- ID:
- ivo://CDS.VizieR/J/ApJ/765/9
- Title:
- Predicted CO and [CII] fluxes of HUDF galaxies
- Short Name:
- J/ApJ/765/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Modern (sub-)millimeter/radio interferometers such as ALMA, JVLA, and the PdBI successor NOEMA will enable us to measure the dust and molecular gas emission from galaxies that have luminosities lower than the Milky Way, out to high redshifts and with unprecedented spatial resolution and sensitivity. This will provide new constraints on the star formation properties and gas reservoir in galaxies throughout cosmic times through dedicated deep field campaigns targeting the CO/[C II] lines and dust continuum emission in the (sub-)millimeter regime. In this paper, we present empirical predictions for such line and continuum deep fields. We base these predictions on the deepest available optical/near-infrared Advanced Camera for Surveys and NICMOS data on the Hubble Ultra Deep Field (over an area of about 12arcmin^2^). Using a physically motivated spectral energy distribution model, we fit the observed optical/near-infrared emission of 13099 galaxies with redshifts up to z=5, and obtain median-likelihood estimates of their stellar mass, star formation rate, dust attenuation, and dust luminosity. We combine the attenuated stellar spectra with a library of infrared emission models spanning a wide range of dust temperatures to derive statistical constraints on the dust emission in the infrared and (sub-)millimeter which are consistent with the observed optical/near-infrared emission in terms of energy balance. This allows us to estimate, for each galaxy, the (sub-)millimeter continuum flux densities in several ALMA, PdBI/NOEMA, and JVLA bands. As a consistency check, we verify that the 850{mu}m number counts and extragalactic background light derived using our predictions are consistent with previous observations. Using empirical relations between the observed CO/[C II] line luminosities and the infrared luminosity of star-forming galaxies, we infer the luminosity of the CO(1-0) and [C II] lines from the estimated infrared luminosity of each galaxy in our sample.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/797/138
- Title:
- Properties of SMG lens candidates
- Short Name:
- J/ApJ/797/138
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Keck-Adaptive Optics and Hubble Space Telescope high resolution near-infrared (IR) imaging for 500{mu}m bright candidate lensing systems identified by the Herschel Multi-tiered Extragalactic Survey and Herschel Astrophysical Terahertz Large Area Survey. Out of 87 candidates with near-IR imaging, 15 (~17%) display clear near-IR lensing morphologies. We present near-IR lens models to reconstruct and recover basic rest-frame optical morphological properties of the background galaxies from 12 new systems. Sources with the largest near-IR magnification factors also tend to be the most compact, consistent with the size bias predicted from simulations and previous lensing models for submillimeter galaxies (SMGs). The rest-frame optical properties of our sample of Herschel-selected lensed SMGs are consistent with those of unlensed SMGs, which suggests that the two populations are similar.
- ID:
- ivo://CDS.VizieR/J/MNRAS/413/2314
- Title:
- Radio and mid-IR counterpart of submm galaxies
- Short Name:
- J/MNRAS/413/2314
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present radio and infrared (3.6-24um) counterparts to submillimetre galaxies (SMGs) detected in the Extended Chandra Deep Field-South with the Large APEX Bolometer Camera (LABOCA) 870um bolometer camera on the 12m Atacama Pathfinder Experiment. Using the Very Large Array at .4GHz and Spitzer, we have identified secure counterparts to 79 of the 126 SMGs [signal-to-noise ratio (S/N)>3.7, S870>4.4mJy] in the field, 62 via their radio and/or 24um emission, the remainder using a colour-flux cut on Infrared Array Camera 3.6um and 5.8um sources chosen to maximize the number of secure, coincident radio and 24um counterparts.
