Cornell marked a significant milestone recently when university representatives traveled to the high, arid desert of Chile for the first board meeting of the institutions planning to build the worlds largest submillimeter wavelength telescope. Read more
$11M gift for Atacama telescope will help astronomers answer fundamental questions about galaxy, star formation
Retired businessman Fred Young '64, M.Eng. '66, MBA '66, has committed $11 million to CCAT, the Cerro Chajnantor Atacama Telescope, a proposed 25-meter aperture telescope that will be the largest, most precise and highest astronomical facility in the world. Read more
Title: The Atacama Cosmology Telescope: Physical Properties and Purity of a Galaxy Cluster Sample Selected via the Sunyaev-Zel'dovich Effect
Authors: Felipe Menanteau, Jorge Gonzalez, Jean-Baptiste Juin, Tobias A. Marriage, Erik Reese, Viviana Acquaviva, Paula Aguirre, John William Appel, Andrew J. Baker, L. Felipe Barrientos, Elia S. Battistelli, J. Richard Bond, Sudeep Das, Mark J. Devlin, Simon Dicker, Amruta J. Deshpande, Joanna Dunkley, Rolando Dunner, Thomas Essinger-Hileman, Joseph W. Fowler, Amir Hajian, Mark Halpern, Matthew Hasselfield, Carlos Hernandez-Monteagudo, Matt Hilton, Adam D. Hincks, Renee Hlozek, John P. Hughes, Kevin M. Huffenberger, Leopoldo Infante, Kent D. Irwin, Jeff Klein, Arthur Kosowsky, Yen-Ting Lin, Danica Marsden, Kavilan Moodley, Michael D. Niemack, Michael R. Nolta, Lyman A. Page, Lucas Parker, Bruce Partridge, Jon Sievers, Neelima Sehgal, David N. Spergel, Suzanne T. Staggs, Daniel Swetz, Eric Switzer, Robert Thornton, Hy Trac, Ryan Warne, Ed Wollack et al. (4 additional authors not shown)
We present optical and X-ray properties for the first confirmed galaxy cluster sample selected by the Sunyaev-Zel'dovich Effect from 148 GHz maps over 455 square degrees of sky made with the Atacama Cosmology Telescope. These maps, coupled with multi-band imaging on 4-meter-class optical telescopes, have yielded a sample of 23 galaxy clusters with redshifts between 0.118 and 1.066. Of these 23 clusters, 10 are newly discovered. The selection of this sample is approximately mass limited and essentially independent of redshift. We provide optical positions, images, redshifts and X-ray fluxes and luminosities for the full sample, and X-ray temperatures of an important subset. The mass limit of the full sample is around 8e14 Msun, with a number distribution that peaks around a redshift of 0.4. For the 10 highest significance SZE-selected cluster candidates, all of which are optically confirmed, the mass threshold is 1e15 Msun and the redshift range is 0.167 to 1.066. Archival observations from Chandra, XMM-Newton, and ROSAT provide X-ray luminosities and temperatures that are broadly consistent with this mass threshold. Our optical follow-up procedure also allowed us to assess the purity of the ACT cluster sample. Eighty (one hundred) percent of the 148 GHz candidates with signal-to-noise ratios greater than 5.1 (5.7) are confirmed as massive clusters. The reported sample represents one of the largest SZE-selected sample of massive clusters over all redshifts within a cosmologically-significant survey volume, which will enable cosmological studies as well as future studies on the evolution, morphology, and stellar populations in the most massive clusters in the Universe.
A giant telescope planned to be built in Chile is expected to find hundreds of thousands of developing galaxies in the early universe, shedding light on the formation of big galaxies in the modern universe. The Cornell Caltech Atacama Telescope (CCAT) will observe at submillimetre wavelengths, which make up part of the microwave portion of the electromagnetic spectrum. With its 25-metre dish, the $100 million telescope will be the largest in the world for submillimetre astronomy when it is finished in 2013.
Five North American and one European institution have created a consortium to oversee the building of the 25-meter sub-millimetre telescope on a high elevation in Chile. Upon completion in 2013, the 100 million dollar instrument, part of the project formally known as the Cornell Caltech Atacama Telescope (CCAT), and located at an 18,400-foot altitude atop Cerro Chajnantor in Chile's Atacama Desert, will be the premier telescope of its kind in the world.
A $100 million telescope planned for the Chilean high desert has moved a big step closer to reality with the formation of an international consortium to oversee its construction. The Cornell Caltech Atacama Telescope would allow astronomers to peer deep into the universe's childhood to observe the birth of the first galaxies and to study star-forming regions in galaxies, including our own.
