In this paper we describe the first data release of the UltraVISTA near-infrared imaging survey of the COSMOS field. We summarise the key goals and design of the survey and provide a detailed ...description of our data reduction techniques. We provide stacked, sky-subtracted images in YJHKs and narrow-band filters constructed from data collected during the first year of UltraVISTA observations. Our stacked images reach 5σAB depths in an aperture of 2″ diameter of ~25 in Y and ~24 in JHKs bands and all have sub-arcsecond seeing. To this 5σ limit, our Ks catalogue contains 216 268 sources. We carry out a series of quality assessment tests on our images and catalogues, comparing our stacks with existing catalogues. The 1σ astrometric rms in both directions for stars selected with 17.0 < Ks(AB) < 19.5 is ~0.08″ in comparison to the publicly-available COSMOS ACS catalogues. Our images are resampled to the same pixel scale and tangent point as the publicly available COSMOS data and so may be easily used to generate multi-colour catalogues using this data. All images and catalogues presented in this paper are publicly available through ESO’s “phase 3” archiving and distribution system and from the UltraVISTA web site.
Context. The Frontier Fields survey is a pioneering observational program aimed at collecting photometric data, both from space (Hubble Space Telescope and Spitzer Space Telescope) and from ...ground-based facilities (VLT Hawk-I), for six deep fields pointing at clusters of galaxies and six nearby deep parallel fields, in a wide range of passbands. The analysis of these data is a natural outcome of the Astrodeep project, an EU collaboration aimed at developing methods and tools for extragalactic photometry and creating valuable public photometric catalogues. Aims. We produce multiwavelength photometric catalogues (from B to 4.5 mu m) for the first two of the Frontier Fields, Abell-2744 and MACS-J0416 (plus their parallel fields). Methods. To detect faint sources even in the central regions of the clusters, we develop a robust and repeatable procedure that uses the public codes Galapagos and Galfit to model and remove most of the light contribution from both the brightest cluster members, and the intra-cluster light. We perform the detection on the processed HST H 160 image to obtain a pure H-selected sample, which is the primary catalogue that we publish. We also add a sample of sources which are undetected in the H 160 image but appear on a stacked infrared image. Photometry on the other HST bands is obtained using SExtractor, again on processed images after the procedure for foreground light removal. Photometry on the Hawk-I and IRAC bands is obtained using our PSF-matching deconfusion code t-phot. A similar procedure, but without the need for the foreground light removal, is adopted for the Parallel fields. Results. The procedure of foreground light subtraction allows for the detection and the photometric measurements of ~2500 sources per field. We deliver and release complete photometric H-detected catalogues, with the addition of the complementary sample of infrared-detected sources. All objects have multiwavelength coverage including B to H HST bands, plus K-band from Hawk-I, and 3.6?4.5 mu m from Spitzer. full and detailed treatment of photometric errors is included. We perform basic sanity checks on the reliability of our results. Conclusions. The multiwavelength photometric catalogues are available publicly and are ready to be used for scientific purposes. Our procedures allows for the detection of outshone objects near the bright galaxies, which, coupled with the magnification effect of the clusters, can reveal extremely faint high redshift sources. Full analysis on photometric redshifts is presented in Paper II.
ABSTRACT
We study the relationships between stellar mass, size, and age within the quiescent population, using two mass-complete spectroscopic samples with log10(M⋆/M⊙) > 10.3, taken from VANDELS at ...1.0 < z < 1.3, and LEGA-C at 0.6 < z < 0.8. Using robust Dn4000 values, we demonstrate that the well-known ‘downsizing’ signature is already in place by z ≃ 1.1, with Dn4000 increasing by ≃ 0.1 across a ≃ 1 dex mass interval for both VANDELS and LEGA-C. We then proceed to investigate the evolution of the quiescent galaxy stellar mass–size relation from z ≃ 1.1 to z ≃ 0.7. We find the median size increases by a factor of 1.9 ± 0.1 at log10(M⋆/M⊙) = 10.5, and see tentative evidence for flattening of the relation, finding slopes of α = 0.72 ± 0.06 and $\alpha =\, 0.56\pm 0.04$ for VANDELS and LEGA-C, respectively. We finally split our sample into galaxies above and below our fitted mass–size relations, to investigate how size and Dn4000 correlate. For LEGA-C, we see a clear difference, with larger galaxies found to have smaller Dn4000 at fixed stellar mass. Due to the faintness and smaller numbers of the VANDELS sample, we cannot confirm whether a similar relation exists at z ≃ 1.1. We consider whether differences in stellar age or metallicity are most likely to drive this size–Dn4000 relation, finding that any metallicity differences are unlikely to fully explain the observed offset, meaning smaller galaxies must be older than their larger counterparts. We find the observed evolution in size, mass, and Dn4000 across the ≃ 2 Gyr from z ∼ 1.1 to z ∼ 0.7 can be explained by a simple toy model in which VANDELS galaxies evolve passively whilst experiencing a series of minor mergers.
