Cosmic Microwave Background


The CfA is collaborating with several other institutions in the construction of a 10 meter diameter millimeter- and submillimeter-wave telescope located at the National Science Foundation Amundsen-Scott South Pole Station. The so-called South Pole Telescope is designed to feed large arrays of detectors and provide a low-background, low-noise environment. The first project, scheduled for 2007 and 2008, is a survey of 4000 square degrees of the southern sky at 2 mm wavelength to an rms noise level of 10 microKelvin (0.8 mJy). Thousands of previously unknown clusters of galaxies will be detected through their Sunyaev-Zel'dovich effect signal; these data will be used to determine cosmological parameters, including the equation of state of the Dark Energy and its time evolution, with unprecedented accuracy. Possible future uses include submillimeter-wave arrays containing tens of thousands of detector elements.

Antony Stark, Christopher Stubbs and Brian Stalder are collaborating on the construction of the Parallel Imager for Southern Cosmological Observations (PISCO) project. PISCO, designed for either Magellan telescope, will observe candidate clusters of galaxies discovered via the Sunyaev-Zeldovich by the South Pole Telescope (SPT), a project on which Stark is a co-PI. PISCO will create four photometric images simultaneously , in g, r, i, and z bands on four Lincoln Labs 3K X 6K CCDs, covering a field of view of 9 arcminutes. This observing mode mitigates weather dependences on photometry, and with real-time data analysis, most cluster redshifts can be determined within a minute, so hundreds of clusters can be observed and characterized in a single night. With the measurement of the evolution of the total number of clusters over the history of the universe, the current models of dark energy and the accelerating universe can be tested. PISCO is also well-suited for follow up observations from other survey telescopes such as Pan-STARRS which will produce a plethora of time-varying or moving objects, such as Supernovae, near-Earth astroids, and Kuiper-Belt objects. Other "narrow-deep" surveys can also be carried out with PISCO approximately three times faster than single-image photometric imagers.


Brian Stalder, Tony Stark