Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Yu-Heng Lin
Claudia Scarlata
Hayley Williams
Wenlei Chen
Patrick Kelly
Danial Langeroodi
Jens Hjorth
John Chisholm
Anton M. Koekemoer
Adi Zitrin
Jose M. Diego
Abstract： We present a new analysis of the rest-frame UV and optical spectra of a sample of three $z>8$ galaxies discovered behind the gravitational lensing cluster RX J2129.4+0009. We combine these observations with those of a sample of $z>7.5$ galaxies from the literature, for which similar measurements are available. As already pointed out in other studies, the high [OIII]$\lambda$5007/[OII]$\lambda$3727 ratios ($O_{32}$) and steep UV continuum slopes ( $\beta$ ) are consistent with the values observed for low redshift Lyman continuum emitters, suggesting that such galaxies contribute to the ionizing budget of the intergalactic medium. We construct a logistic regression model to estimate the probability of a galaxy being a Lyman continuum emitter based on the measured $M_{UV}$, $\beta$, and $O_{32}$ values. Using this probability together with the UV luminosity function, we construct an empirical model that estimates the contribution of high redshift galaxies to reionization based on these observable quantities. Our analysis shows that at $z\sim8$, the average escape fraction of the galaxy population (i.e., including both LyC emitters and non-emitters) varies with $M_{UV}$, with brighter galaxies having larger $f_{esc}$. For $M_{UV}$ $< -$19 we find an average escape fraction of 20$\%$, decreasing to almost zero for $M_{UV}$$>-16$. Galaxies with intermediate UV luminosity ($-19 <$ $M_{UV}$ $< -16$) contribute half of the ionizing photons. The relative contribution of faint versus bright galaxies depends on redshift, with UV bright galaxies ($-23 <$ $M_{UV}$ $< -19$) becoming more important over time and reaching $\approx 40\%$ at the end of reionization around $z=6$.
Peer Review Status:
Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Haojing Yan
Seth H. Cohen
Rogier A. Windhorst
Rolf A. Jansen
Zhiyuan Ma
John F. Beacom
Cheng Cheng
Jia-Sheng Huang
Norman A. Grogin
S. P. Willner
Min Yun
Heidi B. Hammel
Stefanie N. Milam
Christopher J. Conselice
Simon P. Driver
Brenda Frye
Madeline A. Marshall
Anton Koekemoer
Christopher N. A. Willmer
Aaron Robotham
Abstract： Using the first epoch of four-band NIRCam observations obtained by the James Webb Space Telescope (JWST) Prime Extragalactic Areas for Reionization and Lensing Science Program in the Spitzer IRAC Dark Field, we search for F150W and F200W dropouts. In 14.2 arcmin^2, we have found eight F150W dropouts and eight F200W dropouts, all brighter than 27.5 mag (the brightest being ~24 mag) in the band to the red side of the break. As they are detected in multiple bands, these must be real objects. Their nature, however, is unclear, and characterizing their properties is important for realizing the full potential of JWST. If the observed color decrements are due to the Lyman break, these objects should be at z >~ 11.7 and z >~ 15.4, respectively. The color diagnostics show that at least four F150W dropouts are far away from the usual contaminators encountered in dropout searches (red galaxies at much lower redshifts or brown dwarf stars). While the diagnostics of the F200W dropouts are less certain due to the limited number of passbands, at least one of them is likely not a known type of contaminant, and the rest are consistent with either high-redshift galaxies with evolved stellar populations or old galaxies at z ~ 3 to 8. If a significant fraction of our dropouts are indeed at z ~ 12, we have to face the severe problem of explaining their high luminosities and number densities. Spectroscopic identifications of such objects are urgently needed.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Brenda L. Frye
Massimo Pascale
Nicholas Foo
Reagen Leimbach
Nikhil Garuda
Paulina Soto Robles
Jake Summers
Carlos Diaz
Patrick Kamieneski
Lukas Furtak
Seth Cohen
Jose Diego
Benjamin Beauchesne
Rogier Windhorst
Steve Willner
Anton M. Koekemoer
Adi Zitrin
Gabriel Caminha
Karina Caputi
Dan Coe
