231 research outputs found
Molecular Gas, Dust and Star Formation in Galaxies: II. Dust properties and scalings in \sim\ 1600 nearby galaxies
We aim to characterize the relationship between dust properties. We also aim
to provide equations to estimate accurate dust properties from limited
observational datasets.
We assemble a sample of 1,630 nearby (z<0.1) galaxies-over a large range of
Mstar, SFR - with multi-wavelength observations available from wise, iras,
planck and/or SCUBA. The characterization of dust emission comes from SED
fitting using Draine & Li dust models, which we parametrize using two
components (warm and cold ). The subsample of these galaxies with global
measurements of CO and/or HI are used to explore the molecular and/or atomic
gas content of the galaxies.
The total Lir, Mdust and dust temperature of the cold component (Tc) form a
plane that we refer to as the dust plane. A galaxy's sSFR drives its position
on the dust plane: starburst galaxies show higher Lir, Mdust and Tc compared to
Main Sequence and passive galaxies. Starburst galaxies also show higher
specific Mdust (Mdust/Mstar) and specific Mgas (Mgas/Mstar). The Mdust is more
closely correlated with the total Mgas (atomic plus molecular) than with the
individual components. Our multi wavelength data allows us to define several
equations to estimate Lir, Mdust and Tc from one or two monochromatic
luminosities in the infrared and/or sub-millimeter.
We estimate the dust mass and infrared luminosity from a single monochromatic
luminosity within the R-J tail of the dust emission, with errors of 0.12 and
0.20dex, respectively. These errors are reduced to 0.05 and 0.10 dex,
respectively, if the Tc is used. The Mdust is correlated with the total Mism
(Mism \propto Mdust^0.7). For galaxies with Mstar 8.5<log(Mstar/Msun) < 11.9,
the conversion factor \alpha_850mum shows a large scatter (rms=0.29dex). The SF
mode of a galaxy shows a correlation with both the Mgass and Mdust: high
Mdust/Mstar galaxies are gas-rich and show the highest SFRs.Comment: 24 pages, 28 figures, 6 tables, Accepted for publication in A&
The first fall is the hardest: the importance of peculiar galaxy dynamics at infall time for tidal stripping acting at the centers of groups and clusters
GalaxiesLarge scale structure and cosmolog
A new method to constrain the appearance and disappearance of observed jellyfish galaxy tails
Galaxie
Tratamiento con glucocorticoides en pacientes con inflamación relacionada a angiopatía amiloide cerebral: ¿qué tan útil son?
Objective. The objective of this review is to analyze the most recent evidence on the usefulness of glucocorticoids in patients with Inflammation Related to Cerebral Amyloid Angiopathy (IrCAA). Methods. Systematic review. A bibliographic search was carried out in the search engines and databases PubMed, ScienceDirect, Embase, EBSCO and MEDLINE databases, including any article related to the evaluation of the usefulness, efficacy or safety of glucocorticoids on inflammation of the cerebral amyloid angiopathy, would be included, giving priority to original studies and systematic reviews and meta-analyses. Results. It was found that the current evidence on its use is limited, deriving mainly from case reports, case series and retrospective studies. However, it seems that these agents cause a favorable response with partial resolution of the neurological manifestations immediately and/or progressively in the medium and long term, as well as abnormal imaging changes, given by vasogenic edema and cortical and subcortical microbleeds. although the improvement of the latter is not very marked. Conclusion. Current evidence on the use of glucocorticoids and their impact on clinical and neuroimaging outcomes is limited.Objetivo. El objetivo de esta revisión consiste en analizar la evidencia más reciente sobre la utilidad de los glucocorticoides en pacientes con Inflamación relacionada a Angiopatía Amiloide Cerebral (IrAAC). Métodos. Revisión sistemática. Se llevó a cabo una búsqueda bibliográfica en los motores de búsqueda y bases de datos bases de datos PubMed, ScienceDirect, Embase, EBSCO y MEDLINE, incluyendo cualquier artículo relacionado con la evaluación de la utilidad, eficacia o seguridad de los glucocorticoides sobre la inflamación de angiopatía amiloide cerebral, sería incluido, dando prioridad a los estudios originales y a las revisiones sistemáticas y meta-análisis. Resultados. Se encontró que, la evidencia actual sobre su uso es limitada, derivando principalmente de casos reporte, series de casos y estudios retrospectivos. No obstante, parece ser que estos agentes ocasionan una respuesta favorable con solución parcial de las manifestaciones neurológicas de manera inmediata y/o progresiva a mediano y largo plazo, así como de los cambios anormales imagenológicos, dados por edema vasogénico y microsangrados corticales y subcorticales, aunque la mejoría de este último, no es muy marcado. Conclusión. La evidencia actual sobre el uso de glucocorticoides y su impacto sobre desenlaces clínicos y neuroimagenológicos es limitada
Elliptic flow from two- and four-particle correlations in Au + Au collisions at sqrt{s_{NN}} = 130 GeV
Elliptic flow holds much promise for studying the early-time thermalization
attained in ultrarelativistic nuclear collisions. Flow measurements also
provide a means of distinguishing between hydrodynamic models and calculations
which approach the low density (dilute gas) limit. Among the effects that can
complicate the interpretation of elliptic flow measurements are azimuthal
correlations that are unrelated to the reaction plane (non-flow correlations).
