Abstract
The first few 100 Myr at
z
> 10 mark the last major uncharted epoch in the history of the universe, where only a single galaxy (GN-z11 at
z
≈ 11) is currently spectroscopically confirmed. ...Here we present a search for luminous
z
> 10 galaxies with JWST/NIRCam photometry spanning ≈1–5
μ
m and covering 49 arcmin
2
from the public JWST Early Release Science programs (CEERS and GLASS). Our most secure candidates are two
M
UV
≈ −21 systems: GLASS-z12 and GLASS-z10. These galaxies display abrupt ≳1.8 mag breaks in their spectral energy distributions (SEDs), consistent with complete absorption of flux bluewards of Ly
α
that is redshifted to
z
=
12.4
−
0.3
+
0.1
and
z
=
10.4
−
0.5
+
0.4
. Lower redshift interlopers such as quiescent galaxies with strong Balmer breaks would be comfortably detected at >5
σ
in multiple bands where instead we find no flux. From SED modeling we infer that these galaxies have already built up ∼10
9
solar masses in stars over the ≲300–400 Myr after the Big Bang. The brightness of these sources enable morphological constraints. Tantalizingly, GLASS-z10 shows a clearly extended exponential light profile, potentially consistent with a disk galaxy of
r
50
≈ 0.7 kpc. These sources, if confirmed, join GN-z11 in defying number density forecasts for luminous galaxies based on Schechter UV luminosity functions, which require a survey area >10× larger than we have studied here to find such luminous sources at such high redshifts. They extend evidence from lower redshifts for little or no evolution in the bright end of the UV luminosity function into the cosmic dawn epoch, with implications for just how early these galaxies began forming. This, in turn, suggests that future deep JWST observations may identify relatively bright galaxies to much earlier epochs than might have been anticipated.
We use a newly assembled sample of 3545 star-forming galaxies with secure spectroscopic, grism, and photometric redshifts at z = 1.5-2.5 to constrain the relationship between UV slope (β) and dust ...attenuation (LIR/LUV IRX). Our sample significantly extends the range of LUV and β probed in previous UV-selected samples, including those as faint as M1600 = −17.4 ( ) and −2.6 β 0.0. IRX is measured using stacks of deep Herschel data, and the results are compared with predictions of the IRX−β relation for different assumptions of the stellar population model and obscuration curve. We find that z = 1.5-2.5 galaxies have an IRX−β relation that is consistent with the predictions for an SMC curve if we invoke subsolar-metallicity models currently favored for high-redshift galaxies, while the commonly assumed starburst curve overpredicts the IRX at a given β by a factor of 3. IRX is roughly constant with LUV for LUV 3 × 109 L . Thus, the commonly observed trend of fainter galaxies having bluer β may simply reflect bluer intrinsic slopes for such galaxies, rather than lower obscurations. The IRX−β relation for young/low-mass galaxies at z 2 implies a dust curve that is steeper than the SMC. The lower attenuations and higher ionizing photon output for low-metallicity stellar populations point to Lyman continuum production efficiencies, ion, that may be elevated by a factor of 2 relative to the canonical value for L* galaxies, aiding in their ability to keep the universe ionized at z ∼ 2.
We present the Super Eight galaxies-a set of very luminous, high-redshift (7.1 < z < 8.0) galaxy candidates found in the Brightest of Reionizing Galaxies (BoRG) Survey fields. The original sample ...includes eight galaxies that are Y-band dropout objects with H-band magnitudes of mH < 25.5. Four of these objects were originally reported in Calvi et al. Combining new Hubble Space Telescope (HST) WFC3/F814W imaging and Spitzer IRAC data with archival imaging from BoRG and other surveys, we explore the properties of these galaxies. Photometric redshift fitting places six of these galaxies in the redshift range of 7.1 < z < 8.0, resulting in three new high-redshift galaxies and confirming three of the four high-redshift galaxy candidates from Calvi et al. We calculate the half-light radii of the Super Eight galaxies using the HST F160W filter and find that the Super Eight sizes are in line with the typical evolution of size with redshift. The Super Eights have a mean mass of log (M*/M ) ∼10, which is typical for sources in this luminosity range. Finally, we place our sample on the UV z ∼ 8 luminosity function and find that the Super Eight number density is consistent with other surveys in this magnitude and redshift range.
