J/ApJ/937/L33 JWST morphological measurements at 4.4um & 1.5um (Suess+, 2022)
Rest-frame near-infrared sizes of galaxies at cosmic noon: objects in JWST's
mirror are smaller than they appeared.
Suess K.A., Bezanson R., Nelson E.J., Setton D.J., Price S.H.,
van Dokkum P., Brammer G., Labbe I., Leja J., Miller T.B., Robertson B.,
van der Wel A., Weaver J.R., Whitaker K.E.
<Astrophys. J., 937, L33 (2022)>
=2022ApJ...937L..33S 2022ApJ...937L..33S
ADC_Keywords: Galaxies, radius; Morphology; Redshifts; Stars, masses; Infrared
Keywords: Galaxy evolution ; Galaxy formation ; Galaxy radii
Abstract:
Galaxy sizes and their evolution over cosmic time have been studied
for decades and serve as key tests of galaxy formation models.
However, at z≳1 these studies have been limited by a lack of deep,
high-resolution rest-frame infrared imaging that accurately traces
stellar mass distributions. Here, we leverage the new capabilities of
the James Webb Space Telescope (JWST) to measure the 4.4µm sizes of
∼1000 galaxies with logM*/M☉≥9 and 1.0≤z≤2.5 from public
CEERS imaging in the Extended Groth Strip deep field. We compare the
sizes of galaxies measured from NIRCam imaging at 4.4µm
(λrest∼1.6µm) with sizes measured at 1.5µm
(λrest∼5500Å). We find that, on average, galaxy half-light
radii are ∼9% smaller at 4.4µm than 1.5µm in this sample. This
size difference is markedly stronger at higher stellar masses and
redder rest-frame V-J colors: galaxies with M*∼1011M☉ have
4.4µm sizes that are ∼30% smaller than their 1.5µm sizes. Our
results indicate that galaxy mass profiles are significantly more
compact than their rest-frame optical light profiles at cosmic noon,
and demonstrate that spatial variations in age and attenuation are
important, particularly for massive galaxies. The trend we find here
impacts our understanding of the size growth and evolution of
galaxies, and suggests that previous studies based on rest-frame
optical light may not have captured the mass-weighted structural
evolution of galaxies. This paper represents a first step toward a new
understanding of the morphologies of early massive galaxies enabled by
JWST's infrared window into the distant universe.
Description:
The JWST NIRCam F444W (4.4um) and F150W (1.5um) imaging was taken as
part of the Cosmic Evolution Early Release Science (CEERS) program
(Finkelstein+ 2017, JWST Proposal ID 1345) in the AEGIS field. The
F444W observations we use for this project were taken on
2022-Jun-21-28 with total exposure times of ∼1.6-6.3hr per pointing,
covering a total of ∼40sq'. We use mosaicked images and weight maps
created following the procedure outlined in G. Brammer+ 2022 (in prep).
We use stellar masses and photometric redshift estimates ("z_best")
from the v4.1.5 3D-HST catalog (Brammer+ 2012ApJS..200...13B 2012ApJS..200...13B ;
Skelton+ 2014, J/ApJS/214/24 and Momcheva+ 2016, J/ApJS/225/27).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 107 955 Morphological measurements at 1.5um and 4.4um
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See also:
J/MNRAS/427/1666 : Massive galaxies in CANDELS-UDS field (Bruce+, 2012)
J/ApJS/203/24 : Structural param. of gal. in CANDELS (van der Wel+, 2012)
J/ApJ/775/106 : CANDELS passive and massive early-type gal. (Cassata+, 2013)
J/ApJ/763/73 : Surface density profiles of GOODS-S gal. (Szomoru+, 2013)
J/ApJ/771/85 : Dynamical masses of z∼2 quiescent gal. (van de Sande+, 2013)
J/ApJS/214/24 : 3D-HST+CANDELS catalog (Skelton+, 2014)
J/ApJS/219/15 : Morphologies of z=0-10 gal. with HST data (Shibuya+, 2015)
J/ApJS/225/27 : 3D-HST Survey: grism spectra master cat. (Momcheva+, 2016)
J/ApJ/877/103 : Half-mass radii for galaxies at 1.0≤z≤2.5 (Suess+, 2019)
J/ApJ/905/170 : Mass-based structural param. for 3D-HST gal. (Mosleh+, 2020)
J/ApJ/901/74 : ALMA obs. of UDS & GOODS-S massive galaxies (Tadaki+, 2020)
J/MNRAS/506/928 : Stellar mass-size relation for low M* gal. (Nedkova+, 2021)
J/ApJ/925/34 : The COSMOS-DASH morphological catalog (Cutler+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID [13192/40427] Identifier from
Skelton+ 2014, J/ApJS/214/24
(<[SWM2014] AEGIS NNNNN> in Simbad)
7- 11 F5.2 [Msun] logMass [9/11.5] log of stellar mass
13- 16 F4.2 --- zphot [1/3] Photometric redshift
18- 22 F5.2 arcsec re1.5um [0.36/61.64] Effective radius at 1.5 micron
24- 28 F5.2 arcsec e_re1.5um [0/47] Effective radius error at 1.5 micron
30- 33 F4.2 --- n1.5um [0.2/8] Sersic index at 1.5 micron
35- 39 F5.2 --- e_n1.5um [0/12] Sersic index error at 1.5 micron
41- 44 F4.2 --- q1.5um [0.12/0.98] Axis ratio at 1.5 micron
46- 49 F4.2 --- e_q1.5um [0/0.31] Axis ratio error at 1.5 micron
51- 56 F6.2 deg PA1.5um [-90/90] Position angle at 1.5 micron
58- 62 F5.2 deg e_PA1.5um [0.01/29] Position angle error at 1.5 micron
64- 68 F5.2 arcsec re4.4um [0.38/62.7] Effective radius at 4.4 micron
70- 74 F5.2 arcsec e_re4.4um [0/32] Effective radius error at 4.4 micro
76- 79 F4.2 --- n4.4um [0.2/8] Sersic index at 4.4 micron
81- 84 F4.2 --- e_n4.4um [0/1.3] Sersic index error at 4.4 micron
86- 89 F4.2 --- q4.4um [0.13/1] Axis ratio at 4.4 micron
91- 94 F4.2 --- e_q4.4um [0/0.2] Axis ratio error at 4.4 micron
96-101 F6.2 deg PA4.4um [-90/90] Position angle at 4.4 micron
103-107 F5.2 deg e_PA4.4um [0.01/30] Position angle error at 4.4 micron
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Aug-2024