Selecting sources with rising flux densities towards longer wavelengths from Herschel/Spectral and Photometric Imaging Receiver (SPIRE) maps is an efficient way to produce a catalogue rich in ...high-redshift (z > 4) dusty star-forming galaxies. The effectiveness of this approach has already been confirmed by spectroscopic follow-up observations, but the previously available catalogues made this way are limited by small survey areas. Here we apply a map-based search method to 274 deg2 of the Herschel Multi-tiered Extragalactic Survey (HerMES) Large Mode Survey and create a catalogue of 477 objects with SPIRE flux densities S
500 > S
350 > S
250 and a 5σ cut-off S
500 > 52 mJy. From this catalogue we determine that the total number of these ‘red’ sources is at least an order of magnitude higher than predicted by galaxy evolution models. These results are in agreement with previous findings in smaller HerMES fields; however, due to our significantly larger sample size we are also able to investigate the shape of the red source counts for the first time. We have obtained spectroscopic redshift measurements for two of our sources using the Atacama Large Millimeter/submillimeter Array. The redshifts z = 5.1 and 3.8 confirm that with our selection method we can indeed find high-redshift dusty star-forming galaxies.
The AzTEC mm-wavelength camera Wilson, G. W.; Austermann, J. E.; Perera, T. A. ...
Monthly notices of the Royal Astronomical Society,
20/May , Letnik:
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AzTEC is a mm-wavelength bolometric camera utilizing 144 silicon nitride micromesh detectors. Here, we describe the AzTEC instrument architecture and its use as an astronomical instrument. We report ...on several performance metrics measured during a three-month observing campaign at the James Clerk Maxwell Telescope and conclude with our plans for AzTEC as a facility instrument on the Large Millimetre Telescope.
We report our analysis of MACS J0717.5+3745 using 140 and 268 GHz Bolocam data collected at the Caltech Submillimeter Observatory. We detect extended Sunyaev-Zel'dovich (SZ) effect signal at high ...significance in both Bolocam bands, and we employ Herschel-SPIRE observations to subtract the signal from dusty background galaxies in the 268 GHz data. We constrain the two-band SZ surface brightness toward two of the sub-clusters of MACS J0717.5+3745; the main sub-cluster (named C), and a sub-cluster identified in spectroscopic optical data to have a line-of-sight velocity of +3200 km s super(-l) (named B). We determine the surface brightness in two separate ways: via fits of parametric models and via direct integration of the images. For both sub-clusters, we find consistent surface brightnesses from both analysis methods. We constrain spectral templates consisting of relativistically corrected thermal and kinetic SZ signals, using a jointly-derived electron temperature from Chandra and XMM-Newton under the assumption that each sub-cluster is isothermal. The data show no evidence for a kinetic SZ signal toward sub-cluster C, but they do indicate a significant kinetic SZ signal toward sub-cluster B. The model-derived surface brightnesses for sub-cluster B yield a best-fit, line-of-sight velocity of v sub(z) = +3450 + or - 900 km s super(-1), with (1 - Probv sub(2) > or =, slanted 0) = 1.3 x 10 super(-5) (4.2sigma away from 0 for a Gaussian distribution). The directly integrated sub-cluster B SZ surface brightnesses provide a best-fit v sub(z) = +2550 + or - 1050 km s super(-l), with (1 - Probv sub(2) > or =, slanted 0) = 2.2 x 10 super(-3) (2.9sigma).
