119295671
The Blanco Cosmology Survey: Data Acquisition, Processing, Calibration, Quality Diagnostics and Data Release
The Blanco Cosmology Survey (BCS) is a 60 night imaging survey of ~80 deg2 of the southern sky located in two fields: (α, δ) = (5 hr, –55°) and (23 hr, –55°). The survey was carried out between 2005 and 2008 in griz bands with the Mosaic2 imager on the Blanco 4 m telescope. The primary aim of the BCS survey is to provide the data required to optically confirm and measure photometric redshifts for Sunyaev-Zel'dovich effect selected galaxy clusters from the South Pole Telescope and the Atacama Cosmology Telescope. We process and calibrate the BCS data, carrying out point-spread function-corrected model-fitting photometry for all detected objects. The median 10σ galaxy (point-source) depths over the survey in griz are approximately 23.3 (23.9), 23.4 (24.0), 23.0 (23.6), and 21.3 (22.1), respectively. The astrometric accuracy relative to the USNO-B survey is ~45 mas. We calibrate our absolute photometry using the stellar locus in grizJ bands, and thus our absolute photometric scale derives from the Two Micron All Sky Survey, which has ~2% accuracy. The scatter of stars about the stellar locus indicates a systematic floor in the relative stellar photometric scatter in griz that is ~1.9%, ~2.2%, ~2.7%, and ~2.7%, respectively. A simple cut in the AstrOmatic star-galaxy classifier spread_model produces a star sample with good spatial uniformity. We use the resulting photometric catalogs to calibrate photometric redshifts for the survey and demonstrate scatter δz/(1 + z) = 0.054 with an outlier fraction η < 5% to z ~ 1. We highlight some selected science results to date and provide a full description of the released data products.
9158947
The Dark Energy Survey Data Management System: The Processing Framework
The Dark Energy Survey Data Management (DESDM) system will process and archive the data from the Dark Energy Survey (DES) over the five year period of operation. This paper focuses on a new adaptable processing framework developed to perform highly automated, high performance data parallel processing. The new processing framework has been used to process 45 nights of simulated DECam supernova imaging data, and was extensively used in the DES Data Challenge 4, where it was used to process thousands of square degrees of simulated DES data.
119346336
Search for neutrinos from gamma-ray bursts using Super-Kamiokande
Using the Super-Kamiokande neutrino observatory, a search was conducted for neutrinos produced in coincidence with gamma-ray bursts observed by the Burst and Transient Source Experiment detector. Super-Kamiokande data in the neutrino energy range of 7 MeV ~ 100 TeV were analyzed. For gamma-ray bursts that occurred between 1996 April and 2000 May, no statistically significant signal in excess of the background levels was detected. Implied upper limits on associated gamma-ray burst neutrino production are presented.
21908658
Study of Upward Showering Muons in Super-Kamiokande
A small subset of neutrino-induced upward going muons in the SuperKamiokande detector consists of high energy muons that undergo radiative energy losses through bremsstrahlung, pair production and photo-nuclear interactions. The mean energy of the parent neutrinos of these showering upward muons is approximately 1 TeV, allowing the selection of a high energy sample of neutrinos. We present the energy spectrum of the parent neutrinos of these upward showering muons and results based on searches for WIMP-induced neutrinos using these upward showering muons are presented.
9665346
Measurement of galaxy cluster integrated comptonization and mass scaling relations with the South Pole Telescope
We describe a method for measuring the integrated Comptonization (Y_(SZ)) of clusters of galaxies from measurements of the Sunyaev-Zel'dovich (SZ) effect in multiple frequency bands and use this method to characterize a sample of galaxy clusters detected in the South Pole Telescope (SPT) data. We use a Markov Chain Monte Carlo method to fit a β-model source profile and integrate Y_(SZ) within an angular aperture on the sky. In simulated observations of an SPT-like survey that include cosmic microwave background anisotropy, point sources, and atmospheric and instrumental noise at typical SPT-SZ survey levels, we show that we can accurately recover β-model parameters for inputted clusters. We measure Y_(SZ) for simulated semi-analytic clusters and find that Y_(SZ) is most accurately determined in an angular aperture comparable to the SPT beam size. We demonstrate the utility of this method to measure Y_(SZ) and to constrain mass scaling relations using X-ray mass estimates for a sample of 18 galaxy clusters from the SPT-SZ survey. Measuring Y_(SZ) within a 0.'75 radius aperture, we find an intrinsic log-normal scatter of 21% ± 11% in Y_(SZ) at a fixed mass. Measuring Y_(SZ) within a 0.3 Mpc projected radius (equivalent to 0.'75 at the survey median redshift z = 0.6), we find a scatter of 26% ± 9%. Prior to this study, the SPT observable found to have the lowest scatter with mass was cluster detection significance. We demonstrate, from both simulations and SPT observed clusters that Y_(SZ) measured within an aperture comparable to the SPT beam size is equivalent, in terms of scatter with cluster mass, to SPT cluster detection significance.
