Abstract
The Complete Calibration of the Color–Redshift Relation (C3R2) survey is obtaining spectroscopic redshifts in order to map the relation between galaxy color and redshift to a depth of
i
∼ ...24.5 (AB). The primary goal is to enable sufficiently accurate photometric redshifts for Stage
iv
dark energy projects, particularly Euclid and the Nancy Grace Roman Space Telescope (Roman), which are designed to constrain cosmological parameters through weak lensing. We present 676 new high-confidence spectroscopic redshifts obtained by the C3R2 survey in the 2017B–2019B semesters using the DEIMOS, LRIS, and MOSFIRE multiobject spectrographs on the Keck telescopes. Combined with the 4454 redshifts previously published by this project, the C3R2 survey has now obtained and published 5130 high-quality galaxy spectra and redshifts. If we restrict consideration to only the 0.2 <
z
p
< 2.6 range of interest for the Euclid cosmological goals, then with the current data release, C3R2 has increased the spectroscopic redshift coverage of the Euclid color space from 51% (as reported by Masters et al.) to the current 91%. Once completed and combined with extensive data collected by other spectroscopic surveys, C3R2 should provide the spectroscopic calibration set needed to enable photometric redshifts to meet the cosmology requirements for Euclid, and make significant headway toward solving the problem for Roman.
Euclid preparation Huertas-Company, M.; Lanusse, F.; Jullo, E. ...
Astronomy and astrophysics (Berlin),
01/2022, Letnik:
657
Journal Article
Recenzirano
Odprti dostop
We present a machine learning framework to simulate realistic galaxies for the
Euclid
Survey, producing more complex and realistic galaxies than the analytical simulations currently used in
Euclid
. ...The proposed method combines a control on galaxy shape parameters offered by analytic models with realistic surface brightness distributions learned from real
Hubble
Space Telescope observations by deep generative models. We simulate a galaxy field of 0.4 deg
2
as it will be seen by the
Euclid
visible imager VIS, and we show that galaxy structural parameters are recovered to an accuracy similar to that for pure analytic Sérsic profiles. Based on these simulations, we estimate that the
Euclid
Wide Survey (EWS) will be able to resolve the internal morphological structure of galaxies down to a surface brightness of 22.5 mag arcsec
−2
, and the
Euclid
Deep Survey (EDS) down to 24.9 mag arcsec
−2
. This corresponds to approximately 250 million galaxies at the end of the mission and a 50% complete sample for stellar masses above 10
10.6
M
⊙
(resp. 10
9.6
M
⊙
) at a redshift
z
∼ 0.5 for the EWS (resp. EDS). The approach presented in this work can contribute to improving the preparation of future high-precision cosmological imaging surveys by allowing simulations to incorporate more realistic galaxies.
Background
Irradical tumor resections and iatrogenic ureteral injury remain a significant problem during lower abdominal surgery. The aim of the current study was to intraoperatively identify both ...colorectal tumors and ureters in subcutaneous and orthotopic animal models using cRGD-ZW800-1 and near-infrared (NIR) fluorescence.
Methods
The zwitterionic fluorophore ZW800-1 was conjugated to the tumor specific peptide cRGD (targeting integrins) and to the a-specific peptide cRAD. One nmol cRGD-ZW800-1, cRAD-ZW800-1, or ZW800-1 alone was injected in mice bearing subcutaneous HT-29 human colorectal tumors. Subsequently, cRGD-ZW800-1 was injected at dosages of 0.25 and 1 nmol in mice bearing orthotopic HT-29 tumors transfected with luciferase2. In vivo biodistribution and ureteral visualization were investigated in rats. Fluorescence was measured intraoperatively at several time points after probe administration using the FLARE imaging system.
Results
Both subcutaneous and orthotopic tumors could be clearly identified using cRGD-ZW800-1. A significantly higher signal-to-background ratio was observed in mice injected with cRGD-ZW800-1 (2.42 ± 0.77) compared with mice injected with cRAD-ZW800-1 or ZW800-1 alone (1.21 ± 0.19 and 1.34 ± 0.19, respectively) when measured at 24 h after probe administration. The clearance of cRGD-ZW800-1 permitted visualization of the ureters and also generated minimal background fluorescence in the gastrointestinal tract.