We report results from the BICEP2 experiment, a cosmic microwave background (CMB) polarimeter specifically designed to search for the signal of inflationary gravitational waves in the B-mode power ...spectrum around ℓ∼80. The telescope comprised a 26 cm aperture all-cold refracting optical system equipped with a focal plane of 512 antenna coupled transition edge sensor 150 GHz bolometers each with temperature sensitivity of ≈300 μK(CMB)√s. BICEP2 observed from the South Pole for three seasons from 2010 to 2012. A low-foreground region of sky with an effective area of 380 square deg was observed to a depth of 87 nK deg in Stokes Q and U. In this paper we describe the observations, data reduction, maps, simulations, and results. We find an excess of B-mode power over the base lensed-ΛCDM expectation in the range 30 < ℓ < 150, inconsistent with the null hypothesis at a significance of >5σ. Through jackknife tests and simulations based on detailed calibration measurements we show that systematic contamination is much smaller than the observed excess. Cross correlating against WMAP 23 GHz maps we find that Galactic synchrotron makes a negligible contribution to the observed signal. We also examine a number of available models of polarized dust emission and find that at their default parameter values they predict power ∼(5-10)× smaller than the observed excess signal (with no significant cross-correlation with our maps). However, these models are not sufficiently constrained by external public data to exclude the possibility of dust emission bright enough to explain the entire excess signal. Cross correlating BICEP2 against 100 GHz maps from the BICEP1 experiment, the excess signal is confirmed with 3σ significance and its spectral index is found to be consistent with that of the CMB, disfavoring dust at 1.7σ. The observed B-mode power spectrum is well fit by a lensed-ΛCDM+tensor theoretical model with tensor-to-scalar ratio r = 0.20_(-0.05)(+0.07), with r = 0 disfavored at 7.0σ. Accounting for the contribution of foreground, dust will shift this value downward by an amount which will be better constrained with upcoming data sets.
We present results of a new deep 1.1 mm survey using Bolocam, a millimeter-wavelength bolometer array camera designed for mapping large fields at fast scan rates, without chopping. A map, galaxy ...candidate list, and derived number counts are presented. This survey encompasses 324 arcmin super(2) to an rms noise level (filtered for point sources) of s sub(1.1 mm) 1.4 mJy beam super(-1) and includes the entire regions surveyed by the published 8 mJy 850 km JCMT SCUBA and 1.2 mm IRAM MAMBO surveys. We reduced the data using a custom software pipeline to remove correlated sky and instrument noise via a principal component analysis. Extensive simulations and jackknife tests were performed to confirm the robustness of our source candidates and estimate the effects of false detections, bias, and completeness. In total, 17 source candidates were detected at a significance .3.0 s, with six expected false detections. Nine candidates are new detections, while eight candidates have coincident SCUBA 850 km and/or MAMBO 1.2 mm detections. From our observed number counts, we estimate the underlying differential number count distribution of submillimeter galaxies and find it to be in general agreement with previous surveys. Modeling the spectral energy distributions of these submillimeter galaxies after observations of dusty nearby galaxies suggests extreme luminosities of L = (1.0-1.6) x 10 super(13) L sub( )and, if powered by star formation, star formation rates of 500-800 M sub( )yr super(-1).
We report results from the Cryogenic Dark Matter Search at the Soudan Underground Laboratory (CDMS II) featuring the full complement of 30 detectors. A blind analysis of data taken between October ...2006 and July 2007 sets an upper limit on the weakly interacting massive particle (WIMP) nucleon spin-independent cross section of 6.6x10;{-44} cm;{2} (4.6x10;{-44} cm;{2} when combined with previous CDMS II data) at the 90% confidence level for a WIMP mass of 60 GeV/c;{2}. This achieves the best sensitivity for dark matter WIMPs with masses above 44 GeV/c;{2}, and significantly restricts the parameter space for some favored supersymmetric models.
We describe Sunyaev-Zel'dovich (SZ) effect measurements and analysis of the intracluster medium (ICM) pressure profiles of a set of 45 massive galaxy clusters imaged using Bolocam at the Caltech ...Submillimeter Observatory. We deproject the average pressure profile of our sample into 13 logarithmically spaced radial bins between 0.07R sub(500) and 3.5R sub(500), and we find that a generalized Navarro, Frenk, and White (gNFW) profile describes our data with sufficient goodness-of-fit and best-fit parameters (C sub(500), alpha , beta , gamma , P sub(0) = 1.18, 0.86, 3.67, 0.67, 4.29). We use X-ray data to define cool-core and disturbed subsamples of clusters, and we constrain the average pressure profiles of each of these subsamples. We find that, given the precision of our data, the average pressure profiles of disturbed and cool-core clusters are consistent with one another at R > 0.15/Goo, with cool-core systems showing indications of higher pressure at R <, ~ 0.15R sub(500). In addition, for the first time, we place simultaneous constraints on the mass scaling of cluster pressure profiles, their ensemble mean profile, and their radius-dependent intrinsic scatter between 0.1R sub(500) and 2.0R sub(500). The scatter among profiles is minimized at radii between Asymptotically = to0.2R sub(500) and Asymptotically = to0.5R sub(500), with a value of Asymptotically = to20%. These results for the intrinsic scatter are largely consistent with previous analyses, most of which have relied heavily on X-ray derived pressures of clusters at significantly lower masses and redshifts compared to our sample. Therefore, our data provide further evidence that cluster pressure profiles are largely universal with scatter of Asymptotically = to20%-40% about the universal profile over a wide range of masses and redshifts.