"It's very exciting because it's always hard to get a new project initiated. If we can get all these different institutions to support these instruments then it has a very good chance of being built. It's a big step forward to have this agreement" - Tom Phillips, Caltech astronomer.
Project founders Caltech, JPL and Cornell University have now been joined on the project by the University of Colorado at Boulder, the University of British Columbia and the United Kingdom Astronomy Technology Centre.
With such a large group of interested institutions, it is likely the cutting-edge telescope will get funded, officials believe. Plans call for the telescope to be completed in 2013.
Two more institutions sign agreement to advance Cornell Caltech Atacama Telescope project to 'revolutionise astronomy' In a major step forward for the Cornell Caltech Atacama Telescope (CCAT), a proposed 25-metre aperture telescope that will be the largest, most precise and highest astronomical facility in the world, participants announced this week that two more institutions have signed an interim agreement to join the CCAT consortium. The two, the University of Colorado at Boulder and the United Kingdom Astronomy Technology Centre, have committed to pursue formal partnership and to identify the sources for full funding of the project.
Title: The Cornell Caltech Atacama Telescope Authors: Simon J. E. Radford, Riccardo Giovanelli, Thomas A. Sebring, Jonas Zmuidzinas
Cornell University, the California Institute for Technology, and the Jet Propulsion Laboratory are jointly studying the construction of a 25 m diameter telescope for submillimeter astronomy on a high mountain in northern Chile. This Cornell Caltech Atacama Telescope (CCAT) will combine high sensitivity, a wide field of view, and a broad wavelength range to provide an unprecedented capability for deep, large area, multi-colour submillimeter surveys to complement narrow field, high resolution studies with ALMA. CCAT observations will address fundamental themes in contemporary astronomy, notably the formation and evolution of galaxies, the nature of the dark matter and dark energy that comprise most of the content of the universe, the formation of stars and planets, the conditions in circumstellar disks, and the conditions during the early history of the Solar system. The candidate CCAT site, at 5600 m in northern Chile, enjoys superb observing conditions. To accommodate large format bolometer cameras, CCAT is designed with a 20 arcmin field of view. CCAT will incorporate closed loop active control of its segmented primary mirror to maintain a half wavefront error of 10 mum rms or less. Instrumentation under consideration includes both short (650 mum-200 mum) and long (2 mm-750 mum) wavelength bolometer cameras, direct detection spectrometers, and heterodyne receiver arrays. The University of Colorado, a Canadian university consortium, and the UK Astronomy Technology Centre on behalf of the UK community are pursuing participation in the CCAT consortium. When complete early in the next decade, CCAT will be the largest and most sensitive facility of its class as well as the highest altitude astronomical facility on Earth.
Title: Microwave-Sky Simulations and Projections for Galaxy Cluster Detection with the Atacama Cosmology Telescope Authors: Neelima Sehgal (Rutgers), Hy Trac (Princeton), Kevin Huffenberger (JPL/Caltech), Paul Bode (Princeton)
We study the ability of three-frequency, arcminute-resolution microwave measurements to detect galaxy clusters via their Sunyaev-Zel'dovich (SZ) distortion of the microwave background. For this purpose, we have constructed large-area simulations of the microwave sky, and we have made them publicly available to further investigations into optimal data reduction techniques for upcoming SZ cluster surveys. In these sky simulations, galaxy clusters are modelled using N-body simulated dark matter halos plus a gas prescription for the intracluster medium that allows the small scale cluster physics such as star formation and feedback to be realistically incorporated. We also model the primary microwave background, radio and infrared point sources, galactic dust emission, and the SZ flux including kinetic and relativistic contributions. We make use of these simulations to study the cluster scaling relation between integrated SZ flux and cluster mass and find our clusters fit a power-law well, with a power-law index that is steeper than that for self-similar cluster models. Some evolution of the power-law index and normalization with redshift is also observed. These simulations are also used to study cluster detection for the Atacama Cosmology Telescope (ACT). Using a multi-frequency Wiener filter to separate clusters from other microwave components, we find that ACT alone can recover a cluster sample that is ~90% complete above 3*10^{14} M_sun and ~85% pure.
Title: The Atacama Cosmology Telescope Project: A Progress Report Authors: Arthur Kosowsky (University of Pittsburgh), for the ACT Collaboration
The Atacama Cosmology Telescope is a project to map the microwave background radiation at arcminute angular resolution and high sensitivity in three frequency bands over substantial sky areas. Cosmological signals driving such an experiment are reviewed, and current progress in hardware construction is summarised. Complementary astronomical observations in other wavebands are also discussed.