124 research outputs found
JADES: Using NIRCam Photometry to Investigate the Dependence of Stellar Mass Inferences on the IMF in the Early Universe
The detection of numerous and relatively bright galaxies at redshifts z > 9
has prompted new investigations into the star-forming properties of
high-redshift galaxies. Using local forms of the initial mass function (IMF) to
estimate stellar masses of these galaxies from their light output leads to
galaxy masses that are at the limit allowed for the state of the LambdaCDM
Universe at their redshift. We explore how varying the IMF assumed in studies
of galaxies in the early universe changes the inferred values for the stellar
masses of these galaxies. We infer galaxy properties with the SED fitting code
Prospector using varying IMF parameterizations for a sample of 102 galaxies
from the JWST Advanced Deep Extragalactic Survey (JADES) spectroscopically
confirmed to be at z > 6.7, with additional photometry from the JWST
Extragalactic Medium Band Survey (JEMS) for twenty-one galaxies. We demonstrate
that models with stellar masses reduced by a factor of three or more do not
affect the modeled spectral energy distribution (SED).Comment: The Significance statement is required for PNAS submissio
The JWST Advanced Deep Extragalactic Survey: Discovery of an Extreme Galaxy Overdensity at with JWST/NIRCam in GOODS-S
We report the discovery of an extreme galaxy overdensity at in the
GOODS-S field using JWST/NIRCam imaging from JADES and JEMS alongside
JWST/NIRCam wide field slitless spectroscopy from FRESCO. We identified
potential members of the overdensity using HST+JWST photometry spanning
. These data provide accurate and
well-constrained photometric redshifts down to .
We subsequently confirmed galaxies at using JWST
slitless spectroscopy over through a
targeted line search for around the best-fit photometric
redshift. We verified that of these galaxies reside in the field while
galaxies reside in a density around times that of a random
volume. Stellar populations for these galaxies were inferred from the
photometry and used to construct the star-forming main sequence, where
protocluster members appeared more massive and exhibited earlier star formation
(and thus older stellar populations) when compared to their field galaxy
counterparts. We estimate the total halo mass of this large-scale structure to
be using an empirical stellar mass to halo mass relation, which is
likely an underestimate as a result of incompleteness. Our discovery
demonstrates the power of JWST at constraining dark matter halo assembly and
galaxy formation at very early cosmic times.Comment: Resubmitted to ApJ based on reviewer report; main text has 15 pages,
6 figures and 1 table; appendix has 1 page, 2 figure sets, and 2 table
The JWST Advanced Deep Extragalactic Survey: Discovery of an Extreme Galaxy Overdensity at z = 5.4 with JWST/NIRCam in GOODS-S
© 2024 The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/We report the discovery of an extreme galaxy overdensity at in the GOODS-S field using JWST/NIRCam imaging from JADES and JEMS alongside JWST/NIRCam wide field slitless spectroscopy from FRESCO. We identified potential members of the overdensity using HST+JWST photometry spanning . These data provide accurate and well-constrained photometric redshifts down to . We subsequently confirmed galaxies at using JWST slitless spectroscopy over through a targeted line search for around the best-fit photometric redshift. We verified that of these galaxies reside in the field while galaxies reside in a density around times that of a random volume. Stellar populations for these galaxies were inferred from the photometry and used to construct the star-forming main sequence, where protocluster members appeared more massive and exhibited earlier star formation (and thus older stellar populations) when compared to their field galaxy counterparts. We estimate the total halo mass of this large-scale structure to be using an empirical stellar mass to halo mass relation, which is likely an underestimate as a result of incompleteness. Our discovery demonstrates the power of JWST at constraining dark matter halo assembly and galaxy formation at very early cosmic times.Peer reviewe
The galaxies missed by Hubble and ALMA: the contribution of extremely red galaxies to the cosmic census at 3<z<8
Using deep JWST imaging from JADES, JEMS and SMILES, we characterize
optically-faint and extremely red galaxies at that were previously
missing from galaxy census estimates. The data indicate the existence of
abundant, dusty and post-starburst-like galaxies down to M, below
