Abstract
We use CEERS JWST/NIRCam imaging to measure rest-frame near-IR light profiles of 435
M
⋆
> 10
10
M
⊙
galaxies in the redshift range of 0.5 <
z
< 2.3. We compare the resulting rest-frame ...1.5–2
μ
m half-light radii (
R
NIR
) with stellar half-mass radii (
R
M
⋆
) derived with multicolor light profiles from CANDELS Hubble Space Telescope imaging. In general agreement with previous work, we find that
R
NIR
and
R
M
⋆
are up to 40% smaller than the rest-frame optical half-light radius
R
opt
. The agreement between
R
NIR
and
R
M
⋆
is excellent, with a negligible systematic offset (<0.03 dex) up to
z
= 2 for quiescent galaxies and up to
z
= 1.5 for star-forming galaxies. We also deproject the profiles to estimate
R
M
⋆
,
3
D
, the radius of a sphere containing 50% of the stellar mass. We present the
R
−
M
⋆
distribution of galaxies at 0.5 <
z
< 1.5, comparing
R
opt
,
R
M
⋆
, and
R
M
⋆
,
3
D
. The slope is significantly flatter for
R
M
⋆
and
R
M
⋆
,
3
D
compared to
R
opt
, mostly due to downward shifts in size for massive star-forming galaxies, while
R
M
⋆
and
R
M
⋆
,
3
D
do not show markedly different trends. Finally, we show rapid evolution of the size (
R
∝ (1 +
z
)
−1.7±0.1
) of massive (
M
⋆
> 10
11
M
⊙
) quiescent galaxies between
z
= 0.5 and
z
= 2.3, again comparing
R
opt
,
R
M
⋆
, and
R
M
⋆
,
3
D
. We conclude that the main tenets of the evolution of the size narrative established over the past 20 yr, based on rest-frame optical light profile analysis, still hold in the era of JWST/NIRCam observations in the rest-frame near-IR.
Abstract
We present individual star formation histories (SFHs) of ∼3000 massive galaxies (log(
M
*
/
M
⊙
) > 10.5) from the Large Early Galaxy Astrophysics Census spectroscopic survey at a lookback ...time of ∼7 billion yr and quantify the population trends leveraging 20 hr deep-integrated spectra of these ∼1800 star-forming and ∼1200 quiescent galaxies at 0.6 <
z
< 1.0. Essentially all galaxies at this epoch contain stars of age <3 Gyr, in contrast with older massive galaxies today, facilitating better recovery of previous generations of star formation at cosmic noon and earlier. We conduct spectrophotometric analysis using parametric and nonparametric Bayesian stellar population synthesis modeling tools—
Bagpipes
and
Prospector
—to constrain the median SFHs of this mass complete sample and characterize population trends. A consistent picture arises for the late-time stellar mass growth when quantified as
t
50
and
t
90
, corresponding to the age of the Universe when galaxies formed 50% and 90% of their total stellar mass, although the two methods disagree at the earliest formation times (e.g.,
t
10
). Our results reveal trends in both stellar mass and stellar velocity dispersion as in the local Universe—low-mass galaxies with shallower potential wells grow their stellar masses later in cosmic history compared to high-mass galaxies. Unlike local quiescent galaxies, the median duration of late-time star formation (
τ
SF,late
=
t
90
–
t
50
) does not consistently depend on the stellar mass. This census sets a benchmark for future deep spectrophotometric studies of the more distant Universe.
Abstract
We examine the wavelength dependence of radial light profiles based on Sérsic index
n
measurements of 1067 galaxies with
M
*
≥ 10
9.5
M
⊙
and in the redshift range 0.5 <
z
< 3. The sample ...and rest-frame optical light profiles are drawn from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and 3D Hubble Space Telescope (HST); rest-frame near-infrared light profiles are inferred from images collected for the Cosmic Evolution Early Release Science (CEERS) program with the Near Infrared Camera (NIRCam) on board of the James Webb Space Telescope (JWST).
n
shows only a weak dependence on the wavelength, regardless of the redshift, galaxy mass, and type. On average, star-forming galaxies have
n
= 1–1.5 and quiescent galaxies have
n
= 3–4 in the rest-frame optical and near-infrared. The strong correlation at all wavelengths between
n
and star formation activity implies a physical connection between the radial stellar mass profile and star formation activity. The main caveat is that the current sample is too small to discern trends for the most massive galaxies (
M
*
> 10
11
M
⊙
).
From an Italian Registry of patients with upper gastrointestinal hemorrhage (UGIH), we assessed the clinical outcomes and explored the roles of clinical, endoscopic, and therapeutic factors on 30-day ...mortality in a real life setting.
Prospective analysis of consecutive patients endoscoped for UGIH at 23 community and tertiary care institutions from 2003 to 2004. Covariates and outcomes were defined a priori and 30-day follow-up obtained. Logistic regression analysis identified predictors of mortality.
