- ID:
- ivo://CDS.VizieR/J/ApJ/781/2
- Title:
- Redshifts of 1151 galaxies from SDSS
- Short Name:
- J/ApJ/781/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Lines of sight with multiple projected cluster-scale gravitational lenses have high total masses and complex lens plane interactions that can boost the area of magnification, or etendue, making detection of faint background sources more likely than elsewhere. To identify these new "compound" cosmic telescopes, we have found directions in the sky with the highest integrated mass densities, as traced by the projected concentrations of luminous red galaxies (LRGs). We use new galaxy spectroscopy to derive preliminary magnification maps for two such lines of sight with total mass exceeding ~3x10^15^M_{sun}_. From 1151 MMT Hectospec spectra of galaxies down to i_AB_=21.2, we identify two to three group- and cluster-scale halos in each beam. These are well traced by LRGs. The majority of the mass in beam J085007.6+360428 (0850) is contributed by Zwicky 1953, a massive cluster at z=0.3774, whereas beam J130657.5+463219 (1306) is composed of three halos with virial masses of 6x10^14^-2x10^15^M_{sun}_, one of which is A1682. The magnification maps derived from our mass models based on spectroscopy and Sloan Digital Sky Survey photometry alone display substantial etendue: the 68% confidence bands on the lens plane area with magnification exceeding 10 for a source plane of z_s_=10 are [1.2,3.8]arcmin^2^ for 0850 and [2.3,6.7]arcmin^2^ for 1306. In deep Subaru Suprime-Cam imaging of beam 0850, we serendipitously discover a candidate multiply imaged V-dropout source at z_phot_=5.03. The location of the candidate multiply imaged arcs is consistent with the critical curves for a source plane of z=5.03 predicted by our mass model. Incorporating the position of the candidate multiply imaged galaxy as a constraint on the critical curve location in 0850 narrows the 68% confidence band on the lens plane area with {mu}>10 and z_s_=10 to [1.8,4.2]arcmin^2^, an etendue range comparable to that of MACS 0717+3745 and El Gordo, two of the most powerful single cluster lenses known. The significant lensing power of our beams makes them powerful probes of reionization and galaxy formation in the early universe.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/442/2216
- Title:
- Redshifts of galaxies in Abell 1351 field
- Short Name:
- J/MNRAS/442/2216
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to review the internal structure and dynamics of the Abell 1351 cluster, shown to host a radio halo with a quite irregular shape. Our analysis is based on radial velocity data for 135 galaxies obtained at the Telescopio Nazionale Galileo. We combine galaxy velocities and positions to select 95 cluster galaxy members and analyse the internal dynamics of the whole cluster. We also examine X-ray data retrieved from Chandra and XMM archives. We measure the cluster redshift, <z>=0.325, the line-of-sight (LOS) velocity dispersion, {sigma}V~1500km/s, and the X-ray temperature, kT~9keV. From both X-ray and optical data independently, we estimate a large cluster mass, in the 1-4x10^15^h_70_^-1^M_{sun}_. We attribute the extremely high value of {sigma}V to the bimodality in the velocity distribution. We find evidence of a significant velocity gradient and optical 3D substructure. The X-ray analysis also shows many features in favour of a complex cluster structure, probably supporting an ongoing merger of substructures in Abell 1351. The observational scenario agrees with the presence of two main subclusters in the northern region, each with its brightest galaxy (BCG1 and BCG2), detected as the two most important X-ray substructures with a rest-frame LOS velocity difference of {Delta}V_rf_~2500km/s and probably being in large part aligned with the LOS. We conclude that Abell 1351 is a massive merging cluster. The details of the cluster structure allow us to interpret the quite asymmetric radio halo as a 'normal' halo plus a southern relic, strongly supporting a previous suggestion based only on inspection of radio and preliminary X-ray data.
- ID:
- ivo://CDS.VizieR/J/A+A/435/781
- Title:
- Redshifts of galaxies in 21 EIS cluster fields
- Short Name:
- J/A+A/435/781
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out an investigation of the properties of low redshift EIS clusters using both spectroscopy and imaging data. We present new redshifts for 738 galaxies in 21 ESO Imaging Survey (EIS) Cluster fields. We use the "gap"-technique to search for significant overdensities in redshift space and to identify groups/clusters of galaxies corresponding to the original EIS matched filter cluster candidates. In this way we spectroscopically confirm 20 of the 21 cluster candidates with a matched-filter estimated redshift z_MF_=0.2. We have now obtained spectroscopic redshifts for 34 EIS cluster candidates with z_MF_=0.2 (see also Hansen et al., 2002, Cat. <J/A+A/388/1>; Olsen et al., 2003, Cat. <J/A+A/409/439>. Of those we spectroscopically confirm 32 with redshifts ranging from z=0.064 to 0.283. We find that: 1) the velocity dispersions of the systems range from sigma_v_<=130km/s to sigma_v_=1200km/s, typical of galaxy groups to rich clusters; 2) richnesses corresponding to Abell classes R<=1; and 3) concentration indices ranging from C=0.2 to C=1.2. From the analysis of the colours of the galaxy populations we find that 53% of the spectroscopically confirmed systems have a "significant" red sequence. These systems are on average richer and have higher velocity dispersions. We find that the colour of the red sequence galaxies matches passive stellar evolution predictions.
- ID:
- ivo://CDS.VizieR/J/ApJS/150/181
- Title:
- Redshifts of 110 radio-loud AGNs
- Short Name:
- J/ApJS/150/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report accurate redshifts of 110 active galaxies (mostly radio-loud objects at z<0.4) observed in the course of a survey to find broad, double-peaked emission lines. These redshifts are measured from the narrow emission lines of these objects and are accurate to at least one part in 10^4^. For each object we determine a redshift from high- and low-ionization lines separately, as well as an average redshift from all the available lines. We find that in about 15% of cases, the low-ionization lines yield a slightly higher redshift than the high-ionization lines; the average redshift difference amounts to a velocity difference of approximately 80km/s. In addition to the redshift measurements we also report revised redshifts for two objects as well as new classifications for three narrow-line objects.
