three brightest bursts were emitted (i.e. corrected for the observed redshift ) at energies of 70, 60, 94, and 61 GeV in GRBs 080916C, 090510, 090902B, and 090926 respectively. The highest energy gamma-rays require a bulk Lorentz factor of the outflow of nearly 1000 in order to have the rest-frame energies and photon densities be low enough to avoid attenuation by pair production interactions. The Fermi-LAT observations show

3021-477: The use of an imaging Cherenkov camera, coupled with a large 10 m diameter reflector, to make the first definitive detection of a VHE gamma-ray source, the Crab Nebula in 1989. Subsequently, the HEGRA telescope on La Palma demonstrated good sensitivity above 1 TeV using an array of imaging atmospheric Cherenkov telescopes. VERITAS combines the benefits of stereoscopic observations in an array with large reflectors for

3078-839: Was added with an updated agreement in 2008. Representatives from the member institutions form the VERITAS Executive Council (VEC), that serves as the ultimate decision-making authority within the collaboration. In 2008, the collaboration was enlarged by the addition of collaborating institutions that have representation on the VERITAS Science Board, that directs the science program of VERITAS. The initial collaborating institutions were: Adler Planetarium , Barnard College , Cork Institute of Technology , DePauw University , Galway-Mayo Institute of Technology , Grinnell College , National University of Ireland, Galway , University of California, Santa Cruz , University of Iowa and University of Massachusetts, Amherst . As of 2019,

3135-531: Was completed in spring of 2015, and consists of an array of 300 water Cherenkov detectors . It is designed to be more than an order of magnitude more sensitive than its predecessor, Milagro. HAWC monitors the northern sky and makes coincident observations with other wide field of view observatories. HAWC works with other observatories, such as VERITAS , HESS , MAGIC , IceCube and later, CTA , so they can make overlapping multi-wavelength and multi-messenger observations, and to maximize coincident observations with

3192-427: Was favorably reviewed in 2002 and construction of VERITAS started in 2003 at the Fred Lawrence Whipple Observatory . An initial prototype telescope was completed as Telescope #1 and saw first light in 2004. The construction of Telescope #2 was completed in 2005 and first stereo observations started that year. Telescopes #3 and #4 were completed by early 2007 and the first light celebration for the full for telescope array

3249-688: Was on 27-28 April 2007. Regular science operations for VERITAS started in September 2007. The construction of VERITAS was largely funded in the U.S. by Department of Energy , the National Science Foundation , and the Smithsonian Institution . Additional construction funding was provided by Enterprise Ireland (now Science Foundation Ireland ) and the Particle Physics and Astronomy Research Council in

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