Abstract
We present a catalog of about 25,000 images of massive (
M
⋆
≥ 10
9
M
⊙
) galaxies at redshifts 3 ≤
z
≤ 6 from the TNG50 cosmological simulation, tailored for observations at multiple ...wavelengths carried out with JWST. The synthetic images were created with the SKIRT radiative transfer code, including the effects of dust attenuation and scattering. The noiseless images were processed with the
mirage
simulator to mimic the Near Infrared Camera (NIRCam) observational strategy (e.g., noise, dithering pattern, etc.) of the Cosmic Evolution Early Release Science (CEERS) survey. In this paper, we analyse the predictions of the TNG50 simulation for the size evolution of galaxies at 3 ≤
z
≤ 6 and the expectations for CEERS to probe that evolution. In particular, we investigate how sizes depend on the wavelength, redshift, mass, and angular resolution of the images. We find that the effective radius accurately describes the three-dimensional half-mass–radius of the TNG50 galaxies. Sizes observed at 2
μ
m are consistent with those measured at 3.56
μ
m at all redshifts and masses. At all masses, the population of higher-
z
galaxies is more compact than their lower-
z
counterparts. However, the intrinsic sizes are smaller than the mock observed sizes for the most massive galaxies, especially at
z
≲ 4. This discrepancy between the mass and light distributions may point to a transition in the galaxy morphology at
z
= 4–5, where massive compact systems start to develop more extended stellar structures.
22
22
Data publicly released at
https://www.tng-project.org/costantin22
.
•ACE-FTS on SCISAT measures atmospheric HCl profiles.•HCl time series (2004–2017) gives an upper stratospheric trend of −4.8 ± 0.2%/decade.•N2O time series is used to reduce effect of dynamics on the ...HCl trend.•Montreal Protocol continues to be successful in reducing stratospheric chlorine.
The Montreal Protocol has banned the production of long-lived chlorine-containing gases such as chlorofluorocarbons (CFCs) that deplete stratospheric ozone. These halogenated compounds ultimately form HCl in the upper atmosphere; the effectiveness of the Montreal Protocol can therefore be monitored by measuring stratospheric HCl. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) measures infrared solar occultation spectra of the Earth's atmosphere from which altitude profiles of HCl volume mixing ratios (VMRs) are determined. The upper stratospheric HCl VMR time series has a linear trend of −4.8 ± 0.2%/decade for 2004–2017, highlighting the continuing success of the Montreal Protocol.
ABSTRACT
Understanding how bulges grow in galaxies is a critical step towards unveiling the link between galaxy morphology and star-formation. To do so, it is necessary to decompose large sample of ...galaxies at different epochs into their main components (bulges and discs). This is particularly challenging, especially at high redshifts, where galaxies are poorly resolved. This work presents a catalog of bulge-disc decompositions of the surface brightness profiles of ∼17.600 H-band-selected galaxies in the CANDELS fields (F160W < 23, 0 < $z$ < 2) in 4 to 7 filters covering a spectral range of 430 - 1600 $\mathrm{nm}$. This is the largest available catalog of this kind up to $z$ = 2. By using a novel approach based on deep learning to select the best model to fit, we manage to control systematics arising from wrong model selection and obtain less-contaminated samples than previous works. We show that the derived structural properties are within ${\sim }10\hbox{--}20{\rm} \, \%$ of random uncertainties. We then fit stellar population models to the decomposed spectral energy distributions of bulges and discs and derive stellar masses (and stellar mass bulge-to-total ratios) as well as rest-frame colors (U,V,J) for bulges and discs separately. All data products are publicly released with this paper and through the web page https://lerma.obspm.fr/huertas/form_CANDELS and will be used for scientific analysis in forthcoming works.
Abstract
Studying the resolved stellar populations of the different structural components that build massive galaxies directly unveils their assembly history. We aim at characterizing the stellar ...population properties of a representative sample of bulges and pure spheroids in massive galaxies (
M
⋆
> 10
10
M
⊙
) in the GOODS-N field. We take advantage of the spectral and spatial information provided by SHARDS and Hubble Space Telescope data to perform the multi-image spectrophotometric decoupling of the galaxy light. We derive the spectral energy distribution separately for bulges and disks in the redshift range 0.14 <
z
≤ 1 with spectral resolution
R
∼ 50. Analyzing these spectral energy distributions, we find evidence of a bimodal distribution of bulge formation redshifts. We find that 33% of them present old mass-weighted ages, implying a median formation redshift
. They are relics of the early universe embedded in disk galaxies. A second wave, dominant in number, accounts for bulges formed at median redshift
. The oldest (first-wave) bulges are more compact than the youngest. Virtually all pure spheroids (i.e., those without any disk) are coetaneous with the second-wave bulges, presenting a median redshift of formation
. The two waves of bulge formation are distinguishable not only in terms of stellar ages but also in star formation mode. All first-wave bulges formed fast at
z
∼ 6, with typical timescales around 200 Myr. A significant fraction of the second-wave bulges assembled more slowly, with star formation timescales as long as 1 Gyr. The results of this work suggest that the centers of massive disk-like galaxies actually harbor the oldest spheroids formed in the universe.