Abstract： The massive galaxy cluster El Gordo ($z=0.87$) imprints multitudes of gravitationally lensed arcs onto James Webb Space Telescope (JWST) Near-Infrared Camera (NIRCam) images. Eight bands of NIRCam imaging were obtained in the Prime Extragalactic Areas for Reionization and Lensing Science (PEARLS) program (GTO #1176). PSF-matched photometry across a suite of Hubble Space Telescope (HST) and NIRCam filters gives new photometric redshifts. We confirm 54 known image multiplicities and find two new ones and construct a lens model based on the light-traces-mass method. The mass within 500kpc estimated from the lens model is $\sim$$7.0\times10^{14}$M$_{\odot}$ with a mass ratio between the southeastern and northwestern components of $\sim$unity, similar to recent works. A statistical search for substructures recovers only these two components, which are each tightly bound kinematically and are separated in radial velocity by ~300 km s$^{-1}$. We identify a candidate member of a known 4-member $z=4.32$ galaxy overdensity by its model-predicted and photometric redshifts. These five members span a physical extent of $\sim$60 kpc and exhibit multiple components consistent with satellite associations. Thirteen additional candidates selected by spectroscopic/photometric constraints are small and faint, with a mean apparent brightness corrected for lensing magnification that is $\sim$2.2 mag fainter than M*. NIRCam imaging admits a wide range of brightnesses and morphologies for these candidates, suggesting a more diverse galaxy population may be underlying this rare view of a strongly-lensed galaxy overdensity.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Danial Langeroodi
Jens Hjorth
Wenlei Chen
Patrick L. Kelly
Hayley Williams
Yu-Heng Lin
Claudia Scarlata
Adi Zitrin
Tom Broadhurst
Jose M. Diego
Xiaosheng Huang
Alexei V. Filippenko
Ryan J. Foley
Saurabh Jha
Anton M. Koekemoer
Masamune Oguri
Ismael Perez-Fournon
Justin Pierel
Frederick Poidevin
Lou Strolger
Abstract： A tight positive correlation between the stellar mass and the gas-phase metallicity of galaxies has been observed at low redshifts, with only $\sim 0.1$ dex scatter in metallicity. The shape and normalization of this correlation can set strong constraints on theories of galaxy evolution. In particular, its redshift evolution is thought to be determined by stellar and active galactic nucleus feedback-driven outflows, the redshift evolution of the stellar initial mass function or stellar yields, and broadly the star-formation histories of galaxies. The advent of \jwst\ allows probing the mass--metallicity relation at redshifts far beyond what was previously accessible. Here we report the discovery of two emission-line galaxies at redshift $z = 8.15$ and $z = 8.16$ in \jwst\ NIRCam imaging and NIRSpec spectroscopy of galaxies gravitationally lensed by the cluster RX\,J2129.4$+$0009. We measure their metallicities using the strong-line method and their stellar masses through spectral-energy-distribution fitting with a nonparametric star-formation history. We combine these with nine similarly re-analysed galaxies at $7.2 < z < 9.5$ to compile a sample of eleven galaxies at $z \approx 8$ (six with \jwst\ metallicities and five with ALMA metallicities). Based on this sample, we report the first quantitative statistical inference of the mass--metallicity relation at $z\approx8$ (median $z = 8.15$). We measure a $\sim 1.0$ dex redshift evolution in the normalization of the mass--metallicity relation from $z \approx 8$ to the local Universe; at fixed stellar mass, galaxies are 10 times less metal enriched at $z \approx 8$ compared to the present day (abridged).
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Lukas J. Furtak
Ramesh Mainali
Adi Zitrin
Adèle Plat
Seiji Fujimoto
Megan Donahue
Erica J. Nelson
Franz E. Bauer
Ryosuke Uematsu
Gabriel B. Caminha
Felipe Andrade-Santos
Larry D. Bradley
Karina I. Caputi
Stéphane Charlot
Jacopo Chevallard
Dan Coe
Emma Curtis-Lake
Daniel Espada
Brenda L. Frye
Kirsten K. Knudsen
Abstract： We report the discovery of a triply-imaged active galactic nucleus (AGN), lensed by the galaxy cluster MACS J0035.4-2015 ($z_{\mathrm{d}}=0.352$). The object is detected in Hubble Space Telescope (HST) imaging taken for the RELICS program. It appears to have a quasi-stellar nucleus consistent with a point-source, with a de-magnified radius of $r_e\lesssim100$ pc. The object is spectroscopically confirmed to be an AGN at $z_{\mathrm{spec}}=2.063\pm0.005$ showing broad rest-frame UV emission lines, and is detected in both X-ray observations with \textit{Chandra} and in ALCS ALMA band 6 (1.2 mm) imaging. It has a relatively faint rest-frame UV luminosity for a quasar-like object, $M_{\mathrm{UV},1450}=-19.7\pm0.2$. The object adds to just a few quasars or other X-ray sources known to be multiply lensed by a galaxy cluster. Some faint, diffuse emission from the host galaxy is also seen around the nucleus, and nearby there is another fainter object sharing the same multiple-imaging symmetry and geometric redshift, which may be an interacting galaxy or a star-forming knot in the host. We present an accompanying lens model, calculate the magnifications and time delays, and infer physical properties for the source. We find the rest-frame UV continuum and emission lines to be dominated by the AGN, and the optical emission to be dominated by the relatively young ($\sim100$ Myr) host galaxy of modest stellar mass $M_{\star}\simeq10^{9.2} \mathrm{M}_{\odot}$. We also observe variations in the AGN's emission, which may suggest that the AGN used to be more active. This object adds a low-redshift counterpart to several relatively faint AGN recently uncovered at high redshifts with HST and JWST.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Fengwu Sun
