- ID:
- ivo://CDS.VizieR/J/ApJ/788/125
- Title:
- An ALMA survey of ECDFS submillimeter galaxies
- Short Name:
- J/ApJ/788/125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first photometric redshift distribution for a large sample of 870 {mu}m submillimeter galaxies (SMGs) with robust identifications based on observations with ALMA. In our analysis we consider 96 SMGs in the Extended Chandra Deep Field South, 77 of which have 4-19 band photometry. We model the SEDs for these 77 SMGs, deriving a median photometric redshift of z_phot_=2.3+/-0.1. The remaining 19 SMGs have insufficient photometry to derive photometric redshifts, but a stacking analysis of Herschel observations confirms they are not spurious. Assuming that these SMGs have an absolute H-band magnitude distribution comparable to that of a complete sample of z~1-2 SMGs, we demonstrate that they lie at slightly higher redshifts, raising the median redshift for SMGs to z_phot_=2.5+/-0.2. Critically we show that the proportion of galaxies undergoing an SMG-like phase at z>=3 is at most 35%+/-5% of the total population. We derive a median stellar mass of M_*_=(8+/-1)x10^10^ M_{sun}_, although there are systematic uncertainties of up to 5x for individual sources. Assuming that the star formation activity in SMGs has a timescale of ~100 Myr, we show that their descendants at z~0 would have a space density and M_H_ distribution that are in good agreement with those of local ellipticals. In addition, the inferred mass-weighted ages of the local ellipticals broadly agree with the look-back times of the SMG events. Taken together, these results are consistent with a simple model that identifies SMGs as events that form most of the stars seen in the majority of luminous elliptical galaxies at the present day.
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- ID:
- ivo://CDS.VizieR/J/ApJ/850/83
- Title:
- DANCING-ALMA. I. submm/mm continuum sources
- Short Name:
- J/ApJ/850/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the large statistics of the galaxy effective radius Re in the rest-frame far-infrared (FIR) wavelength R_e(FIR)_ obtained from 1627 Atacama Large Millimeter/submillimeter Array (ALMA) 1mm band maps that become public by 2017 July. Our ALMA sample consists of 1034 sources with the star formation rate ~100-1000M_{sun}_/yr and the stellar mass ~10^10^-10^11.5^M_{sun}_ at z=0-6. We homogeneously derive R_e(FIR)_ and FIR luminosity LFIR of our ALMA sources via the uv-visibility method with the exponential disk model, carefully evaluating selection and measurement incompletenesses by realistic Monte-Carlo simulations. We find that there is a positive correlation between R_e(FIR)_ and LFIR at the >99% significance level. The best-fit power-law function, R_e(FIR)_{propto}L_FIR_^{alpha}^, provides {alpha}=0.28+/-0.07, and shows that R_e(FIR)_ at a fixed LFIR decreases toward high redshifts. The best-fit {alpha} and the redshift evolution of R_e(FIR)_ are similar to those of Re in the rest-frame UV (optical) wavelength R_e(UV)_ (R_e(Opt)_) revealed by Hubble Space Telescope (HST) studies. We identify that our ALMA sources have significant trends of R_e(FIR)_<~R_e(UV)_ and R_e(Opt)_, which suggests that the dusty starbursts take place in compact regions. Moreover, R_e(FIR)_ of our ALMA sources is comparable to R_e(Opt)_ of quiescent galaxies at z~1-3 as a function of stellar mass, supporting the evolutionary connection between these two galaxy populations. We also investigate rest- frame UV and optical morphologies of our ALMA sources with deep HST images, and find that ~30%-40% of our ALMA sources are classified as major mergers. This indicates that dusty starbursts are triggered by not only the major mergers but also the other mechanism(s).
- ID:
- ivo://CDS.VizieR/J/ApJ/862/96
- Title:
- Dusty star-forming galaxies with LABOCA 870um obs.