Using data for Au + Au collisions at sqrt{s_{NN}} = 130 GeV from the STAR TPC,
it is found that four-particle correlation analyses can reliably separate flow
and non-flow correlation signals. The latter account for on average about 15%
of the observed second-harmonic azimuthal correlation, with the largest
relative contribution for the most peripheral and the most central collisions.
The results are also corrected for the effect of flow variations within
centrality bins. This effect is negligible for all but the most central bin,
where the correction to the elliptic flow is about a factor of two. A simple
new method for two-particle flow analysis based on scalar products is
described. An analysis based on the distribution of the magnitude of the flow
vector is also described.Comment: minor text change
Rapidity and centrality dependence of proton and antiproton production from 197Au + 197Au collisions at √SNN = 130 GeV
We report on the rapidity and centrality dependence of proton and antiproton transverse mass distributions from 197Au + 197Au collisions at sqrt[sNN ]=130 GeV as measured by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). Our results are from the rapidity and transverse momentum range of |y| <0.5 and 0.35< pt <1.00 GeV/c . For both protons and antiprotons, transverse mass distributions become more convex from peripheral to central collisions demonstrating characteristics of collective expansion. The measured rapidity distributions and the mean transverse momenta versus rapidity are flat within |y| <0.5 . Comparisons of our data with results from model calculations indicate that in order to obtain a consistent picture of the proton (antiproton) yields and transverse mass distributions the possibility of prehadronic collective expansion may have to be taken into account
Identified baryon and meson distributions at large transverse momenta from Au+Au collisions at GeV
Transverse momentum spectra of , and up to 12 GeV/c
at mid-rapidity in centrality selected Au+Au collisions at GeV are presented. In central Au+Au collisions, both and
show significant suppression with respect to binary scaling at
4 GeV/c. Protons and anti-protons are less suppressed than
, in the range 1.5 6 GeV/c. The and
ratios show at most a weak dependence and no significant
centrality dependence. The ratios in central Au+Au collisions approach
the values in p+p and d+Au collisions at 5 GeV/c. The results at high
indicate that the partonic sources of , and have
similar energy loss when traversing the nuclear medium.Comment: 6 pages, 4 figure
Transverse momentum and collision energy dependence of high hadron suppression in Au+Au collisions at ultrarelativistic energies
We report high statistics measurements of inclusive charged hadron production
in Au+Au and p+p collisions at \sqrtsNN=200 GeV. A large, approximately
constant hadron suppression is observed in central Au+Au collisions for
5\lt\pT\lt12 GeV/c. The collision energy dependence of the yields and the
centrality and \pT dependence of the suppression provide stringent constraints
on theoretical models of suppression. Models incorporating initial-state gluon
saturation or partonic energy loss in dense matter are largely consistent with
observations. We observe no evidence of \pT-dependent suppression, which may be
expected from models incorporating jet attentuation in cold nuclear matter or
scattering of fragmentation hadrons.Comment: Final journal version. Data tables for figures may be downloaded from
the STAR home page: http://www.star.bnl.gov --> Publications --> Access to
STAR published dat
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