One thousand and twenty patients were included. A total of 46 patients died for an overall 4.5% mortality rate. In all, 85% of deaths were associated with one or more major comorbidity. Sixteen of 46 patients (35%) died within the first 24 h of the onset of bleeding. Of these, eight had been categorized as ASA class 1 or 2 and none of them was operated upon, despite a failure of endoscopic intention to treatment in four. Regression analysis showed advanced age, presence of severe comorbidity, low hemoglobin levels at presentation, and worsening health status as the only independent predictors of 30-day mortality (P < 0.001). The acute use of a PPI exerted a protective effect (OR 0.23, 95% CI 0.09-0.73). Recurrent bleeding was low (3.2%). Rebleeders accounted for only 11% of the total patients deceased (OR 3.27, 95% CI 1.5-11.2).
These results indicate that 30-day mortality for nonvariceal bleeding is low. Deaths occurred predominantly in elderly patients with severe comorbidities or those with failure of endoscopic intention to treatment.
The many colours of the TNG100 simulation Gebek, Andrea; Trčka, Ana; Baes, Maarten ...
Monthly Notices of the Royal Astronomical Society,
06/2024, Letnik:
531, Številka:
4
Journal Article
Recenzirano
Odprti dostop
ABSTRACT We apply the 3D dust radiative transfer code skirt to the low-redshift (z ≤ 0.1) galaxy population in the TNG100 cosmological simulation, the fiducial run of the IllustrisTNG project. We ...compute global fluxes and spectral energy distributions (SEDs) from the far-ultraviolet to the submillimetre for $\approx 60\, 000$ galaxies, with the same post-processing methodology that was previously applied to the TNG50 simulation. We verify that TNG100 reproduces observational luminosity functions at low redshifts to excellent precision, unlike TNG50. Additionally, we test the realism of our TNG100 plus skirt fluxes by comparing various flux and colour relations to data from the GAMA survey. TNG100 broadly reproduces the observed distributions, but we predict ultraviolet colours that are too blue by $\approx 0.4\, \mathrm{mag}$, possibly related to the extinction in the star-forming regions subgrid model not being selective enough. Furthermore, we find that the simulated galaxies exhibit mid-infrared fluxes elevated by up to $\approx 0.5\, \mathrm{mag}$ that we attribute to overly effective stochastic heating of the diffuse dust. All synthetic broad-band fluxes and SEDs are made publicly available in three orientations and four apertures, and can readily be used to study TNG100 galaxies in a mock observational fashion.
ABSTRACT
We present and publicly release a new star-forming regions emission library TODDLERS (Time evolution of Observables including Dust Diagnostics and Line Emission from Regions containing young ...Stars) for the publicly available radiative transfer code SKIRT. The library generation involves the spherical evolution of a homogeneous gas cloud around a young stellar cluster that accounts for stellar feedback processes including stellar winds, supernovae, and radiation pressure, as well as the gravitational forces on the gas. The semi-analytical evolution model is coupled with the photoionization code Cloudy to calculate time-dependent UV–mm spectral energy distributions (SEDs) from star-forming regions of varying metallicity, star-formation efficiency, birth-cloud density, and mass. The calculated SEDs include the stellar, nebular, and dust continuum emission along with a wide range of emission lines originating from H ii, photodissociation, and molecular gas regimes tabulated at high resolution. The SEDs incorporated in SKIRT are generated by calculating a stellar-mass normalized luminosity, which assumes that each emission source is composed of a power-law population of star-forming clouds. When compared to the previous treatment of star-forming regions in SKIRT, TODDLERS shows a better agreement with low-redshift observational data in the IR wavelength range while offering a more comprehensive line-emission support. This paves the way for a variety of applications using simulated galaxies at low and high redshift.
Aims
. We test whether we can predict optical spectra from deep-field photometry of distant galaxies. Our goal is to perform a comparison in data space, highlighting the differences between predicted ...and observed spectra.
Methods
. The Large Early Galaxy Astrophysics Census (LEGA-C) provides high-quality optical spectra of thousands of galaxies at redshift 0.6 <
z
< 1. Broadband photometry of the same galaxies, drawn from the recent COSMOS2020 catalog, is used to predict the optical spectra with the spectral energy distribution (SED) fitting code Prospector and the MILES stellar library. The observed and predicted spectra are compared in terms of two age and metallicity-sensitive absorption features (H
δ
A
and Fe4383).
Results
. The global bimodality of star-forming and quiescent galaxies in photometric space is recovered with the model spectra. However, the presence of a systematic offset in the Fe4383 line strength and the weak correlation between the observed and modeled line strength imply that accurate age or metallicity determinations cannot be inferred from photometry alone.