Abstract
Cellulose-pulping requires chemicals such as Cl
2
, ClO
2
, H
2
O
2
, and O
2
. The black liquor (BL) generated exhibits a high chemical oxygen demand (COD), five-day biochemical oxygen ...demand (BOD
5
), and chlorophenol content, along with an augmented colour and increased pH. BL is often discharged into water bodies, where it has a negative impact on the environment. Towards that end, laccases are of great interest for bioremediation, since they can degrade aromatic and non-aromatic compounds while reducing O
2
to water instead of H
2
O
2
. As such, we evaluated
Pleurotus ostreatus
and
Pichia pastoris
(which produces rPOXA 1B laccase) in the treatment of synthetic BL (SBL) in an “
in vitro
” modified Kraft process followed by CuO/TiO
2
/visible light photocatalysis. Treating SBL with
P. ostreatus
viable biomass (VB) followed by CuO/TiO
2
/visible light photocatalysis resulted in 80.3% COD removal and 70.6% decolourisation. Toxic compounds such as 2-methylphenol, 4-methylphenol, and 2-methoxyphenol were eliminated. Post-treated SBL exhibited low phytotoxicity, as evidenced by a
Lactuca sativa
L seed germination index (GI) > 50%. Likewise, SBL treatment with
P. pastoris
followed by VB/CuO/TiO
2
/
visible light photocatalysis resulted in 63.7% COD removal and 46% decolourisation. Moreover, this treatment resulted in the elimination of most unwanted compounds, with the exception of 4-chlorophenol. The
Lactuca sativa
L seed GI of the post-treated SBL was 40%, indicating moderate phytotoxicity.
ABSTRACT
Tidal features in the outskirts of galaxies yield unique information about their past interactions and are a key prediction of the hierarchical structure formation paradigm. The Vera C. ...Rubin Observatory is poised to deliver deep observations for potentially millions of objects with visible tidal features, but the inference of galaxy interaction histories from such features is not straightforward. Utilizing automated techniques and human visual classification in conjunction with realistic mock images produced using the NewHorizon cosmological simulation, we investigate the nature, frequency, and visibility of tidal features and debris across a range of environments and stellar masses. In our simulated sample, around 80 per cent of the flux in the tidal features around Milky Way or greater mass galaxies is detected at the 10-yr depth of the Legacy Survey of Space and Time (30–31 mag arcsec−2), falling to 60 per cent assuming a shallower final depth of 29.5 mag arcsec−2. The fraction of total flux found in tidal features increases towards higher masses, rising to 10 per cent for the most massive objects in our sample (M⋆ ∼ 1011.5 M⊙). When observed at sufficient depth, such objects frequently exhibit many distinct tidal features with complex shapes. The interpretation and characterization of such features varies significantly with image depth and object orientation, introducing significant biases in their classification. Assuming the data reduction pipeline is properly optimized, we expect the Rubin Observatory to be capable of recovering much of the flux found in the outskirts of Milky Way mass galaxies, even at intermediate redshifts (z < 0.2).
We report the results of a comprehensive study of the relationship between galaxy size, stellar mass and specific star formation rate (sSFR) at redshifts 1.3 < z < 1.5. Based on a mass-complete (M
≥ ...6 × 1010 M), spectroscopic sample from the UK Infrared Deep Sky Survey (UKIDSS) Ultradeep Survey, with accurate stellar-mass measurements derived from spectro-photometric fitting, we find that at z 1.4 the location of massive galaxies on the size-mass plane is determined primarily by their sSFR. At this epoch, we find that massive galaxies which are passive (sSFR ≤ 0.1 Gyr−1) follow a tight size-mass relation, with half-light radii a factor of f
g = 2.4 ± 0.2 smaller than their local counterparts. Moreover, amongst the passive sub-sample we find no evidence that the off-set from the local size-mass relation is a function of stellar population age. In contrast, we find that massive star-forming galaxies at this epoch lie closer to the local late-type size-mass relation and are only a factor of f
g = 1.6 ± 0.2 smaller than observed locally. Based on a sub-sample with dynamical-mass estimates, which consists of both passive and star-forming objects, we also derive an independent estimate of f
g = 2.3 ± 0.3 for the typical growth in half-light radius between z 1.4 and the present day. Focusing on the passive sub-sample, we conclude that to produce the necessary evolution predominantly via major mergers would require an unfeasible number of merger events and overpopulate the high-mass end of the local stellar-mass function. In contrast, we find that a scenario in which mass accretion is dominated by minor mergers can comfortably produce the necessary evolution, whereby an increase in stellar mass of only a factor of 2, accompanied by size growth of a factor of 3.5, is required to reconcile the size-mass relation at z 1.4 with that observed locally. Finally, we note that a significant fraction (44 ± 12 per cent) of the passive galaxies in our sample have a disc-like morphology, providing additional evidence that separate physical processes are responsible for the quenching of star formation and morphological transformation in massive galaxies.
