Bound star clusters observed in a lensed galaxy 460 Myr after the Big Bang
Angela Adamo, Larry D. Bradley, Eros Vanzella, Adélaïde Claeyssens, Brian Welch, Jose M Diego, Guillaume Mahler, Masamune Oguri, Keren Sharon, Abdurro'uf, Tiger… 展开作者
Angela Adamo, Larry D. Bradley, Eros Vanzella, Adélaïde Claeyssens, Brian Welch, Jose M Diego, Guillaume Mahler, Masamune Oguri, Keren Sharon, Abdurro'uf, Tiger Yu-Yang Hsiao, Xinfeng Xu, Matteo Messa, Augusto E. Lassen, Erik Zackrisson, Gabriel Brammer, Dan Coe, Vasily Kokorev, Massimo Ricotti, Adi Zitrin, Seiji Fujimoto, Akio K. Inoue, Tom Resseguier, Jane R. Rigby, Yolanda Jiménez-Teja, Rogier A. Windhorst, Takuya Hashimoto, Yoichi Tamura
The Cosmic Gems arc is among the brightest and highly magnified galaxies observed at redshift $z\sim10.2$. However, it is an intrinsically UV faint galaxy, in the range of those now thought to drive the reionization of the Universe. Hitherto the smallest features resolved in a galaxy at a comparable redshift are between a few hundreds and a few tens of parsecs. Here we report JWST observations of the Cosmic Gems. The light of the galaxy is resolved into five star clusters located in a region smaller than 70 parsec. They exhibit minimal dust attenuation and low metallicity, ages younger than 50 Myr and intrinsic masses of $\sim10^6$ M$_{\odot}$. Their lensing-corrected sizes are approximately 1 pc, resulting in stellar surface densities near $10^5$~M$_{\odot}$/pc$^2$, three orders of magnitude higher than typical young star clusters in the local universe. Despite the uncertainties inherent to the lensing model, they are consistent with being gravitationally bound stellar systems, i.e., proto-globular clusters. We conclude that star cluster formation and feedback likely contributed to shape the properties of galaxies during the epoch of reionization. [Abridged]
While most of the inter-galactic medium (IGM) today is permeated by ionized hydrogen, it was largely filled with neutral hydrogen for the first 700 million years after the Big Bang. The process that ionized the IGM (cosmic reionization) is expected to be spatially inhomogeneous, with fainter galaxies playing a significant role. However, we still have only a few direct constraints on the reionization process. Here we report the first spectroscopic confirmation of two galaxies and very likely a third galaxy in a group (hereafter EGS77) at redshift z = 7.7, merely 680 Myrs after the Big Bang. The…
We develop a new method to infer the temporal, geometric, and energetic properties of galaxy outflows, by combining stellar spectral modeling to infer starburst ages, and absorption lines to measure velocities. If winds are accelerated with time during a starburst event, then these two measurements enable us to solve for the wind radius, similarly to length scales and the Hubble parameter in Big Bang cosmology. This wind radius is the vital, but hard-to-constrain parameter in wind physics. We demonstrate the method using spectra of 87 starburst galaxies at z=0.05-0.44, finding that winds accel…
With JWST, new opportunities to study the evolution of galaxies in the early Universe are emerging. Spitzer constraints on rest-optical properties of $z\gtrsim7$ galaxies demonstrated the power of using galaxy stellar masses and star formation histories (SFHs) to indirectly infer the cosmic star formation history. However, only the brightest individual $z\gtrsim8$ objects could be detected with Spitzer, making it difficult to robustly constrain activity at $z\gtrsim10$. Here, we leverage the greatly improved rest-optical sensitivity of JWST at $z\gtrsim8$ to constrain the ages of seven UV-brig…
Galaxies throughout the last 12 Gyr of cosmic time follow a single, universal relation that connects their star-formation rates (SFRs), stellar masses ($M_\star$) and chemical abundances. Deviation from these fundamental scaling relations would imply a drastic change in the processes that regulate galaxy evolution. Observations have hinted at the possibility that this relation may be broken in the very early universe. However, until recently, chemical abundances of galaxies could be only measured reliably as far back as redshift $z=3.3$. With JWST, we can now characterize the SFR, $M_\star$, a…