the sensitivity limit of Spitzer and ALMA. Modeling the NIRCam and HST
photometry of these red sources can result in extreme, high values for both
stellar mass and star formation rate (SFR); however, including 7 MIRI filters
out to 21m results in decreased mass (median 0.6 dex for
logM/M10), and SFR (median 10 for SFR100
M/yr). At , our sample includes a high fraction of little red
dots (LRDs; NIRCam-selected dust-reddened AGN candidates). We significantly
measure older stellar populations in the LRDs out to rest-frame 3m (the
stellar bump) and rule out a dominant contribution from hot dust emission, a
signature of AGN contamination to stellar population measurements. This allows
us to measure their contribution to the cosmic census at , below the
typical detection limits of ALMA (). We find that
these sources, which are overwhelmingly missed by HST and ALMA, could
effectively double the obscured fraction of the star formation rate density at
compared to some estimates, showing that prior to JWST, the obscured
contribution from fainter sources could be underestimated. Finally, we identify
five sources with evidence for Balmer breaks and high stellar masses at
. While spectroscopy is required to determine their nature, we
discuss possible measurement systematics to explore with future data.Comment: submitted to AAS Journals, comments welcome
The Cosmos in its Infancy: JADES Galaxy Candidates at z > 8 in GOODS-S and GOODS-N
We present a catalog of 717 candidate galaxies at selected from 125
square arcminutes of NIRCam imaging as part of the JWST Advanced Deep
Extragalactic Survey (JADES). We combine the full JADES imaging dataset with
data from the JEMS and FRESCO JWST surveys along with extremely deep existing
observations from HST/ACS for a final filter set that includes fifteen
JWST/NIRCam filters and five HST/ACS filters. The high-redshift galaxy
candidates were selected from their estimated photometric redshifts calculated
using a template fitting approach, followed by visual inspection from seven
independent reviewers. We explore these candidates in detail, highlighting
interesting resolved or extended sources, sources with very red long-wavelength
slopes, and our highest redshift candidates, which extend to .
We also investigate potential contamination by stellar objects, and do not find
strong evidence from SED fitting that these faint high-redshift galaxy
candidates are low-mass stars. Over 93\% of the sources are newly identified
from our deep JADES imaging, including 31 new galaxy candidates at . Using 42 sources in our sample with measured spectroscopic redshifts from
NIRSpec and FRESCO, we find excellent agreement to our photometric redshift
estimates, with no catastrophic outliers and an average difference of . These sources comprise one of the
most robust samples for probing the early buildup of galaxies within the first
few hundred million years of the Universe's history.Comment: v2: 40 pages, 18 figures, submitted to AAS Journals, online data
catalog (JADES Deep only) found at https://doi.org/10.5281/zenodo.809252
The Cosmos in its Infancy: JADES Galaxy Candidates at z > 8 in GOODS-S and GOODS-N
© 2024. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, see: https://creativecommons.org/licenses/by/4.0/We present a catalog of 717 candidate galaxies at z > 8 selected from 125 square arcmin of NIRCam imaging as part of the JWST Advanced Deep Extragalactic Survey (JADES). We combine the full JADES imaging data set with data from the JWST Extragalactic Medium Survey and First Reionization Epoch Spectroscopic COmplete Survey (FRESCO) along with extremely deep existing observations from Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) for a final filter set that includes 15 JWST/NIRCam filters and five HST/ACS filters. The high-redshift galaxy candidates were selected from their estimated photometric redshifts calculated using a template-fitting approach, followed by visual inspection from seven independent reviewers. We explore these candidates in detail, highlighting interesting resolved or extended sources, sources with very red long-wavelength slopes, and our highest-redshift candidates, which extend to z phot ∼ 18. Over 93% of the sources are newly identified from our deep JADES imaging, including 31 new galaxy candidates at z phot > 12. We also investigate potential contamination by stellar objects, and do not find strong evidence from spectral energy distribution fitting that these faint high-redshift galaxy candidates are low-mass stars. Using 42 sources in our sample with measured spectroscopic redshifts from NIRSpec and FRESCO, we find excellent agreement to our photometric redshift estimates, with no catastrophic outliers and an average difference of 〈Δz = z phot − z spec〉 = 0.26. These sources comprise one of the most robust samples for probing the early buildup of galaxies within the first few hundred million years of the Universe’s history.Peer reviewe