ABSTRACT
Interactions between galaxies leave distinguishable imprints in the form of tidal features, which hold important clues about their mass assembly. Unfortunately, these structures are ...difficult to detect because they are low surface brightness features, so deep observations are needed. Upcoming surveys promise several orders of magnitude increase in depth and sky coverage, for which automated methods for tidal feature detection will become mandatory. We test the ability of a convolutional neural network to reproduce human visual classifications for tidal detections. We use as training ∼6000 simulated images classified by professional astronomers. The mock Hyper Suprime Cam Subaru (HSC) images include variations with redshift, projection angle, and surface brightness (μlim = 26–35 mag arcsec−2). We obtain satisfactory results with accuracy, precision, and recall values of Acc = 0.84, P = 0.72, and R = 0.85 for the test sample. While the accuracy and precision values are roughly constant for all surface brightness, the recall (completeness) is significantly affected by image depth. The recovery rate shows strong dependence on the type of tidal features: we recover all the images showing shell features and 87 per cent of the tidal streams; these fractions are below 75 per cent for mergers, tidal tails, and bridges. When applied to real HSC images, the performance of the model worsens significantly. We speculate that this is due to the lack of realism of the simulations, and take it as a warning on applying deep learning models to different data domains without prior testing on the actual data.
Abstract
Background
It is important to identify patients at increased risk of worsening of left ventricular ejection fraction (LVEF) after a myocardial infarction (MI). We aimed to identify the ...association of various potential biomarkers with LVEF impairment after an MI in South American patients.
Methods
We studied adult patients admitted to a University Hospital and diagnosed with an acute MI. Plasma concentrations of high-sensitivity C-reactive protein (hsCRP), proprotein convertase subtilisin/kexin type 9 (PCSK9), N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and heart-type fatty-acid-binding protein (FABP3) were determined in samples drawn shortly after the event. Participants had a follow-up visit at least 45 days after the event. The primary endpoint was defined as any decline in LVEF at follow-up relative to baseline.
Results
The study included 106 patients (77.4% men, 22.6% women), mean age was 64.1, mean baseline LVEF was 56.6, 19% had a prior MI. We obtained a follow-up evaluation in 100 (94.4%) of participants, mean follow-up time was 163 days. There was a significant correlation between baseline PCSK9 and hsCRP (r = 0.39,
p
< 0.001). Baseline hsCRP concentrations were higher in patients who developed the endpoint than in those who did not (32.1 versus 21.2 mg/L,
p
= 0.066). After multivariate adjustment, baseline PCSK9, male sex and age were significantly associated with impairment in LVEF. The absolute change in LVEF was inversely correlated with baseline hsCRP (standardized coefficient = − 0.246,
p
= 0.004).
Conclusion
High plasma levels of PCSK9 and hsCRP were associated with early decreases in LVEF after an MI in Latin American patients.
Context.
We present ASTRODEEP-GS43, a new multi-wavelength photometric catalogue of the GOODS-South field, which builds and improves upon the previously released CANDELS catalogue.
Aims.
We provide ...photometric fluxes and corresponding uncertainties in 43 optical and infrared bands (25 wide and 18 medium filters), as well as the photometric redshifts and physical properties of the 34930 CANDELS
H
-detected objects, plus an additional sample of 178
H
-dropout sources, of which 173 are
K
s
-detected and five are IRAC-detected.
Methods.
We keep the CANDELS photometry in seven bands (CTIO
U
,
Hubble
Space Telescope WFC3, and ISAAC-
K
) and measure from scratch the fluxes in the other 36 (23 from Subaru SuprimeCAM and
Magellan Baade
FourStar and the rest from VIMOS, HST ACS, HAWK-I
K
s
, and
Spitzer
IRAC) with state-of-the-art template-fitting techniques. We then compute new photometric redshifts with three different software tools and take the median value as a best estimate. We finally evaluate new physical parameters from spectral energy distribution (SED) fitting, comparing them to previously published ones.
Results.
Comparing to a sample of 3931 high quality spectroscopic redshifts, for the new photometric redshifts we obtain a normalised median absolute deviation of 0.015, with 3.01% of outliers on the full catalogue (0.011 and 0.22% on the bright end at
I
814 < 22.5). This is similar to the best available published samples of photometric redshifts, such as the COSMOS UltraVISTA catalogue.
Conclusions.
The ASTRODEEP-GS43 results are in qualitative agreement with previously published catalogues of the GOODS-South field, improving on them particularly in terms of SED sampling and photometric redshift estimates. The catalogue is available for download from the
ASTRODEEP
website.
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