Eiichi Egami
Seiji Fujimoto
Timothy Rawle
Franz E. Bauer
Kotaro Kohno
Ian Smail
Pablo G. Pérez-González
Yiping Ao
Scott C. Chapman
Francoise Combes
Miroslava Dessauges-Zavadsky
Daniel Espada
Jorge González-López
Anton M. Koekemoer
Vasily Kokorev
Minju M. Lee
Kana Morokuma-Matsui
Alejandra M. Muñoz Arancibia
Masamune Oguri
Abstract： We present an ALMA-Herschel joint analysis of sources detected by the ALMA Lensing Cluster Survey (ALCS) at 1.15 mm. Herschel/PACS and SPIRE data at 100-500 $\mu$m are deblended for 180 ALMA sources in 33 lensing cluster fields that are either detected securely (141 sources; in our main sample) or tentatively at S/N$\geq$4 with cross-matched HST/Spitzer counterparts, down to a delensed 1.15-mm flux density of $\sim0.02$ mJy. We performed far-infrared spectral energy distribution modeling and derived the physical properties of dusty star formation for 125 sources (109 independently) that are detected at $>2\sigma$ in at least one Herschel band. 27 secure ALCS sources are not detected in any Herschel bands, including 17 optical/near-IR-dark sources that likely reside at $z=4.2\pm1.2$. The 16-50-84 percentiles of the redshift distribution are 1.15-2.08-3.59 for ALCS sources in the main sample, suggesting an increasing fraction of $z\simeq1-2$ galaxies among fainter millimeter sources ($f_{1150}\sim 0.1$ mJy). With a median lensing magnification factor of $\mu = 2.6_{-0.8}^{+2.6}$, ALCS sources in the main sample exhibit a median intrinsic star-formation rate of $94_{-54}^{+84}\,\mathrm{M}_\odot\,\mathrm{yr}^{-1}$, lower than that of conventional submillimeter galaxies at similar redshifts by a factor of $\sim$3. Our study suggests weak or no redshift evolution of dust temperature with $L_\mathrm{IR}<10^{12}\,\mathrm{L}_\odot$ galaxies within our sample at $z \simeq 0 - 2$. At $L_\mathrm{IR}>10^{12}\,\mathrm{L}_\odot$, the dust temperatures show no evolution across $z \simeq 1 -4$ while being lower than those in the local Universe. For the highest-redshift source in our sample ($z=6.07$), we can rule out an extreme dust temperature ($>$80 K) that was reported for MACS0416 Y1 at $z=8.31$.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abdurro'uf
Dan Coe
Intae Jung
Henry C. Ferguson
Gabriel Brammer
Kartheik G. Iyer
Larry D. Bradley
Pratika Dayal
Rogier A. Windhorst
Adi Zitrin
Ashish Kumar Meena
Masamune Oguri
Jose M. Diego
Vasily Kokorev
Paola Dimauro
Angela Adamo
Christopher J. Conselice
Brian Welch
Eros Vanzella
Tiger Yu-Yang Hsiao
Abstract： We study the spatially resolved stellar populations of 444 galaxies at
$0.3
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Jose M. Diego
Ashish K. Meena
Nathan J. Adams
Tom Broadhurst
Liang Dai
Dan Coe
Brenda Frye
Patrick Kelly
Anton M. Koekemoer
Massimo Pascale
S. P. Willner
Erik Zackrisson
Adi Zitrin
Rogier A. Windhorst
Seth H. Cohen
Rolf A. Jansen
Jake Summers
Scott Tompkins
Christopher J. Conselice
Simon P. Driver
Abstract： The first JWST data on the massive colliding cluster El Gordo confirm 23
known families of multiply lensed images and identify 8 new members of these
families. Based on these families, which have been confirmed spectroscopically
by MUSE, we derived an initial lens model. This model guided the identification
of 37 additional families of multiply lensed galaxies, among which 28 are
entirely new systems, and 9 were previously known. The initial lens model
determined geometric redshifts for the 37 new systems. The geometric redshifts
agree reasonably well with spectroscopic or photometric redshifts when those
are available. The geometric redshifts enable two additional models that
include all 60 families of multiply lensed galaxies spanning a redshift range
$2
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Lukas J. Furtak
Adi Zitrin
John R. Weaver
Hakim Atek
Rachel Bezanson
Ivo Labbe
Katherine E. Whitaker
Joel Leja
Sedona H. Price
Gabriel B. Brammer
Bingjie Wang
Danilo Marchesini
Richard Pan
Pratika Dayal
Pieter van Dokkum
Robert Feldmann
Seiji Fujimoto
Marijn Franx
Gourav Khullar
