- ID:
- ivo://CDS.VizieR/J/ApJ/785/144
- Title:
- SL2S galaxy-scale sample of lens candidates
- Short Name:
- J/ApJ/785/144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present RINGFINDER, a tool for finding galaxy-scale strong gravitational lenses in multi-band imaging data. By construction, the method is sensitive to configurations involving a massive foreground ETG and a faint, background, blue source. RINGFINDER detects the presence of blue residuals embedded in an otherwise smooth red light distribution by difference imaging in two bands. The method is automated for efficient application to current and future surveys, having originally been designed for the 150 deg^2^ Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). We describe each of the steps of RINGFINDER. We then carry out extensive simulations to assess completeness and purity. For sources with magnification {mu}>4, RINGFINDER reaches 42% (25%) completeness and 29% (86%) purity before (after) visual inspection. The completeness of RINGFINDER is substantially improved in the particular range of Einstein radii 0.8"<=R_Ein_<=2.0" and lensed images brighter than g=22.5, where it can be as high as ~70%. RINGFINDER does not introduce any significant bias in the source or deflector population. We conclude by presenting the final catalog of RINGFINDER CFHTLS galaxy-scale strong lens candidates. Additional information obtained with Hubble Space Telescope and Keck adaptive optics high-resolution imaging, and with Keck and Very Large Telescope spectroscopy, is used to assess the validity of our classification and measure the redshift of the foreground and the background objects. From an initial sample of 640000 ETGs, RINGFINDER returns 2500 candidates, which we further reduce by visual inspection to 330 candidates. We confirm 33 new gravitational lenses from the main sample of candidates, plus an additional 16 systems taken from earlier versions of RINGFINDER. First applications are presented in the Strong Lensing Legacy Survey galaxy-scale lens sample paper series.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/105/393
- Title:
- Small Drift Scan Survey Galaxies Northern Sky
- Short Name:
- J/AJ/105/393
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The file is an ASCII text file containing data for 1053 galaxies brighter than 18.0 mag. in the filter used. The effective wavelength of this filter for objects that have the color of galaxies closely matches that of Thuan and Gunn r filter. The strip covered in the survey is 12 arcmin wide by 60 degree long. The observations were carried out on the night of 23 May 1990, using the drift scanning technique, with the 24 inch telescope of the Whipple Observatory. The effective integration time was 57 s.
- ID:
- ivo://CDS.VizieR/J/ApJ/791/57
- Title:
- SN host galaxies basic information
- Short Name:
- J/ApJ/791/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog (Barbon et al., cat II/227) with the Sloan Digital Sky Survey (SDSS) Data Release 7 (Strauss et al., 2002AJ....124.1810S). We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters D_n_(4000), H{delta}_A_, stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low D_n_(4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high D_n_(4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (~0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/1567
- Title:
- Sou323 ICRF reference sample
- Short Name:
- J/MNRAS/466/1567
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to evaluate the possibility of improving the International Celestial Reference System realization starting from the ICRF2 catalogue by investigating the coordinate time series of radio sources observed by the very long baseline interferometry between 1979 and 2016. Sources with long observational history are selected as the candidates and the least-squares fits with special handling of the weights are performed to derive the linear drifts of the source coordinates. Then the sources are sorted, based on the normalized linear drift (i) over the whole sky, and (ii) in four homolographic areas divided by declinations. The axial stability of the reference system and sky distribution defined by the selected sources are evaluated, which are acted as the criterion for the final source lists. With our improved source selection scheme, two groups of sources are proposed and considered suitable for defining a more stable and homogeneous celestial reference system compared to the second version of the current International Celestial Reference Frame (ICRF2). The number of sources in the final lists are 323 and 294, respectively, and the global rotations of the axes derived from apparent motion of the sources are about two times better th
- ID:
- ivo://CDS.VizieR/J/other/ApL/30.1
- Title:
- Southern catalogue of isolated pairs extension
- Short Name:
- J/other/ApL/30.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The paper presents a sample of double galaxies selected from The Surface Photometry Catalog of the ESO-Uppsala Galaxies (Cat. <VII/115>) using the Karachentsev (1972: K72, Cat. <VII/77>) criteria. Considering the large and growing number of observing facilities in that hemisphere, the sample aims to supply investigators with targets as homogeneous as possible to those in the Northern Catalog of Isolated Pairs of Galaxies (K72) which have been studied in a large frequency range. The paper discusses the sample degree of completeness, separation and velocity distributions. First inferences are sketched from the morphological association of pair members and from the study of the Holmberg effect. Being the primary purpose of the paper to provide a tool to investigators, an Atlas of images for the 301 best candidate pairs obtained using the Digitized Sky Survey (The Digitized Sky Survey was produced at the Space Telescope Science Institute (ST ScI) under U.S. Government grant NAG W-2166) is given. The Atlas reports for each pair member the relevant data as obtained from the current literature.