ABSTRACT
We study the rest-frame optical mass–size relation of bulges and discs from z ∼ 2 to z ∼ 0 for a complete sample of massive galaxies in the CANDELS fields using two-component Sérsic models. ...Discs and star-forming galaxies follow similar mass–size relations. The mass–size relation of bulges is less steep than the one of quiescent galaxies (best-fitting slope of 0.7 for quiescent galaxies against 0.4 for bulges). We find little dependence of the structural properties of massive bulges and discs with the global morphology of galaxies (disc versus bulge dominated) and the star formation activity (star-forming versus quiescent). This result suggests similar bulge formation mechanisms for most massive galaxies and also that the formation of the bulge component does not significantly affect the disc structure. Our results pose a challenge to current cosmological models that predict distinct structural properties for stellar bulges arising from mergers and disc instabilities.
•Linear trends of atmospheric HFC-134a and CHF3 from ACE-FTS data.•Description of HFC-134a and CHF3 retrievals.•Comparison with Advanced Global Atmospheric Gases Experiment (AGAGE) data.
The Montreal ...Protocol banned the production of major ozone depleting substances such as chlorofluorocarbons (CFCs) to protect the Earth’s ozone layer. The resulting increased production and emissions of CFC-replacement hydrofluorocarbons (HFCs) has caused a dramatic increase in their atmospheric abundances. Although these HFCs do not contribute directly to the depletion of the ozone layer because they contain no chlorine, they are powerful greenhouse gases with large global warming potentials. In January 2019, the Kigali Amendment to the Montreal Protocol came into force to phase out long-lived HFCs. The two most abundant HFCs in the atmosphere, HFC-134a (CF3CH2F) and HFC-23 (CHF3), are measured from orbit by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). These measurements will be useful for monitoring the Kigali Amendment to the Montreal Protocol. Analysis of the ACE-FTS measurements provides near-global distributions and confirms the rapid increase in HFC-134a (4.9 ± 0.1 ppt per year) and HFC-23 (0.75 ± 0.02 ppt per year) volume mixing ratios (VMRs).
Abstract
Background
This article summarizes the ERA-EDTA Registry’s 2016 Annual Report, by describing the epidemiology of renal replacement therapy (RRT) for end-stage renal disease (ESRD) in 2016 ...within 36 countries.
Methods
In 2017 and 2018, the ERA-EDTA Registry received data on patients undergoing RRT for ESRD in 2016 from 52 national or regional renal registries. In all, 32 registries provided individual patient data and 20 provided aggregated data. The incidence and prevalence of RRT and the survival probabilities of these patients were determined.
Results
In 2016, the incidence of RRT for ESRD was 121 per million population (pmp), ranging from 29 pmp in Ukraine to 251 pmp in Greece. Almost two-thirds of patients were men, over half were aged ≥65 years and almost a quarter had diabetes mellitus as their primary renal diagnosis. Treatment modality at the start of RRT was haemodialysis for 84% of patients. On 31 December 2016, the prevalence of RRT was 823 pmp, ranging from 188 pmp in Ukraine to 1906 pmp in Portugal. In 2016, the transplant rate was 32 pmp, varying from 3 pmp in Ukraine to 94 pmp in the Spanish region of Catalonia. For patients commencing RRT during 2007–11, the 5-year unadjusted patient survival probability on all RRT modalities combined was 50.5%. For 2016, the incidence and prevalence of RRT were higher among men (187 and 1381 pmp) than women (101 and 827 pmp), and men had a higher rate of kidney transplantation (59 pmp) compared with women (33 pmp). For patients starting dialysis and for patients receiving a kidney transplant during 2007–11, the adjusted patient survival probabilities appeared to be higher for women than for men.
Abstract
Visual inspections of the first optical rest-frame images from JWST have indicated a surprisingly high fraction of disk galaxies at high redshifts. Here, we alternatively apply ...self-supervised machine learning to explore the morphological diversity at
z
≥ 3. Our proposed data-driven representation scheme of galaxy morphologies, calibrated on mock images from the TNG50 simulation, is shown to be robust to noise and to correlate well with the physical properties of the simulated galaxies, including their 3D structure. We apply the method simultaneously to F200W and F356W galaxy images of a mass-complete sample (
M
*
/
M
⊙
> 10
9
) at 3 ≤
z
≤ 6 from the first JWST/NIRCam CEERS data release. We find that the simulated and observed galaxies do not exactly populate the same manifold in the representation space from contrastive learning. We also find that half the galaxies classified as disks—either convolutional neural network-based or visually—populate a similar region of the representation space as TNG50 galaxies with low stellar specific angular momentum and nonoblate structure. Although our data-driven study does not allow us to firmly conclude on the true nature of these galaxies, it suggests that the disk fraction at
z
≥ 3 remains uncertain and possibly overestimated by traditional supervised classifications. Deeper imaging and spectroscopic follow-ups as well as comparisons with other simulations will help to unambiguously determine the true nature of these galaxies, and establish more robust constraints on the emergence of disks at very high redshift.
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