- ID:
- ivo://CDS.VizieR/J/AJ/134/169
- Title:
- Redshifts of UDF emission-line objects
- Short Name:
- J/AJ/134/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present redshifts for 115 emission-line objects in the Hubble Ultra Deep Field identified through the Grism ACS Program for Extragalactic Science (GRAPES) project using the slitless grism spectroscopy mode of the Advanced Camera for Surveys on the Hubble Space Telescope (HST). The sample was selected by an emission-line search on all extracted one-dimensional GRAPES spectra. We identify the emission lines using line wavelength ratios where multiple lines are detected in the grism wavelength range (5800{AA}<~lambda<~9600{AA}), and using photometric redshift information where multiple lines are unavailable. We then derive redshifts using the identified lines.
- ID:
- ivo://CDS.VizieR/J/ApJS/112/245
- Title:
- Redshift survey for IRAS galaxies
- Short Name:
- J/ApJS/112/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the third and final paper (Yamada et al., 1993ApJS...89...57Y and Takata et al., Cat. <J/A+AS/104/529>) of our systematic visual search for IRAS galaxies behind the Milky Way at |b|<=15{deg}. This paper presents a catalog of 950 IRAS galaxies with 60{mu}m flux densities larger than 0.6Jy located between l=0{deg} and 150{deg}, of which 293 are newly identified by this search. We made a redshift survey for the identified galaxies and obtained new redshift data of 171 galaxies. We also present newly measured redshifts of 27 IRAS galaxies between l=150{deg} and 225{deg} at |b|<=15{deg}. In this paper we studied the structure of the Local void using IRAS galaxies and galaxies from the Third Reference Catalogue of Bright Galaxies (Cat. <VII/155>) in the region l=30{deg}-120{deg} and b=-50{deg} to +30{deg}. The center of the Local void turned out to be located at l~60{deg}, b~-15{deg}, and cz~2500km/s, and the size is about 2500km/s along the direction toward the center.
- ID:
- ivo://CDS.VizieR/J/MNRAS/283/367
- Title:
- Redshift survey in Per-Psc and Pav-Ind
- Short Name:
- J/MNRAS/283/367
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The list of the measured galaxies is given in Table 3 together with COSMOS coordinates and apparent magnitude. These parameters (plus diameter, axis ratio and position angle) were used to perform cross-identification with the PGC/LEDA objects after reduction to the RC3 system (de Vaucouleurs et al., 1990, see cat. <VII/155>). Both cross correlation results (from `rvsao') and emission line results (from `emsao') are presented. A few galaxies with published redshifts were also observed to derive our external error (see section 3 of the paper).
- ID:
- ivo://CDS.VizieR/J/MNRAS/367/1261
- Title:
- Redshift survey in 15 quasar fields
- Short Name:
- J/MNRAS/367/1261
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the relative distribution of the gaseous contents of the Universe (as traced by a sample of Ly{alpha} absorbers), and the luminous baryonic matter (as traced by a redshift survey of galaxies in the same volume searched for Ly{alpha} absorbers), along 16 lines of sight (LOS) between redshifts 0 and 1. Our galaxy redshift survey was made with the multi-object spectrograph on the Canada-France-Hawaii Telescope and, when combined with galaxies from the literature in the same LOS, gives us a galaxy sample of 636 objects. By combining this with an absorption-line sample of 406 absorbing systems drawn from published works, we are able to study the relationship between gas and galaxies over the latter half of the age of the Universe.
- ID:
- ivo://CDS.VizieR/J/ApJ/750/168
- Title:
- Redshift survey in the Subaru GTO2deg^2^ field
- Short Name:
- J/ApJ/750/168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use a dense redshift survey in the foreground of the Subaru GTO2deg^2^ weak-lensing field (centered at 16:04:44+43:11'24 (2000) to assess the completeness and comment on the purity of massive halo identification in the weak-lensing map. The redshift survey (published here) includes 4541 galaxies; 4405 are new redshifts measured with the Hectospec on the MMT. Among the weak-lensing peaks with a signal to noise greater than 4.25, 2/3 correspond to individual massive systems; this result is essentially identical to the Geller et al. (2010ApJ...709..832G) test of the Deep Lens Survey (DLS) field F2. The Subaru map, based on images in substantially better seeing than the DLS, enables detection of less massive halos at fixed redshift as expected. We demonstrate that the procedure adopted by Miyazaki et al. (2002ApJ...580L..97M) for removing some contaminated peaks from the weak-lensing map improves agreement between the lensing map and the redshift survey in the identification of candidate massive systems.
- ID:
- ivo://CDS.VizieR/J/AJ/162/193
- Title:
- Redshift survey nearby galaxy cluster A2626
- Short Name:
- J/AJ/162/193
- Date:
- 16 Mar 2022 00:18:57
- Publisher:
- CDS
- Description:
- New MMT/Hectospec spectroscopy centered on the galaxy cluster A2626 and covering a ~1.8deg^2^ area out to z~0.46 more than doubles the number of galaxy redshifts in this region. The spectra confirm four clusters previously identified photometrically. A2625, which was previously thought to be a close neighbor of A2626, is in fact much more distant. The new data show six substructures associated with A2626 and five more associated with A2637. There is also a highly collimated collection of galaxies and galaxy groups between A2626 and A2637 having at least three and probably four substructures. At larger scales, the A2626-A2637 complex is not connected to the Pegasus-Perseus filament.