- ID:
- ivo://CDS.VizieR/J/MNRAS/465/3558
- Title:
- HATLAS candidate lensed galaxies
- Short Name:
- J/MNRAS/465/3558
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 80 candidate strongly lensed galaxies with flux density above 100mJy at 500{mu}m extracted from the Herschel Astrophysical Terahertz Large Area Survey, over an area of 600deg^2^. Available imaging and spectroscopic data allow us to confirm the strong lensing in 20 cases and to reject it in one case. For other eight objects, the lensing scenario is strongly supported by the presence of two sources along the same line of sight with distinct photometric redshifts. The remaining objects await more follow-up observations to confirm their nature. The lenses and the background sources have median redshifts z_L_=0.6 and z_S_=2.5, respectively, and are observed out to z_L_=1.2 and z_S_=4.2. We measure the number counts of candidate lensed galaxies at 500{mu}m and compare them with theoretical predictions, finding a good agreement for a maximum magnification of the background sources in the range 10-20. These values are consistent with the magnification factors derived from the lens modelling of individual systems. The catalogue presented here provides sub-mm bright targets for follow-up observations aimed at exploiting gravitational lensing, to study with unprecedented details the morphological and dynamical properties of dusty star-forming regions in z>=1.5 galaxies.
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Search Results
- 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/ApJ/903/111
- Title:
- HCN, HNC, H13CN & HC3N of Galactic Center map. II.
- Short Name:
- J/ApJ/903/111
- Date:
- 15 Mar 2022
- Publisher:
- CDS
- Description:
- We report a statistical analysis exploring the origin of the overall low star formation efficiency (SFE) of the Galactic central molecular zone (CMZ) and the SFE diversity among the CMZ clouds using a wide-field HCN J=4-3 map, whose optically thin critical density (~10^7^/cm^3^) is the highest among the tracers ever used in CMZ surveys. Logistic regression is performed to empirically formulate star formation probability of 195 HCN clumps, 13 of which contain star formation signatures. The explanatory parameters in the best-fit model are reduced into the virial parameter {alpha}_vir_ without significant contribution from other parameters, whereas the performance of the model without {alpha}_vir_ is no better than that using randomly generated data. The threshold {alpha}_vir_ is 6, which translates into a volume density (n_H_2__) of 10^4.6^/cm^3^ with the n_H_2__-{alpha}_vir_ correlation. The scarcity of the low-{alpha}_vir_ clumps, whose fraction to all HCN clumps is 0.1, can be considered as one of the immediate causes of the suppressed SFE. No correlation between the clump size or mass and star formation probability is found, implying that HCN J= 4-3 does not immediately trace the mass of star-forming gas above a threshold density. Meanwhile, star-forming and non-star-forming clouds are degenerate in the physical parameters of the CS J=1-0 clouds, highlighting the efficacy of the HCN J=4-3 line to probe star-forming regions in the CMZ. The timescale of the high-{alpha}_vir_ to low-{alpha}_vir_ transition is <~2Myr, which is consistent with the tidal compression and X1/X2 orbit transition models but possibly does not fit the cloud-cloud collision picture.
- ID:
- ivo://CDS.VizieR/J/A+A/606/A125
- Title:
- HD163296 DCO+, DCN and N_2_D+ data cubes
- Short Name:
- J/A+A/606/A125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deuterium fractionation has been used to study the thermal history of prestellar environments. Their formation pathways trace different regions of the disk and may shed light into the physical structure of the disk, including locations of important features for planetary formation. We aim to constrain the radial extent of the main deuterated species; we are particularly interested in spatially characterizing the high and low temperature pathways for enhancing deuteration of these species. We observed the disk surrounding the Herbig Ae star HD 163296 using ALMA in Band 6 and obtained resolved spectral imaging data of DCO^+^ (J=3-2), DCN (J=3-2) and N_2_D^+^ (J=3-2) with synthesized beam sizes of 0.53"x0.42", 0.53"x0.42", and 0.50"x0.39", respectively. We adopted a physical model of the disk from the literature and use the 3D radiative transfer code LIME to estimate an excitation temperature profile for our detected lines. We modeled the radial emission profiles of DCO^+^, DCN, and N_2_D^+^, assuming their emission is optically thin, using a parametric model of their abundances and our excitation temperature estimates.