ABSTRACT We present scaling relations between the integrated Sunyaev-Zel'dovich effect (SZE) signal, , its X-ray analogue, , and total mass, , for the 45 galaxy clusters in the Bolocam X-ray SZ ...(BOXSZ) sample. All parameters are integrated within . values are measured using SZE data collected with Bolocam, operating at 140 GHz at the Caltech Submillimeter Observatory. The temperature, , and mass, , of the intracluster medium are determined using X-ray data collected with Chandra, and is derived from assuming a constant gas mass fraction. Our analysis accounts for several potential sources of bias, including selection effects, contamination from radio point sources, and the loss of SZE signal due to noise filtering and beam-smoothing effects. We measure the - scaling to have a power-law index of 0.84 0.07, and a fractional intrinsic scatter in of at fixed , both of which are consistent with previous analyses. We also measure the scaling between and , finding a power-law index of 1.06 0.12 and a fractional intrinsic scatter in at fixed mass of . While recent SZE scaling relations using X-ray mass proxies have found power-law indices consistent with the self-similar prediction of 5/3, our measurement stands apart by differing from the self-similar prediction by approximately 5 . Given the good agreement between the measured - scalings, much of this discrepancy appears to be caused by differences in the calibration of the X-ray mass proxies adopted for each particular analysis.
We present a status update on the development of a phonon-mediated particle detector using kinetic inductance detector (KID). The design is intended for
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kg substrate, using
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KIDs on ...a single readout line, to image the athermal phonon distribution at < 1 mm position resolution and
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eV energy resolution. The design specification is set by the need to improve position reconstruction fidelity while maintaining low energy threshold for future rare-event searches such as for low-mass dark matter. We report on the design, which shows negligible crosstalk and > 95% inductor current uniformity, using the coplanar waveguide feedline, ground shield, and a new class of KIDs with symmetric coplanar stripline (sCPS) inductor. The multiplexing is designed upon the frequency-geometry relation we develop for the sCPS KIDs. We introduce the fabrications of the Nb RF assessment prototypes and the high phonon collection efficiency Al–Nb devices. We achieve
≲
0.07% frequency displacement on a 80-KID RF assessment prototype, and the result indicates that we may place more than 180 resonances in our 0.4 GHz readout band with minimal frequency misordering. The coupling quality factors are
∼
10
5
as designed. Finally, we update our work in progress in fabricating the
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KID, bi-material,
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kg detectors, and the expected position and energy resolutions.
We present initial results from our ongoing program to image the Sunyaev-Zel'dovich (SZ) effect in galaxy clusters at 143 GHz using Bolocam; five clusters and one blank field are described in this ...manuscript. The images have a resolution of 58 arcsec and a radius of 6-7 arcmin, which is approximately r 500-2r 500 for these clusters. We effectively high-pass filter our data in order to subtract noise sourced by atmospheric fluctuations, but we are able to obtain unbiased images of the clusters by deconvolving the effects of this filter. The beam-smoothed rms is 10 Delta *mKCMB in these images; with this sensitivity, we are able to detect the SZ signal to beyond r 500 in binned radial profiles. We have fit our images to beta and Nagai models, fixing spherical symmetry or allowing for ellipticity in the plane of the sky, and we find that the best-fit parameter values are in general consistent with those obtained from other X-ray and SZ data. Our data show no clear preference for the Nagai model or the beta model due to the limited spatial dynamic range of our images. However, our data show a definitive preference for elliptical models over spherical models, quantified by an F ratio of 20 for the two models. The weighted mean ellipticity of the five clusters is = 0.27 ? 0.03, consistent with results from X-ray data. Additionally, we obtain model-independent estimates of Y 500, the integrated SZ y-parameter over the cluster face to a radius of r 500, with systematics-dominated uncertainties of 10%. Our Y 500 values, which are free from the biases associated with model-derived Y 500 values, scale with cluster mass in a way that is consistent with both self-similar predictions and expectations of a 10% intrinsic scatter.
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