The most distant galaxies known are at z~10-11, observed 400-500 Myr after the Big Bang. The few z~10-11 candidates discovered to date have been exceptionally small- barely resolved, if at all, by the Hubble Space Telescope. Here we present the discovery of SPT0615-JD, a fortuitous z~10 (z_phot=9.9+/-0.6) galaxy candidate stretched into an arc over ~2.5" by the effects of strong gravitational lensing. Discovered in the Reionization Lensing Cluster Survey (RELICS) Hubble Treasury program and companion S-RELICS Spitzer program, this candidate has a lensed H-band magnitude of 25.7+/-0.1 AB mag. W…
We study the population of star-forming clumps in A521-sys1, a $\rm z=1.04$ system gravitationally lensed by the foreground ($\rm z=0.25$) cluster Abell 0521. The galaxy presents one complete counter--image with a mean magnification of $\rm μ\sim4$ and a wide arc containing two partial images of A521-sys1 with magnifications reaching $\rm μ>20$, allowing the investigations of clumps down to scales of $\rm R_{eff}<50$ pc. We identify 18 unique clumps with a total of 45 multiple images. Intrinsic sizes and UV magnitudes reveal clumps with elevated surface brightnesses, comparable to similar syst…
We investigate the blue and optical rest-frame sizes (lambda~2300A-4000A) of three compact star-forming regions in a galaxy at z=4 strongly lensed (x30, x45, x100) by the Hubble Frontier Field galaxy cluster A2744 using GLASS-ERS JWST/NIRISS imaging at 1.15um, 1.50mu and 2.0mu with PSF < 0.1". In particular, the Balmer break is probed in detail for all multiply-imaged sources of the system. With ages of a few tens of Myr, stellar masses in the range (0.7-4.0) x 10^6 Msun and optical/ultraviolet effective radii spanning the interval 3 < R_eff < 20 pc, such objects are currently the highest reds…
A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang. The abundance of star-forming galaxies is known to decline from redshifts of about 6 to 10, but a key question is the extent of star formation at even earlier times, corresponding to the period when the first galaxies might have emerged. Here we present spectroscopic observations of MACS1149-JD1, a gravitationally lensed galaxy observed when the Universe was less than four per cent of its present age. We detect an emis…
We present deep spectroscopic observations of a Lyman-break galaxy candidate (hereafter MACS1149-JD) at $z\sim9.5$ with the $\textit{Hubble}$ Space Telescope ($\textit{HST}$) WFC3/IR grisms. The grism observations were taken at 4 distinct position angles, totaling 34 orbits with the G141 grism, although only 19 of the orbits are relatively uncontaminated along the trace of MACS1149-JD. We fit a 3-parameter ($z$, F160W mag, and Ly$α$ equivalent width) Lyman-break galaxy template to the three least contaminated grism position angles using an MCMC approach. The grism data alone are best fit with …
We present the results of combined deep Keck/NIRC2, HST/WFC3 near-infrared and Herschel far infrared observations of an extremely star forming dusty lensed galaxy identified from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS J133542.9+300401). The galaxy is gravitationally lensed by a massive WISE identified galaxy cluster at $z\sim1$. The lensed galaxy is spectroscopically confirmed at $z=2.685$ from detection of $\rm {CO (1 \rightarrow 0)}$ by GBT and from detection of $\rm {CO (3 \rightarrow 2)}$ obtained with CARMA. We use the combined spectroscopic and imaging observatio…
We present the HST WFC3/F275W UV imaging observations of A2218-Flanking, a lensed compact dwarf galaxy at redshift $z\approx2.5$. The stellar mass of A2218-Flanking is $\log(M/M_{\odot}=9.14$ and SFR is 12.5$M_\odot$yr$^{-1}$ after correcting the magnification. This galaxy has a young galaxy age of 127 Myr and a compact galaxy size of $r_{1/2}=2.4$kpc. The HST UV imaging observations cover the rest-frame Lyman continuum (LyC) emission ($\sim800$Å) from A2218-Flanking. We firmly detect ($14σ$) the LyC emission in A2218-Flanking in the F275W image. Together with the HST F606W images, we find tha…