Erica J. Nelson
Abstract： We present a new parametric lens model for the massive galaxy cluster Abell~2744 based on the new ultra-deep JWST imaging taken in the framework of the UNCOVER program. These observations constitute the deepest JWST images of a lensing cluster to date, adding to the existing deep Hubble Space Telescope (HST) images and the recent JWST ERS and DDT data taken for this field. The wide field-of-view of UNCOVER ($\sim45$ arcmin$^2$) extends beyond the cluster's well-studied central core and reveals a spectacular wealth of prominent lensed features around two massive cluster sub-structures in the north and north-west, where no multiple images were previously known. The 75 newly uncovered multiple images and candidates of 16 sources allow us, for the first time, to constrain the lensing properties and total mass distribution around these extended cluster structures using strong lensing (SL). Our model yields an effective Einstein radius of $\theta_{E,\mathrm{main}}\simeq23''$ for the main cluster core (for $z_{\mathrm{s}}=2$), enclosing a mass of $M(\theta<\theta_{E,\mathrm{main}})\simeq7.7\times10^{13}$ M$_{\odot}$, and $\theta_{E,\mathrm{NW}}\simeq13''$ for the newly discovered north-western SL structure enclosing $M(\theta<\theta_{E,\mathrm{NW}})\simeq2.2\times10^{13}$ M$_{\odot}$. The northern clump is somewhat less massive with $\theta_{E,\mathrm{N}}\simeq7''$ enclosing $M(\theta<\theta_{E,\mathrm{N}})\simeq8\times10^{12}$ M$_{\odot}$. We find the northern sub-structures of Abell~2744 to broadly agree with the findings from weak lensing (WL) and align with the filamentary structure found by these previous studies. Our model in particular reveals a large area of high magnifications between the various cluster structures, which will be paramount for lensed galaxy studies in the UNCOVER field. The model is made publicly available to accompany the first UNCOVER data release.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Patrick L. Kelly
Wenlei Chen
Amruth Alfred
Thomas J. Broadhurst
Jose M. Diego
Najmeh Emami
Alexei V. Filippenko
Allison Keen
Sung Kei Li
Jeremy Lim
Ashish K. Meena
Masamune Oguri
Claudia Scarlata
Tommaso Treu
Hayley Williams
Liliya L. R. Williams
Rui Zhou
Adi Zitrin
Ryan J. Foley
Saurabh W. Jha
Abstract： Once only accessible in nearby galaxies, we can now study individual stars across much of the observable universe aided by galaxy-cluster gravitational lenses. When a star, compact object, or multiple such objects in the foreground galaxy-cluster lens become aligned, they can magnify a background individual star, and the timescale of a magnification peak can limit its size to tens of AU. The number and frequency of microlensing events therefore opens a window into the population of stars and compact objects, as well as high-redshift stars. To assemble the first statistical sample of stars in order to constrain the initial mass function (IMF) of massive stars at redshift z=0.7-1.5, the abundance of primordial black holes in galaxy-cluster dark matter, and the IMF of the stars making up the intracluster light, we are carrying out a 192-orbit program with the Hubble Space Telescope called "Flashlights," which is now two-thirds complete owing to scheduling challenges. We use the ultrawide F200LP and F350LP long-pass WFC3 UVIS filters and conduct two 16-orbit visits separated by one year. Having an identical roll angle during both visits, while difficult to schedule, yields extremely clean subtraction. Here we report the discovery of more than a dozen bright microlensing events, including multiple examples in the famous "Dragon Arc" discovered in the 1980s, as well as the "Spocks" and "Warhol" arcs that have hosted already known supergiants. The ultradeep observer-frame ultraviolet-through-optical imaging is sensitive to hot stars, which will complement deep James Webb Space Telescope infrared imaging. We are also acquiring Large Binocular Telescope LUCI and Keck-I MOSFIRE near-infrared spectra of the highly magnified arcs to constrain their recent star-formation histories.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Hayley Williams
Patrick L. Kelly
Wenlei Chen
Gabriel Brammer
Adi Zitrin
Tommaso Treu
Claudia Scarlata
Anton M. Koekemoer
Masamune Oguri
Yu-Heng Lin
Jose M. Diego
Mario Nonino
Jens Hjorth
Danial Langeroodi
Tom Broadhurst
Noah Rogers
Ismael Perez-Fournon
Ryan J. Foley
Saurabh Jha
Alexei V. Filippenko
