The QMAP and MAT/TOCO Experiments for Measuring Anisotropy in the Cosmic Microwave Background
Abstract
We describe two related experiments that measured the anisotropy in the cosmic microwave background (CMB). QMAP was a balloon-borne telescope that flew twice in 1996, collecting data on degree angular scales with an array of six high electron mobility transistor-based amplifiers (HEMTs). QMAP used an interlocking scan strategy to directly produce high signal-to-noise ratio CMB maps over a limited region of sky. The QMAP gondola was then refitted for ground-based work as the MAT/TOCO experiment. Observations were made from 5200 m on Cerro Toco in Northern Chile in 1997 and 1998 using time domain beam synthesis. MAT/TOCO measured the rise and fall of the CMB angular spectrum, thereby localizing the position of the first peak to lpeak=216+/-14. In addition to describing the instruments, we discuss the data selection methods, check for systematic errors, and compare the MAT/TOCO results to those from recent experiments. The previously reported data are updated to account for a small calibration shift and corrected to account for a small contribution from known sources of foreground emission. The resulting amplitude of the first peak for 160<l<240 is δTpeak=80.9+/-3.4+/-5.1 μK, where the first uncertainty is statistical and the second is from calibration.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- June 2002
- DOI:
- 10.1086/339686
- arXiv:
- arXiv:astro-ph/0108030
- Bibcode:
- 2002ApJS..140..115M
- Keywords:
-
- Cosmology: Cosmic Microwave Background;
- Instrumentation: Miscellaneous;
- Astrophysics
- E-Print:
- 31 pages, 11 figures, Submitted to ApJ