In this letter, we reconstruct the formation pathway of MRG-S0851, a massive, $\log M_*/M_\odot=11.02\pm0.04$, strongly lensed, red, galaxy at $z=1.883\pm0.001$. While the global photometry and spatially-resolved outskirts of MRG-S0851 imply an early-formation scenario with a slowly decreasing or constant star-formation history, a joint fit of 2D grism spectroscopy and photometry reveals a more complex scenario: MRG-S0851 is likely to be experiencing a centrally-concentrated rejuvenation in the inner $\sim$1 kpc in the last $\sim$100 Myr of evolution. We estimate $0.5\pm0.1\%$ of the total ste…
The upcoming $\textit{James Webb Space Telescope}$ ($\textit{JWST}$) will allow observations of high-redshift galaxies at fainter detection levels than ever before, and $\textit{JWST}$ surveys targeting gravitationally lensed fields are expected to bring $z\gtrsim 6$ objects with very low star formation rate (SFR) within reach of spectroscopic studies. As galaxies at lower and lower star formation activity are brought into view, many of the standard methods used in the analysis of integrated galaxy spectra are at some point bound to break down, due to violation of the assumptions of a well-sam…
We report the very bright detection of cold molecular gas with the IRAM NOEMA interferometer of the strongly lensed source WISE J132934.18+224327.3 at z=2.04, the so-called Cosmic Eyebrow. This source has a similar spectral energy distribution from optical-mid/IR to submm/radio but significantly higher fluxes than the well-known lensed SMG SMMJ 2135, the Cosmic Eyelash at z=2.3. The interferometric observations identify unambiguously the location of the molecular line emission in two components, component CO32-A with I_CO(3-2)=52.2+-0.9 Jy km s^-1 and component CO32-B with I_CO(3-2)=15.7+-0.7 …
Mirror images of lensed star clusters with mismatched spectral energy distributions: A possible signature of top-heavy stellar initial mass functions and extreme stars in high-redshift star clusters
Uppsala University（乌普萨拉大学）；Instituto de Física de Cantabria (CSIC-UC)（坎塔布里亚物理研究所（CSIC-UC））；Stockholm University（斯德哥尔摩大学）；Università degli studi di Padova（帕多瓦大学）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）
The first deep-field observations of the JWST have immediately yielded a surprisingly large number of very high redshift candidates, pushing the frontier of observability well beyond $z\gtrsim10$. We here present a detailed SED-fitting analysis of the 15 gravitationally lensed $z\sim10-16$ galaxy candidates detected behind the galaxy cluster SMACS J0723.3-7327 in Atek et al. (2022) using the BEAGLE tool. Our analysis makes use of dynamical considerations to place limits on the ages of these galaxies and of all three published SL models of the cluster to account for lensing systematics. We find…
We discovered Bowen emission arising from a strongly lensed (i.e., with magnification factor $μ$>20) source hosted in the Sunburst arc at z=2.37. We claim this source is plausibly a transient stellar object and study the unique ultraviolet lines emerging from it. In particular, narrow ($σ$_v ~ 40 km/s) ionisation lines of Fe fluoresce after being exposed to Lya radiation that pumps selectively their atomic levels. Data from VLT/MUSE, X-Shooter and ESPRESSO observations (the latter placed at the focus of the four UTs) at increasing spectral resolution of R=2500, 11400 and R=70000, respectively,…
We present COOL J1323+0343, an early-type galaxy at $z = 1.0153 \pm 0.0006$, strongly lensed by a cluster of galaxies at z = $z = 0.353 \pm 0.001$. This object was originally imaged by DECaLS and noted as a gravitational lens by COOL-LAMPS, a collaboration initiated to find strong-lensing systems in recent public optical imaging data, and confirmed with follow-up data. With ground-based grzH imaging and optical spectroscopy from the Las Campanas Observatory and the Nordic Optical Telescope, we derive a stellar mass, metallicity, and star-formation history from stellar-population synthesis mode…
Using the Australia Telescope Compact Array (ATCA), we conducted a survey of CO J=1-0 and J=2-1 line emission towards strongly lensed high-redshift dusty star forming galaxies (DSFGs) previously discovered with the South Pole Telescope (SPT). Our sample comprises 17 sources that had CO-based spectroscopic redshifts obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Atacama Pathfinder Experiment (APEX). We detect all sources with known redshifts in either CO J=1-0 or J=2-1. Twelve sources are detected in the 7-mm continuum. The derived CO luminosities imply gas masses…
