168 research outputs found
MUSE crowded field 3D spectroscopy in NGC 300 III. Characterizing extremely faint HII regions and diffuse ionized gas
There are known differences between the physical properties of HII and
diffuse ionized gas (DIG), but most of the studied regions in the literature
are relatively bright. We compiled a faint sample of 390 HII regions with
median =34.7 in the spiral galaxy NGC300, derived their
physical properties in terms of metallicity, density, extinction, and
kinematics, and performed a comparative analysis of the properties of the DIG.
We used MUSE data of nine fields in NGC300, covering a galactocentric distance
of zero to ~450 arcsec (~4 projected kpc), including spiral arm and inter-arm
regions. We binned the data in dendrogram leaves and extracted all strong
nebular emission lines. We identified HII and DIG regions and compared their
electron densities, metallicity, extinction, and kinematic properties. We also
tested the effectiveness of unsupervised machine-learning algorithms in
distinguishing between the HII and DIG regions. The gas density in the HII and
DIG regions is close to the low-density limit in all fields. The average
velocity dispersion in the DIG is higher than in the HII regions, which can be
explained by the DIG being 1.8 kK hotter than HII gas. The DIG manifests a
lower ionization parameter than HII gas, and the DIG fractions vary between
15-77%, with strong evidence of a contribution by hot low-mass evolved stars
and shocks to the DIG ionization. Most of the DIG is consistent with no
extinction and an oxygen metallicity that is indistinguishable from that of the
HII gas.We observe a flat metallicity profile in the central region, without a
sign of a gradient. The differences between extremely faint HII and DIG regions
follow the same trends and correlations as their much brighter cousins. HII and
DIG are so heterogeneous, however, that the differences within each class are
larger than the differences between the two classes.Comment: Accepted in A&
SEOM clinical guidelines for the treatment of head and neck cancer (2017)
Head and neck cancer (HNC) is defined as malignant tumours located in the upper aerodigestive tract and represents 5% of oncologic cases in adults in Spain. More than 90% of these tumours have squamous histology. In an effort to incorporate evidence obtained since 2013 publication, Spanish Society of Medical Oncology (SEOM) presents an update of HNC diagnosis and treatment guideline. The eighth edition of TNM classification, published in January 2017, introduces important changes for p16-positive oropharyngeal tumours, for lip and oral cavity cancer and for N3 category. In addition, there are new data about induction chemotherapy and the role of immunotherapy in HNC
The MUSE-Wide survey: Three-dimensional clustering analysis of Lyman- emitters at
We present an analysis of the spatial clustering of 695 Ly-emitting
galaxies (LAE) in the MUSE-Wide survey. All objects have spectroscopically
confirmed redshifts in the range . We employ the K-estimator of
Adelberger et al. (2005), adapted and optimized for our sample. We also explore
the standard two-point correlation function approach, which is however less
suited for a pencil-beam survey such as ours. The results from both approaches
are consistent. We parametrize the clustering properties by, (i) modelling the
clustering signal with a power law (PL), and (ii) adopting a Halo Occupation
Distribution (HOD) model. Applying HOD modeling, we infer a large-scale bias of
at a median redshift of the number of
galaxy pairs , while the PL analysis
results in
(Mpc and ). The
implied typical dark matter halo (DMH) mass is
. We study
possible dependencies of the clustering signal on object properties by
bisecting the sample into disjoint subsets, considering Ly luminosity,
UV absolute magnitude, Ly equivalent width, and redshift as variables.
We find a suggestive trend of more luminous Ly emitters residing in
more massive DMHs than their lower Ly luminosity counterparts. We also
compare our results to mock LAE catalogs based on a semi-analytic model of
galaxy formation and find a stronger clustering signal than in our observed
sample. By adopting a galaxy-conserving model we estimate that the LAEs in the
MUSE-Wide survey will typically evolve into galaxies hosted by halos of
at redshift zero,
suggesting that we observe the ancestors of present-day galaxy groups.Comment: Accepted for publication in A&A. 22 pages, 20 figures, 4 table
Equivalent widths of Lyman emitters in MUSE-Wide and MUSE-Deep
The aim of this study is to better understand the connection between the
Lyman rest-frame equivalent width (EW) and spectral properties as
well as ultraviolet (UV) continuum morphology by obtaining reliable EW
histograms for a statistical sample of galaxies and by assessing the fraction
of objects with large equivalent widths. We used integral field spectroscopy
from MUSE combined with broad-band data from the Hubble Space Telescope (HST)
to measure EW. We analysed the emission lines of Lyman
emitters (LAEs) detected in the full MUSE-Wide (one hour exposure time) and
MUSE-Deep (ten hour exposure time) surveys and found UV continuum counterparts
in archival HST data. We fitted the UV continuum photometric images using the
Galfit software to gain morphological information on the rest-UV emission and
fitted the spectra obtained from MUSE to determine the double peak fraction,
asymmetry, full-width at half maximum, and flux of the Lyman line. The
two surveys show different histograms of Lyman EW. In MUSE-Wide,
of objects have EW \r{A}, while this fraction is only
in MUSE-Deep and for the full sample. This includes objects
without HST continuum counterparts (one-third of our sample), for which we give
lower limits for EW. The object with the highest securely measured EW
has EW \r{A} (the highest lower limit being EW \r{A}).
