31 research outputs found
The Thermal Design, Characterization, and Performance of the SPIDER Long-Duration Balloon Cryostat
We describe the SPIDER flight cryostat, which is designed to cool six
millimeter-wavelength telescopes during an Antarctic long-duration balloon
flight. The cryostat, one of the largest to have flown on a stratospheric
payload, uses liquid helium-4 to deliver cooling power to stages at 4.2 and 1.6
K. Stainless steel capillaries facilitate a high flow impedance connection
between the main liquid helium tank and a smaller superfluid tank, allowing the
latter to operate at 1.6 K as long as there is liquid in the 4.2 K main tank.
Each telescope houses a closed cycle helium-3 adsorption refrigerator that
further cools the focal planes down to 300 mK. Liquid helium vapor from the
main tank is routed through heat exchangers that cool radiation shields,
providing negative thermal feedback. The system performed successfully during a
17 day flight in the 2014-2015 Antarctic summer. The cryostat had a total hold
time of 16.8 days, with 15.9 days occurring during flight.Comment: 15 pgs, 17 fig
Semi-analytical approach to magnetized temperature autocorrelations
The cosmic microwave background (CMB) temperature autocorrelations, induced
by a magnetized adiabatic mode of curvature inhomogeneities, are computed with
semi-analytical methods. As suggested by the latest CMB data, a nearly
scale-invariant spectrum for the adiabatic mode is consistently assumed. In
this situation, the effects of a fully inhomogeneous magnetic field are
scrutinized and constrained with particular attention to harmonics which are
relevant for the region of Doppler oscillations. Depending on the parameters of
the stochastic magnetic field a hump may replace the second peak of the angular
power spectrum. Detectable effects on the Doppler region are then expected only
if the magnetic power spectra have quasi-flat slopes and typical amplitude
(smoothed over a comoving scale of Mpc size and redshifted to the epoch of
gravitational collapse of the protogalaxy) exceeding 0.1 nG. If the magnetic
energy spectra are bluer (i.e. steeper in frequency) the allowed value of the
smoothed amplitude becomes, comparatively, larger (in the range of 20 nG). The
implications of this investigation for the origin of large-scale magnetic
fields in the Universe are discussed. Connections with forthcoming experimental
observations of CMB temperature fluctuations are also suggested and partially
explored.Comment: 40 pages, 13 figure
An overview of the current status of CMB observations
In this paper we briefly review the current status of the Cosmic Microwave
Background (CMB) observations, summarising the latest results obtained from CMB
experiments, both in intensity and polarization, and the constraints imposed on
the cosmological parameters. We also present a summary of current and future
CMB experiments, with a special focus on the quest for the CMB B-mode
polarization.Comment: Latest CMB results have been included. References added. To appear in
"Highlights of Spanish Astrophysics V", Proceedings of the VIII Scientific
Meeting of the Spanish Astronomical Society (SEA) held in Santander, 7-11
July, 200
Stochastic backgrounds of relic gravitons: a theoretical appraisal
Stochastic backgrounds or relic gravitons, if ever detected, will constitute
a prima facie evidence of physical processes taking place during the earliest
stages of the evolution of the plasma. The essentials of the stochastic
backgrounds of relic gravitons are hereby introduced and reviewed. The pivotal
observables customarily employed to infer the properties of the relic gravitons
are discussed both in the framework of the CDM paradigm as well as in
neighboring contexts. The complementarity between experiments measuring the
polarization of the Cosmic Microwave Background (such as, for instance, WMAP,
Capmap, Quad, Cbi, just to mention a few) and wide band interferometers (e.g.
Virgo, Ligo, Geo, Tama) is emphasized. While the analysis of the microwave sky
strongly constrains the low-frequency tail of the relic graviton spectrum,
wide-band detectors are sensitive to much higher frequencies where the spectral
energy density depends chiefly upon the (poorly known) rate of
post-inflationary expansion.Comment: 94 pages, 32 figure
ANALISIS REPRESENTASI TRADISI KEMATIAN PADA NOVEL PUYA KE PUYA KARYA FAISAL ODDANG
Death tradition is a ceremonial process that is done from generation to generation as the delivery of died people before actually going to another world (immortality).One of death traditions in Indonesia that is still done and well-known to foreign countries is Rambu Solo’ in Toraja. Rambu Solo’ is done as the process of perfecting died people. Death tradition is depicted in Puya Ke Puya novel by Faisal Oddang. Based on that thing, the problem formulation in this research, are (1) how is the representation of death ceremony stages in Puya Ke Puya novel by Faisal Oddang, (2) how are the meanings of death ceremony stages in Puya Ke Puya novel by Faisal Oddang.
