2907589
The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) 2005: Calibration and Targeted Sources
The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) operated successfully during a 100 hr flight from northern Sweden in 2005 June (BLAST05). As part of the calibration and pointing procedures, several compact sources were mapped, including solar system, Galactic, and extragalactic targets, specifically Pallas, CRL 2688, LDN 1014, IRAS 20126+4104, IRAS 21078+5211, IRAS 21307+5049, IRAS 22134+5834, IRAS 23011+6126, K3-50, W75N, and Mrk 231. One additional source, Arp 220, was observed and used as our primary calibrator. Details of the overall BLAST05 calibration procedure are discussed here. The BLAST observations of each compact source are described, flux densities and spectral energy distributions are reported, and these are compared with previous measurements at other wavelengths. The 250, 350, and 500 μm BLAST data can provide useful constraints to the amplitude and slope of the submillimeter continuum, which in turn may be useful for the improved calibration of other submillimeter instruments.
119489530
Breaking the 'redshift deadlock' - I. Constraining the star formation history of galaxies with submillimetre photometric redshifts
Future extragalactic submillimetre and millimetre surveys have the potential to provide a sensitive census of the level of obscured star formation in galaxies at all redshifts. While in general there is good agreement between the source counts from existing Submillimetre Common User Bolometer Array (SCUBA; 850-µm) and Max Planck Millimetre Bolometer Array (MAMBO; 1.25-mm) surveys of different depths and areas, it remains difficult to determine the redshift distribution and bolometric luminosities of the submillimetre and millimetre galaxy population. This is principally due to the ambiguity in identifying an individual submillimetre source with its optical, IR or radio counterpart which, in turn, prevents a confident measurement of the spectroscopic redshift. Additionally, the lack of data measuring the rest-frame FIR spectral peak of the submillimetre galaxies gives rise to poor constraints on their rest-frame FIR luminosities and star formation rates. In this paper we describe Monte Carlo simulations of ground-based, balloon-borne and satellite submillimetre surveys that demonstrate how the restframe FIR‐submillimetre spectral energy distributions (250‐850 µm) can be used to derive photometric redshifts with an rms accuracy of ±0.4 over the range 0 3 × 10 12 L� ) with an accuracy of ∼20 per cent.
19329844
Overview of the Atacama Cosmology Telescope: receiver, instrumentation, and telescope systems
The Atacama Cosmology Telescope was designed to measure small-scale anisotropies in the cosmic microwave background and detect galaxy clusters through the Sunyaev-Zel'dovich effect. The instrument is located on Cerro Toco in the Atacama Desert, at an altitude of 5190 m. A 6 m off-axis Gregorian telescope feeds a new type of cryogenic receiver, the Millimeter Bolometer Array Camera. The receiver features three 1000-element arrays of transition-edge sensor bolometers for observations at 148 GHz, 218 GHz, and 277 GHz. Each detector array is fed by free space millimeter-wave optics. Each frequency band has a field of view of approximately 22' × 26'. The telescope was commissioned in 2007 and has completed its third year of operations. We discuss the major components of the telescope, camera, and related systems, and summarize the instrument performance.
119263001
The Balloon-borne Large Aperture Submillimeter Telescope: BLAST
The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) is a suborbital surveying experiment designed to study the evolutionary history and processes of star formation in local galaxies (including the Milky Way) and galaxies at cosmological distances. The BLAST continuum camera, which consists of 270 detectors distributed between three arrays, observes simultaneously in broadband (30%) spectral windows at 250, 350, and 500 μm. The optical design is based on a 2 m diameter telescope, providing a diffraction-limited resolution of 30'' at 250 μm. The gondola pointing system enables raster mapping of arbitrary geometry, with a repeatable positional accuracy of ~30''; postflight pointing reconstruction to 5'' rms is achieved. The onboard telescope control software permits autonomous execution of a preselected set of maps, with the option of manual override. In this paper we describe the primary characteristics and measured in-flight performance of BLAST. BLAST performed a test flight in 2003 and has since made two scientifically productive long-duration balloon flights: a 100 hr flight from ESRANGE (Kiruna), Sweden to Victoria Island, northern Canada in 2005 June; and a 250 hr, circumpolar flight from McMurdo Station, Antarctica, in 2006 December.