We report on the discovery of three especially bright candidate galaxies. Five sources were targeted for follow-up with the Hubble Space Telescope (HST)/Wide Field Camera 3 (WFC3), selected from a ...larger sample of 16 bright ( mag) candidate Lyman break galaxies (LBGs) identified over 1.6 degrees2 of the COSMOS/UltraVISTA field. These were selected as Y and J dropouts by leveraging the deep (Y-to- mag, ) NIR data from the UltraVISTA DR3 release, deep ground-based optical imaging from the CFHTLS and Suprime-Cam programs, and Spitzer/IRAC mosaics combining observations from the SMUVS and SPLASH programs. Through the refined spectral energy distributions, which now also include new HyperSuprimeCam g-, r-, i-, z-, and Y-band data, we confirm that 3/5 galaxies have robust , consistent with the initial selection. The remaining 2/5 galaxies have a nominal . However, with HST data alone, these objects have increased probability of being at . We measure mean UV continuum slopes for the three galaxies, marginally bluer than similarly luminous in CANDELS but consistent with previous measurements of similarly luminous galaxies at . The circularized effective radius for our brightest source is 0.9 0.3 kpc, similar to previous measurements for a bright galaxy and bright galaxies. Finally, enlarging our sample to include the six brightest LBGs identified over UltraVISTA (i.e., including three other sources from Labbé et al.) we estimate for the first time the volume density of galaxies at the extreme bright end ( mag) of the UV luminosity function. Despite this exceptional result, the still large statistical uncertainties do not allow us to discriminate between a Schechter and a double-power-law form.
ABSTRACT
We have derived luminosity functions and set constraints on the UV luminosity and SFR density from z ∼ 17 to z ∼ 8, using the three most-studied JWST/NIRCam data sets, the SMACS0723, GLASS ...Parallel, and CEERS fields. We first used our own selections on two independent reductions of these data sets using the latest calibrations. A total of 18 z ∼ 8, 12 z ∼ 10, 5 z ∼ 13, and 1 z ∼ 17 candidate galaxies are identified over these fields in our primary reductions, with a similar number of candidates in our secondary reductions. We then use these two reductions, applying a quantitative discriminator, to segregate the full set of z ≥ 8 candidates reported over these fields from the literature, into three different samples, ‘robust’, ‘solid’, and ‘possible’. Using all of these samples, we then derive UV LF and luminosity density results at z ≥ 8, finding substantial differences. For example, including the full set of ‘solid’ and ‘possible’ z ≥ 12 candidates from the literature, we find UV luminosity densities, which are ∼7× and ∼20× higher than relying on the ‘robust’ candidates alone. These results indicate the evolution of the UV LF and luminosity densities at z ≥ 8 is still extremely uncertain, emphasizing the need for spectroscopy and deeper NIRCam + optical imaging to obtain reliable results. Nevertheless, even with the very conservative ‘robust’ approach to selections, both from our own and those of other studies, we find the luminosity density from luminous (MUV < −19) galaxies to be ∼2 × larger than is easily achievable using constant star formation efficiency models, similar to what other early JWST results have suggested.
We measure the evolution of the specific star formation rate (sSFR = SFR/M sub(stellar)) between redshift 4 and 6 to assess the reported "constant" sSFR at z > 2. We derive stellar masses and star ...formation rates (SFRs) for a large sample of 750 z ~ 4-6 galaxies in the GOODS-S field by fitting stellar population models to their spectral energy distributions. We evaluate different star formation histories (SFHs, constant and rising with time) and the impact of optical emission lines. Assuming no contribution from emission lines, the sSFR for galaxies at 5 x 10 super(9) M sub(odot) evolves weakly at z > 2 (sSFR(z) is proportional to (1 + z) super(0.6+ or -0.1)), consistent with previous results. Even accounting for emission lines, the observed sSFR(z) trends at z > 2 are still in tension with theoretical expectations.
Abstract
We present the deepest Spitzer/InfraRed Array Camera (IRAC) 3.6, 4.5, 5.8, and 8.0
μ
m wide-area mosaics yet over the Great Observatories Origins Deep Survey (GOODS)-N and GOODS-S fields as ...part of the GOODS Reionization Era wide-Area Treasury from Spitzer (GREATS) project. We reduced and mosaicked in a self-consistent way observations taken by the 11 different Spitzer/IRAC programs over the two GOODS fields from 12 yr of Spitzer cryogenic and warm-mission data. The cumulative depth in the 3.6
μ
m and 4.5
μ
m bands amounts to ∼4260 hr, ∼1220 hr of which are new very deep observations from the GREATS program itself. In the deepest area, the full-depth mosaics reach ≳200 hr over an area of ∼100 arcmin
2
, corresponding to a sensitivity of ∼29 AB magnitude at 3.6
μ
m (1
σ
for point sources). Archival cryogenic 5.8
μ
m and 8.0
μ
m band data (a cumulative 976 hr) are also included in the release. The mosaics are projected onto the tangential plane of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey/GOODS at a 0.″3 pixel
−1
scale. This paper describes the methodology enabling, and the characteristics of, the public release of the mosaic science images, the corresponding coverage maps in the four IRAC bands, and the empirical point-spread functions (PSFs). These PSFs enable mitigation of the source blending effects by taking into account the complex position-dependent variation in the IRAC images. The GREATS data products are in the Infrared Science Archive. We also release the deblended 3.6–8.0
μ
m photometry 9192 Lyman-break galaxies at
z
∼ 3.5–10. GREATS will be the deepest mid-infrared imaging until the James Webb Space Telescope and, as such, constitutes a major resource for characterizing early galaxy assembly.