A recently quenched galaxy 700 million years after the Big Bang
© 2024 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Local and low-redshift (10^{10}~M_{\odot}=UV=\pm0.03\times 10^8~M_\odot$) falls in a range that is sensitive to various feedback mechanisms, which can result in perhaps only temporary quenching.Peer reviewe
JADES + JEMS: A Detailed Look at the Buildup of Central Stellar Cores and Suppression of Star Formation in Galaxies at Redshifts 3 < z < 4.5
We present a spatially resolved study of stellar populations in 6 galaxies
with stellar masses at using 14-filter
JWST/NIRCam imaging from the JADES and JEMS surveys. The 6 galaxies are
visually selected to have clumpy substructures with distinct colors over
rest-frame \r{A}, including a bright dominant stellar core that is
close to their stellar-light centroids. With 23-filter photometry from HST to
JWST, we measure the stellar-population properties of individual structural
components via SED fitting using Prospector. We find that the central stellar
cores are times more massive than the Toomre mass, indicating they
may not form via in-situ fragmentation. The stellar cores have stellar ages of
Gyr that are similar to the timescale of clump inward migration due
to dynamical friction, suggesting that they likely instead formed through the
coalescence of giant stellar clumps. While they have not yet quenched, the 6
galaxies are below the star-forming main sequence by dex. Within each
galaxy, we find that the specific star formation rate is lower in the central
stellar core, and the stellar-mass surface density of the core is already
similar to quenched galaxies of the same masses and redshifts. Meanwhile, the
stellar ages of the cores are either comparable to or younger than the
extended, smooth parts of the galaxies. Our findings are consistent with model
predictions of the gas-rich compaction scenario for the buildup of galaxies'
central regions at high redshifts. We are likely witnessing the coeval
formation of dense central cores, along with the onset of galaxy-wide quenching
at .Comment: 32 pages, 16 figures, submitted to ApJ. Comments are welcom
JADES: Detecting [OIII] Emitters and Testing Strong Line Calibrations in the High- Universe with Ultra-deep JWST/NIRSpec Spectroscopy up to
© 2024 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/We present ten novel [OIII]λ4363 auroral line detections up to z ∼ 9.5 measured from ultra-deep JWST/NIRSpec MSA spectroscopy from the JWST Advanced Deep Extragalactic Survey (JADES). We leverage the deepest spectroscopic observations taken thus far with NIRSpec to determine electron temperatures and oxygen abundances using the direct Te method. We directly compare these results against a suite of locally calibrated strong-line diagnostics and recent high-z calibrations. We find the calibrations fail to simultaneously match our JADES sample, thus warranting a self-consistent revision of these calibrations for the high-z Universe. We find a weak dependence between R2 and O3O2 with metallicity, thus suggesting these line ratios are inefficient in the high-z Universe as metallicity diagnostics and degeneracy breakers. We find R3 and R23 are still correlated with metallicity, but we find a tentative flattening of these diagnostics, thus suggesting future difficulties when applying these strong line ratios as metallicity indicators in the high-z Universe. We also propose and test an alternative diagnostic based on a different combination of R3 and R2 with a higher dynamic range. We find a reasonably good agreement (median offset of 0.002 dex, median absolute offset of 0.13 dex) with the JWST sample at low metallicity, but future investigations are required on larger samples to probe past the turnover point. At a given metallicity, our sample demonstrates higher ionization and excitation ratios than local galaxies with rest-frame EWs(Hβ) ≈200 − 300 Å. However, we find the median rest-frame EWs(Hβ) of our sample to be ∼2× less than the galaxies used for the local calibrations. This EW discrepancy combined with the high ionization of our galaxies does not offer a clear description of [OIII]λ4363 production in the high-z Universe, thus warranting a much deeper examination into the factors influencing these processes.Peer reviewe
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