31 research outputs found
Solar cycle variability of Mars dayside exospheric temperatures: Model evaluation of underlying thermal balances
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95086/1/grl25450.pd
ALMA-IMF IX: Catalog and Physical Properties of 315 SiO Outflow Candidates in 15 Massive Protoclusters
We present a catalog of 315 protostellar outflow candidates detected in SiO
J=5-4 in the ALMA-IMF Large Program, observed with ~2000 au spatial resolution,
0.339 km/s velocity resolution, and 2-12 mJy/beam (0.18-0.8 K) sensitivity. We
find median outflow masses, momenta, and kinetic energies of ~0.3 M,
4 M km/s, and 10 erg, respectively. Median outflow lifetimes
are 6,000 years, yielding median mass, momentum, and energy rates of
= 10 M yr, = 10 M km/s
yr, and = 1 L. We analyze these outflow properties
in the aggregate in each field. We find correlations between field-aggregated
SiO outflow properties and total mass in cores (~35), and no
correlations above 3 with clump mass, clump luminosity, or clump
luminosity-to-mass ratio. We perform a linear regression analysis and find that
the correlation between field-aggregated outflow mass and total clump mass -
which has been previously described in the literature - may actually be
mediated by the relationship between outflow mass and total mass in cores. We
also find that the most massive SiO outflow in each field is typically
responsible for only 15-30% of the total outflow mass (60% upper limit). Our
data agree well with the established mechanical force-bolometric luminosity
relationship in the literature, and our data extend this relationship up to L
10 L and 1 M km/s yr.
Our lack of correlation with clump L/M is inconsistent with models of
protocluster formation in which all protostars start forming at the same time.Comment: 46 pages, 14 figures, 10 tables. This publication has an associated
Zenodo entry, which can be found here: https://zenodo.org/records/835059
ALMA-IMF. VII. First release of the full spectral line cubes: Core kinematics traced by DCN J=(3-2)
ALMA-IMF is an Atacama Large Millimeter/submillimeter Array (ALMA) Large
Program designed to measure the core mass function (CMF) of 15 protoclusters
chosen to span their early evolutionary stages. It further aims to understand
their kinematics, chemistry, and the impact of gas inflow, accretion, and
dynamics on the CMF. We present here the first release of the ALMA-IMF line
data cubes (DR1), produced from the combination of two ALMA 12m-array
configurations. The data include 12 spectral windows, with eight at 1.3mm and
four at 3mm. The broad spectral coverage of ALMA-IMF (~6.7 GHz bandwidth
coverage per field) hosts a wealth of simple atomic, molecular, ionised, and
complex organic molecular lines. We describe the line cube calibration done by
ALMA and the subsequent calibration and imaging we performed. We discuss our
choice of calibration parameters and optimisation of the cleaning parameters,
and we demonstrate the utility and necessity of additional processing compared
to the ALMA archive pipeline. As a demonstration of the scientific potential of
these data, we present a first analysis of the DCN (3-2) line. We find that DCN
traces a diversity of morphologies and complex velocity structures, which tend
to be more filamentary and widespread in evolved regions and are more compact
in the young and intermediate-stage protoclusters. Furthermore, we used the DCN
(3-2) emission as a tracer of the gas associated with 595 continuum cores
across the 15 protoclusters, providing the first estimates of the core systemic
velocities and linewidths within the sample. We find that DCN (3-2) is detected
towards a higher percentage of cores in evolved regions than the young and
intermediate-stage protoclusters and is likely a more complete tracer of the
core population in more evolved protoclusters. The full ALMA 12m-array cubes
for the ALMA-IMF Large Program are provided with this DR1 release.Comment: 75 pages (21 main body; 54 appendix), 37 figures. The ALMA-IMF DR1
line release is hosted at https://dataverse.harvard.edu/dataverse/alma-im
ALMA-IMF. IX. Catalog and physical properties of 315 SiO outflow candidates in 15 massive protoclusters
We present a catalog of 315 protostellar outflow candidates detected in SiO J = 5 − 4 in the ALMA-IMF Large Program, observed with ∼2000 au spatial resolution, 0.339 km s−1 velocity resolution, and 2–12 mJy beam−1 (0.18–0.8 K) sensitivity. We find median outflow masses, momenta, and kinetic energies of ∼0.3 M ⊙, 4 M ⊙ km s−1, and 1045 erg, respectively. Median outflow lifetimes are 6000 yr, yielding median mass, momentum, and energy rates of Ṁ = 10−4.4 M ⊙ yr−1, Ṗ = 10−3.2 M ⊙ km s−1 yr−1, and Ė = 1 L ⊙. We analyze these outflow properties in the aggregate in each field. We find correlations between field-aggregated SiO outflow properties and total mass in cores (∼3σ–5σ), and no correlations above 3σ with clump mass, clump luminosity, or clump luminosity-to-mass ratio. We perform a linear regression analysis and find that the correlation between field-aggregated outflow mass and total clump mass—which has been previously described in the literature—may actually be mediated by the relationship between outflow mass and total mass in cores. We also find that the most massive SiO outflow in each field is typically responsible for only 15%–30% of the total outflow mass (60% upper limit). Our data agree well with the established mechanical force−bolometric luminosity relationship in the literature, and our data extend this relationship up to L ≥ 106 L ⊙ and Ṗ ≥ 1 M ⊙ km s−1 yr−1. Our lack of correlation with clump L/M is inconsistent with models of protocluster formation in which all protostars start forming at the same time
The natural concentration of the conjugated linoleic acid, cis-9,trans-11 in milk-fat has anti-atherogenic effects in hyperlipidemic hamsters.