We investigate the connection between EW and Lyman spectral or UV
continuum morphological properties. The survey depth has to be taken into
account when studying EW distributions. We find that in general, high
EW objects can have a wide range of spectral and UV morphological
properties, which might reflect that the underlying causes for high EW
values are equally varied. (abridged)Comment: 28 pages, 21 + 1 figures, 7 + 1 tables, accepted for publication in
A&
NGDEEP Epoch 1: Spatially Resolved H Observations of Disk and Bulge Growth in Star-Forming Galaxies at 0.6-2.2 from JWST NIRISS Slitless Spectroscopy
We study the H equivalent width, EW(H), maps of 19 galaxies
at in the Hubble Ultra Deep Field (HUDF) derived from NIRISS
slitless spectroscopy as part of the Next Generation Deep Extragalactic
Exploratory Public (NGDEEP) Survey. Our galaxies mostly lie on the
star-formation main sequence with a stellar mass range of , and are therefore characteristic of "typical" star-forming
galaxies at these redshifts. Leveraging deep HST and JWST broad-band images,
spanning 0.4-4 m, we perform spatially-resolved fitting of the spectral
energy distributions (SEDs) for these galaxies and construct specific star
formation rate (sSFR) and stellar-mass-weighted age maps. We compare these to
the EW(H) maps with a spatial resolution of 1 kpc. The
pixel-to-pixel EW(H) increases with increasing sSFR and with decreasing
age, with the average trend slightly different from the relations derived from
integrated fluxes of galaxies from the literature. Quantifying the radial
profiles of EW(H), sSFR, and age, the majority (84%) of galaxies show
positive EW(H) gradients, positive sSFR gradients, and negative age
gradients, in line with the the inside-out quenching scenario. A few galaxies
(16%) show inverse (and flat) trends possibly due to merging or starbursts.
Comparing the distributions of EW(H) and sSFR to the star formation
history models as a function of galactocentric radius, the central region of
galaxies (e.g., their bulges) have experienced, at least one, rapid
star-formation episodes, which leads to the formation of bulge, while their
outer regions (e.g., disks) grow in a more steady-state. These results
demonstrate the ability to study resolved star formation in distant galaxies
with JWST NIRISS.Comment: 22 pages, 11 figure
JADES + JEMS: A Detailed Look at the Buildup of Central Stellar Cores and Suppression of Star Formation in Galaxies at Redshifts 3 < z < 4.5
We present a spatially resolved study of stellar populations in 6 galaxies
with stellar masses at using 14-filter
JWST/NIRCam imaging from the JADES and JEMS surveys. The 6 galaxies are
visually selected to have clumpy substructures with distinct colors over
rest-frame \r{A}, including a bright dominant stellar core that is
close to their stellar-light centroids. With 23-filter photometry from HST to
JWST, we measure the stellar-population properties of individual structural
components via SED fitting using Prospector. We find that the central stellar
cores are times more massive than the Toomre mass, indicating they
may not form via in-situ fragmentation. The stellar cores have stellar ages of
Gyr that are similar to the timescale of clump inward migration due
to dynamical friction, suggesting that they likely instead formed through the
coalescence of giant stellar clumps. While they have not yet quenched, the 6
galaxies are below the star-forming main sequence by dex. Within each
galaxy, we find that the specific star formation rate is lower in the central
stellar core, and the stellar-mass surface density of the core is already
similar to quenched galaxies of the same masses and redshifts. Meanwhile, the
stellar ages of the cores are either comparable to or younger than the
extended, smooth parts of the galaxies. Our findings are consistent with model
predictions of the gas-rich compaction scenario for the buildup of galaxies'
central regions at high redshifts. We are likely witnessing the coeval
formation of dense central cores, along with the onset of galaxy-wide quenching
at .Comment: 32 pages, 16 figures, submitted to ApJ. Comments are welcom
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Recalibration of the delirium prediction model for ICU patients (PRE-DELIRIC): a multinational observational study
Purpose
Recalibration and determining discriminative power, internationally, of the existing delirium prediction model (PRE-DELIRIC) for intensive care patients.
Methods
A prospective multicenter cohort study was performed in eight intensive care units (ICUs) in six countries. The ten predictors (age, APACHE-II, urgent and admission category, infection, coma, sedation, morphine use, urea level, metabolic acidosis) were collected within 24 h after ICU admission. The confusion assessment method for the intensive care unit (CAM-ICU) was used to identify ICU delirium. CAM-ICU screening compliance and inter-rater reliability measurements were used to secure the quality of the data.
Results
A total of 2,852 adult ICU patients were screened of which 1,824 (64 %) were eligible for the study. Main reasons for exclusion were length of stay <1 day (19.1 %) and sustained coma (4.1 %). CAM-ICU compliance was mean (SD) 82 ± 16 % and inter-rater reliability 0.87 ± 0.17. The median delirium incidence was 22.5 % (IQR 12.8–36.6 %). Although the incidence of all ten predictors differed significantly between centers, the area under the receiver operating characteristic (AUROC) curve of the eight participating centers remained good: 0.77 (95 % CI 0.74–0.79). The linear predictor and intercept of the prediction rule were adjusted and resulted in improved re-calibration of the PRE-DELIRIC model.
Conclusions
In this multinational study, we recalibrated the PRE-DELIRIC model. Despite differences in the incidence of predictors between the centers in the different countries, the performance of the PRE-DELIRIC-model remained good. Following validation of the PRE-DELIRIC model, it may facilitate implementation of strategies to prevent delirium and aid improvements in delirium management of ICU patients
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