South Pole Telescope (SPT)
The South Pole Telescope (SPT) is a ten-meter diameter telescope operating at the National Science Foundation South Pole research station (image above by Daniel Luong-Van). The telescope is designed to conduct large-area millimeter and sub-millimeter wavelength surveys of faint, low-contrast emission, as required to map primary and secondary anisotropies in the cosmic microwave background (CMB). A description of the receivers used on the SPT is given below.
From 2008 to 2011, the SPT-SZ receiver carried out a 2500 square-degree survey of the southern sky at high galactic latitude. The instrument had spectral bands centered at 95, 150, and 220 GHz, with 1 arcminute resolution at 150 GHz. Science highlights include:
From 2012 through 2016, the SPT was equipped with the polarization-sensitive SPTpol receiver, configured to observe in two spectral bands centered at 95 and 150 GHz, with 1 arcminute resolution at 150 GHz. The primary survey conducted with SPTpol was a "wedding-cake" survey of a 500 square-degree region of the southern sky at high Galactic latitudes, with a deeper survey of 100 square degrees within that region. An extended, shallower survey of a further ~2800 square degrees was conducted during the Austral summers. Science highlights include:
In January 2017, the SPT-3G receiver was installed on the SPT. SPT-3G represents nearly an order-of-magnitude upgrade from SPTpol in instantaneous sensitivity, owing primarily to the increase in detector number (from ~1,500 to ~16,000) enabled by reconfigured optics and trichroic, dual-polarization detector pixels. SPT-3G is configured to observe in three spectral bands centered at 95, 150, and 220 GHz, with 1 arcminute resolution at 150 GHz. Since 2018, SPT-3G has been used primarily to survey a 1500-square-degree region of low-foreground sky (an area that coincides with the BICEP-3 / BICEP Array field and includes the 500-square-degree SPTpol and BICEP-Keck fields), with a target depth of 2-3 uK-arcmin in temperature at 95 and 150 GHz. As with SPTpol, an extended survey is being conducted (over ~2500 square degrees with target noise levels of <~10 uK-arcmin) during the Austral summers.
Further details on SPT may be found at http://pole.uchicago.edu/public/