International audienc
Lipid atherogenic risk markers can be more favourably influenced by the cis-9,trans-11-octadecadienoate isomer than a conjugated linoleic acid mixture or fish oil in hamsters
The aim of our present study was to compare the efficiency of conjugated linoleic acids (CLA) and fish oil in modulating atherogenic risk markers. Adult male hamsters were given a cholesterol-rich diet (0.6 g/kg) for 8 weeks; the diet was supplemented with 5 g cis-9,trans-11-CLA isomer/kg, 12 g CLA mixture (CLA-mix)/kg, 12 g fish oil/kg or 12 g fish oil + 12 g CLA-mix/kg. The plasma cholesterol status was improved only with the cis-9,trans-11-CLA (HDL-cholesterol and HDL-cholesterol:LDL-cholesterol ratio, P<0.05), but was of borderline significance for CLA-mix (HDL-cholesterol:LDL-cholesterol ratio, P=0.06), with an increase (33-40 %) in the liver lipoprotein receptors (scavenger receptor-type I and LDL ApoB/E receptor) and HDL-binding protein 2 (P<0.05). A 100 % pigment gallstones incidence and a slight insulin resistance (homeostatic model assessment index) were observed in the CLA-mix-fed hamsters (P=-0.031). In comparison, fish-oil feeding alone improved merely the scavenger receptor-type I and HDL-binding protein 2 liver status and faeces sterol output. For most of our present observations, the concomitant intake of fish oil and CLA-mix gave dominant effects that were exclusive and specific to one or the other oil. In conclusion, part of the beneficial effects of CLA in the present study can be ascribed to the cis-9,trans-11-isomer, and these did not generally overlap with those of fish oil. In addition, the CLA-mix effects are clearly affected by the marine (n-3) fatty acids. © The Authors 2004
Three-dimensional structure in the Mars H corona revealed by IUVS on MAVEN
Loss of water to space via neutral hydrogen escape has been an important process throughout Martian history. Contemporary loss rates can be constrained through observations of the extended neutral hydrogen atmosphere of Mars in scattered sunlight at 121.6 nm. Historically, such observations have been interpreted with coupled density and radiative transfer models, inferring escape fluxes from brightness profiles gathered by flybys, orbiters, and telescope observations. Here we demonstrate that the spherical symmetry assumed by prior analyses cannot reproduce observations by the Imaging Ultraviolet Spectrograph (IUVS) on the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. We present unique observations of the Mars H corona to large radial distances and mapping results from initial MAVEN science at Mars. These observations represent the first detection of three-dimensional structure in the H corona of Mars, with implications for understanding the atmosphere today and the loss of H to space throughout Martian history. © 2015. American Geophysical Union. All Rights Reserved
Study of the Martian cold oxygen corona from the OI 130.4nm by IUVS/MAVEN
First observations of the OI 130.4nm resonant line performed by the Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile EvolutioN mission (MAVEN) are presented in this paper. This emission line is observed during the different orbit phases of MAVEN. The atomic oxygen density and the temperature at 200km are retrieved from an automatic pipeline using a radiative transfer model for resonant scattering lines for a selection of coronal profiles. These selected profiles are representative of the coronal scans done during the first months of the mission (from November 2014 to January 2015). The derived oxygen density and the temperature near the exobase are in the predicted range by the current thermospheric models of Mars for moderate solar activity, and some diurnal variations are observed. However, the absolute calibration of the instrument significantly limits the accuracy of density and temperature results. © 2015. American Geophysical Union. All Rights Reserved
ALMA-IMF IX: Catalog and Physical Properties of 315 SiO Outflow Candidates in 15 Massive Protoclusters
We present a catalog of 315 protostellar outflow candidates detected in SiO J=5-4 in the ALMA-IMF Large Program, observed with ~2000 au spatial resolution, 0.339 km/s velocity resolution, and 2-12 mJy/beam (0.18-0.8 K) sensitivity. We find median outflow masses, momenta, and kinetic energies of ~0.3 M, 4 M km/s, and 10 erg, respectively. Median outflow lifetimes are 6,000 years, yielding median mass, momentum, and energy rates of = 10 M yr, = 10 M km/s yr, and = 1 L. We analyze these outflow properties in the aggregate in each field. We find correlations between field-aggregated SiO outflow properties and total mass in cores (~35), and no correlations above 3 with clump mass, clump luminosity, or clump luminosity-to-mass ratio. We perform a linear regression analysis and find that the correlation between field-aggregated outflow mass and total clump mass - which has been previously described in the literature - may actually be mediated by the relationship between outflow mass and total mass in cores. We also find that the most massive SiO outflow in each field is typically responsible for only 15-30% of the total outflow mass (60% upper limit). Our data agree well with the established mechanical force-bolometric luminosity relationship in the literature, and our data extend this relationship up to L 10 L and 1 M km/s yr. Our lack of correlation with clump L/M is inconsistent with models of protocluster formation in which all protostars start forming at the same time