580 research outputs found
TRIS III: the diffuse galactic radio emission at
We present values of temperature and spectral index of the galactic diffuse
radiation measured at 600 and 820 MHz along a 24 hours right ascension circle
at declination . They have been obtained from a subset of
absolute measurements of the sky temperature made with TRIS, an experiment
devoted to the measurement of the Cosmic Microwave Background temperature at
decimetric-wavelengths with an angular resolution of about .
Our analysis confirms the preexisting picture of the galactic diffuse
emission at decimetric wavelength and improves the accuracy of the measurable
quantities. In particular, the signal coming from the halo has a spectral index
in the range above 600 MHz, depending on the sky position. In the
disk, at TRIS angular resolution, the free-free emission accounts for the 11%
of the overall signal at 600 MHz and 21% at 1420 MHz. The polarized component
of the galactic emission, evaluated from the survey by Brouw and Spoelstra,
affects the observations at TRIS angular resolution by less than 3% at 820 MHz
and less than 2% at 600 MHz. Within the uncertainties, our determination of the
galactic spectral index is practically unaffected by the correction for
polarization.
Since the overall error budget of the sky temperatures measured by TRIS at
600 MHz, that is 66 mK(systematic)18 mK (statistical), is definitely smaller
than those reported in previous measurements at the same frequency, our data
have been used to discuss the zero levels of the sky maps at 150, 408, 820 and
1420 MHz in literature. Concerning the 408 MHz survey, limiting our attention
to the patch of sky corresponding to the region observed by TRIS, we suggest a
correction of the base-level of K.Comment: Accepted for publication in the Astrophysical Journa
TRIS I: Absolute Measurements of the Sky Brightness Temperature at 0.6, 0.82 and 2.5 GHz
At frequencies close to 1 GHz the sky diffuse radiation is a superposition of
radiation of Galactic origin, the 3 K Relic or Cosmic Microwave Background
Radiation, and the signal produced by unresolved extragalactic sources. Because
of their different origin and space distribution the relative importance of the
three components varies with frequency and depends on the direction of
observation. With the aim of disentangling the components we built TRIS, a
system of three radiometers, and studied the temperature of the sky at , and GHz using geometrically scaled antennas
with identical beams (HPBW = ). Observations
included drift scans along a circle at constant declination
which provided the dependence of the sky signal on the
Right Ascension, and absolute measurement of the sky temperature at selected
points along the same scan circle. TRIS was installed at Campo Imperatore (lat.
= N, long.= , elevation = 2000 m a.s.l.) in
Central Italy, close to the Gran Sasso Laboratory.Comment: Accepted for publication in The Astrophysical Journa
Deciphering the local Interstellar spectra of primary cosmic ray species with HelMod
Local interstellar spectra (LIS) of primary cosmic ray (CR) nuclei, such as
helium, oxygen, and mostly primary carbon are derived for the rigidity range
from 10 MV to ~200 TV using the most recent experimental results combined with
the state-of-the-art models for CR propagation in the Galaxy and in the
heliosphere. Two propagation packages, GALPROP and HelMod, are combined into a
single framework that is used to reproduce direct measurements of CR species at
different modulation levels, and at both polarities of the solar magnetic
field. The developed iterative maximum-likelihood method uses GALPROP-predicted
LIS as input to HelMod, which provides the modulated spectra for specific time
periods of the selected experiments for model-data comparison. The interstellar
and heliospheric propagation parameters derived in this study are consistent
with our prior analyses using the same methodology for propagation of CR
protons, helium, antiprotons, and electrons. The resulting LIS accommodate a
variety of measurements made in the local interstellar space (Voyager 1) and
deep inside the heliosphere at low (ACE/CRIS, HEAO-3) and high energies
(PAMELA, AMS-02).Comment: 13 pages, 13 figures, 6 tables, ApJ in press. arXiv admin note: text
overlap with arXiv:1704.0633
HelMod in the works: from direct observations to the local interstellar spectrum of cosmic-ray electrons
The local interstellar spectrum (LIS) of cosmic-ray (CR) electrons for the
energy range 1 MeV to 1 TeV is derived using the most recent experimental
results combined with the state-of-the-art models for CR propagation in the
Galaxy and in the heliosphere. Two propagation packages, GALPROP and HelMod,
are combined to provide a single framework that is run to reproduce direct
measurements of CR species at different modulation levels, and at both
polarities of the solar magnetic field. An iterative maximum-likelihood method
is developed that uses GALPROP-predicted LIS as input to HelMod, which provides
the modulated spectra for specific time periods of the selected experiments for
model-data comparison. The optimized HelMod parameters are then used to adjust
GALPROP parameters to predict a refined LIS with the procedure repeated subject
to a convergence criterion. The parameter optimization uses an extensive data
set of proton spectra from 1997-2015. The proposed CR electron LIS accommodates
both the low-energy interstellar spectra measured by Voyager 1 as well as the
high-energy observations by PAMELA and AMS-02 that are made deep in the
heliosphere; it also accounts for Ulysses counting rate features measured out