Abstract： Given their extremely faint apparent brightness, the nature of the first galaxies and how they reionized the Universe's gas are not yet understood. Here we report the discovery, in JWST imaging, of a highly magnified, low mass (log(Mstellar/Msun) = 7.63+0.22-0.24) galaxy visible when the Universe was only 510 Myr old, and follow-up JWST spectroscopy from Lyman alpha to [O III] 5007 A in its rest frame. We detect the [O III] 5007 A and H Beta emission lines with a respective signal-to-noies ratio of 40 and 7, and five additional lines with signal-to-noise greater than 3. The galaxy's magnification of approximately 20 allows us to measure a radius of 16.4+10.7-7.0 pc, which is a factor of 9.3+10.5-4.4 (3.5 sigma) smaller than galaxies with comparable luminosity at z = 6 - 8.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Ashish Kumar Meena
Adi Zitrin
Yolanda Jiménez-Teja
Erik Zackrisson
Wenlei Chen
Dan Coe
Jose M. Diego
Paola Dimauro
Lukas J. Furtak
Patrick L. Kelly
Masamune Oguri
Brian Welch
Abdurro'uf
Felipe Andrade-Santos
Angela Adamo
Rachana Bhatawdekar
Maruša Bradač
Larry D. Bradley
Pratika Dayal
Megan Donahue
Abstract： We report the discovery of two extremely magnified lensed star candidates behind the galaxy cluster MACS J0647.7+7015, in recent multi-band James Webb Space Telescope (JWST) NIRCam observations. The candidates are seen in a previously known, $z_{phot}\simeq4.8$ dropout giant arc that straddles the critical curve. The candidates lie near the expected critical curve position but lack clear counter images on the other side of it, suggesting these are possibly stars undergoing caustic crossings. We present revised lensing models for the cluster, including multiply imaged galaxies newly identified in the JWST data, and use them to estimate a background macro-magnification of at least $\gtrsim90$ and $\gtrsim50$ at the positions of the two candidates, respectively. With these values, we expect effective, caustic-crossing magnifications of $10^4-10^5$ for the two star candidates. The Spectral Energy Distributions (SEDs) of the two candidates match well spectra of B-type stars with best-fit surface temperatures of $\sim10,000$ K, and $\sim12,000$ K, respectively, and we show that such stars with masses $\gtrsim20$ M$_{\odot}$ and $\gtrsim50$ M$_{\odot}$, respectively, can become sufficiently magnified to be observed. We briefly discuss other alternative explanations and conclude these are likely lensed stars, but also acknowledge that the less magnified candidate may instead be or reside in a star cluster. These star candidates constitute the second highest-redshift examples to date after Earendel at $z_{phot}\simeq6.2$, establishing further the potential of studying extremely magnified stars to high redshifts with the JWST. Planned visits including NIRSpec observations will enable a more detailed view of the candidates already in the near future.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Lukas J. Furtak
Adi Zitrin
Adèle Plat
Seiji Fujimoto
Bingjie Wang
Erica J. Nelson
Ivo Labbé
Rachel Bezanson
Gabriel B. Brammer
Pieter van Dokkum
Ryan Endsley
Karl Glazebrook
Jenny E. Greene
Joel Leja
Sedona H. Price
Renske Smit
Daniel P. Stark
John R. Weaver
Katherine E. Whitaker
Hakim Atek
Abstract： Recent JWST/NIRcam imaging taken for the ultra-deep UNCOVER program reveal a very red, triply imaged, compact dropout object at $z_{\mathrm{phot}}\simeq7.66$ which is prominently lensed by the galaxy cluster Abell 2744 ($z_{\mathrm{d}}=0.308$). All three images are very compact, i.e. unresolved, with an inferred de-lensed size upper limit of $r_{e}\lesssim35$ pc. The observed F444W magnitude of the three images is $m\sim25-26$ AB and the source's absolute UV magnitude is $M_{\mathrm{UV},1450}=-16.81\pm0.09$, after correcting for magnification. From the sum of observed fluxes and from a spectral energy distribution (SED) fit we obtain lower limits on the bolometric luminosities of $L_{\mathrm{bol}}\gtrsim10^{43} \frac{\mathrm{erg}}{\mathrm{s}}$ and $L_{\mathrm{bol}}\gtrsim10^{44} \frac{\mathrm{erg}}{\mathrm{s}}$ for the source, respectively. Based on its compact, point-like appearance, its positions in color-color and $M_{\mathrm{UV}}$-size diagrams and the SED analysis, we tentatively conclude that this object could be a faint quasar-like object, i.e., an extreme emission line object whose nebular emission is boosted by an active galactic nucleus (AGN). We discuss various alternative origins for the object's emission features, including a massive star cluster, a cluster of Population III, supermassive, or dark stars, or a direct-collapse black hole. Although populations of red galaxies at similar photometric redshifts have been detected with JWST, this object is unique in that its high-redshift nature is corroborated geometrically by lensing, that it is unresolved despite being magnified -- and thus intrinsically even more compact -- and that it occupies notably distinct regions in both size-luminosity and color-color space. The planned UNCOVER JWST/NIRSpec observations (scheduled in Cycle 1) will enable a more detailed analysis of this object.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Rogier A. Windhorst