Conclusions
This study appears to be the first to demonstrate both clear tumor demarcation and ureteral visualization after a single intravenous injection of a targeted NIR fluorophore. As a low dose of cRGD-ZW800-1 provided clear tumor identification, clinical translation of these results should be possible.
Transition between differentiation states in development occurs swift but the mechanisms leading to epigenetic and transcriptional reprogramming are poorly understood. The pediatric cancer ...neuroblastoma includes adrenergic (ADRN) and mesenchymal (MES) tumor cell types, which differ in phenotype, super-enhancers (SEs) and core regulatory circuitries. These cell types can spontaneously interconvert, but the mechanism remains largely unknown. Here, we unravel how a NOTCH3 intracellular domain reprogrammed the ADRN transcriptional landscape towards a MES state. A transcriptional feed-forward circuitry of NOTCH-family transcription factors amplifies the NOTCH signaling levels, explaining the swift transition between two semi-stable cellular states. This transition induces genome-wide remodeling of the H3K27ac landscape and a switch from ADRN SEs to MES SEs. Once established, the NOTCH feed-forward loop maintains the induced MES state. In vivo reprogramming of ADRN cells shows that MES and ADRN cells are equally oncogenic. Our results elucidate a swift transdifferentiation between two semi-stable epigenetic cellular states.
Context. The standard cosmological model is based on the fundamental assumptions of a spatially homogeneous and isotropic universe on large scales. An observational detection of a violation of these ...assumptions at any redshift would immediately indicate the presence of new physics.
Aims. We quantify the ability of the Euclid mission, together with contemporary surveys, to improve the current sensitivity of null tests of the canonical cosmological constant Λ and the cold dark matter (ΛCDM) model in the redshift range 0 < z < 1.8.
Methods. We considered both currently available data and simulated Euclid and external data products based on a ΛCDM fiducial model, an evolving dark energy model assuming the Chevallier-Polarski-Linder parameterization or an inhomogeneous Lemaître-Tolman-Bondi model with a cosmological constant Λ, and carried out two separate but complementary analyses: a machine learning reconstruction of the null tests based on genetic algorithms, and a theory-agnostic parametric approach based on Taylor expansion and binning of the data, in order to avoid assumptions about any particular model.
Results. We find that in combination with external probes, Euclid can improve current constraints on null tests of the ΛCDM by approximately a factor of three when using the machine learning approach and by a further factor of two in the case of the parametric approach. However, we also find that in certain cases, the parametric approach may be biased against or missing some features of models far from ΛCDM.
Conclusions. Our analysis highlights the importance of synergies between Euclid and other surveys. These synergies are crucial for providing tighter constraints over an extended redshift range for a plethora of different consistency tests of some of the main assumptions of the current cosmological paradigm.
Euclid preparation van Mierlo, S. E.; Caputi, K. I.; Atek, H. ...
Astronomy and astrophysics (Berlin),
10/2022, Letnik:
666
Journal Article
Recenzirano
Odprti dostop
Context.
The
Euclid
mission is expected to discover thousands of
z
> 6 galaxies in three deep fields, which together will cover a ∼50 deg
2
area. However, the limited number of
Euclid
bands (four) ...and the low availability of ancillary data could make the identification of
z
> 6 galaxies challenging.
Aims.
In this work we assess the degree of contamination by intermediate-redshift galaxies (
z
= 1–5.8) expected for
z
> 6 galaxies within the Euclid Deep Survey.
Methods.
This study is based on ∼176 000 real galaxies at
z
= 1–8 in a ∼0.7 deg
2
area selected from the UltraVISTA ultra-deep survey and ∼96 000 mock galaxies with 25.3 ≤
H
< 27.0, which altogether cover the range of magnitudes to be probed in the Euclid Deep Survey. We simulate
Euclid
and ancillary photometry from fiducial 28-band photometry and fit spectral energy distributions to various combinations of these simulated data.
Results.