19993933
Analysis of Sunyaev-Zel'dovich effect mass-observable relations using South Pole Telescope observations of an X-ray selected sample of low-mass galaxy clusters and groups
We use microwave observations from the South Pole Telescope (SPT) to examine the Sunyaev–Zel'dovich effect (SZE) signatures of a sample of 46 X-ray selected groups and clusters drawn from ∼6 deg^2 of the XMM–Newton Blanco Cosmology Survey. These systems extend to redshift z = 1.02 and probe the SZE signal to the lowest X-ray luminosities (≥10^(42) erg s^(−1)) yet; these sample characteristics make this analysis complementary to previous studies. We develop an analysis tool, using X-ray luminosity as a mass proxy, to extract selection-bias-corrected constraints on the SZE significance and Y500 mass relations. The former is in good agreement with an extrapolation of the relation obtained from high-mass clusters. However, the latter, at low masses, while in good agreement with the extrapolation from the high-mass SPT clusters, is in tension at 2.8σ with the Planck constraints, indicating the low-mass systems exhibit lower SZE signatures in the SPT data. We also present an analysis of potential sources of contamination. For the radio galaxy point source population, we find 18 of our systems have 843 MHz Sydney University Molonglo Sky Survey sources within 2 arcmin of the X-ray centre, and three of these are also detected at significance >4 by SPT. Of these three, two are associated with the group brightest cluster galaxies, and the third is likely an unassociated quasar candidate. We examine the impact of these point sources on our SZE scaling relation analyses and find no evidence of biases. We also examine the impact of dusty galaxies using constraints from the 220 GHz data. The stacked sample provides 2.8σ significant evidence of dusty galaxy flux, which would correspond to an average underestimate of the SPT Y_(500) signal that is (17 ± 9) per cent in this sample of low-mass systems. Finally, we explore the impact of future data from SPTpol and XMM-XXL, showing that it will lead to a factor of 4 to 5 tighter constraints on these SZE mass–observable relations.
30114466
Amplitudes for Higgs bosons plus four partons
In this talk we consider amplitudes for processes involving a Higgs boson, either scalar or pseudoscalar, plus four light partons. These amplitudes are relevant to the production of a Higgs boson plus two jets in hadronic collisions. They are also relevant to calculating the transverse momentum spectrum for Higgs bosons at next-to-leading order in the strong coupling. We work in the limit that the top quark is much heavier than the Higgs bosons and use effective Lagrangians for the interactions of gluons with the Higgs bosons. We present the amplitudes involving a Higgs boson and: 1) four gluons, 2) two quarks and two gluons; and 3) four quarks. We show that the pseudoscalar amplitudes are nearly identical to those for the scalar case, the only differences being the overall size and the relative signs between terms.
16162456
Production of a Higgs pseudoscalar plus two jets in hadronic collisions
We consider the production of a Higgs pseudoscalar accompanied by two jets in hadronic collisions. We work in the limit that the top quark is much heavier than the Higgs pseudoscalar and use an effective Lagrangian for the interactions of gluons with the pseudoscalar. We compute the amplitudes involving: 1) four gluons and the pseudoscalar, 2) two quarks, two gluons and the pseudoscalar and 3) four quarks and the pseudoscalar. We find that the pseudoscalar amplitudes are nearly identical to those for the scalar case, the only differences being the overall size and the relative signs between terms. We present numerical cross sections for proton-proton collisions with center-of-mass energy 14 TeV.
125296528
Low-mass Higgs searches at the Tevatron