Seth H. Cohen
Rolf A. Jansen
Jake Summers
Scott Tompkins
Christopher J. Conselice
Simon P. Driver
Haojing Yan
Dan Coe
Brenda Frye
Norman Grogin
Anton Koekemoer
Madeline A. Marshall
Rosalia O'Brien
Nor Pirzkal
Aaron Robotham
Russell E. Ryan,
Christopher N. A. Willmer
Timothy Carleton
Jose M. Diego
Abstract： We give an overview and describe the rationale, methods, and first results from NIRCam images of the JWST "Prime Extragalactic Areas for Reionization and Lensing Science" ("PEARLS") project. PEARLS uses up to eight NIRCam filters to survey several prime extragalactic survey areas: two fields at the North Ecliptic Pole (NEP); seven gravitationally lensing clusters; two high redshift proto-clusters; and the iconic backlit VV 191 galaxy system to map its dust attenuation. PEARLS also includes NIRISS spectra for one of the NEP fields and NIRSpec spectra of two high-redshift quasars. The main goal of PEARLS is to study the epoch of galaxy assembly, AGN growth, and First Light. Five fields, the JWST NEP Time-Domain Field (TDF), IRAC Dark Field (IDF), and three lensing clusters, will be observed in up to four epochs over a year. The cadence and sensitivity of the imaging data are ideally suited to find faint variable objects such as weak AGN, high-redshift supernovae, and cluster caustic transits. Both NEP fields have sightlines through our Galaxy, providing significant numbers of very faint brown dwarfs whose proper motions can be studied. Observations from the first spoke in the NEP TDF are public. This paper presents our first PEARLS observations, their NIRCam data reduction and analysis, our first object catalogs, the 0.9-4.5 $\mu$m galaxy counts and Integrated Galaxy Light. We assess the JWST sky brightness in 13 NIRCam filters, yielding our first constraints to diffuse light at 0.9-4.5 {\mu}m. PEARLS is designed to be of lasting benefit to the community.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Tiger Yu-Yang Hsiao
Dan Coe
Abdurro'uf
Lily Whitler
Intae Jung
Gourav Khullar
Ashish Kumar Meena
Pratika Dayal
Kirk S. S. Barrow
Lillian Santos-Olmsted
Adam Casselman
Eros Vanzella
Mario Nonino
Yolanda Jimenez-Teja
Masamune Oguri
Daniel P. Stark
Lukas J. Furtak
Adi Zitrin
Angela Adamo
Gabriel Brammer
Abstract： MACS0647$-$JD is a triply-lensed $z\sim11$ galaxy originally discovered with the Hubble Space Telescope. Here we report new JWST imaging, which clearly resolves MACS0647$-$JD as having two components that are either merging galaxies or stellar complexes within a single galaxy. Both are very small, with stellar masses $\sim10^8\,M_\odot$ and radii $r<100\,\rm pc$. The brighter larger component "A" is intrinsically very blue ($\beta\sim-2.6$), likely due to very recent star formation and no dust, and is spatially extended with an effective radius $\sim70\,\rm pc$. The smaller component "B" appears redder ($\beta\sim-2$), likely because it is older ($100-200\,\rm Myr$) with mild dust extinction ($A_V\sim0.1\,\rm mag$), and a smaller radius $\sim20\,\rm pc$. We identify galaxies with similar colors in a high-redshift simulation, finding their star formation histories to be out of phase. With an estimated stellar mass ratio of roughly 2:1 and physical projected separation $\sim400\,\rm pc$, we may be witnessing a galaxy merger 400 million years after the Big Bang. We also identify a candidate companion galaxy C $\sim3\,{\rm kpc}$ away, likely destined to merge with galaxies A and B. The combined light from galaxies A+B is magnified by factors of $\sim$8, 5, and 2 in three lensed images JD1, 2, and 3 with F356W fluxes $\sim322$, $203$, $86\,\rm nJy$ (AB mag 25.1, 25.6, 26.6). MACS0647$-$JD is significantly brighter than other galaxies recently discovered at similar redshifts with JWST. Without magnification, it would have AB mag 27.3 ($M_{UV}=-20.4$). With a high confidence level, we obtain a photometric redshift of $z=10.6\pm0.3$ based on photometry measured in 6 NIRCam filters spanning $1-5\rm\mu m$, out to $4300\,\r{A}$ rest-frame. JWST NIRSpec observations planned for January 2023 will deliver a spectroscopic redshift and a more detailed study of the physical properties of MACS0647$-$JD.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Massimo Pascale
Brenda L. Frye
Jose Diego
Lukas J. Furtak
Adi Zitrin
Tom Broadhurst
Christopher J. Conselice
