85 research outputs found
Weighting CMB and Galactic synchrotron polarisation
We review the present knowledge of the diffuse Galactic synchrotron emission
in polarisation. At microwave frequencies, we assess the expected contamination
to the CMB polarisation angular power spectrum, for and modes, as
expected after the WMAP first year measurements.Comment: 6 pages, 4 figures, proc. of the CMBnet workshop, 20-21 Feb. 2003,
Oxford, U
Cosmic Microwave Background Polarisation: foreground contrast and component separation
We evaluate the expected level of foreground contamination to the cosmic
microwave background (CMB) polarised radiation, focusing on the diffuse
emission from our own Galaxy. In particular, we perform a first attempt to
simulate an all sky template of polarised emission from thermal dust. This
study indicates that the foreground contamination to CMB modes is likely to
be relevant on all frequencies, and even at high Galactic latitudes. We review
the recent developments in the design of data analysis techniques dedicated to
the separation of CMB and foreground emissions in multi-frequency observations,
exploiting their statistical independence. We argue that the high quality and
detail of the present CMB observations represent an almost ideal statistical
dataset where these algorithms can operate with excellent performance. We
explicitly show that the recovery of CMB modes is possible even if they are
well below the foreground level, working at the arcmin. resolution at an almost
null computational cost. This capability well represents the great potentiality
of these new data analysis techniques, which should be seriously taken into
account for implementation in present and future CMB observations.Comment: 10 pages, 4 figures, to be published in the proceedings of ``The
Cosmic Microwave Background and its Polarization", New Astronomy Reviews,
(eds. S. Hanany and K.A. Olive). Maps and software downloads at
http://planck.mpa-garching.mpg.de/ and
http://www.sissa.it/~bacci/cmb/downloads
Separating polarized cosmological and galactic emissions for CMB B-mode polarization experiments
In this work we study the relevance of the component separation technique
based on the Independent Component Analysis (ICA) and investigate its
performance in the context of a limited sky coverage observation and from the
viewpoint of our ability to differentiate between cosmological models with
different primordial B-mode content. We focus on the low Galactic emission sky
patch, corresponding to the target of several operating and planned CMB
experiments and which, in many respects, adequately represents a typical
"clean" high latitude sky. We consider two fiducial observations, one operating
at low (40, 90 GHz) and one at high (150, 350 GHz) frequencies and thus
dominated by the synchrotron and thermal dust emission, respectively. We use a
parallel version of the FASTICA code to explore a substantial parameter space
including Gaussian pixel noise level, observed sky area and the amplitude of
the foreground emission and employ large Monte Carlo simulations to quantify
errors and biases pertinent to the reconstruction for different choices of the
parameter values. We identify a large subspace of the parameter space for which
the quality of the CMB reconstruction is excellent. For both the cosmological
models, with and without the primordial gravitational waves, we find that
FASTICA performs extremely well even in the cases when the B mode CMB signal is
up to a few times weaker than the foreground contamination and the noise
amplitude is comparable with the total CMB polarized emission. In addition we
discuss limiting cases of the noise and foreground amplitudes, for which the
ICA approach fails.Comment: 19 pages, 12 figures, 5 tables, replaced to match published versio
Intranasal ketorolac and opioid in treatment of acute renal colic
The usual treatment of pain in acute renal colic is analgesic in intravenous (IV) route. We tried a rapid, non-painful, non-invasive route of administration using intranasal ketorolac plus fentanyl versus IV standard treatment with non steroidal anti-inflammatory drug plus opioid for the relief of pain in renal colic presenting patients to an Emergency Department (ED). We conducted a prospective nonblinded clinical trial. A sample of 82 adult patients with clinical diagnosis of acute renal colic was included to receive either intravenous ketorolac plus fentanyl or intranasal ketorolac plus fentanyl. Pain score was rated by using a 10 cm visual analogue scale at 0, 30 and 60 minutes after the treatment. Primary outcome was pain reduction. Secondary outcomes were adverse events and rescue treatment. Eighty-two patients were enrolled. The first forty-one patients received intranasal ketorolac plus fentanyl and the second forty-one received intravenous ketorolac plus fentanyl. There were not statistically significant differences in reduction of pain between the two groups at 30 and 60 minutes (P-value at 30=0,225; P-value at 60=0,312) although the trend was in favour of IV group. There were no significant differences between the groups with regard to secondary outcomes (adverse events and rescue treatment). Intranasal ketorolac and fentanyl are equivalent in analgesic effect to intravenous ketorolac and fentanyl treatment for ED patients with acute renal colic and the intranasal treatment can be considered a valid alternative to the standard intravenous treatment
Galactic foreground contribution to the BEAST CMB Anisotropy Maps
We report limits on the Galactic foreground emission contribution to the
Background Emission Anisotropy Scanning Telescope (BEAST) Ka- and Q-band CMB
anisotropy maps. We estimate the contribution from the cross-correlations
between these maps and the foreground emission templates of an H map,
a de-striped version of the Haslam et al. 408 MHz map, and a combined 100
m IRAS/DIRBE map. Our analysis samples the BEAST
declination band into 24 one-hour (RA) wide sectors with pixels
each, where we calculate: (a) the linear correlation coefficient between the
anisotropy maps and the templates; (b) the coupling constants between the
specific intensity units of the templates and the antenna temperature at the
BEAST frequencies and (c) the individual foreground contributions to the BEAST
anisotropy maps. The peak sector contributions of the contaminants in the
Ka-band are of 56.5% free-free with a coupling constant of
K/R, and 67.4% dust with K/(MJy/sr). In the Q-band the
corresponding values are of 64.4% free-free with K/R and 67.5%
dust with K/(MJy/sr). Using a lower limit of 10% in the
relative uncertainty of the coupling constants, we can constrain the sector
contributions of each contaminant in both maps to % in 21 (free-free), 19
(dust) and 22 (synchrotron) sectors. At this level, all these sectors are found
outside of the b region. By performing the same
correlation analysis as a function of Galactic scale height, we conclude that
the region within should be removed from the BEAST maps for
CMB studies in order to keep individual Galactic contributions below %
of the map's rms.Comment: 17 pages PostScript file. Better resolution figures can be found in
the web page http://www.das.inpe.br/~alex/beast_foregrounds.html. Accepted
for publication in the ApJ Suppl. Serie
Observing the Evolution of the Universe
How did the universe evolve? The fine angular scale (l>1000) temperature and
polarization anisotropies in the CMB are a Rosetta stone for understanding the
evolution of the universe. Through detailed measurements one may address
everything from the physics of the birth of the universe to the history of star
formation and the process by which galaxies formed. One may in addition track
the evolution of the dark energy and discover the net neutrino mass.
