- ID:
- ivo://CDS.VizieR/J/MNRAS/405/2243
- Title:
- GMOS/WIYN spectroscopic catalogue
- Short Name:
- J/MNRAS/405/2243
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the largest spectroscopic follow-up performed in SWIRE ELAIS-N1. We were able to determine redshifts for 289 extragalactic sources. The values of spectroscopic redshifts of the latter have been compared with the estimated values from our photometric redshift code with very good agreement between the two for both galaxies and quasars.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/PASJ/70/S10
- Title:
- GOLDRUSH I. UV magnitudes
- Short Name:
- J/PASJ/70/S10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the UV luminosity functions (LFs) at z~4, 5, 6, and 7 based on the deep large-area optical images taken by the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP). On the 100 deg^2^ sky of the HSC SSP data available to date, we take enormous samples consisting of a total of 579565 dropout candidates at z~4-7 by the standard color selection technique, 358 out of which are spectroscopically confirmed by our follow-up spectroscopy and other studies. We obtain UV LFs at z~4-7 that span a very wide UV luminosity range of ~0.002-100L^*^_UV_(-26<M_UV_<-14mag) by combining LFs from our program and the ultra-deep Hubble Space Telescope legacy surveys. We derive three parameters of the best-fit Schechter function, {Phi}^*^, M_UV_, and {alpha}, of the UV LFs in the magnitude range where the active galactic nucleus (AGN) contribution is negligible, and find that and {Phi}^*^ decrease from z~4 to 7 with no significant evolution of M_UV_. Because our HSC SSP data bridge the LFs of galaxies and AGNs with great statistical accuracy, we carefully investigate the bright end of the galaxy UV LFs that are estimated by the subtraction of the AGN contribution either aided by spectroscopy or the best-fit AGN UV LFs. We find that the bright end of the galaxy UV LFs cannot be explained by the Schechter function fits at >2{sigma} significance, and require either double power-law functions or modified Schechter functions that consider a magnification bias due to gravitational lensing.
- ID:
- ivo://CDS.VizieR/J/MNRAS/372/1425
- Title:
- Gravitational lensing analysis of Abell 1689
- Short Name:
- J/MNRAS/372/1425
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have derived the mass distribution of galaxy cluster Abell 1689 within 0.3h^-1^_70_Mpc of the cluster centre using its strong lensing (SL) effect on 32 background galaxies, which are mapped in altogether 107 multiple images. The multiple images are based on some from the literature with modifications to both include new and exclude some of the original image systems. The cluster profile is explored further out to ~2.5h^-1^_70_Mpc with weak lensing (WL) shear measurements from the literature. The masses of ~200 cluster galaxies are measured with the Fundamental Plane (FP) in order to model accurately the small-scale mass structure in the cluster. The cluster galaxies are modelled as elliptical truncated isothermal spheres. The scalings of the truncation radii with the velocity dispersions of galaxies are assumed to match those of: (i) field galaxies; and (ii) theoretical expectations for galaxies in dense environments. The dark matter (DM) component of the cluster is described by either non-singular isothermal ellipsoids (NSIE) or elliptical versions of the universal DM profile (elliptical Navarro, Frenk & White, ENFW). To account for substructure in the DM we allow for two DM haloes.
144. Group of quasars
- ID:
- ivo://CDS.VizieR/J/MNRAS/249/218
- Title:
- Group of quasars
- Short Name:
- J/MNRAS/249/218
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have found evidence for a large, elongated group of at least ten quasars with largest dimension ~100-200h-1Mpc at z~1.3, in the direction of ESO/SERC field 927, which has the field centre (1950) 10h40m00s, 05deg00'00". There are probably further members that have not yet been observed. The morphology of the group seems to be like a clump, but there might be some sub-grouping on scales ~20h-1Mpc. The group is similar in size and number of quasars to that found by Crampton, Cowley & Hartwick (1989). The fact that two such groups are now known is evidence that the distribution of quasars is not so simple as was previously thought: at large scales (>10h-1Mpc) the majority of quasars may be distributed uniformly and at random, but rare, large groups also occur. The groups may be large physical structures, but a strong association with the large structures of galaxies seems doubtful.
- ID:
- ivo://CDS.VizieR/J/MNRAS/335/10
- Title:
- H{alpha} survey of Abell 1689
- Short Name:
- J/MNRAS/335/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of an H{alpha} survey in the rich cluster A 1689 at z=0.18, using the LDSS++ spectrograph on the Anglo-Australian Telescope (AAT). We obtained spectra covering redshifted H{alpha} at z=0.16-0.22, for 522 galaxies brighter than I=22.5, covering a field of 8.7x8.7arcmin^2^ (~1.1x1.1h^-1^Mpc at z=0.18). We securely detect H{alpha} emission in 46 of these galaxies; accounting for selection effects arising from sampling and cluster membership, we determine that 24+/-4 per cent of cluster members brighter than M_R_=-16.5+5logh are detected with H{alpha} flux greater than 4h^-2^x10^38^erg/s. From a Hubble Space Telescope mosaic covering 7.5x10.0arcmin, we determine morphologies for 199 galaxies brighter than I=21, and find that ~20 per cent of the cluster members are of type Sa or later. More than 90 per cent of cluster spirals show H{alpha} emission, compared with less than 10 per cent of E and S0 galaxies.
- ID:
- ivo://CDS.VizieR/J/A+AS/137/299
- Title:
- Hamburg/SAO Survey for ELGs. II.
