The Atacama Cosmology Telescope: Calibration with WMAP Using Cross-Correlations
astro-ph.CO
/ Authors
Amir Hajian, Viviana Acquaviva, Peter A. R. Ade, Paula Aguirre, Mandana Amiri, John William Appel, L. Felipe Barrientos, Elia S. Battistelli, J. Richard Bond, Ben Brown
and 57 more authors
Bryce Burger, Jay Chervenak, Sudeep Das, Mark J. Devlin, Simon R. Dicker, W. Bertrand Doriese, Joanna Dunkley, Rolando Dunner, Thomas Essinger-Hileman, Ryan P. Fisher, Joseph W. Fowler, Mark Halpern, Matthew Hasselfield, Carlos Hernandez-Monteagudo, Gene C. Hilton, Matt Hilton, Adam D. Hincks, Renee Hlozek, Kevin M. Huffenberger, David H. Hughes, John P. Hughes, Leopoldo Infante
/ Abstract
We present a new calibration method based on cross-correlations with WMAP and apply it to data from the Atacama Cosmology Telescope (ACT). ACT's observing strategy and map making procedure allows an unbiased reconstruction of the modes in the maps over a wide range of multipoles. By directly matching the ACT maps to WMAP observations in the multipole range of 400 < ell < 1000, we determine the absolute calibration with an uncertainty of 2% in temperature. The precise measurement of the calibration error directly impacts the uncertainties in the cosmological parameters estimated from the ACT power spectra. We also present a combined map based on ACT and WMAP data that has high signal-to-noise over a wide range of multipoles.