M. Farhang

Cosmological parameters from pre-planck cosmic microwave background measurements

Erminia Calabrese, Renée A. Hlozek, Nick Battaglia, Elia S. Battistelli, J. Richard Bond, Jens Chluba, Devin Crichton, Sudeep Das, 8 Mark J. Devlin, Joanna Dunkley, Rolando Dünner, Marzieh Farhang, 11 Megan B. Gralla, Amir Hajian, Mark Halpern, Matthew Hasselfield, 12 Adam D. Hincks, Kent D. Irwin, Arthur Kosowsky, Thibaut Louis, Tobias A. Marriage, 2, 15 Kavilan Moodley, Laura Newburgh, Michael D. Niemack, 13, 17 Michael R. Nolta, Lyman A. Page, Neelima Sehgal, Blake D. Sherwin, Jonathan L. Sievers, Cristóbal Sifón, David N. Spergel, Suzanne T. Staggs, Eric R. Switzer, and Edward J. Wollack Sub-department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH, UK Dept. of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544, USA Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA Department of Physics, University of Rome ‘Sapienza’, Piazzale Aldo Moro 5, I-00185 Rome, Italy CITA, University of Toronto, Toronto, ON M5S 3H8, Canada Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686, USA High Energy Physics Division, Argonne National Laboratory, 9700 S Cass Avenue, Lemont, IL 60439, USA BCCP, LBL and Department of Physics, University of California, Berkeley, CA 94720, USA Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd St., Philadelphia,PA 19104,USA Departamento de Astronomı́a y Astrof́ısica, Pontifićıa Universidad Católica de Chile, Casilla 306, Santiago 22, Chile Department of Astronomy and Astrophysics, University of Toronto, 50 St George , Toronto, ON, M5S 3H4 Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4, Canada NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305, USA Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544,USA Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa Department of Physics, Cornell University, Ithaca, NY, USA 14853 Physics and Astronomy Department, Stony Brook University, Stony Brook, NY 11794-3800, USA Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden, Netherlands NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA

SPIDER: A balloon-borne CMB polarimeter for large angular scales

We describe SPIDER, a balloon-borne instrument to map the polarization of the millimeter-wave sky with degree angular resolution. Spider consists of six monochromatic refracting telescopes, each illuminating a focal plane of large-format antenna-coupled bolometer arrays. A total of 2,624 superconducting transition-edge sensors are distributed among three observing bands centered at 90, 150, and 280 GHz. A cold half-wave plate at the aperture of each telescope modulates the polarization of incoming light to control systematics. SPIDERs first flight will be a 20-30-day Antarctic balloon campaign in December 2011. This flight will map ~8% of the sky to achieve unprecedented sensitivity to the polarization signature of the gravitational wave background predicted by inflationary cosmology. The SPIDER mission will also serve as a proving ground for these detector technologies in preparation for a future satellite mission.

SPIDER: a balloon-borne large-scale CMB polarimeter

Spider is a balloon-borne experiment that will measure the polarization of the Cosmic Microwave Background over a large fraction of a sky at ~ 1° resolution. Six monochromatic refracting millimeter-wave telescopes with large arrays of antenna-coupled transition-edge superconducting bolometers will provide system sensitivities of 4.2 and 3.1 μKcmb√s at 100 and 150 GHz, respectively. A rotating half-wave plate will modulate the polarization sensitivity of each telescope, controlling systematics. Bolometer arrays operating at 225 GHz and 275 GHz will allow removal of polarized galactic foregrounds. In a 2-6 day first flight from Alice Springs, Australia in 2010, Spider will map 50% of the sky to a depth necessary to improve our knowledge of the reionization optical depth by a large factor.

Design and performance of the SPIDER instrument

Here we describe the design and performance of the SPIDER instrument. SPIDER is a balloon-borne cosmic microwave background polarization imager that will map part of the sky at 90, 145, and 280 GHz with subdegree resolution and high sensitivity. This paper discusses the general design principles of the instrument inserts, mechanical structures, optics, focal plane architecture, thermal architecture, and magnetic shielding of the TES sensors and SQUID multiplexer. We also describe the optical, noise, and magnetic shielding performance of the 145 GHz prototype instrument insert.

Modeling and characterization of the SPIDER half-wave plate

Spider is a balloon-borne array of six telescopes that will observe the Cosmic Microwave Background. The 2624 antenna-coupled bolometers in the instrument will make a polarization map of the CMB with approximately one-half degree resolution at 145 GHz. Polarization modulation is achieved via a cryogenic sapphire half-wave plate (HWP) skyward of the primary optic. We have measured millimeter-wave transmission spectra of the sapphire at room and cryogenic temperatures. The spectra are consistent with our physical optics model, and the data gives excellent measurements of the indices of A-cut sapphire. We have also taken preliminary spectra of the integrated HWP, optical system, and detectors in the prototype Spider receiver. We calculate the variation in response of the HWP between observing the CMB and foreground spectra, and estimate that it should not limit the Spider constraints on inflation.

Pre-flight integration and characterization of the SPIDER balloon-borne telescope

We present the results of integration and characterization of the Spider instrument after the 2013 pre-flight campaign. Spider is a balloon-borne polarimeter designed to probe the primordial gravitational wave signal in the degree-scale B-mode polarization of the cosmic microwave background. With six independent telescopes housing over 2000 detectors in the 94 GHz and 150 GHz frequency bands, Spider will map 7.5% of the sky with a depth of 11 to 14 μK•arcmin at each frequency, which is a factor of ~5 improvement over Planck. We discuss the integration of the pointing, cryogenic, electronics, and power sub-systems, as well as pre-flight characterization of the detectors and optical systems. Spider is well prepared for a December 2014 flight from Antarctica, and is expected to be limited by astrophysical foreground emission, and not instrumental sensitivity, over the survey region.

Spider Optimization II: Optical, Magnetic and Foreground Effects

SPIDER is a balloon-borne instrument designed to map the polarization of the cosmic microwave background (CMB) with degree-scale resolution over a large fraction of the sky. SPIDERs main goal is to measure the amplitude of primordial gravitational waves through their imprint on the polarization of the CMB if the tensor-to-scalar ratio, r, is greater than 0.03. To achieve this goal, instrumental systematic errors must be controlled with unprecedented accuracy. Here, we build on previous work to use simulations of SPIDER observations to examine the impact of several systematic effects that have been characterized through testing and modeling of various instrument components. In particular, we investigate the impact of the non-ideal spectral response of the half-wave plates, coupling between focal-plane components and Earths magnetic field, and beam mismatches and asymmetries. We also present a model of diffuse polarized foreground emission based on a three-dimensional model of the Galactic magnetic field and dust, and study the interaction of this foreground emission with our observation strategy and instrumental effects. We find that the expected level of foreground and systematic contamination is sufficiently low for SPIDER to achieve its science goals.

A New Limit on CMB Circular Polarization from SPIDER

We present a new upper limit on CMB circular polarization from the 2015 flight of SPIDER, a balloon-borne telescope designed to search for

Attitude determination for balloon-borne experiments

B

Semi-blind Eigen Analyses of Recombination Histories Using Cosmic Microwave Background Data

-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the non-zero circular-to-linear polarization coupling of the HWP polarization modulators, data from SPIDERs 2015 Antarctic flight provide a constraint on Stokes