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5791. SCUBA-2 cosmology legacy survey
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.
5792. SCUBA-2 Cosmology Legacy Survey
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 .
5793. SCUBA-2 EGS deep field
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.
5794. SCUBA-2 galaxies in 850um survey
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.
5795. SCUBA-2 high-redshift galaxies sample
ID:
ivo://CDS.VizieR/J/ApJ/784/9
Title:
SCUBA-2 high-redshift galaxies sample
Short Name:
J/ApJ/784/9
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use the James Clerk Maxwell Telescope's SCUBA-2 camera to image a 400 arcmin^2^ area surrounding the GOODS-N field. The 850 {mu}m rms noise ranges from a value of 0.49 mJy in the central region to 3.5 mJy at the outside edge. From these data, we construct an 850 {mu}m source catalog to 2 mJy containing 49 sources detected above the 4{sigma} level. We use an ultradeep (11.5 {mu}Jy at 5{sigma}) 1.4 GHz image obtained with the Karl G. Jansky Very Large Array together with observations made with the Submillimeter Array to identify counterparts to the submillimeter galaxies. For most cases of multiple radio counterparts, we can identify the correct counterpart from new and existing Submillimeter Array data. We have spectroscopic redshifts for 62% of the radio sources in the 9' radius highest sensitivity region (556/894) and 67% of the radio sources in the GOODS-N region (367/543). We supplement these with a modest number of additional photometric redshifts in the GOODS-N region (30). We measure millimetric redshifts from the radio to submillimeter flux ratios for the unidentified submillimeter sample, assuming an Arp 220 spectral energy distribution. We find a radio-flux-dependent K-z relation for the radio sources, which we use to estimate redshifts for the remaining radio sources. We determine the star formation rates (SFRs) of the submillimeter sources based on their radio powers and their submillimeter fluxes and find that they agree well. The radio data are deep enough to detect star-forming galaxies with SFRs>2000 M_{sun}_/yr to z~6. We find galaxies with SFRs up to ~6000 M_{sun}_/yr over the redshift range z=1.5-6, but we see evidence for a turn-down in the SFR distribution function above 2000 M_{sun}_/yr.
5796. SCUBA-2 & LABOCA obs. of HATLAS ultrared galaxies
ID:
ivo://CDS.VizieR/J/ApJ/832/78
Title:
SCUBA-2 & LABOCA obs. of HATLAS ultrared galaxies
Short Name:
J/ApJ/832/78
Date:
21 Oct 2021
Publisher:
CDS
Description:
Until recently, only a handful of dusty, star-forming galaxies (DSFGs) were known at z>4, most of them significantly amplified by gravitational lensing. Here, we have increased the number of such DSFGs substantially, selecting galaxies from the uniquely wide 250, 350, and 500{mu}m Herschel-ATLAS imaging survey on the basis of their extremely red far-infrared colors and faint 350 and 500{mu}m flux densities, based on which, they are expected to be largely unlensed, luminous, rare, and very distant. The addition of ground-based continuum photometry at longer wavelengths from the James Clerk Maxwell Telescope and the Atacama Pathfinder Experiment allows us to identify the dust peak in their spectral energy distributions (SEDs), with which we can better constrain their redshifts. We select the SED templates that are best able to determine photometric redshifts using a sample of 69 high-redshift, lensed DSFGs, then perform checks to assess the impact of the CMB on our technique, and to quantify the systematic uncertainty associated with our photometric redshifts, {sigma}=0.14(1+z), using a sample of 25 galaxies with spectroscopic redshifts, each consistent with our color selection. For Herschel-selected ultrared galaxies with typical colors of S_500_/S_250_~2.2 and S_500_/S_350_~1.3 and flux densities, S500~50mJy, we determine a median redshift, z_phot_=3.66, an interquartile redshift range, 3.30-4.27, with a median rest-frame 8-1000{mu}m luminosity, L_IR_, of 1.3x10^13^L_{sun}_. A third of the galaxies lie at z>4, suggesting a space density, {rho}_z>4_, of ~6x10^-7^Mpc^-3^. Our sample contains the most luminous known star-forming galaxies, and the most overdense cluster of starbursting proto-ellipticals found to date.
5797. SCUBA-2 850um obs. of Herschel gal.
ID:
ivo://CDS.VizieR/J/MNRAS/477/1099
Title:
SCUBA-2 850um obs. of Herschel gal.
