The TopHat Experiment: A Balloon‐borne Instrument for Mapping Millimeter and Submillimeter Emission

Abstract

The TopHat experiment was designed to measure the anisotropy in the cosmic microwave background radiation on angular scales from 0N3 to 30 and the thermal emission from both Galactic and extragalactic dust. The balloon-borne instrument had five spectral bands spanning frequencies from 175 to 630 GHz. The telescope was a compact, 1 m, onaxis Cassegrain telescope designed to scan the sky at a fixed elevation of 78 . The radiometer used cryogenic bolometers coupled to a single feed horn via a dichroic filter system. The observing strategy was intended to efficiently cover a region 48 in diameter centered on the south polar cap with a highly cross-linked and redundant pattern with nearly uniform sky coverage. The Long Duration Balloon flight over Antarctica in 2001 January surveyed about 6% of the sky. Here we describe the design of the instrument and the achieved in-flight performance and provide a brief discussion of the data analysis.

A biochemical landscape of A-to-I RNA editing in the human brain transcriptome

“…For each ICE condition (CEÀ, CE+, and CE++), the sequence reads were mapped to the human NCBI Build 36 reference sequence (hg18) as well as to the transcriptome reference (UCSC Genes on hg18 version, a total of 66,803 genes) using BWA aligner (v5.1) (Li and Durbin 2009), allowing four and five mismatches to the genomic and transcriptome references, respectively. We did not use splice-aware mapping software such as TopHat (Silverberg et al 2005) so as to avoid a mapping error caused by the exon-first approach, especially on pseudogene regions (Garber et al 2011). To reduce mapping errors, local realignments were done by a Smith Waterman algorithm (Smith and Waterman 1981), and the realigned reads with <95% identities to the reference were discarded.…”

Balloon-borne Cosmic Microwave Background experiments

“…[1][2][3][4]) has been crucial for starting the so-called precision cosmology era. The LDB flight opportunities have been used by the BOOMERanG experiment [1], the TopHAT experiment [27], and more recently by a second generation of array-based CMB polarimeters: EBEX [28][29][30][31] and SPIDER [32][33][34]. Important missions to survey the CMB and polarized dust at high frequencies have been proposed [35].…”

Technology development for the ExaVolt Antenna (EVA) suborbital ultra-high energy particle observatory

“…To accomplish this, the telescope spun at a constant rate about its vertical axis. The Medium-Scale Anisotropy Measurement/TopHat collaboration (MSAM/TopHat) included researchers at: University of Chicago, Danish Space Research Institute, NASA/Goddard Space Flight Center, University of Wisconsin at Madison [19]. Fig.…”

“…To accomplish a measure of the orientation and attitude of this system, we plan to explore a separate metrology system to locate fiducials married to the surfaces of the outer balloon and inner membranes at strategic locations. We anticipate that such a system could be located and powered from a small balloon-top package; such packages have been deployed successfully in the TopHat mission [19], and other smaller efforts. For orientation and attitude to be transferred from the balloon top to the inner surfaces, including the reflector and feed array, we anticipate a need for severalcm-level precision.…”