Construction of Veritas Telescope Array Begins

Mount Hopkins, AZ – The Smithsonian Astrophysical Observatory reports the
start of construction of VERITAS, the Very Energetic Radiation Imaging
Telescope Array System. The project is being funded by the Department of
Energy and the National Science Foundation. VERITAS will be an array of
four 12-meter-diameter optical reflectors with ultra-fast cameras which
together will form one of the most sensitive very high energy gamma-ray
observatories in the world. Each of the four telescopes will have 350 mirror
facets creating its 12-meter aperture and each will be equipped with a 499
pixel camera. The target date for completion of construction is October 1,
2006. The project budget for construction is $13.1 million.

VERITAS will be located in Horseshoe Canyon at the 5800 foot level on Kitt
Peak in southern Arizona. This site is within the leasehold for Kitt Peak
National Observatory and provides high altitude and easy access with
excellent shielding from artificial lights.

The VERITAS Collaboration has built a prototype telescope and camera to
demonstrate the design concepts for the full VERITAS array. This prototype
will be upgraded to provide one of the four telescopes of VERITAS. The
prototype telescope is located at a temporary site at the Whipple
Observatory Administrative Complex, and it will be moved to the Kitt Peak
site in 2006.

The technique used to detect very high energy gamma rays was pioneered at
the Smithsonian’s Whipple Observatory using the 10-meter optical reflector
built in 1968. Very high energy gamma rays (photons with energy more than a
million times the energy of a photon of visible light) interact with the
upper atmosphere and initiate a cascade or shower of particles. The showers
lead to a short burst of blue light. Using arrays of fast photo-detectors at
the focus of the large optical reflector the Whipple group recorded the
image of the cascade of particles and showed that they could identify those
initiated by gamma rays from the much more numerous background produced by
charged cosmic rays.

Using this technique the Whipple group, with their collaborators, detected
the first source of TeV gamma-rays in the Galaxy in 1989 (the Crab Nebula, a
supernova remnant) and the first extragalactic source in 1992 (Markarian
421, an active galactic nucleus or quasar). Since that time a number of
overseas observatories have adopted the Whipple technique and more than a
dozen sources have been established.

VERITAS will have a sensitivity that exceeds that of the existing Whipple
telescope by a factor of ten and it is anticipated that more than a hundred
sources will be detected. The scientific objectives of the project include
the study of pulsars, supernova remnants, x-ray binaries, black holes,
active galactic nuclei, and gamma-ray bursts. These cosmic particle
accelerators may make possible the investigation of new physics at extreme
energies which are only just matched on Earth by giant particle
accelerators.

The VERITAS Collaboration includes seven institutions in the U.S.A. and
three non-USA institutions (in Canada, Ireland and the U.K.); the U.S.
institutions are the Smithsonian Astrophysical Observatory, Iowa State
University, Purdue University, the University of California at Los Angeles,
the University of Chicago, the University of Utah, and Washington University
at St. Louis. The non-USA institutions are McGill University in Canada, the
National University of Ireland, University College, Dublin, and the
University of Leeds in the United Kingdom. Through its Associates Program,
VERITAS will serve the observing needs of scientists at additional
institutions. The Smithsonian Astrophysical Observatory is the lead
organization and host for VERITAS, and the Project Office is at the Whipple
Observatory Administrative Complex in Amado, Arizona. In addition to funding
from the Department of Energy and National Science Foundation, the project
receives support from the Smithsonian Institution, PPARC in the U.K.,
Enterprise-Ireland in Ireland and NSERC in Canada.

VERITAS will come into operation prior to the 2007 launch of NASA’s
Gamma-ray Large Area Space Telescope (GLAST), for which DOE is a partner in
the main instrument, the Large Area Telescope. GLAST is the next large
space-based gamma-ray telescope and will overlap VERITAS’s lower energy
range, the first time that space- and ground-based telescopes have provided
such complementarity. Together VERITAS and GLAST will make observations of
cosmic gamma rays over five decades of energy and greatly extend our
knowledge of the universe at extreme energies.

Further information on VERITAS is available at
http://veritas.sao.arizona.edu or from the Public Information Office of the
Whipple Observatory at 520-670-5706.

An artist’s conception of the VERITAS array is online at:
http://cfa-www.harvard.edu/press/pr0412image.html

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for
Astrophysics is a joint collaboration between the Smithsonian Astrophysical
Observatory and the Harvard College Observatory. CfA scientists, organized
into six research divisions, study the origin, evolution and ultimate fate
of the universe.