Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Jorge A. Zavala
Veronique Buat
Caitlin M. Casey
Denis Burgarella
Steven L. Finkelstein
Micaela B. Bagley
Laure Ciesla
Emanuele Daddi
Mark Dickinson
Henry C. Ferguson
Maximilien Franco
E. F. Jim'enez-Andrade
Jeyhan S. Kartaltepe
Anton M. Koekemoer
Aurélien Le Bail
E. J. Murphy
Casey Papovich
Sandro Tacchella
Stephen M. Wilkins
Itziar Aretxaga
Abstract： Lyman Break Galaxy (LBG) candidates at z>10 are rapidly being identified in JWST/NIRCam observations. Due to the (redshifted) break produced by neutral hydrogen absorption of rest-frame UV photons, these sources are expected to drop out in the bluer filters while being well detected in redder filters. However, here we show that dust-enshrouded star-forming galaxies at lower redshifts (z<7) may also mimic the near-infrared (near-IR) colors of z>10 LBGs, representing potential contaminants in LBG candidate samples. First, we analyze CEERS-DSFG-1, a NIRCam dropout undetected in the F115W and F150W filters but detected at longer wavelengths. Combining the JWST data with (sub)millimeter constraints, including deep NOEMA interferometric observations, we show that this source is a dusty star-forming galaxy (DSFG) at z~5.1. We also present a tentative 2.6sigma SCUBA-2 detection at 850um around a recently identified z~16 LBG candidate in the same field and show that, if the emission is real and associated with this candidate, the available photometry is consistent with a z~5 dusty galaxy with strong nebular emission lines despite its blue near-IR colors. Further observations on this candidate are imperative to mitigate the low confidence of this tentative submillimeter emission and its positional uncertainty. Our analysis shows that robust (sub)millimeter detections of NIRCam dropout galaxies likely imply z=4-6 redshift solutions, where the observed near-IR break would be the result of a strong rest-frame optical Balmer break combined with high dust attenuation and strong nebular line emission, rather than the rest-frame UV Lyman break. This provides evidence that DSFGs may contaminate searches for ultra high-redshift LBG candidates from JWST observations.
Peer Review Status:
Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Micaela B. Bagley
Nor Pirzkal
Steven L. Finkelstein
Casey Papovich
Danielle A. Berg
Jennifer M. Lotz
Gene C. K. Leung
Henry C. Ferguson
Anton M. Koekemoer
Mark Dickinson
Jeyhan S. Kartaltepe
Dale D. Kocevski
Rachel S. Somerville
L. Y. Aaron Yung
Bren E. Backhaus
Caitlin M. Casey
Marco Castellano
Óscar A. Chávez Ortiz
Katherine Chworowsky
Isabella G. Cox
Abstract： We present the Next Generation Deep Extragalactic Exploratory Public (NGDEEP)
Survey, a deep slitless spectroscopic and imaging Cycle 1 JWST treasury survey
designed to constrain feedback mechanisms in low-mass galaxies across cosmic
time. NGDEEP targets the Hubble Ultra Deep Field (HUDF) with NIRISS slitless
spectroscopy (f~1.2e-18 erg/s/cm^2, 5sigma) to measure metallicities and
star-formation rates (SFRs) for low-mass galaxies through the peak of the
cosmic SFR density (0.5
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Caitlin M. Casey
Jeyhan S. Kartaltepe
Nicole E. Drakos
Maximilien Franco
Santosh Harish
Louise Paquereau
Olivier Ilbert
Caitlin Rose
Isabella G. Cox
James W. Nightingale
Brant E. Robertson
John D. Silverman
Anton M. Koekemoer
Richard Massey
Henry Joy McCracken
Jason Rhodes
Hollis B. Akins
Aristeidis Amvrosiadis
Rafael C. Arango-Toro
Micaela B. Bagley
Abstract： We present the survey design, implementation, and outlook for COSMOS-Web, a
255 hour treasury program conducted by the James Webb Space Telescope in its
first cycle of observations. COSMOS-Web is a contiguous 0.54 deg$^2$ NIRCam
imaging survey in four filters (F115W, F150W, F277W, and F444W) that will reach
5$\sigma$ point source depths ranging $\sim$27.5-28.2 magnitudes. In parallel,
we will obtain 0.19 deg$^2$ of MIRI imaging in one filter (F770W) reaching
5$\sigma$ point source depths of $\sim$25.3-26.0 magnitudes. COSMOS-Web will
build on the rich heritage of multiwavelength observations and data products
available in the COSMOS field. The design of COSMOS-Web is motivated by three
primary science goals: (1) to discover thousands of galaxies in the Epoch of
Reionization ($6
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Jeyhan S. Kartaltepe
Caitlin Rose
Brittany N. Vanderhoof
Elizabeth J. McGrath
Luca Costantin
Isabella G. Cox
L. Y. Aaron Yung
Dale D. Kocevski
Stijn Wuyts
Henry C. Ferguson Brett H. Andrews
Micaela B. Bagley
Steven L. Finkelstein
Ricardo O. Amorin
Pablo Arrabal Haro
Bren E. Backhaus
Peter Behroozi
Laura Bisigello
Antonello Calabro
Caitlin M. Casey
Rosemary T. Coogan
Abstract： We present a comprehensive analysis of the evolution of the morphological and structural properties of a large sample of galaxies at z=3-9 using early JWST CEERS NIRCam observations. Our sample consists of 850 galaxies at z>3 detected in both CANDELS HST imaging and JWST CEERS NIRCam images to enable a comparison of HST and JWST morphologies. Our team conducted a set of visual classifications, with each galaxy in the sample classified by three different individuals. We also measure quantitative morphologies using the publicly available codes across all seven NIRCam filters. Using these measurements, we present the fraction of galaxies of each morphological type as a function of redshift. Overall, we find that galaxies at z>3 have a wide diversity of morphologies. Galaxies with disks make up a total of 60\% of galaxies at z=3 and this fraction drops to ~30% at z=6-9, while galaxies with spheroids make up ~30-40% across the whole redshift range and pure spheroids with no evidence for disks or irregular features make up ~20%. The fraction of galaxies with irregular features is roughly constant at all redshifts (~40-50%), while those that are purely irregular increases from ~12% to ~20% at z>4.5. We note that these are apparent fractions as many selection effects impact the visibility of morphological features at high redshift. The distributions of S\'ersic index, size, and axis ratios show significant differences between the morphological groups. Spheroid Only galaxies have a higher S\'ersic index, smaller size, and higher axis ratio than Disk/Irregular galaxies. Across all redshifts, smaller spheroid and disk galaxies tend to be rounder. Overall, these trends suggest that galaxies with established disks and spheroids exist across the full redshift range of this study and further work with large samples at higher redshift is needed to quantify when these features first formed.
Peer Review Status:Awaiting Review
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