We demonstrate that identifying
z
> 6 galaxies with
Euclid
data alone will be very effective, with a
z
> 6 recovery of 91% (88%) for bright (faint) galaxies. For the UltraVISTA-like bright sample, the percentage of
z
= 1–5.8 contaminants amongst apparent
z
> 6 galaxies as observed with
Euclid
alone is 18%, which is reduced to 4% (13%) by including ultra-deep
Rubin
(
Spitzer
) photometry. Conversely, for the faint mock sample, the contamination fraction with
Euclid
alone is considerably higher at 39%, and minimised to 7% when including ultra-deep
Rubin
data. For UltraVISTA-like bright galaxies, we find that
Euclid
(
I
E
−
Y
E
) > 2.8 and (
Y
E
−
J
E
) < 1.4 colour criteria can separate contaminants from true
z
> 6 galaxies, although these are applicable to only 54% of the contaminants as many have unconstrained (
I
E
−
Y
E
) colours. In the best scenario, these cuts reduce the contamination fraction to 1% whilst preserving 81% of the fiducial
z
> 6 sample. For the faint mock sample, colour cuts are infeasible; we find instead that a 5
σ
detection threshold requirement in at least one of the
Euclid
near-infrared bands reduces the contamination fraction to 25%.
Euclid preparation Bretonnière, H.; Kuchner, U.; Merlin, E. ...
Astronomy and astrophysics (Berlin),
03/2023, Letnik:
671
Journal Article
Recenzirano
Odprti dostop
The various
Euclid
imaging surveys will become a reference for studies of galaxy morphology by delivering imaging over an unprecedented area of 15 000 square degrees with high spatial resolution. In ...order to understand the capabilities of measuring morphologies from
Euclid
-detected galaxies and to help implement measurements in the pipeline of the Organisational Unit MER of the Euclid Science Ground Segment, we have conducted the Euclid Morphology Challenge, which we present in two papers. While the companion paper focusses on the analysis of photometry, this paper assesses the accuracy of the parametric galaxy morphology measurements in imaging predicted from within the Euclid Wide Survey. We evaluate the performance of five state-of-the-art surface-brightness-fitting codes,
DeepLeGATo
,
Galapagos-2
,
Morfometryka
,
ProFit
and
SourceXtractor++
, on a sample of about 1.5 million simulated galaxies (350 000 above 5
σ
) resembling reduced observations with the
Euclid
VIS and NIR instruments. The simulations include analytic Sérsic profiles with one and two components, as well as more realistic galaxies generated with neural networks. We find that, despite some code-specific differences, all methods tend to achieve reliable structural measurements (< 10% scatter on ideal Sérsic simulations) down to an apparent magnitude of about
I
E
= 23 in one component and
I
E
= 21 in two components, which correspond to a signal-to-noise ratio of approximately 1 and 5, respectively. We also show that when tested on non-analytic profiles, the results are typically degraded by a factor of 3, driven by systematics. We conclude that the official
Euclid
Data Releases will deliver robust structural parameters for at least 400 million galaxies in the Euclid Wide Survey by the end of the mission. We find that a key factor for explaining the different behaviour of the codes at the faint end is the set of adopted priors for the various structural parameters.
Whole-genome sequencing detected structural rearrangements of TERT in 17 of 75 high-stage neuroblastomas, with five cases resulting from chromothripsis. Rearrangements were associated with increased ...TERT expression and targeted regions immediately up- and downstream of TERT, positioning a super-enhancer close to the breakpoints in seven cases. TERT rearrangements (23%), ATRX deletions (11%) and MYCN amplifications (37%) identify three almost non-overlapping groups of high-stage neuroblastoma, each associated with very poor prognosis.