- Short Name:
- J/ApJ/862/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present images obtained with LABOCA of a sample of 22 galaxies selected via their red Herschel SPIRE colors. We aim to see if these luminous, rare, and distant galaxies are signposting dense regions in the early universe. Our 870{mu}m survey covers an area of ~1deg^2^ down to an average rms of 3.9mJy/beam, with our five deepest maps going 2x deeper still. We catalog 86 dusty star-forming galaxies (DSFGs) around our "signposts," detected above a significance of 3.5{sigma}. This implies a 100+/-30% overdensity of S_870_>8.5mJy (or L_FIR_=6.7x10^12^-2.9x10^13^L_{sun}_) DSFGs, excluding our signposts, when comparing our number counts to those in "blank fields." Thus, we are 99.93% confident that our signposts are pinpointing overdense regions in the universe, and 95% [50%] confident that these regions are overdense by a factor of at least >=1.5x[2x]. Using template spectral energy distributions (SEDs) and SPIRE/LABOCA photometry, we derive a median photometric redshift of z=3.2+/-0.2 for our signposts, with an inter-quartile range of z=2.8-3.6, somewhat higher than expected for 850{mu}m selected galaxies. We constrain the DSFGs that are likely responsible for this overdensity to within |{delta}_z_|<=0.65 of their respective signposts. These "associated" DSFGs are radially distributed within (physical) distances of 1.6+/-0.5Mpc from their signposts, have median star formation rates (SFRs) of ~(1.0+/-0.2)x10^3^M_{sun}_/yr (for a Salpeter stellar initial mass function) and median gas reservoirs of ~1.7x10^11^M_{sun}_. These candidate protoclusters have average total SFRs of at least ~(2.3+/-0.5)x10^3^M_{sun}_/yr and space densities of 9x10^-7^Mpc^-3^, consistent with the idea that their constituents may evolve to become massive early-type galaxies in the centers of the rich galaxy clusters we see today.
- ID:
- ivo://CDS.VizieR/J/ApJ/749/65
- Title:
- H-ATLAS search for strongly lensed galaxies
- Short Name:
- J/ApJ/749/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- While the selection of strongly lensed galaxies (SLGs) with 500{mu}m flux density S_500_>100mJy has proven to be rather straightforward, for many applications it is important to analyze samples larger than the ones obtained when confining ourselves to such a bright limit. Moreover, only by probing to fainter flux densities is it possible to exploit strong lensing to investigate the bulk of the high-z star-forming galaxy population. We describe HALOS (the Herschel-ATLAS Lensed Objects Selection), a method for efficiently selecting fainter candidate SLGs, reaching a surface density of =~1.5-2/deg^2^, i.e., a factor of about 4-6 higher than that at the 100mJy flux limit. HALOS will allow the selection of up to ~1000 candidate SLGs (with amplifications {mu}>~2) over the full H-ATLAS survey area. Applying HALOS to the H-ATLAS Science Demonstration Phase field (=~14.4deg^2^) we find 31 candidate SLGs, whose candidate lenses are identified in the VIKING near-infrared catalog. Using the available information on candidate sources and candidate lenses we tentatively estimate a =~72% purity of the sample. As expected, the purity decreases with decreasing flux density of the sources and with increasing angular separation between candidate sources and lenses. The redshift distribution of the candidate lensed sources is close to that reported for most previous surveys for lensed galaxies, while that of candidate lenses extends to redshifts substantially higher than found in the other surveys. The counts of candidate SLGs are also in good agreement with model predictions. Even though a key ingredient of the method is the deep near-infrared VIKING photometry, we show that H-ATLAS data alone allow the selection of a similarly deep sample of candidate SLGs with an efficiency close to 50%; a slightly lower surface density (=~ 1.45/deg2) can be reached with a ~70% efficiency.