- ID:
- ivo://CDS.VizieR/J/MNRAS/358/149
- Title:
- HDFN SCUBA Super-map. III
- Short Name:
- J/MNRAS/358/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new submillimetre (submm) super-map in the Hubble Deep Field North (HDF-N) region (Great Observatories Origins Deep Survey North, GOODS-N, field), containing 40 statistically robust sources at 850um. This map contains additional data, and several new sources, including one of the brightest blank-sky extragalactic submm sources ever detected. We have used the Advanced Camera for Surveys (ACS) Hubble Space Telescope (HST) images and ground-based near-infrared (IR) observations from the Great Observatories Origins Deep Survey (GOODS), along with deep radio observations, to develop a systematic approach for counterpart identification. With the depth achieved by this survey, optical counterparts have been found for all the radio-detected (RD) submm sources.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A75
- Title:
- HD 97048 H13CO+ and HC15N first detections
- Short Name:
- J/A+A/629/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of different molecular lines in protoplanetary disks provide valuable information on the gas kinematics, as well as constraints on the radial density and temperature structure of the gas. With ALMA we have detected H13CO+ (J=4-3) and HC15N (J=4-3) in the HD 97048 protoplanetary disk for the first time. We compare these new detections to the ringed continuum mm-dust emission and the spatially resolved CO (J=3-2) and HCO+ (J=4-3) emission. The radial distributions of the H^13^CO^+^ and HC^15^N emission show hints of ringed sub-structure whereas, the optically thick tracers, CO and HCO+, do not. We calculate the HCO^+^/H^13^CO^+^ intensity ratio across the disk and find that it is radially constant (within our uncertainties). We use a physio-chemical parametric disk structure of the HD 97048 disk with an analytical prescription for the HCO^+^ abundance distribution to generate synthetic observations of the HCO^+^ and H^13^CO^+^ disk emission assuming LTE. The best by-eye fit models require radial variations in the HCO^+^/H^13^CO^+^ abundance ratio and an overall enhancement in H^13^CO^+^ relative to HCO^+^. This highlights the need to consider isotope selective chemistry and in particular low temperature carbon isotope exchange reactions. This also points to the presence of a reservoir of cold molecular gas in the outer disk (T<10K, R>200au). Chemical models are required to confirm that isotope-selective chemistry alone can explain the observations presented here. With these data, we cannot rule out that the known dust substructure in the HD 97048 disk is responsible for the observed trends in molecular line emission, and higher spatial resolution observations are required to fully explore the potential of optically thin tracers to probe planet-carved dust gaps. We also report non-detections of H^13^CO^+^ and HC^15^N in the HD 100546 protoplanetary disk.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/1989
- Title:
- HerMES Large Mode Survey catalogue
- Short Name:
- J/MNRAS/462/1989
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Selecting sources with rising flux densities towards longer wavelengths from Herschel/Spectral and Photometric Imaging Receiver (SPIRE) maps is an efficient way to produce a catalogue rich in high-redshift (z>4) dusty star-forming galaxies. The effectiveness of this approach has already been confirmed by spectroscopic follow-up observations, but the previously available catalogues made this way are limited by small survey areas. Here we apply a map-based search method to 274deg^2^ of the Herschel Multi-tiered Extragalactic Survey (HerMES) Large Mode Survey and create a catalogue of 477 objects with SPIRE flux densities S_500_>S_350_>S_250_ and a 5{sigma} cut-off S_500_>52mJy. From this catalogue we determine that the total number of these 'red' sources is at least an order of magnitude higher than predicted by galaxy evolution models. These results are in agreement with previous findings in smaller HerMES fields; however, due to our significantly larger sample size we are also able to investigate the shape of the red source counts for the first time. We have obtained spectroscopic redshift measurements for two of our sources using the Atacama Large Millimeter/submillimeter Array. The redshifts z=5.1 and 3.8 confirm that with our selection method we can indeed find high-redshift dusty star-forming galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/3146
- Title:
- Herschel-ATLAS DR1 (HATLAS)
- Short Name:
- J/MNRAS/462/3146
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first major data release of the largest single key-project in area carried out in open time with the Herschel Space Observatory. The Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) is a survey of 600 deg^2^ in five photometric bands - 100, 160, 250, 350 and 500 microns - with the Photoconductor Array Camera and Spectrometer and Spectral and Photometric Imaging Receiver (SPIRE) cameras. In this paper and the companion (Bourne at al., 2016MNRAS.462.1714B), we present the survey of three fields on the celestial equator, covering a total area of 161.6 deg2 and previously observed in the Galaxy and Mass Assembly (GAMA) spectroscopic survey. This paper describes the Herschel images and catalogues of the sources detected on the SPIRE 250 micron images. The 1 sigma noise for source detection, including both confusion and instrumental noise, is 7.4, 9.4 and 10.2mJy at 250, 350 and 500 microns. Our catalogue includes 120 230 sources in total, with 113 995, 46 209 and 11 011 sources detected at >4 sigma at 250, 350 and 500 microns. The catalogue contains detections at >3{sigma} at 100 and 160 microns for 4650 and 5685 sources, and the typical noise at these wavelengths is 44 and 49mJy. We include estimates of the completeness of the survey and of the effects of flux bias and also describe a novel method for determining the true source counts. The H-ATLAS source counts are very similar to the source counts from the deeper HerMES survey at 250 and 350 microns, with a small difference at 500 microns.
- 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/MNRAS/415/2336
- Title:
- Herschel-ATLAS Science Demonstration Catalog
- Short Name:
- J/MNRAS/415/2336
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Herschel Astrophysical Terahertz Large Area Survey (Herschel-ATLAS) is a survey of 550deg^2^ with the Herschel Space Observatory in five far-infrared and submillimetre bands. The first data for the survey, observations of a field 4x4deg^2^ in size, were taken during the Science Demonstration Phase (SDP), and reach a 5{sigma} noise level of 33.5mJy/beam at 250um. This paper describes the source extraction methods used to create the corresponding SDP catalogue, which contains 6876 sources, selected at 250um, within ~14deg^2^.