We present a detailed spectroscopic analysis of a galaxy at $z \simeq 4.88$ that is, by chance, magnified $\sim 30 \times$ by gravitational lensing. Only three sources at $z \gtrsim 5$ are known with such high magnification. This particular source has been shown to exhibit widespread, high equivalent width CIV $λ$ 1549 Å emission, implying it is a unique example of a metal-poor galaxy with a hard radiation field, likely representing the galaxy population responsible for cosmic reionisation. Using UV nebular line ratio diagnostics, VLT/X-shooter observations rule out strong AGN activity, indica…
We report the detection of a massive neutral gas outflow in the z=2.09 gravitationally lensed Dusty Star-Forming Galaxy HATLASJ085358.9+015537 (G09v1.40), seen in absorption with the OH+(1_1-1_0) transition using spatially resolved (0.5"x0.4") Atacama Large Millimeter/submillimeter Array (ALMA) observations. The blueshifted OH+ line is observed simultaneously with the CO(9-8) emission line and underlying dust continuum. These data are complemented by high angular resolution (0.17"x0.13") ALMA observations of CH+(1-0) and underlying dust continuum, and Keck 2.2 micron imaging tracing the stella…
A Glimpse of the Stellar Populations and Elemental Abundances of Gravitationally Lensed, Quiescent Galaxies at $z\gtrsim 1$ with Keck Deep Spectroscopy
We present ALMA detections of the [NII] 205$μ$m and CO(12-11) emission lines, and the tentative detection of [CI] $^3$P$_1$ - $^3$P$_0$ for the strongly lensed ($μ$=5.7$\pm$0.5) dusty, star-forming galaxy SPT-S J213242-5802.9 (hereafter SPT2132-58) at z=4.77. The [NII] and CO(12-11) lines are detected at 11.5 and 8.5 $σ$ level, respectively, by our band-6 observations. The [CI] line is detected at 3.2 $σ$ after a re-analysis of existing band-3 data. The [CI] luminosity implies a gas mass of 3.8$\pm$1.2$\times$10$^{10}$ M$_\odot$, and consequently a very short depletion timescale of 34$\pm$13 M…
We report the discovery of a molecular wind signature from a massive intensely star-forming clump of a few $10^9$ Msun, in the strongly gravitationally lensed submillimeter galaxy "the Emerald" (PLCK_G165.7+49.0) at z=2.236. The Emerald is amongst the brightest high-redshift galaxies on the submillimeter sky, and was initially discovered with the Planck satellite. The system contains two magnificient structures with projected lengths of 28.5" and 21" formed by multiple, near-infrared arcs, falling behind a massive galaxy cluster at z=0.35, as well as an adjacent filament that has so far escape…
We report two secure ($z=3.775, 4.012$) and one tentative ($z\approx3.767$) spectroscopic confirmations of massive and quiescent galaxies through $K$-band observations with Keck/MOSFIRE and VLT/X-Shooter. The stellar continuum emission, the absence of strong nebular emission lines and the lack of significant far-infrared detections confirm the passive nature of these objects, disfavoring the alternative solution of low-redshift dusty star-forming interlopers. We derive stellar masses of $\mathrm{log}(M_{\star}/M_\odot)\sim11$ and ongoing star formation rates placing these galaxies $\gtrsim 1-2…
We report the detection of CO(1 - 0) line emission from seven Planck and Herschel selected hyper luminous (LIR(8-1000um) > 10^13Lsun) infrared galaxies with the Green Bank Telescope (GBT). CO(1 - 0) measurements are a vital tool to trace the bulk molecular gas mass across all redshifts. Our results place tight constraints on the total gas content of these most apparently luminous high-z star-forming galaxies (apparent IR luminosities of LIR > 10^(13-14) Lsun), while we confirm their predetermined redshifts measured using the Large Millimeter Telescope, LMT (zCO = 1.33 - 3.26). The CO(1 - 0) li…