118673948
The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) 2005: A 4 deg2 Galactic Plane Survey in Vulpecula (ℓ = 59°)
We present the first results from a new 250, 350, and 500 μm Galactic plane survey taken with the Balloon-borne Large-Aperture Submillimeter Telescope (BLAST) in 2005. This survey's primary goal is to identify and characterize high-mass protostellar objects (HMPOs). The region studied here covers 4 deg^2 near the open cluster NGC 6823 in the constellation Vulpecula (l = 59°). We find 60 compact sources (<60'' diameter) detected simultaneously in all three bands. Their SEDs are constrained through BLAST, IRAS, Spitzer MIPS, and MSX photometry, with inferred dust temperatures spanning ~12-40 K assuming a dust emissivity index β = 1.5. The luminosity-to-mass ratio, a distance-independent quantity, spans ~0.2-130 L_☉ M^(−1)_☉. Distances are estimated from coincident ^(13)CO(1→ 0) velocities combined with a variety of other velocity and morphological data in the literature. In total, 49 sources are associated with a molecular cloud complex encompassing NGC 6823 (distance ~2.3 kpc), 10 objects with the Perseus arm (~8.5 kpc), and one object is probably in the outer Galaxy (~14 kpc). Near NGC 6823, the inferred luminosities and masses of BLAST sources span ~40-10^4 L_☉ and ~15-700 M_☉, respectively. The mass spectrum is compatible with molecular gas masses in other high-mass star-forming regions. Several luminous sources appear to be ultracompact H II regions powered by early B stars. However, many of the objects are cool, massive gravitationally bound clumps with no obvious internal radiation from a protostar, and hence excellent HMPO candidates.
27705474
ACTPol: a polarization-sensitive receiver for the Atacama Cosmology Telescope
The six-meter Atacama Cosmology Telescope (ACT) in Chile was built to measure the cosmic microwave background (CMB) at arcminute angular scales. We are building a new polarization sensitive receiver for ACT (ACTPol). ACTPol will characterize the gravitational lensing of the CMB and aims to constrain the sum of the neutrino masses with ~ 0.05 eV precision, the running of the spectral index of inflation-induced fluctuations, and the primordial helium abundance to better than 1 %. Our observing fields will overlap with the SDSS BOSS survey at optical wavelengths, enabling a variety of cross-correlation science, including studies of the growth of cosmic structure from Sunyaev-Zel'dovich observations of clusters of galaxies as well as independent constraints on the sum of the neutrino masses. We describe the science objectives and the initial receiver design.
53975074
Future 'realtime' solar neutrino experiments
I summarize here the goals of the future solar neutrino program, and the proposed experiments.
118349856
The Sudbury Neutrino Observatory
This review paper provides a summary of the published results of the Sudbury Neutrino Observatory (SNO) experiment that was carried out by an international scientific collaboration with data collected during the period from 1999 to 2006. By using heavy water as a detection medium, the SNO experiment demonstrated clearly that solar electron neutrinos from 8B decay in the solar core change into other active neutrino flavors in transit to Earth. The reaction on deuterium that has equal sensitivity to all active neutrino flavors also provides a very accurate measure of the initial solar flux for comparison with solar models. This review summarizes the results from three phases of solar neutrino detection as well as other physics results obtained from analyses of the SNO data.
122178298
Results and Prospects for SNO
Abstract I describe here the results of the Low Energy Threshold Analysis (LETA) of the Sudbury Neutrino Observatory (SNO) Phase I and Phase II data sets, and the prospects for future results from SNO.
120848727
Final state branching ratio in the Be 7 decay
The fractional decay branch in the EC decay of $^{7}\mathrm{Be}$ leading to the first excited state of $^{7}\mathrm{Li}$ has been measured. $^{7}\mathrm{Be}$ ions from a beam produced by a tandem Van de Graaff accelerator were implanted into a surface-barrier detector; the decay $\ensuremath{\gamma}$ rays were then counted using a well-shielded Ge(Li) detector of known absolute efficiency. The resulting decay branch, (10.10\ifmmode\pm\else\textpm\fi{}0.45)%, is in good agreement with previously published values and in strong disagreement with a recent measurement.
5706423
BLIND ANALYSIS IN NUCLEAR AND PARTICLE PHYSICS
▪ Abstract During the past decade, blind analysis has become a widely used tool in nuclear and particle physics measurements. A blind analysis avoids the possibility of experimenters biasing their result toward their own preconceptions by preventing them from knowing the answer until the analysis is complete. There is at least circumstantial evidence that such a bias has affected past measurements, and as experiments have become costlier and more difficult and hence harder to reproduce, the possibility of bias has become a more important issue than in the past. We describe here the motivations for performing a blind analysis, and give several modern examples of successful blind analysis strategies.