Primordial features, in particular oscillatory signals, imprinted in the primordial power spectrum of density perturbations represent a clear window of opportunity for detecting new physics at ...high-energy scales. Future spectroscopic and photometric measurements from the Euclid space mission will provide unique constraints on the primordial power spectrum, thanks to the redshift coverage and high-accuracy measurement of nonlinear scales, thus allowing us to investigate deviations from the standard power-law primordial power spectrum. We consider two models with primordial undamped oscillations superimposed on the matter power spectrum described by 1 + X sin ( ω X Ξ X + 2 πϕ X ), one linearly spaced in k space with Ξ lin ≡ k / k * where k * = 0.05 Mpc −1 and the other logarithmically spaced in k space with Ξ log ≡ ln( k / k * ). We note that X is the amplitude of the primordial feature, ω X is the dimensionless frequency, and ϕ X is the normalised phase, where X = {lin, log}. We provide forecasts from spectroscopic and photometric primary Euclid probes on the standard cosmological parameters Ω m, 0 , Ω b, 0 , h , n s , and σ 8 , and the primordial feature parameters X , ω X , and ϕ X . We focus on the uncertainties of the primordial feature amplitude X and on the capability of Euclid to detect primordial features at a given frequency. We also study a nonlinear density reconstruction method in order to retrieve the oscillatory signals in the primordial power spectrum, which are damped on small scales in the late-time Universe due to cosmic structure formation. Finally, we also include the expected measurements from Euclid ’s galaxy-clustering bispectrum and from observations of the cosmic microwave background (CMB). We forecast uncertainties in estimated values of the cosmological parameters with a Fisher matrix method applied to spectroscopic galaxy clustering (GC sp ), weak lensing (WL), photometric galaxy clustering (GC ph ), the cross correlation (XC) between GC ph and WL, the spectroscopic galaxy clustering bispectrum, the CMB temperature and E -mode polarisation, the temperature-polarisation cross correlation, and CMB weak lensing. We consider two sets of specifications for the Euclid probes (pessimistic and optimistic) and three different CMB experiment configurations, that is, Planck , Simons Observatory (SO), and CMB Stage-4 (CMB-S4). We find the following percentage relative errors in the feature amplitude with Euclid primary probes: for the linear (logarithmic) feature model, with a fiducial value of X = 0.01, ω X = 10, and ϕ X = 0: 21% (22%) in the pessimistic settings and 18% (18%) in the optimistic settings at a 68.3% confidence level (CL) using GC sp +WL+GC ph +XC. While the uncertainties on the feature amplitude are strongly dependent on the frequency value when single Euclid probes are considered, we find robust constraints on X from the combination of spectroscopic and photometric measurements over the frequency range of (1, 10 2.1 ). Due to the inclusion of numerical reconstruction, the GC sp bispectrum, SO-like CMB reduces the uncertainty on the primordial feature amplitude by 32%–48%, 50%–65%, and 15%–50%, respectively. Combining all the sources of information explored expected from Euclid in combination with the future SO-like CMB experiment, we forecast lin ≃ 0.010 ± 0.001 at a 68.3% CL and log ≃ 0.010 ± 0.001 for GC sp (PS rec + BS)+WL+GC ph +XC+SO-like for both the optimistic and pessimistic settings over the frequency range (1, 10 2.1 ).
The
Euclid
space telescope will survey a large dataset of cosmic voids traced by dense samples of galaxies. In this work we estimate its expected performance when exploiting angular photometric void ...clustering, galaxy weak lensing, and their cross-correlation. To this aim, we implemented a Fisher matrix approach tailored for voids from the
Euclid
photometric dataset and we present the first forecasts on cosmological parameters that include the void-lensing correlation. We examined two different probe settings, pessimistic and optimistic, both for void clustering and galaxy lensing. We carried out forecast analyses in four model cosmologies, accounting for a varying total neutrino mass,
M
ν
, and a dynamical dark energy (DE) equation of state,
w
(
z
), described by the popular Chevallier-Polarski-Linder parametrization. We find that void clustering constraints on
h
and Ω
b
are competitive with galaxy lensing alone, while errors on
n
s
decrease thanks to the orthogonality of the two probes in the 2D-projected parameter space. We also note that, as a whole, with respect to assuming the two probes as independent, the inclusion of the void-lensing cross-correlation signal improves parameter constraints by 10 − 15%, and enhances the joint void clustering and galaxy lensing figure of merit (FoM) by 10% and 25%, in the pessimistic and optimistic scenarios, respectively. Finally, when further combining with the spectroscopic galaxy clustering, assumed as an independent probe, we find that, in the most competitive case, the FoM increases by a factor of 4 with respect to the combination of weak lensing and spectroscopic galaxy clustering taken as independent probes. The forecasts presented in this work show that photometric void clustering and its cross-correlation with galaxy lensing deserve to be exploited in the data analysis of the
Euclid
galaxy survey and promise to improve its constraining power, especially on
h
, Ω
b
, the neutrino mass, and the DE evolution.
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