We obtained ALMA spectroscopy and imaging to investigate the origin of the unexpected sub-mm emission toward the most distant quiescent galaxy known to date, ZF-COSMOS-20115 at z=3.717. We show here that this sub-mm emission is produced by another massive, compact and extremely obscured galaxy, located only 3.1 kpc away from the quiescent galaxy. We dub the quiescent and dusty galaxies Jekyll and Hyde, respectively. No dust emission is detected at the location of Jekyll, implying SFR < 13 Msun/yr, which is the most stringent upper limit ever obtained for a quiescent galaxy at these redshifts. …
We present a high-resolution kinematic study of the massive main-sequence star-forming galaxy (SFG) SDSS J090122.37+181432.3 (J0901) at z=2.259, using 0.36 arcsec ALMA CO(3-2) and 0.1-0.5 arcsec SINFONI/VLT H-alpha observations. J0901 is a rare, strongly-lensed but otherwise normal massive (log(M_star/M_sun)~11) main sequence SFG, offering a unique opportunity to study a typical massive SFG under the microscope of lensing. Through forward dynamical modeling incorporating lensing deflection, we fit the CO and H-alpha kinematics in the image plane out to about one disk effective radius (R_e ~ 4 …
We report the discovery of RG1M0150, a massive, recently quenched galaxy at z=2.636 that is multiply imaged by the cluster MACSJ0150.3-1005. We derive a stellar mass of log M_*=11.49+0.10-0.16 and a half-light radius of R_e,maj =1.8+-0.4 kpc. Taking advantage of the lensing magnification, we are able to spatially resolve a remarkably massive yet compact quiescent galaxy at z>2 in ground-based near-infrared spectroscopic observations using Magellan/FIRE and Keck/MOSFIRE. We find no gradient in the strength of the Balmer absorption lines over 0.6 R_e - 1.6 R_e, which are consistent with an age o…
We investigate the strongly lensed (μx10-100) Lyman continuum (LyC) galaxy, dubbed Sunburst, at z=2.37, taking advantage of a new accurate model of the lens. A characterization of the intrinsic (delensed) properties of the galaxy yields a size of ~3 sq.kpc, a luminosity Muv=-20.3,and a stellar mass M~10^9 Msun;16% of the ultraviolet light is located in a 3 Myr old gravitationally-bound young massive star cluster (YMC) with an effective radius of Re~8 pc and a dynamical mass of ~10^7 Msun (similar to the stellar mass), from which LyC radiation is detected (λ< 912A). The inferred outflowing gas …
High-redshift dusty star-forming galaxies with very high star formation rates (500 -- 3000 M$_{\odot}$ yr$^{-1}$) are key to understanding the formation of the most extreme galaxies in the early Universe. Characterising the gas reservoir of these systems can reveal the driving factor behind the high star formation. Using molecular gas tracers like high-J CO lines, neutral carbon lines and the dust continuum, we can estimate the gas density and radiation field intensity in their interstellar media. In this paper, we present high resolution ($\sim$0.4$^{\prime\prime}$) observations of CO(7-6), […
Lensed stars in galaxy-galaxy strong lensing -- a JWST prediction for the Cosmic Horseshoe
The University of Hong Kong（香港大学）；University of Portsmouth（朴茨茅斯大学）；Instituto de Física de Cantabria (CSIC-UC)（坎塔布里亚物理研究所（CSIC-UC））；University of Basque Country UPV/EHU（巴斯克大学）；Ikerbasque, Basque Foundation for Science（伊克尔巴斯基，巴斯克科学基金会）；Donostia International Physics Center（圣塞巴斯蒂安国际物理中心）；University of Minnesota（明尼苏达大学）；Universidade Federal do Rio Grande do Sul（南里奥格兰德联邦大学）
We present an analysis of all prime HST legacy fields spanning >800 arcmin^2 for the search of z~10 galaxy candidates and the study of their UV luminosity function (LF). In particular, we present new z~10 candidates selected from the full Hubble Frontier Field (HFF) dataset. Despite the addition of these new fields, we find a low abundance of z~10 candidates with only 9 reliable sources identified in all prime HST datasets that include the HUDF09/12, the HUDF/XDF, all the CANDELS fields, and now the HFF survey. Based on this comprehensive search, we find that the UV luminosity function decreas…
Deep rest-optical observations are required to accurately constrain the stellar populations of $z\sim8$ galaxies. Due to significant limitations in the availability of such data for statistically complete samples, observational results have been limited to modest numbers of bright or lensed sources. To revolutionize the present characterization of $z\sim8$ galaxies, we exploit the ultradeep ($\sim27$ mag, $3σ$) Spitzer/IRAC $3.6μ$m and $4.5μ$m data, probing the rest-frame optical at $z\sim8$, over $\sim200$ arcmin$^2$ of the GOODS fields from the recently completed GOODS Re-ionization Era wide…