Conclusions
. For now we caution that photometry-based estimates of stellar population properties are determined mostly by the modeling approach and not the physical properties of galaxies, even when using the highest-quality photometric datasets and state-of-the-art fitting techniques. When exploring a new physical parameter space (i.e. redshift or galaxy mass) high-quality spectroscopy is always needed to inform the analysis of photometry.
Galaxy sizes correlate with many other important properties of galaxies, and the cosmic evolution of galaxy sizes is an important observational diagnostic for constraining galaxy evolution models. ...The effective radius is probably the most widely used indicator of galaxy size. We used the TNG50-SKIRT Atlas to investigate the wavelength dependence of the effective radius of galaxies at optical and near-infrared (NIR) wavelengths. We find that, on average, the effective radius in every band exceeds the stellar mass effective radius, and that this excess systematically decreases with increasing wavelength. The optical g -band (NIR K s -band) effective radius is on average 58% (13%) larger than the stellar mass effective radius. Effective radii measured from dust-obscured images are systematically larger than those measured from dust-free images, although the effect is limited (8.7% in the g -band, 2.1% in the K s -band). We find that stellar population gradients are the dominant factor (about 80%) in driving the wavelength dependence of the effective radius, and that differential dust attenuation is a secondary factor (20%). Comparing our results to recent observational data, we find offsets in the absolute values of the median effective radii, up to 50% for the population of blue galaxies. We find better agreement in the slope of the wavelength dependence of the effective radius, with red galaxies having a slightly steeper slope than green–blue galaxies. Comparing our effective radii with those of galaxies from the Siena Galaxy Atlas in separate bins in z -band absolute magnitude and g − z colour, we find excellent agreement for the reddest galaxies, but again significant offsets for the blue populations: up to 70% for galaxies around M z = −21.5. This difference in median effective radius for the bluer galaxies is most probably due to intrinsic differences in the morphological structure of observed and TNG50 simulated galaxies. Finally, we find that the median effective radius in any broadband filter increases systematically with decreasing u − r colour and with increasing galaxy stellar mass, total SFR, sSFR, and dust-to-stellar-mass ratio. For the slope of the wavelength dependence of R e , however, there does not seem to be a systematic, monotonic correlation with any of these global properties.
Galaxy morphology is a powerful diagnostic to assess the realism of cosmological hydrodynamical simulations. Determining the morphology of simulated galaxies requires the generation of synthetic ...images through 3D radiative transfer post-processing that properly accounts for different stellar populations and interstellar dust attenuation. We use the SKIRT code to generate the TNG50-SKIRT Atlas, a synthetic UV to near-infrared broadband image atlas for a complete stellar-mass selected sample of 1154 galaxies extracted from the TNG50 cosmological simulation at z = 0. The images have a high spatial resolution (100 pc) and a wide field of view (160 kpc). In addition to the dust-obscured images, we also release dust-free images and physical parameter property maps with matching characteristics. As a sanity check and preview application we discuss the UVJ diagram of the galaxy sample. We investigate the effect of dust attenuation on the UVJ diagram and find that it affects both the star-forming and the quiescent galaxy populations. The quiescent galaxy region is polluted by younger and star-forming highly inclined galaxies, while dust attenuation induces a separation in inclination of the star-forming galaxy population, with low-inclination galaxies remaining at the blue side of the diagram and high-inclination galaxies systematically moving towards the red side. This image atlas can be used for a variety of other applications, including galaxy morphology studies and the investigation of local scaling relations. We publicly release the images and parameter maps, and we invite the community to use them.
Background
Bismuth quadruple (BQT) and non‐bismuth quadruple (N‐BQT) therapies are the recommended first‐line treatments for Helicobacter (H.) pylori infection.
Objective
To compare the efficacy of ...BQT and N‐BQT in clinical practice in an area with high clarithromycin resistance, choosing the regimen on the basis of previous exposure to clarithromycin.
Methods
A total of 404 consecutive H pylori‐positive, naïve patients were enrolled. A total of 203 patients without previous exposure to clarithromycin received N‐BQT, 100 patients for 10 days and 103 for 14 days, whereas 201 with previous exposure to clarithromycin received 10‐day BQT. Efficacy and treatment‐related adverse events were assessed.
Results and Conclusions
Eradication rates by intention‐to‐treat analysis were 88.2% for N‐BQT and 91.5% for BQT (P = .26); per‐protocol analysis eradication rates were 91.2% and 95.8% for N‐BQT and BQT, respectively (P = .07). Eradication rates were significantly higher with 14‐day than 10‐day CT (P < .003). Almost all patients had a good compliance with both N‐BQT (95.6%) and BQT (95%). Adverse events occurred in 24.1% and 26.9% (P = .53) of patients in the N‐BQT and BQT group, respectively. In conclusion, clarithromycin‐containing non‐bismuth or bismuth quadruple therapy, based on the knowledge of previous clarithromycin exposure, is effective and safe even in an area of high prevalence of clarithromycin‐resistant H pylori strains.