- ID:
- ivo://CDS.VizieR/J/ApJS/236/30
- Title:
- Herschel-ATLAS (H-ATLAS) DR2
- Short Name:
- J/ApJS/236/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) is a survey of 660deg^2^ with the PACS and SPIRE cameras in five photometric bands: 100, 160, 250, 350, and 500{mu}m. This is the second of three papers describing the data release for the large fields at the south and north Galactic poles (NGP and SGP). In this paper we describe the catalogs of far-infrared and submillimeter sources for the NGP and SGP, which cover 177.1deg^2^ and 303.4deg^2^, respectively. The catalogs contain 118980 sources for the NGP field and 193527 sources for the SGP field detected at more than 4{sigma} significance in any of the 250, 350, or 500{mu}m bands. The source detection is based on the 250{mu}m map, and we present photometry in all five bands for each source, including aperture photometry for sources known to be extended. The rms positional accuracy for the faintest sources is about 2.4" in both RA and DEC. We present a statistical analysis of the catalogs and discuss the practical issues-completeness, reliability, flux boosting, accuracy of positions, accuracy of flux measurements-necessary to use the catalogs for astronomical projects.
- ID:
- ivo://CDS.VizieR/J/AJ/155/17
- Title:
- Infrared photometric study of Wolf-Rayet galaxies
- Short Name:
- J/AJ/155/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We collected observational data on 781 Wolf-Rayet (WR) galaxies from the literature to photometrically study their infrared properties measured by the 2MASS, WISE, IRAS, AKARI, and Herschel missions. It is found that in the 1-5 {mu}m range the radiations of WR galaxies are dominated by the free-free emissions from the stellar winds and the circumstellar dust from the late-type stars in the host galaxy. In the 5-22 {mu}m range, the radiation of WR galaxies is dominated by the free-free emissions and the synchrotron radiation from the central active galactic nucleus (AGN; but not always present). In the 22-140 {mu}m range, the radiations of WR galaxies are dominated by the free-free emissions and the star formation/starburst activities. In the 250-500 {mu}m range, the radiation of WR galaxies is dominated by the free-free emissions. In addition, the comparison with the non-WR galaxies is made. It is shown that some star formation WR galaxies have redder near-infrared colors than non-WR star-forming galaxies probably due to the gas emission in the near-infrared. In the 2-5 {mu}m region WR galaxies have redder colors due to the thermal emission from circumstellar dust of late-type stars and the enhanced gas emission. In the 5-22 {mu}m region, both WR galaxies and non-WR galaxies have similar behavior, indicative of having similar free-free emission as the dominant radiation. In the 25-140 {mu}m region, both types of galaxies also have similar behavior, indicative of having free-free emission from the stellar winds or the thermal radiation from the starburst/star formation as the dominant radiation.
- ID:
- ivo://CDS.VizieR/J/ApJ/756/28
- Title:
- IR counterparts to submm H-ATLAS galaxies
- Short Name:
- J/ApJ/756/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Spitzer-IRAC data to identify near-infrared counterparts to submillimeter galaxies detected with Herschel-SPIRE at 250{mu}m in the Herschel Astrophysical Terahertz Large Area Survey. Using a likelihood ratio analysis we identify 146 reliable IRAC counterparts to 123 SPIRE sources out of the 159 in the survey area. We find that, compared to the field population, the SPIRE counterparts occupy a distinct region of the 3.6 and 4.5{mu}m color-magnitude space, and we use this property to identify 23 further counterparts to 13 SPIRE sources. The IRAC identification rate of 86% is significantly higher than those that have been demonstrated with wide-field ground-based optical and near-IR imaging of Herschel fields. We estimate a false identification rate of 3.6%, corresponding to 4-5 sources. Among the 73 counterparts that are undetected in Sloan Digital Sky Survey, 57 have both 3.6 and 4.5{mu}m coverage. Of these, 43 have [3.6]-[4.5]>0, indicating that they are likely to be at z>~1.4. Thus, ~40% of identified SPIRE galaxies are likely to be high-redshift (z>~1.4) sources. We discuss the statistical properties of the IRAC-identified SPIRE galaxy sample including far-IR luminosities, dust temperatures, star formation rates, and stellar masses. The majority of our detected galaxies have 10^10^-10^11^L_{sun}_ total IR luminosities and are not intense starbursting galaxies as those found at z~2, but they have a factor of 2-3 above average specific star formation rates compared to near-IR selected galaxy samples.