The extremely rapid assembly of the earliest galaxies during the first billion years of cosmic history is a major challenge for our understanding of galaxy formation physics
. The advent of the James ...Webb Space Telescope (JWST) has exacerbated this issue by confirming the existence of galaxies in substantial numbers as early as the first few hundred million years
. Perhaps even more surprisingly, in some galaxies, this initial highly efficient star formation rapidly shuts down, or quenches, giving rise to massive quiescent galaxies as little as 1.5 billion years after the Big Bang
. However, due to their faintness and red colour, it has proven extremely challenging to learn about these extreme quiescent galaxies, or to confirm whether any existed at earlier times. Here we report the spectroscopic confirmation of a massive quiescent galaxy, GS-9209, at redshift, z = 4.658, just 1.25 billion years after the Big Bang, using the JWST Near-Infrared Spectrograph (NIRSpec). From these data we infer a stellar mass of M
= 3.8 ± 0.2 × 10
M
, which formed over a roughly 200 Myr period before this galaxy quenched its star-formation activity at Formula: see text, when the Universe was approximately 800 Myr old. This galaxy is both a likely descendent of the highest-redshift submillimetre galaxies and quasars, and a likely progenitor for the dense, ancient cores of the most massive local galaxies.
We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying the physical processes that shape galaxies in the distant universe. 3D-HST provides ...rest-frame optical spectra for a sample of ~7000 galaxies at 1 < z < 3.5, the epoch when ~60% of all star formation took place, the number density of quasars peaked, the first galaxies stopped forming stars, and the structural regularity that we see in galaxies today must have emerged. 3D-HST will cover three quarters (625 arcmin super(2)) of the CANDELS Treasury survey area with two orbits of primary WFC3/G141 grism coverage and two to four orbits with the ACS/G800L grism in parallel. In the IR, these exposure times yield a continuum signal-to-noise ratio of ~5 per resolution element at H sub(140) ~ 23.1 and a 5sigma emission-line sensitivity of ~5 x 10- super(17) erg s super(-1) cm super(2) for typical objects, improving by a factor of ~2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide continuous wavelength coverage from 1.1 to 1.6 mu m at a spatial resolution of ~0."13, which, combined with their depth, makes them a unique resource for studying galaxy evolution. We present an overview of the preliminary reduction and analysis of the grism observations, including emission-line and redshift measurements from combined fits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis yields redshift estimates with a precision of sigma(z)= 0.0034(1 + z), or sigma(v) approx = 1000 km s super(-1). We illustrate how the generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types of objects, including a quasar at z = 4.7, quiescent galaxies at z ~ 2, and the most distant T-type brown dwarf star known. The combination of the CANDELS and 3D-HST surveys will provide the definitive imaging and spectroscopic data set for studies of the 1 < z < 3.5 universe until the launch of the James Webb Space Telescope.
Anti-programmed cell death 1 (anti-PD-1) and PD ligand 1 (PD-L1) immune checkpoint therapies (ICTs) provided durable responses only in a subset of cancer patients. Thus, biomarkers are needed to ...predict nonresponders and offer them alternative treatments. We recently implicated discoidin domain receptor tyrosine kinase 2 (DDR2) as a contributor to anti-PD-1 resistance in animal models; therefore, we sought to investigate whether this gene family may provide ICT response prediction.
We assessed mRNA expression of DDR2 and its family member DDR1. Transcriptome analysis of bladder cancer (BCa) models in which DDR1 and 2 were perturbed was used to derive DDR1- and DDR2-driven signature scores. DDR mRNA expression and gene signature scores were evaluated using BCa-The Cancer Genome Atlas (n = 259) and IMvigor210 (n = 298) datasets, and their relationship to BCa subtypes, pathway enrichment, and immune deconvolution analyses was performed. The potential of DDR-driven signatures to predict ICT response was evaluated and independently validated through a statistical framework in bladder and lung cancer cohorts. All statistical tests were 2-sided.
DDR1 and DDR2 showed mutually exclusive gene expression patterns in human tumors. DDR2high BCa exhibited activation of immune pathways and a high immune score, indicative of a T-cell-inflamed phenotype, whereas DDR1high BCa exhibited a non-T-cell-inflamed phenotype. In IMvigor210 cohort, tumors with high DDR1 (hazard ratio HR = 1.53, 95% confidence interval CI = 1.16 to 2.06; P = .003) or DDR2 (HR = 1.42, 95% CI = 1.01 to 1.92; P = .04) scores had poor overall survival. Of note, DDR2high tumors from IMvigor210 and CheckMate 275 (n = 73) cohorts exhibited poorer overall survival (HR = 1.56, 95% CI = 1.20 to 2.06; P < .001) and progression-free survival (HR = 1.77 95%, CI = 1.05 to 3.00; P = .047), respectively. This result was validated in independent cancer datasets.
These findings implicate DDR1 and DDR2 driven signature scores in predicting ICT response.
PDF