Although observations of high-redshift quasars demonstrate that many supermassive black holes (BHs) reached large masses within one billion years after the Big Bang, the origin of the first BHs is still a mystery. A promising way to constrain the origin of the first BHs is to explore the average properties of $z\gtrsim6$ BHs. However, typical BHs remain hidden from X-ray surveys, which is due to their relatively faint nature and the limited sensitivity of X-ray telescopes. Gravitational lensing provides an attractive way to study this unique galaxy population as it magnifies the faint light fr…
Early steps in the hierarchical assembly of a Milky Way-mass galaxy 1 Gyr after the Big Bang
Dunlap Institute for Astronomy and Astrophysics（邓拉普天体物理与天文研究所）；Department of Astronomy and Physics and Institute for Computational Astrophysics, Saint Mary’s University（圣玛丽大学天文物理系及计算天体物理研究所）；Waseda Research Institute for Science and Engineering, Faculty of Science and Engineering, Waseda University（早稻田大学理工学部理工学研究科）；Kapteyn Astronomical Institute, University of Groningen（格罗宁根大学卡佩恩天文研究所）；Faculty of Mathematics and Physics, University of Ljubljana（卢布尔雅那大学数学物理学院）；Department of Physics and Astronomy, University of California Davis（加州大学戴维斯分校物理与天文学系）
We present rest-frame far-infrared (FIR) and optical observations of the host galaxy of GRB090423 at z=8.23 from the Atacama Large Millimeter Array (ALMA) and the Spitzer Space Telescope, respectively. The host remains undetected to 3-sigma limits of Fnu(222 GHz)<33 microJy and Fnu(3.6 micron)<81 nJy. The FIR limit is about 20 times fainter than the luminosity of the local ULIRG Arp220, and comparable to the local starburst M82. Comparing to model spectral energy distributions we place a limit on the IR luminosity of L_IR(8-1000 micron)<3e10 Lsun, corresponding to a limit on the obscured star …
LEGGOS: Direct abundances of N, O, Ne, S, and Ar in five lensed galaxies at Cosmic Noon
International Space Science Institute（国际空间科学研究所）；University of Washington（华盛顿大学）；University of Pittsburgh（匹兹堡大学）；NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；University of Maryland, Baltimore County（马里兰大学巴尔的摩县分校）；Center for Research and Exploration in Space Science and Technology（空间科学与技术研究探索中心）；University of Michigan（密歇根大学）；University of Cincinnati（辛辛那提大学）；University of Arizona（亚利桑那大学）；Eureka Scientific（尤里卡科学公司）
Galaxy clusters magnify background objects through strong gravitational lensing. Typical magnifications for lensed galaxies are factors of a few but can also be as high as tens or hundreds, stretching galaxies into giant arcs. Individual stars can attain even higher magnifications given fortuitous alignment with the lensing cluster. Recently, several individual stars at redshift $z \sim 1 - 1.5$ have been discovered, magnified by factors of thousands, temporarily boosted by microlensing. Here we report observations of a more distant and persistent magnified star at redshift $z_{\rm phot} = 6.2…
Spatially Resolved Physical Properties of Young Star Clusters and Star-forming Clumps in the Brightest z>6 Galaxy, the Strongly Lensed Cosmic Spear at z=6.2
Indiana University（印第安纳大学）；The Johns Hopkins University（约翰斯·霍普金斯大学）；Space Telescope Science Institute (STScI)（太空望远镜科学研究所）；Association of Universities for Research in Astronomy (AURA), Inc.（天体物理研究大学协会）；Northwestern University（西北大学）
(abridged) We present the IRAM-30m observations of multiple-J CO and CI line emission in a sample of redshift ~2-4 Herschel-ATLAS SMGs. A non-negligible effect of differential lensing is found for the CO emission lines, which could have caused significant underestimations of the linewidths, hence of the dynamical masses. The CO SLEDs are found to be similar to those of the local starburst-dominated ULIRGs and of the previously studied SMGs. After correcting for lensing amplification, we derived the global properties of the bulk of molecular gas in the SMGs using non-LTE radiative transfer mode…