Liang Dai
Leonardo Ferreira
Nathan J. Adams
Jeremy Lim
Ashish K. Meena
Stephen M. Wilkins
Rachana Bhatawdekar
Nicholas Foo
Patrick Kelly
Wenlei Chen
Patrick Kamieneski
Rogier A. Windhorst
Abstract： The first deep field images from the James Webb Space Telescope (JWST) of the galaxy cluster SMACS~J0723.3-7327 reveal a wealth of new lensed images at uncharted infrared wavelengths, with unprecedented depth and resolution. Here we securely identify 14 new sets of multiply imaged galaxies totalling 42 images, adding to the five sets of bright and multiply-imaged galaxies already known from Hubble Space Telescope data. We find examples of arcs crossing critical curves, allowing detailed community follow-up, such as JWST spectroscopy for precise redshift determinations, and measurements of the chemical abundances and of the detailed internal gas dynamics of very distant, young galaxies. One such arc contains a pair of compact knots that are magnified by a factor of hundreds, and features a microlensed transient. We also detect an Einstein cross candidate only visible thanks to JWST's superb resolution. Our parametric lens model is available through the following link: https://www.dropbox.com/sh/gwup2lvks0jsqe5/AAC2RRSKce0aX-lIFCc9vhBXa?dl=0, and will be regularly updated using additional spectroscopic redshifts. The model is constrained by 16 of these sets of multiply imaged galaxies, three of which have spectroscopic redshifts, and reproduces the multiple images to better than an rms of $0.5^{\prime \prime}$, allowing for accurate magnification estimates of high-redshift galaxies. The intracluster light extends beyond the cluster members, exhibiting large-scale features that suggest a significant past dynamical disturbance. This work represents a first taste of the enhanced power JWST will have for lensing-related science.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Rachel Bezanson
Ivo Labbe
Katherine E. Whitaker
Joel Leja
Sedona H. Price
Marijn Franx
Gabe Brammer
Danilo Marchesini
Adi Zitrin
Bingjie Wang
John R. Weaver
Lukas J. Furtak
Hakim Atek
Dan Coe
Sam E. Cutler
Pratika Dayal
Pieter van Dokkum
Robert Feldmann
Natascha Forster Schreiber
Seiji Fujimoto
Abstract： In this paper we describe the survey design for the Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization (UNCOVER) Cycle 1 JWST Treasury program, which executed its early imaging component in November 2022. The UNCOVER survey includes ultradeep ($\sim29-30\mathrm{AB}$) imaging of $\sim$45 arcmin$^2$ on and around the well-studied Abell 2744 galaxy cluster at $z=0.308$ and will follow-up ${\sim}500$ galaxies with extremely deep low-resolution spectroscopy with the NIRSpec/PRISM during the summer of 2023. We describe the science goals, survey design, target selection, and planned data releases. We also present and characterize the depths of the first NIRCam imaging mosaic, highlighting previously unparalleled resolved and ultradeep 2-4 micron imaging of known objects in the field. The UNCOVER primary NIRCam mosaic spans 28.8 arcmin$^2$ in seven filters (F115W, F150W, F200W, F277W, F356W, F410M, F444W) and 16.8 arcmin$^2$ in our NIRISS parallel (F115W, F150W, F200W, F356W, and F444W). To maximize early community use of the Treasury data set, we publicly release full reduced mosaics of public JWST imaging including 45 arcmin$^2$ NIRCam and 17 arcmin$^2$ NIRISS mosaics on and around the Abell 2744 cluster, including the Hubble Frontier Field primary and parallel footprints.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Ashish Kumar Meena
Wenlei Chen
Adi Zitrin
Patrick L. Kelly
Miriam Golubchik
Rui Zhou
Amruth Alfred
Tom Broadhurst
Jose M. Diego
Masamune Oguri
Liliya L. R. Williams
Alexei V. Filippenko
Sung Kei Li
Abstract： We report the discovery of a transient seen in a strongly lensed arc at redshift $z_{\rm s}=1.2567$ in \emph{Hubble Space Telescope} imaging of the Abell 370 galaxy cluster. The transient is detected at $29.51\pm0.14$ AB mag in a WFC3/UVIS F200LP difference image made using observations from two different epochs, obtained in the framework of the \emph{Flashlights} program, and is also visible in the F350LP band ($m_{\rm F350LP}\sim30.53$ AB). The transient is observed on the negative-parity side of the critical curve at a distance of $\sim 0.6''$ from it, greater than previous examples of lensed stars. The large distance from the critical curve yields a significantly smaller macro-magnification, but our simulations show that bright, O/B-type supergiants can reach sufficiently high magnifications to be seen at the observed position and magnitude. In addition, the observed transient image is a trailing image with an observer-frame time delay of $\sim+0.8$ days from its expected counterpart, so that any transient lasting for longer than that should have also been seen on the minima side and is thus excluded. This, together with the blue color we measure for the transient ($m_{\rm F200LP} - m_{\rm F350LP} \sim [-0.7,-1]$ AB mag), rules out most other transient candidates such as (kilo)novae, for example, and makes a lensed star the prime candidate. Assuming the transient is indeed a lensed star as suggested, many more such events should be detected in the near future in cluster surveys with the \emph{Hubble Space Telescope} and \emph{James Webb Space Telescope}.