of the ecliptic plane. The interstellar and heliospheric propagation parameters
derived in this study agree well with our earlier results for CR protons,
helium nuclei, and anti-protons propagation and LIS obtained in the same
framework.Comment: 11 pages, 14 figures, 4 tables; ApJ, in pres
ARCADE 2 Measurement of the Extra-Galactic Sky Temperature at 3-90 GHz
The ARCADE 2 instrument has measured the absolute temperature of the sky at
frequencies 3, 8, 10, 30, and 90 GHz, using an open-aperture cryogenic
instrument observing at balloon altitudes with no emissive windows between the
beam-forming optics and the sky. An external blackbody calibrator provides an
{\it in situ} reference. Systematic errors were greatly reduced by using
differential radiometers and cooling all critical components to physical
temperatures approximating the CMB temperature. A linear model is used to
compare the output of each radiometer to a set of thermometers on the
instrument. Small corrections are made for the residual emission from the
flight train, balloon, atmosphere, and foreground Galactic emission. The ARCADE
2 data alone show an extragalactic rise of mK at 3.3 GHz in addition
to a CMB temperature of K. Combining the ARCADE 2 data with
data from the literature shows a background power law spectrum of [K] from 22 MHz to 10 GHz ( GHz)
in addition to a CMB temperature of K.Comment: 11 pages 5 figures Submitted to Ap
Parenteral protein formulations: an overview of approved products within the European Union
The study presented is a comprehensive overview of commercial parenteral protein formulations, approved by the European Medicines Agency (EMA), 1995-2018. The objective of this overview was to analyse current trends in the design of commercial parenteral protein products and thereby support formulation scientists in the design of new formulations. The main data source was the publicly available European Public Assessment Reports (EPARs) published by the EMA for each authorised product. An analysis of the percentage of formulations in a liquid and lyophilised form was conducted. In addition, the number of products containing individual excipients, classified into functional categories is provided. Finally, the overview includes comprehensive details of product compositions obtained from EMA, US Food and Drug Administration (FDA) and product Marketing Authorisation Holder. Data analysis highlighted trends in the number of products approved, and the higher percentage of liquid parenteral protein formulations (66%) compared to lyophilised formulations (34%). This overview identifies the most commonly incorporated excipients employed as buffering agents, stabilisers/bulking agents, surfactants, preservatives and tonicifiers, including their concentration ranges of use in both liquid and lyophilised formulation approaches. Finally, antibody-based formulations were a particular focus of this overview. The relationship between parenteral routes of administration and antibody concentrations in approved products was also investigated
The contribution of the Unresolved Extragalactic Radio Sources to the Brightness Temperature of the sky
The contribution of the Unresolved Extragalactic Radio Sources to the diffuse
brightness of the sky was evaluated using the source number - flux measurements
available in literature. We first optimized the fitting function of the data
based on number counts distribution. We then computed the brightness
temperature at various frequencies from 151 MHz to 8440 MHz and derived its
spectral dependence. As expected the frequency dependence can be described by a
power law with a spectral index , in agreement with the
flux emitted by the {\it steep spectrum} sources. The contribution of {\it flat
spectrum} sources becomes relevant at frequencies above several GHz. Using the
data available in literature we improved our knowledge of the brightness of the
unresolved extragalactic radio sources. The results obtained have general
validity and they can be used to disentangle the various contributions of the
sky brightness and to evaluate the CMB temperature.Comment: Accepted for publication in the Astrophysical Journa
Angular Power Spectra of the Millimeter Wavelength Background Light from Dusty Star-forming Galaxies with the South Pole Telescope
We use data from the first 100 square-degree field observed by the South Pole
Telescope (SPT) in 2008 to measure the angular power spectrum of temperature
anisotropies contributed by the background of dusty star-forming galaxies
(DSFGs) at millimeter wavelengths. From the auto and cross-correlation of 150
and 220 GHz SPT maps, we significantly detect both Poisson distributed and, for
the first time at millimeter wavelengths, clustered components of power from a
background of DSFGs. The spectral indices between 150 and 220 GHz of the
Poisson and clustered components are found to be 3.86 +- 0.23 and 3.8 +- 1.3
respectively, implying a steep scaling of the dust emissivity index beta ~ 2.
The Poisson and clustered power detected in SPT, BLAST (at 600, 860, and 1200
GHz), and Spitzer (1900 GHz) data can be understood in the context of a simple
model in which all galaxies have the same graybody spectrum with dust
emissivity index of beta = 2 and dust temperature T_d = 34 K. In this model,
half of the 150 GHz background light comes from redshifts greater than 3.2. We
also use the SPT data to place an upper limit on the amplitude of the kinetic
Sunyaev-Zel'dovich power spectrum at l = 3000 of 13 uK^2 at 95% confidence.Comment: 18 pages, 9 figure
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