We are at the dawn of a new era in which hundreds of square degrees of sky
can be mapped with arcminute resolution and sensitivities measured in
microKelvin. Acquiring these data requires the use of special purpose
telescopes such as the Atacama Cosmology Telescope (ACT), located in Chile, and
the South Pole Telescope (SPT). These new telescopes are outfitted with a new
generation of custom mm-wave kilo-pixel arrays. Additional instruments are in
the planning stages.Comment: Science White Paper submitted to the US Astro2010 Decadal Survey.
Full list of 177 author available at http://cmbpol.uchicago.ed
Validation of techniques to mitigate copper surface contamination in CUORE
In this article we describe the background challenges for the CUORE
experiment posed by surface contamination of inert detector materials such as
copper, and present three techniques explored to mitigate these backgrounds.
Using data from a dedicated test apparatus constructed to validate and compare
these techniques we demonstrate that copper surface contamination levels better
than 10E-07 - 10E-08 Bq/cm2 are achieved for 238U and 232Th. If these levels
are reproduced in the final CUORE apparatus the projected 90% C.L. upper limit
on the number of background counts in the region of interest is 0.02-0.03
counts/keV/kg/y depending on the adopted mitigation technique.Comment: 10 pages, 6 figures, 6 table
Search for 14.4 keV solar axions from M1 transition of Fe-57 with CUORE crystals
We report the results of a search for axions from the 14.4 keV M1 transition
from Fe-57 in the core of the sun using the axio-electric effect in TeO2
bolometers. The detectors are 5x5x5 cm3 crystals operated at about 10 mK in a
facility used to test bolometers for the CUORE experiment at the Laboratori
Nazionali del Gran Sasso in Italy. An analysis of 43.65 kg d of data was made
using a newly developed low energy trigger which was optimized to reduce the
detectors energy threshold. An upper limit of 0.63 c kg-1 d-1 was established
at 95% C.L.. From this value, a lower bound at 95% C.L. was placed on the
Peccei-Quinn energy scale of fa >= 0.76 10**6 GeV for a value of S=0.55 for the
flavor-singlet axial vector matrix element. Bounds are given for the interval
0.15 < S < 0.55.Comment: 14 pages, 6 figures, submitted to JCA
PRISM (Polarized Radiation Imaging and Spectroscopy Mission): A White Paper on the Ultimate Polarimetric Spectro-Imaging of the Microwave and Far-Infrared Sky
PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to
ESA in response to the Call for White Papers for the definition of the L2 and
L3 Missions in the ESA Science Programme. PRISM would have two instruments: (1)
an imager with a 3.5m mirror (cooled to 4K for high performance in the
far-infrared---that is, in the Wien part of the CMB blackbody spectrum), and
(2) an Fourier Transform Spectrometer (FTS) somewhat like the COBE FIRAS
instrument but over three orders of magnitude more sensitive. Highlights of the
new science (beyond the obvious target of B-modes from gravity waves generated
during inflation) made possible by these two instruments working in tandem
include: (1) the ultimate galaxy cluster survey gathering 10e6 clusters
extending to large redshift and measuring their peculiar velocities and
temperatures (through the kSZ effect and relativistic corrections to the
classic y-distortion spectrum, respectively) (2) a detailed investigation into
the nature of the cosmic infrared background (CIB) consisting of at present
unresolved dusty high-z galaxies, where most of the star formation in the
universe took place, (3) searching for distortions from the perfect CMB
blackbody spectrum, which will probe a large number of otherwise inaccessible
effects (e.g., energy release through decaying dark matter, the primordial
power spectrum on very small scales where measurements today are impossible due
to erasure from Silk damping and contamination from non-linear cascading of
power from larger length scales). These are but a few of the highlights of the
new science that will be made possible with PRISM.Comment: 20 pages Late
Implementation and performances of the IPbus protocol for the JUNO Large-PMT readout electronics
The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino
detector currently under construction in China. Thanks to the tight
requirements on its optical and radio-purity properties, it will be able to
perform leading measurements detecting terrestrial and astrophysical neutrinos
in a wide energy range from tens of keV to hundreds of MeV. A key requirement
for the success of the experiment is an unprecedented 3% energy resolution,
guaranteed by its large active mass (20 kton) and the use of more than 20,000
20-inch photo-multiplier tubes (PMTs) acquired by high-speed, high-resolution
sampling electronics located very close to the PMTs. As the Front-End and
Read-Out electronics is expected to continuously run underwater for 30 years, a
reliable readout acquisition system capable of handling the timestamped data
stream coming from the Large-PMTs and permitting to simultaneously monitor and
operate remotely the inaccessible electronics had to be developed. In this
contribution, the firmware and hardware implementation of the IPbus based
readout protocol will be presented, together with the performances measured on
final modules during the mass production of the electronics
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