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Miriam Golubchik
Adi Zitrin
Justin Pierel
Lukas J. Furtak
Ashish K. Meena
Or Graur
Patrick L. Kelly
Dan Coe
Felipe Andrade-Santos
Maor Asif
Larry D. Bradley
Wenlei Chen
Brenda L. Frye
Sebastian Gomez
Saurabh Jha
Guillaume Mahler
Mario Nonino
Louis-Gregory Strolger
Yuanyuan Su
Abstract： The Reionization Cluster Survey (RELICS) imaged 41 galaxy clusters with the Hubble Space Telescope (HST), in order to detect lensed and high-redshift galaxies. Each cluster was imaged to about 26.5 AB mag in three optical and four near-infrared bands, taken in two distinct visits separated by varying time intervals. We make use of the multiple near-infrared epochs to search for transient sources in the cluster fields, with the primary motivation of building statistics for bright caustic crossing events in gravitational arcs. Over the whole sample, we do not find any significant ($\gtrsim5 \sigma$) caustic crossing events, in line with expectations from semi-analytic calculations but in contrast to what may be naively expected from previous detections of some bright events, or from deeper transient surveys that do find high rates of such events. Nevertheless, we find six prominent supernova (SN) candidates over the 41 fields: three of them were previously reported and three are new ones reported here for the first time. Out of the six candidates, four are likely core-collapse (CC) SNe -- three in cluster galaxies, and among which only one was known before, and one slightly behind the cluster at $z\sim0.6-0.7$. The other two are likely Ia -- both of them previously known, one probably in a cluster galaxy, and one behind it at $z\simeq2$. Our study supplies empirical bounds for the rate of caustic crossing events in galaxy cluster fields to typical HST magnitudes, and lays the groundwork for a future SN rate study.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Seiji Fujimoto
Kotaro Kohno
Masami Ouchi
Masamune Oguri
Vasily Kokorev
Gabriel Brammer
Fengwu Sun
Franz E. Bauer
Gabriel B. Caminha
Bunyo Hatsukade
Johan Richard
Ian Smail
Akiyoshi Tsujita
Yoshihiro Ueda
Ryosuke Uematsu
Adi Zitrin
Dan Coe
Jean-Paul Kneib
Marc Postman
Keiichi Umetsu
Abstract： We present a statistical study of 180 dust continuum sources identified in 33 massive cluster fields by the ALMA Lensing Cluster Survey (ALCS) over a total of 133 arcmin$^{2}$ area, homogeneously observed at 1.2 mm. ALCS enables us to detect extremely faint mm sources by lensing magnification, including near-infrared (NIR) dark objects showing no counterparts in existing {\it Hubble Space Telescope} and {\it Spitzer} images. The dust continuum sources belong to a blind sample ($N=141$) with S/N $\gtrsim$ 5.0 (a purity of $>$ 0.99) or a secondary sample ($N=39$) with S/N= $4.0-5.0$ screened by priors. With the blind sample, we securely derive 1.2-mm number counts down to $\sim7$ $\mu$Jy, and find that the total integrated 1.2mm flux is 20.7$^{+8.5}_{-6.5}$ Jy deg$^{-2}$, resolving $\simeq$ 80 % of the cosmic infrared background light. The resolved fraction varies by a factor of $0.6-1.1$ due to the completeness correction depending on the spatial size of the mm emission. We also derive infrared (IR) luminosity functions (LFs) at $z=0.6-7.5$ with the $1/V_{\rm max}$ method, finding the redshift evolution of IR LFs characterized by positive luminosity and negative density evolution. The total (=UV+IR) cosmic star-formation rate density (SFRD) at $z>4$ is estimated to be $161^{+25}_{-21}$ % of the established measurements, which were almost exclusively based on optical$-$NIR surveys. Although our general understanding of the cosmic SFRD is unlikely to change beyond a factor of 2, these results add to the weight of evidence for an additional ($\approx 60$ %) SFRD component contributed by the faint-mm population, including NIR dark objects.
Peer Review Status:Awaiting Review
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