Short Name:
J/MNRAS/477/1099
Date:
21 Oct 2021
Publisher:
CDS
Description:
High-redshift, luminous, dusty star-forming galaxies (DSFGs) constrain the extremity of galaxy formation theories. The most extreme are discovered through follow-up on candidates in large area surveys. Here, we present extensive 850um SCUBA-2 follow-up observations of 188 red DSFG candidates from the Herschel Multitiered Extragalactic Survey (HerMES) Large Mode Survey, covering 274deg^2^. We detected 87% with a signal-to-noise ratio >3 at 850um. We introduce a new method for incorporating the confusion noise in our spectral energy distribution fitting by sampling correlated flux density fluctuations from a confusion limited map. The new 850um data provide a better constraint on the photometric redshifts of the candidates, with photometric redshift errors decreasing from {sigma}_z_/(1+z)~0.21 to 0.15. Comparison spectroscopic redshifts also found little bias (<(z-z_spec_)/(1+z_spec_)>=0.08). The mean photometric redshift is found to be 3.6 with a dispersion of 0.4 and we identify 21 DSFGs with a high probability of lying at z>4. After simulating our selection effects we find number counts are consistent with phenomenological galaxy evolution models. There is a statistically significant excess of WISE-1 and SDSS sources near our red galaxies, giving a strong indication that lensing may explain some of the apparently extreme objects. Nevertheless, our sample includes examples of galaxies with the highest star formation rates in the Universe (>>10^3^M_{sun}_/yr).
5798. SCUBA-2 850um survey in {sigma} Ori cluster
ID:
ivo://CDS.VizieR/J/MNRAS/435/1671
Title:
SCUBA-2 850um survey in {sigma} Ori cluster
Short Name:
J/MNRAS/435/1671
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results from a large 850um survey of the {sigma} Orionis cluster using the SCUBA-2 camera on the James Clerk Maxwell Telescope. The 0.5 diameter circular region we surveyed contains 297 young stellar objects with an age estimated at about 3Myr. We detect nine of these objects, eight of which have infrared excesses from an inner disc. We also serendipitously detect three non-stellar sources at >5{sigma} that are likely background submillimetre galaxies. The nine detected stars have inferred disc masses ranging from 5 to about 17M_Jup_, assuming similar dust properties as Taurus discs and an interstellar medium gas-to-dust ratio of 100. There is a net positive signal towards the positions of the individually undetected infrared excess sources indicating a mean disc mass of 0.5M_Jup_. Stacking the emission towards those stars without infrared excesses constrains their mean disc mass to less than 0.3M_Jup_, or an equivalent Earth mass in dust. The submillimetre luminosity distribution is significantly different from that in the younger Taurus region, indicating disc mass evolution as star-forming regions age and the infrared excess fraction decreases. Submillimetre Array observations reveal CO emission towards four sources demonstrating that some, but probably not much, molecular gas remains in these relatively evolved discs. These observations provide new constraints on the dust and gas mass of protoplanetary discs during the giant planet building phase and provide a reference level for future studies of disc evolution.
5799. SDF galaxies multi-photometry
ID:
ivo://CDS.VizieR/J/ApJ/657/738
Title:
SDF galaxies multi-photometry
Short Name:
J/ApJ/657/738
Date:
21 Oct 2021
Publisher:
CDS
Description:
SDF (Subaru Deep Field) line-emitting galaxies in four narrow-band filters at low and intermediate redshifts are presented. Broadband colors, follow-up optical spectroscopy, and multiple NB filters are used to distinguish H{alpha}, [OII], and [OIII] emitters at z=0.07-1.47 to construct their LFs. These LFs are derived down to faint magnitudes, allowing for an accurate determination of the faint-end slope. With a large (N~200) sample for each redshift interval, a Schechter profile is fitted to each LF.
5800. S Dor variables
ID:
ivo://CDS.VizieR/J/A+A/366/508
Title:
S Dor variables
Short Name:
J/A+A/366/508
Date:
21 Oct 2021
Publisher:
CDS
Description:
The goal in writing this paper is five fold: (1) to summarize the scientific achievements in the 20th century on S Dor variables (or LBVs); (2) to present an inventory of these variables in the Galaxy and the Magellanic Clouds with a description of their physical state and instability properties; (3) to emphasize the photometric achievements of the various types of instabilities. Generally this seems to be a neglected item resulting in a number of misunderstandings continuously wandering through literature; (4) to investigate the structure of the S Dor-area on the HR-diagram; (5) to estimate the total numbers of S Dor variables in the three stellar systems.