- ID:
- ivo://CDS.VizieR/J/ApJ/886/48
- Title:
- Radio & opt/NIR counterparts of S2COSMOS submm galaxies
- Short Name:
- J/ApJ/886/48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify multi-wavelength counterparts to 1147 submillimeter sources from the S2COSMOS SCUBA-2 survey of the COSMOS field by employing a recently developed radio+machine-learning method trained on a large sample of Atacama Large Millimeter/submillimeter Array (ALMA)-identified submillimeter galaxies (SMGs), including 260 SMGs identified in the AS2COSMOS pilot survey. In total, we identify 1222 optical/near-infrared (NIR)/radio counterparts to the 897 S2COSMOS submillimeter sources with S_850_>1.6mJy, yielding an overall identification rate of (78+/-9)%. We find that (22+/-5)% of S2COSMOS sources have multiple identified counterparts. We estimate that roughly 27% of these multiple counterparts within the same SCUBA-2 error circles very likely arise from physically associated galaxies rather than line-of-sight projections by chance. The photometric redshift of our radio+machine-learning-identified SMGs ranges from z=0.2 to 5.7 and peaks at z=2.3+/-0.1. The AGN fraction of our sample is (19+/-4)%, which is consistent with that of ALMA SMGs in the literature. Comparing with radio/NIR-detected field galaxy population in the COSMOS field, our radio+machine-learning-identified counterparts of SMGs have the highest star formation rates and stellar masses. These characteristics suggest that our identified counterparts of S2COSMOS sources are a representative sample of SMGs at z<~3. We employ our machine-learning technique to the whole COSMOS field and identified 6877 potential SMGs, most of which are expected to have submillimeter emission fainter than the confusion limit of our S2COSMOS surveys (S_850um_<~1.5mJy). We study the clustering properties of SMGs based on this statistically large sample, finding that they reside in high-mass dark matter halos ((1.2+/-0.3)x10^13^h^-1^M_{sun}_), which suggests that SMGs may be the progenitors of massive ellipticals we see in the local universe.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A35
- Title:
- Radio spectra of HDF850.1
- Short Name:
- J/A+A/562/A35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New high-resolution maps with the IRAM interferometer of the redshifted C+ 158um line and the 0.98mm dust continuum of HDF850.1 at z=5.185 show the source to have a blueshifted northern component and a redshifted southern component, with a projected separation of 0.3", or 2kpc. We interpret these components as primordial galaxies that are merging to form a larger galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/820/82
- Title:
- S2CLS: multiwavelength counterparts to SMGs
- Short Name:
- J/ApJ/820/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multiwavelength identifications for the counterparts of 1088 submillimeter sources detected at 850{mu}m in the SCUBA-2 Cosmology Legacy Survey (S2CLS) study of the UKIRT Infrared Deep Sky Survey-Ultra-Deep Survey (UDS) field. By utilizing an Atacama Large Millimeter Array (ALMA) pilot study on a subset of our bright SCUBA-2 sample as a training set, along with the deep optical-near-infrared (OIR) data available in this field, we develop a novel technique, Optical-IR Triple Color (OIRTC), using z-K, K-[3.6], [3.6]-[4.5] colors to select the candidate submillimeter galaxy (SMG) counterparts. By combining radio identification and the OIRTC technique, we find counterpart candidates for 80% of the Class = 1 >=4{sigma} SCUBA-2 sample, defined as those that are covered by both radio and OIR imaging and the base sample for our scientific analyses. Based on the ALMA training set, we expect the accuracy of these identifications to be 82%+/-20%, with a completeness of 69%+/-16%, essentially as accurate as the traditional p-value technique but with higher completeness. We find that the fraction of SCUBA-2 sources having candidate counterparts is lower for fainter 850{mu}m sources, and we argue that for follow-up observations sensitive to SMGs with S_850_>~1mJy across the whole ALMA beam, the fraction with multiple counterparts is likely to be >40% for SCUBA-2 sources at S_850_>~4mJy. We find that the photometric redshift distribution for the SMGs is well fit by a lognormal distribution, with a median redshift of z=2.3+/-0.1. After accounting for the sources without any radio and/or OIRTC counterpart, we estimate the median redshift to be z=2.6+/-0.1 for SMGs with S_850_>1mJy. We also use this new large sample to study the clustering of SMGs and the far-infrared properties of the unidentified submillimeter sources by stacking their Herschel SPIRE far-infrared emission.
- ID:
- ivo://CDS.VizieR/J/MNRAS/436/430
- Title:
- SCUBA-2 cosmology legacy survey
- Short Name:
- J/MNRAS/436/430
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the multiwavelength properties of a sample of 450-{mu}m-selected sources from the SCUBA-2 Cosmology Legacy Survey. A total of 69 sources were identified above 4{sigma} in deep SCUBA-2 450-{mu}m observations overlapping the UDS and COSMOS fields and covering 210arcmin^2^ to a typical depth of {sigma}_450_=1.5mJy. Reliable cross-identifications are found for 58 sources (84 percent) in Spitzer and Hubble Space Telescope WFC3/IR data. The photometric redshift distribution (dN/dz) of 450-{mu}m-selected sources is presented, showing a broad peak in the redshift range 1<z<3 and a median of z=1.4. Combining the SCUBA-2 photometry with Herschel SPIRE data from HerMES, the submm spectral energy distribution (SED) is examined via the use of modified blackbody fits, yielding aggregate values for the IR luminosity, dust temperature and emissivity of <L_IR_>=10^12^+/-0.8L_{sun}_, <T_D_>=42+/-11K and <{beta}_D_>=1.6+/-0.5, respectively. The relationship between these SED parameters and the physical properties of galaxies is investigated, revealing correlations between T_D_ and L_IR_ and between {beta}D and both stellar mass and effective radius. The connection between the star formation rate (SFR) and stellar mass is explored, with 24 percent of 450-{mu}m sources found to be `starbursts', i.e. displaying anomalously high specific SFRs. However, both the number density and observed properties of these `starburst' galaxies are found to be consistent with the population of normal star-forming galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/1789
