J/ApJ/982/51 UNCOVER survey: redshift cat. from JWST sp. in A2744 (Price+, 2025)
The UNCOVER survey: first release of Ultradeep JWST/NIRSpec PRISM spectra for
∼700 galaxies from z∼0.3-13 in A2744.
Price S.H., Bezanson R., Labbe I., Furtak L.J., de Graaff A., Greene J.E.,
Kokorev V., Setton D.J., Suess K.A., Brammer G., Cutler S.E., Leja J.,
Pan R., Wang B., Weaver J.R., Whitaker K.E., Atek H., Burgasser A.J.,
Chemerynska I., Dayal P., Feldmann R., Forster Schreiber N.M.,
Fudamoto Y., Fujimoto S., Glazebrook K., Goulding A.D., Khullar G.,
Kriek M., Marchesini D., Maseda M.V., Miller T.B., Muzzin A.,
Nanayakkara T., Nelson E., Oesch P.A., Shipley H., Smit R., Taylor E.N.,
van Dokkum P., Williams C.C., Zitrin A.
<Astrophys. J., 982, 51 (2025)>
=2025ApJ...982...51P 2025ApJ...982...51P
ADC_Keywords: Galaxies; Spectra, infrared; Redshifts; Clusters, galaxy
Keywords: Galaxy evolution ; Galaxy formation ; High-redshift galaxies
Abstract:
We present the design and observations of low-resolution JWST/NIRSpec
PRISM spectroscopy from the Ultradeep NIRSpec and NIRCam ObserVations
before the Epoch of Reionization (UNCOVER) Cycle 1 JWST Treasury
program. Targets are selected using JWST/NIRCam photometry from
UNCOVER and other programs, and cover a wide range of categories and
redshifts to ensure the legacy value of the survey. These categories
include the first galaxies at z≳10, faint galaxies during the Epoch
of Reionization (z∼6-8), high-redshift active galactic nuclei (z≥6),
Population III star candidates, distant quiescent and dusty galaxies
(1≲z≲6), and filler galaxies sampling redshift-color-magnitude space
from z∼0.1-13. Seven NIRSpec microshutter array masks across the
extended A2744 cluster were observed, along with NIRCam parallel
imaging in nine filters (F090W, F115W, F150W, F200W, F277W, F356W,
F410M, F444W, and F480M) over a total area of ∼26arcmin2, overlapping
existing Hubble Space Telescope coverage from programs including the
Hubble Frontier Fields and BUFFALO. We successfully observed
553 objects down to mF444W∼30 AB, and by leveraging mask overlaps,
we reach total on-target exposure times ranging from 2.4 to 16.7hr. We
demonstrate the success rate and distribution of the confirmed
redshifts, and also highlight the rich information revealed by these
ultradeep spectra for a subset of our targets. An updated lens model
of A2744 is also presented, including 14 additional spectroscopic
redshifts and finding a total cluster mass of
MSL=(2.1±0.3)x1015M☉.
Description:
Targets are primarily selected from photometric catalogs constructed
from all publicly available HST and JWST imaging over A2744 as of
2023-June. The JWST/NIRCam observations are: UNCOVER (PIs: Labbe and
Bezanson, JWST-GO-2561; Bezanson+ 2024ApJ...974...92B 2024ApJ...974...92B), the Early
Release Science program GLASS (PI: Treu, JWST-ERS-1324;
Treu+ 2022ApJ...935..110T 2022ApJ...935..110T), and a Director's Discretionary program
(PI: Chen, JWST-DD-2756), providing a total of eight filters: F090W,
F115W, F150W, F200W, F277W, F356W, F410M, and F444W. The archival HST
data consist of HST-GO-11689 (PI: Dupke), HST-GO-13386 (PI: Rodney),
HST-DD-13495 (PI: Lotz; Lotz+ 2017ApJ...837...97L 2017ApJ...837...97L), and HST-GO-15117
(PI: Steinhardt; Steinhardt+ 2020ApJS..247...64S 2020ApJS..247...64S), providing coverage
in seven filters: F435W, F606W, F814W, F105W, F125W, F140W, and F160W.
The majority of the targets are selected from the UNCOVER
NIRCam-selected catalog (as presented in Weaver+ 2024, J/ApJS/270/7),
using internal version v2.2.0. See Section 2.1.
The JWST NIRSpec/PRISM observations are split into seven MSA mask
configurations, with per-mask exposure times of 2.6-4.4hr. In total,
668 unique targets are assigned to masks, with total planned exposure
times ranging from 2.6 to 17.4hr.
The NIRSpec observations were taken on 2023 July 31-August 2.
See Section 2.2.
We publicly release reduced 1D and 2D spectra for all objects observed
in summer 2023 along with a spectroscopic redshift catalog and the
updated lens model of the cluster
(https://jwst-uncover.github.io/DR4.html and on Zenodo (DR4.1.1)
doi:10.5281/zenodo.14559840).
