2002-2003 Science Planning Summary

Aeronomy & Astrophysics

Dr. Vladimir Papitashvili
Program Manager

AO-373-O

NSF/OPP 00-94541
Station: South Pole Station
RPSC POC: Paul Sullivan
Research Site(s): South Pole Station

DASI (Degree Angular Scale Interferometer)
Dr. John E. Carlstrom
University of Chicago
Astronomy and Astrophysics
jc@hyde.uchicago.edu
http://astro.uchicago.edu/DASI

Deploying Team Members: John E Carlstrom . Allan Day . John M Kovac . Erik M Leitch . Clement L Pryke . John K Cartwright . Amber D Miller . Dan Siegal . Miles Smith
Research Objectives: Researchers plan to continue cosmological observations with the degree angular scale interferometer (DASI) which was first deployed at the Amundsen–Scott South Pole Station during the 1999–2000 austral summer. DASI provides continuous high-quality measurements of the cosmic microwave background (CMB) radiation anisotropy over the critical range of angular scales spanning the first three acoustic peaks in the CMB power spectrum. The data are transferred daily to the University of Chicago, where analysis is keeping pace with the data rate. Plans are to publish the resulting power spectrum by the end of the year.

During the next austral winter, researchers will use DASI to measure the currently undetected polarization of the CMB anisotropy. The measurements will provide a critical test of the standard theory of the early universe. The observations will use full Stokes parameters, allowing a measurement of the cross-correlation of total intensity and polarization anisotropy. Project team members will construct new receiver components to reconfigure DASI from 30 giga-Hertz (GHz) to 100 GHz for intensity and polarization measurements of the fine-scale CMB anisotropy power spectrum. These new capabilities will allow detailed observations of the Sunyaev-Zel’dovich Effect (SZE) in nearby galaxy clusters and allow SZE surveys from massive clusters.

These proposed efforts complement other ongoing and planned CMB experiments with instruments in Chile and at the South Pole. These three instruments can view the same region of the sky and will provide detailed power spectra over this angular range, thereby gathering crucial data for understanding foreground contamination. Working together, these three instruments will allow this essentially unexplored but theoretically important portion of the CMB anisotropy power spectrum to be fully determined.

Outreach and education related to the project will be disseminated and implemented through established structures and mechanisms. These programs, which reach out to local and distant K–12 teachers and students, will use the excitement of exploring our universe to help attract women and minorities to science. Graduate and undergraduate education and research will be integrated into the construction of the instrumentation, as well as the data analysis.


Field Season Overview:
This field season, project team members will perform annual cryogenic maintenance. The telescope, electronics and data acquisition system will be serviced and prepared for another winter season of observations. One team member will winter-over.