- Title:
- SCUBA-2 Cosmology Legacy Survey
- Short Name:
- J/MNRAS/465/1789
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of ~3000 submillimetre sources detected (>=3.5{sigma}) at 850um over ~5deg^2^ surveyed as part of the James Clerk Maxwell Telescope (JCMT) SCUBA-2 Cosmology Legacy Survey (S2CLS). This is the largest survey of its kind at 850um, increasing the sample size of 850um selected submillimetre galaxies by an order of magnitude. The wide 850um survey component of S2CLS covers the extragalactic fields: UKIDSS-UDS, COSMOS, Akari-NEP, Extended Groth Strip, Lockman Hole North, SSA22 and GOODS-North. The average 1{sigma} depth of S2CLS is 1.2mJy/beam, approaching the SCUBA-2 850um confusion limit, which we determine to be {sigma}_c_~=0.8mJy/beam. We measure the 850um number counts, reducing the Poisson errors on the differential counts to approximately 4 per cent at S850~=3mJy. With several independent fields, we investigate field-to-field variance, finding that the number counts on 0.5{deg}-1{deg} scales are generally within 50 per cent of the S2CLS mean for S850>3mJy, with scatter consistent with the Poisson and estimated cosmic variance uncertainties, although there is a marginal (2{sigma}) density enhancement in GOODS-North. The observed counts are in reasonable agreement with recent phenomenological and semi-analytic models, although determining the shape of the faint-end slope (S850<3mJy) remains a key test. The large solid angle of S2CLS allows us to measure the bright-end counts: at S850>10mJy there are approximately 10 sources per square degree, and we detect the distinctive up-turn in the number counts indicative of the detection of local sources of 850um emission, and strongly lensed high-redshift galaxies. All calibrated maps and the catalogue are made publicly available at https://zenodo.org/record/57792#.W41TsRg68eM .
- ID:
- ivo://CDS.VizieR/J/MNRAS/464/3369
- Title:
- SCUBA-2 EGS deep field
- Short Name:
- J/MNRAS/464/3369
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep observations at 450 and 850{mu}m in the Extended Groth Strip field taken with the SCUBA-2 camera mounted on the James Clerk Maxwell Telescope as part of the deep SCUBA-2 Cosmology Legacy Survey (S2CLS), achieving a central instrumental depth of {sigma}_450_=1.2mJy/beam and {sigma}_850_=0.2mJy/beam. We detect 57 sources at 450{mu}m and 90 at 850{mu}m with signal-to-noise ratio >3.5 over ~70arcmin^2^. From these detections, we derive the number counts at flux densities S_450_>4.0mJy and S_850_>0.9mJy, which represent the deepest number counts at these wavelengths derived using directly extracted sources from only blank-field observations with a single-dish telescope. Our measurements smoothly connect the gap between previous shallower blank-field single-dish observations and deep interferometric ALMA results. We estimate the contribution of our SCUBA-2 detected galaxies to the cosmic infrared background (CIB), as well as the contribution of 24{mu}m-selected galaxies through a stacking technique, which add a total of 0.26+/-0.03 and 0.07+/-0.01MJy/sr, at 450 and 850{mu}m, respectively. These surface brightnesses correspond to 60+/-20 and 50+/-20 per cent of the total CIB measurements, where the errors are dominated by those of the total CIB. Using the photometric redshifts of the 24{mu}m-selected sample and the redshift distributions of the submillimetre galaxies, we find that the redshift distribution of the recovered CIB is different at each wavelength, with a peak at z~1 for 450{mu}m and at z~2 for 850{mu}m, consistent with previous observations and theoretical models.
- ID:
- ivo://CDS.VizieR/J/MNRAS/458/4321
- Title:
- SCUBA-2 galaxies in 850um survey
- Short Name:
- J/MNRAS/458/4321
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the properties of the galaxies selected from the deepest 850-{mu}m survey undertaken to date with (Submillimetre Common-User Bolometer Array 2) SCUBA-2 on the James Clerk Maxwell Telescope as part of the SCUBA-2 Cosmology Legacy Survey. A total of 106 sources (>5{sigma}) were uncovered at 850{mu}m from an area of ~=150 arcmin^2^ in the centre of the COSMOS/UltraVISTA/Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) field, imaged to a typical depth of {sigma}_850_~=0.25mJy. We utilize the available multifrequency data to identify galaxy counterparts for 80 of these sources (75 per cent), and to establish the complete redshift distribution for this sample, yielding . We have also been able to determine the stellar masses of the majority of the galaxy identifications, enabling us to explore their location on the star formation rate:stellar mass (SFR:M*) plane. Crucially, our new deep 850-{mu}m-selected sample reaches flux densities equivalent to SFR~=100M_{sun}_/yr, enabling us to confirm that sub-mm galaxies form the high-mass end of the 'main sequence' (MS) of star-forming galaxies at z>1.5 (with a mean specific SFR of sSFR=2.25+/-0.19Gyr^-1^ at z~=2.5). Our results are consistent with no significant flattening of the MS towards high masses at these redshifts. However, our results add to the growing evidence that average sSFR rises only slowly at high redshift, resulting in log_10_sSFR being an apparently simple linear function of the age of the Universe.