The method used in this research is descriptive method of analysis using literary anthropology approach. The source of data in this study is Puya Ke Puya novel by Faisal Oddang by concerning data quotations, sentences, as well as units of stories in the novel. Data found in this researh is processed through several stages, such as (1) collecting data, (2) classifying data, (3) data assessment, (4) drawing conclusion.
The result of the analysis and discussion shows that in Puya Ke Puya novel by Faisal Oddang, it is found two processes of ceremonial stages and the meaning of process stages as representation of death tradition in Rambu Solo '. Death ceremony stages are (1) before death ceremony process and (2) during death ceremony process. Before the ceremony, there are several things that are need to be done and prepared by the family including holding big family meeting to determine when the Rambu Solo’ ceremony will be held, determining the level of death ceremony, preparing or buying buffaloes and pigs, preparing the necessary equipments. The next stage is the process of death ceremony. In this stage which includes Mappassulu ', Mangriu' Batu, Mapopengkaloa, Ma'pasonglo, Tau-tau, Lantang, Mappasilaga Tedong, Mantunu Tedong and ipalao. The meaning of Rambu Solo’ ceremony stage is a process of completion of died people so that they can get to puya. If it is not celebrated, thw aoul of died people will be stuck between heaven and earth in uncertain fate or become ghosts. It is also believed that it brings misfortune for families of died people. This is the belief of Toraja people
Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine
[This corrects the article DOI: 10.1186/s13054-016-1208-6.]
Cosmological birefringence due to CPT-even Chern–Simons-like term with Kalb–Ramond and scalar fields
We study the CPT-even dimension-six Chern–Simons-like term by including dynamical Kalb–Ramond and scalar fields to examine the cosmological birefringence. We show that the combined effect of a neutrino current and a Kalb–Ramond field could induce a sizable rotation polarization angle in the cosmic microwave background radiation polarization
Observations of the temperature and polarization anisotropies with BOOMERANG 2003
The BOOMERANG experiment completed its final long duration balloon (LDB)
flight over Antarctica in January 2003. The focal plane was upgraded to
accommodate four sets of 145 GHz polarization sensitive bolometers
(PSBs), identical to those to be flown on the Planck HFI instrument.
Approximately, 195 hours of science observations were obtained during
this flight, including 75 hours distributed over 1.84\% of the sky and an
additional 120 hours concentrated on a region covering 0.22\% of the sky.
We derive the angular power spectra of the cosmic microwave background
(CMB) temperature and polarization anisotropies from these data. The
temperature anisotropies are detected with high signal to noise on
angular scales ranging from several degrees to {\tilde10 arcminutes. The
curl-free (EE) component is detected at \tilde4.8, and a
two-sigma upper limit on the curl (BB) component of 8.6
K is obtained on scales corresponding to
\tilde0.5\deg. Both the temperature and polarization anisotropies are
found to be consistent with a concordance CDM cosmology that is
seeded by adiabatic density perturbations. In addition to the CMB
observations, BOOMERANG03 surveyed a \tilde300 square degree region
centered on the Galactic plane. These observations represent the first
light for polarization sensitive bolometers, which are currently
operational in two South-Pole based polarimeters, as well as Planck HFI,
at frequencies ranging from 100 to 350 GHz (3 mm to 850 m).
CMB polarization with BOOMERANG 2003
This paper reports results from the BOOMERANG 2003 flights, devoted to
the measurement of intensity and polarization of the cosmic microwave
background radiation. In particular, it is focused on the power angular
power spectra and on the control of possible contamination from
systematic effects and foregrounds
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SPIDER: probing the early Universe with a suborbital polarimeter
We evaluate the ability of SPIDER, a balloon-borne polarimeter, to detect a divergence-free polarization pattern (B-modes) in the cosmic microwave background (CMB). In the inflationary scenario, the amplitude of this signal is proportional to that of the primordial scalar perturbations through the tensor-to-scalar ratio r. We show that the expected level of systematic error in the SPIDER instrument is significantly below the amplitude of an interesting cosmological signal with r = 0.03. We present a scanning strategy that enables us to minimize uncertainty in the reconstruction of the Stokes parameters used to characterize the CMB, while accessing a relatively wide range of angular scales. Evaluating the amplitude of the polarized Galactic emission in the SPIDER field, we conclude that the polarized emission from interstellar dust is as bright or brighter than the cosmological signal at all SPIDER frequencies (90 GHz, 150 GHz, and 280 GHz), a situation similar to that found in the "Southern Hole." We show that two similar to 20-day flights of the SPIDER instrument can constrain the amplitude of the B-mode signal to r < 0.03 (99% CL) even when foreground contamination is taken into account. In the absence of foregrounds, the same limit can be reached after one 20-day flight