- Short Name:
- J/A+AS/137/299
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the second part of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS therein, SAO - Special Astrophysical Observatory, Russia) which is based on the digitized objective-prism photoplates database of the Hamburg Quasar Survey (HQS). The main goal of the project is the search for emission-line galaxies (ELG) in order to create a new deep sample of blue compact/HII galaxies (BCG) in a large sky area. Another important goal of this work is to search for new extremely low-metallicity galaxies. In this paper we present new results of spectroscopy obtained with the 6m Russian telescope. The main ELG candidate selection criteria applied are blue or flat enough continuum (near 4000A) and the presence of strong or moderate emission lines close to 5000A recognized on digitized prism spectra of galaxies with the survey estimated B-magnitudes in the range 16 - 19.5. No other criteria were applied. The spectroscopy resulted in detection and quantitative spectral classification of 134 emission-line objects. For 121 of them the redshifts are determined for the first time. For 13 ELGs known before emission line ratios are presented at first time. 108 of 134 emission-line objects are classified as BCG/HII galaxies and 6 probable BCGs, 6 as QSOs, 1 as Seyfert galaxy, 1 as super-association in a dwarf spiral galaxy, 2 as probable LINERs, 14 are low excitation objects - either of starburst nuclei (SBN), or dwarf amorphous nuclei starburst galaxy (DANS) type -, and 1 nonclassified. 23 galaxies did not show significant emission lines. The five most metal-deficient BCGs discovered have oxygen abundances log(O/H)+12 in the range 7.4 to 7.7, similar to the most metal-deficient BCGs known before.
- ID:
- ivo://CDS.VizieR/J/A+AS/142/417
- Title:
- Hamburg/SAO Survey for ELGs. III.
- Short Name:
- J/A+AS/142/417
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the third list with results of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS therein, SAO - Special Astrophysical Observatory, Russia). This survey is based on the digitized objective-prism photoplate database of the Hamburg Quasar Survey (HQS). Here, we present new spectroscopic results of candidates which were obtained in 1998 with the 2.1m KPNO and the 2.2m Calar Alto telescopes. All candidates are selected in the declination band +35{deg} to +40{deg}. The follow-up spectroscopy with the 2m class telescopes confirmed 85 emission-line objects out of 113 observed candidates and allowed their quantitative spectral classification. For 80 of them, the redshifts are determined for the first time. For 5 previously known Emission-Line Galaxies (ELGs), line ratios are presented for the first time. We could classify 55 out of the 85 emission-line objects as BCG/HII galaxies or probable BCGs (Blue Compact Galaxies) , 4 - as QSOs, 6 - as Seyfert galaxies, 1 - as super-association in a subluminous spiral galaxy, and 11 are low-excitation objects - either starburst nuclei (SBN), or dwarf amorphous nuclei starburst galaxies (DANS). We could not classify 8 ELGs. Further, for 8 more galaxies we did not detect any significant emission lines.
- 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.
- ID:
- ivo://CDS.VizieR/J/MNRAS/473/1751
- Title:
- Herschel Bright Sources (HerBS)
- Short Name:
- J/MNRAS/473/1751
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Herschel Bright Sources (HerBS) sample, a sample of bright, high-redshift Herschel sources detected in the 616.4deg^2^ Herschel Astrophysical Terahertz Large Area Survey. The HerBS sample contains 209 galaxies, selected with a 500um flux density greater than 80mJy and an estimated redshift greater than 2. The sample consists of a combination of hyperluminous infrared galaxies and lensed ultraluminous infrared galaxies during the epoch of peak cosmic star formation. In this paper, we present Submillimetre Common-User Bolometer Array 2 (SCUBA-2) observations at 850um of 189 galaxies of the HerBS sample, 152 of these sources were detected. We fit a spectral template to the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) and 850um SCUBA-2 flux densities of 22 sources with spectroscopically determined redshifts, using a two-component modified blackbody spectrum as a template. We find a cold- and hot-dust temperature of 21.29^+1.35^_-1.66_ and 45.80^+2.88^_-3.48_K, a cold-to-hot dust mass ratio of 26.62^+5.61^_-6.74_ and a {beta} of 1.83^+0.14^_-0.28_. Thee poor quality of the fit suggests that the sample of galaxies is too diverse to be explained by our simple model. Comparison of our sample to a galaxy evolution model indicates that the fraction of lenses are high. Out of the 152 SCUBA-2 detected galaxies, the model predicts 128.4+/-2.1 of those galaxies to be lensed (84.5 per cent). The SPIRE 500um flux suggests that out of all 209 HerBS sources, we expect 158.1+/-1.7 lensed sources, giving a total lensing fraction of 76 per cent.
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/3861
- Title:
- Herschel protocluster survey
- Short Name:
- J/MNRAS/460/3861
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a Herschel/Spectral and Photometric Imaging Receiver (SPIRE) survey of three protoclusters at z=2-3 (2QZCluster, HS1700, SSA22). Based on the SPIRE colours (S_350_/S_250_ and S_500_/S_350_) of 250{mu}m sources, we selected high-redshift dusty star-forming galaxies potentially associated with the protoclusters. In the 2QZCluster field, we found a 4{sigma} overdensity of six SPIRE sources around 4.5-arcmin (~2.2Mpc) from a density peak of H {alpha} emitters at z=2.2. In the HS1700 field, we found a 5{sigma} overdensity of eight SPIRE sources around 2.1-arcmin (~1.0Mpc) from a density peak of Lyman-break galaxies at z=2.3. We did not find any significant overdensities in SSA22 field, but we found three 500 {mu}m sources are concentrated 3-arcmin (~1.4Mpc) east to the Ly {alpha} emitters overdensity. If all the SPIRE sources in these three overdensities are associated with protoclusters, the inferred star formation rate densities are 10^3^-10^4^ times higher than the average value at the same redshifts. This suggests that dusty star formation activity could be very strongly enhanced in z~2-3 protoclusters. Further observations are needed to confirm the redshifts of the SPIRE sources and to investigate what processes enhance the dusty star formation activity in z~2-3 protoclusters.