- ID:
- ivo://CDS.VizieR/VII/116
- Title:
- Southern Galaxy Catalogue (SGC)
- Short Name:
- VII/116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (Abstract in the documentation file "docu.txt") The "Southern Galaxy Catalogue" provides a finding list of galaxies larger than about 1.5 to 2 arc minutes, south of declination -17 degrees. It includes, as far as possible, precise positions, morphological types, luminosity classifications, and diameters. It is essentially complete for logD>1.52.
- ID:
- ivo://CDS.VizieR/J/MNRAS/287/472
- Title:
- Southern Milky Way galaxies velocities
- Short Name:
- J/MNRAS/287/472
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A redshift survey of galaxies located in the direction of the southern Milky Way has been carried out using the FLAIR multi-objects system on the 1.2-m UK Schmidt Telescope (UKST) at the Anglo-Australian Observatory in Australia. The galaxy sample was extracted from the LEDA (<http://www-obs.univ-lyon1.fr/base/>) and COSMOS (Cat. <J/A+AS/117/519>) data bases but essentially by scanning by eye four plates of the UKST/SERC Survey in the region between the Centaurus complex and the Pavo-Indus (PI) wall. The galaxies selected have high central surface brightnesses and are distributed evenly over the whole search area. The majority of the galaxies have apparent magnitudes in the range 11.5<B_J_<17. Redshifts were determined for 211 galaxies with one additional object being found to be Galactic - a planetary nebula. A highly significant density enhancement is found in the galaxy distribution at 5000km/s or 67Mpc (H_0_=75km/s/Mpc). This suggests that a connection exists between the Centaurus complex and the PI wall across the zone of avoidance (ZOA) associated with the Milky Way and as such could be one of the larger structures in the nearby Universe.
- ID:
- ivo://CDS.VizieR/J/MNRAS/444/2456
- Title:
- Spectral galaxy pairs from SDSS DR9
- Short Name:
- J/MNRAS/444/2456
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectral galaxy pairs (hereafter as SGPs) are composite galaxy spectra that contain two independent redshift systems. These spectra are useful for studying the dust properties of the foreground galaxies. In this article, a total of 165 spectra of SGPs are mined from the Sloan Digital Sky Survey (SDSS) Data Release 9 (DR9) using the concept of 'membership degree' from fuzzy set theory, especially defined to be suitable for fuzzy identification of emission lines. The spectra and images of this sample are classified according to their membership degree and image features, respectively. Many of the second redshift systems are too small or too dim to select from SDSS images alone, making the sample a potentially unique source of information on dust effects in low-luminosity or low surface brightness galaxies, which are underrepresented in morphological pair samples. The dust extinction of those objects with high membership degree is also estimated by Balmer decrement. Additionally, analyses for a series of spectroscopic observations of one SGP from 165 systems indicate that a newly star-forming region of our Milky Way might exist.
- ID:
- ivo://CDS.VizieR/J/A+AS/131/295
- Title:
- Spectral survey of Case emission-line galaxies
- Short Name:
- J/A+AS/131/295
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of the follow-up spectroscopy of 178 emission-line galaxy (ELG) candidates from the Case objective-prism survey and nine Markarian galaxies with the 6m telescope are described. Only the candidates classified in the Case survey as those with emission lines were observed with the aim to form a statistical sample of blue compact galaxies (BCGs) with strong emission lines in the zone RA: 8h-16h, and DE: =+29deg-+38deg. We present the redshifts, equivalent widths and flux ratios for the strongest lines and the spectrum type for most of the galaxies with detected emission lines. A significant fraction (about 23%) of the observed Case galaxies do not show emission lines in blue. Preliminary analysis of the data is presented and the properties of the observed ELGs are compared with those of other known samples.
- ID:
- ivo://CDS.VizieR/J/ApJS/135/41
- Title:
- Spectroscopic and photometric redshifts
- Short Name:
- J/ApJS/135/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comparison between the catalog of spectroscopic redshifts in the Hubble Deep Field (HDF) recently published by Cohen and collaborators (2000, cat. <J/ApJ/538/29>) and the redshifts that our group (Fernandez-Soto et al., 1999, Cat. <J/ApJ/513/34>) has measured for the same objects using photometric techniques. This comparison is performed in order to fully characterize the errors associated with the photometric redshift technique. The compilation of spectroscopic redshifts incorporates previously published results, corrections to previously published wrong values, and new data, and it includes over 140 objects in the HDF proper. It represents the deepest, cleanest, most complete spectroscopic catalog ever compiled.