- ID:
- ivo://CDS.VizieR/J/A+A/614/A140
- Title:
- Large Quasar Astrometric Catalogue 4, LQAC-4
- Short Name:
- J/A+A/614/A140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From an astrometric point of view, quasars constitute the best and almost ideal reference objects in the celestial sphere, with a priori no significant proper motion. Since the third release of the Large Quasar Astrometric Catalogue (LQAC-3, Cat. J/A+A/583/A75), a large number of quasars have been discovered, in particular those coming from the DR12Q release of the SDSS (Paris et al., 2017, Cat. VII/279). Moreover, for cross-matched objects, we have taken advantage of the very accurate determinations of the quasars identified within the recent Gaia DR1 catalogue (2018, Cat. I/345). Following the same procedure as in the three previous releases of the LQAC, our aim is to compile the large majority of all the quasars recorded so far. Our goal is to record their best coordinates and substantial information concerning their physical properties such as the redshift as well as multi-bands apparent and absolute magnitudes. Emphasis is given to the results of the cross-matches with the Gaia DR1 catalogue. New quasars coming from the DR12Q release were cross-matched with the precedent LQAC-3 compilation with a 1" search radius, in order to add the objects without counterpart to the LQAC-4 compilation. A similar cross-match was done with Gaia DR1 to identify the known quasars detected by Gaia. This enables one to improve significantly the positioning of these objects, and in parallel to study the astrometric performance of the individual catalogues of the LQAC-4 compilation. Finally, a new method was used to determine absolute magnitudes. Our final catalogue, called LQAC-4, contains 443 725 objects. This is roughly 37.82% more than the number of objects recorded in the LQAC-3. Among them, 249071 were found in common with the Gaia DR1, with a 1" search radius. That corresponds to 56.13% of the whole population in the compilation. The LQAC-4 delivers to the astronomical community a nearly complete catalogue of spectroscopically confirmed quasars (including a small proportion of compact AGNs), with the aim of giving their best equatorial coordinates with respect to the ICRF2 and with exhaustive additional information. For more than 50% of the sample, these coordinates come from the very recent Gaia DR1.
- ID:
- ivo://CDS.VizieR/J/ApJ/692/422
- Title:
- MAMBO observations of SWIRE sources
- Short Name:
- J/ApJ/692/422
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on-off pointed MAMBO observations at 1.2mm of 61 Spitzer-selected star-forming galaxies from the Spitzer Wide Area Infrared Extragalactic Legacy survey (SWIRE). The sources are selected on the basis of bright 24um fluxes (F24um>0.4mJy) and of stellar dominated near-infrared spectral energy distributions in order to favor z~2 starburst galaxies. The average 1.2mm flux for the whole sample is 1.5+/-0.2mJy. Our analysis focuses on 29 sources in the Lockman Hole field where the average 1.2mm flux (1.9+/-0.3mJy) is higher than in other fields (1.1+/-0.2mJy). The analysis of the multiwavelength spectral energy distributions indicates that these sources are starburst galaxies with far-infrared luminosities from 10^12^ to 10^13.3^L_{sun}_, and stellar masses of ~0.2-6x10^11^M_{sun}_. Compared to submillimeter selected galaxies (SMGs), the SWIRE-MAMBO sources are among those with the largest 24um/1.2mm flux ratios. The origin of such large ratios is investigated by comparing the average mid-infrared spectra and the stacked far-infrared spectral energy distributions of the SWIRE-MAMBO sources and of SMGs.
- 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.