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
00 14 20.02 -30 23 17.8 A2744 = ACO 2744
----------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 134 668 Redshift catalog from UNCOVER NIRSpec/PRISM spectra
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See also:
J/ApJ/801/44 : HST lensing analysis of the CLASH sample (Zitrin+, 2015)
J/ApJ/928/87 : Strongest cluster lenses (Fox+, 2022)
J/ApJ/952/84 : GLASS-JWST ERSP. III. A2744 JWST & MUSE obs. (Bergamini+, 2023)
J/A+A/670/A60 : Abell 2744 members (Bergamini+, 2023)
J/ApJ/947/20 : Color-selected quiescent gal. at z>3 in JWST (Valentino+, 2023)
J/ApJS/275/36 : ALMA Lensing Cluster Survey (ALCS) 1.2mm (Fujimoto+, 2024)
J/ApJS/270/12 : UNCOVER SPS cat. for robust sources up to z∼15 (Wang+, 2024)
J/ApJS/270/7 : The UNCOVER phot. cat. of A2744 wiht HST+JWST (Weaver+, 2024)
http://jwst-uncover.github.io/DR4.html : The UNCOVER & MegaScience surveys
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- MSA [2008/60157] Object identification number
for MSA design
(<[PBL2025] MSA NNNNN> in Simbad)
(id_msa) (1)
7- 16 F10.8 deg RAdeg [3.51/3.65] Right Ascension (J2000) (ra) (1)
18- 29 F12.8 deg DEdeg [-30.5/-30.3] Declination (J2000) (dec) (1)
31- 36 F6.3 --- zspec [0/13.17]? Spectroscopic redshift
(z_spec) (2)
38- 43 F6.3 --- zspec16 [0.09/12.91]? 16th percentile, zspec, p(z)
dist (z_spec16) (2)
45- 50 F6.3 --- zspec50 [0.13/13.16]? 50th percentile, zspec, p(z)
dist (z_spec50) (2)
52- 57 F6.3 --- zspec84 [0.13/13.22]? 84th percentile, zspec, p(z)
dist (z_spec84) (2)
59 I1 --- q_zspec [0/3] Redshift quality flag
(3=secure) (flagzspecqual) (2)
61 I1 --- spFl [0/1] Spectrum flag
(flagsuccessfulspectrum) (3)
63 I1 --- bkgFl [0/1] Local background subtraction flag
(flagpotentiallocalbackgroundissue) (4)
65 I1 --- elFl [0/1]? Feature flag, 2+ emission lines
(flagemissionlines) (5)
67 I1 --- bkelFl [0/1]? Feature flag, break+emission line
(flaglineand_break) (5)
69 I1 --- bkabsFl [0/1]? Feature flag, break+absorption
(flagbreakstrongabsfeatures_only) (5)
71 I1 --- bkFl [0/1]? Feature flag, break only
(flagbreakonly) (5)
73 I1 --- bumpFl [0/1]? Feature flag, stellar bump only
(flagstellarbump_only) (5)
75- 90 A16 --- zbestMeth Fit method for best-fit redshift
(methodbestzfit)
92- 107 A16 --- zerrMeth Fit method for redshift
uncertainties/percentiles (method_zuncert)
109- 112 F4.1 h Texp [0/16.7] Total exposure time (texp_tot)
114- 122 A9 --- masks List of masks on which each object was
included
124- 128 I5 --- DR3 [10065/67255]?=-9999 Closest match UNCOVER
DR3 ID (id_DR3) (6)
130- 134 F5.3 arcsec sepDR3 [0/0.24]? Separation of UNCOVER DR3 and MSA
(sep_DR3) (6)
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Note (1): Internal identifier and positions used for object
identification (version 2.2).
Note (2): A missing value (NaN) implies there is no redshift included
in this release, or the specific interval is unavailable.
Redshifts are not provided for any fits with q_zspec<2 as those
values are unreliable and should not be used.
For the few objects where the redshifts are fixed to zspec=0 (brown
dwarfs), the "fit method" is noted as "fixed" and therefore there is
no 16th-50th-84th fit interval for the redshift, as the redshift was
not fit.
For analysis, using redshifts with quality flag=3 or =2 is recommended.
Redshift quality flag as follows:
3 = secure, based on two or more secure spectral features (e.g.,
two robustly-detected emission lines, one clear break and one
robust emission line, two robustly-detected absorption
features);
2 = solid, based on one broad continuum feature or two less
robust features (e.g., a break or stellar bump, or two
marginally-detected emission lines, or one
marginally-detected emission lines and a break);
1 = tentative but unreliable redshift;
0 = no redshift.
Note (3): Spectrum flag as follows:
1 = successfully observed and reduced spectrum;
0 = no spectrum/data quality issue.
Note (4): Local background subtraction issue flag does not preclude
the measurement of robust redshifts, nor the use of this spectrum
for science analysis --rather this is an advisory flag to alert
users to inspect the 2D spectrum and evaluate if this background
issue could impact their planned analysis. The Local background
subtraction issue flag is as follows:
1 = objects with potential issues from galaxy/ICL light in the
neighboring shutters;
0 = no local background subtraction issues.
Note (5): Feature flags as follows:
1 = Has feature, in category;
0 = no feature.
Note (6): UNCOVER DR3 identifiers and positions from
Suess+ 2024ApJ...976..101S 2024ApJ...976..101S ; Weaver 2024, J/ApJS/270/7 and
Wang+ 2024, J/ApJS/270/12.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 20-Feb-2026