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Start Over Subject radio galaxies Validation Level 2
491. VVDS14h redshift catalog
ID:
ivo://CDS.VizieR/J/MNRAS/473/1879
Title:
VVDS14h redshift catalog
Short Name:
J/MNRAS/473/1879
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use observations made with the Giant Metrewave Radio Telescope (GMRT) to probe the neutral hydrogen (HI) gas content of field galaxies in the VIMOS VLT Deep Survey (VVDS) 14h field at z~=0.32. Because the HI emission from individual galaxies is too faint to detect at this redshift, we use an HI spectral stacking technique using the known optical positions and redshifts of the 165 galaxies in our sample to co-add their HI spectra and thus obtain the average HI mass of the galaxies. Stacked HI measurements of 165 galaxies show that >~95 per cent of the neutral gas is found in blue, star-forming galaxies. Among these galaxies, those having lower stellar mass are more gas rich than more massive ones. We apply a volume correction to our HI measurement to evaluate the HI gas density at z~=0.32 as {OMETA}_HI_=(0.50+/-0.18)x10^-3^ in units of the cosmic critical density. This value is in good agreement with previous results at z<0.4, suggesting no evolution in the neutral hydrogen gas density over the last ~4Gyr. However the z~=0.32 gas density is lower than that at z~5 by at least a factor of two.
492. Warps of galaxies
ID:
ivo://CDS.VizieR/J/A+A/391/519
Title:
Warps of galaxies
Short Name:
J/A+A/391/519
Date:
21 Oct 2021
Publisher:
CDS
Description:
From a comparison of the different parameters of warped galaxies in the radio, and especially in the visible, we find that: a) No large galaxy (large mass or radius) has been found to have high amplitude in the warp, and there is no correlation of size/mass with the degree of asymmetry of the warp. b) The disc density and the ratio of dark to luminous mass show an opposing trend: smaller values give more asymmetric warps in the inner radii (optical warps) but show no correlation with the amplitude of the warp; however, in the external radii is there no correlation with asymmetry. c) A third anticorrelation appears in a comparison of the amplitude and degree of asymmetry in the warped galaxies. Hence, it seems that very massive dark matter haloes have nothing to do with the formation of warps but only with the degree of symmetry in the inner radii, and are unrelated to the warp shape for the outermost radii. Denser discs show the same dependence.
493. WERGS. II. SED fitting with optical, IR & radio data
ID:
ivo://CDS.VizieR/J/ApJS/243/15
Title:
WERGS. II. SED fitting with optical, IR & radio data
Short Name:
J/ApJS/243/15
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present physical properties of radio galaxies (RGs) with f_1.4GHz_>1mJy discovered by Subaru Hyper Suprime-Cam (HSC) and Very Large Array Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. For 1056 FIRST RGs at 0<z<=1.7 with HSC counterparts in about 100deg^2^, we compiled multi-wavelength data of optical, near-infrared (IR), mid-IR, far-IR, and radio (150MHz). We derived their color excess (E(B-V)_*_), stellar mass, star formation rate (SFR), IR luminosity, the ratio of IR and radio luminosity (q_IR_), and radio spectral index ({alpha}_radio_) that are derived from the spectral energy distribution (SED) fitting with CIGALE. We also estimated Eddington ratio based on stellar mass and integration of the best-fit SEDs of active galactic nucleus (AGN) component. We found that E(B-V)_*_, SFR, and IR luminosity clearly depend on redshift while stellar mass, q_IR_, and {alpha}_radio_ do not significantly depend on redshift. Since optically faint (i_AB_>=21.3) RGs that are newly discovered by our RG survey tend to be high redshift, they tend to not only have a large dust extinction and low stellar mass but also have high SFR and AGN luminosity, high IR luminosity, and high Eddington ratio compared with optically bright ones. The physical properties of a fraction of RGs in our sample seem to differ from a classical view of RGs with massive stellar mass, low SFR, and low Eddington ratio, demonstrating that our RG survey with HSC and FIRST provides us curious RGs among entire RG population.
494. Wide-Angle-Tailed radio galaxies redshifts
ID:
ivo://CDS.VizieR/J/AJ/120/2269
Title:
Wide-Angle-Tailed radio galaxies redshifts
Short Name:
J/AJ/120/2269
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new redshifts and positions for 635 galaxies in nine rich clusters containing wide-angle tailed (WAT) radio galaxies. Combined with existing data, we now have a sample of 18 WAT-containing clusters with more than 10 redshifts. This sample contains a substantial portion of the WAT clusters in the VLA 20 cm survey of Abell clusters, including 75% of WAT clusters in the complete survey (z<=0.09), and 20% of WAT clusters with z>0.09. It is a representative sample, which should not contain biases other than selection by radio morphology. We graphically present the new data using histograms and sky maps. A semiautomated procedure is used to search for emission lines in the spectra in order to add and verify galaxy redshifts. We find that the average apparent fraction of emission-line galaxies is about 9% in both the clusters and the field. We investigate the magnitude completeness of our redshift surveys with CCD data for a test case, Abell 690. This case indicates that our galaxy target lists are deeper than the detection limit of a typical MX exposure, and they are 82% complete down to R=19.0. The importance of the uniformity of the placement of fibers on targets is posited, and we evaluate this in our data sets. We find some cases of nonuniformities which may influence dynamical analyses. A second paper will use this database to look for correlations between the WAT radio morphology and the cluster's dynamical state.
495. WIYN spectroscopy in the deep SWIRE field
ID:
ivo://CDS.VizieR/J/ApJS/182/625
Title:
WIYN spectroscopy in the deep SWIRE field
Short Name:
J/ApJS/182/625
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of spectroscopy using HYDRA on the WIYN 3.5m telescope of objects in the deep SWIRE radio field. The goal of the project was to determine spectroscopic redshifts for as many of the brighter objects in the field as possible, especially those detected in the radio and at 24um. These redshifts are primarily being used in studies of galaxy evolution and the connection of that evolution to active galactic nuclei and star formation. Redshifts measured for 365 individual objects are reported. The redshifts range from 0.03 to 2.5, mostly with z<0.9. The sources were selected to be within the WIYN HYDRA field of approximately 30' in radius from the center of the SWIRE deep field, 10:46:00, +59:01:00 (J2000). Optical sources for spectroscopic observation were selected from an r-band image of the field. A priority list of spectroscopic targets was established in the following order: 20cm detections, 24m detections, galaxies with r<20 and the balance made up of fainter galaxies in the field. We provide a table listing the galaxy positions, measured redshift and error, and note any emission lines that were visible in the spectrum. In practice, almost all the galaxies with r<19 were observed including all of the radio sources and most of the 24um sources with r<20 and a sample of radio sources which had fainter optical counterparts on the r-band image.
496. WMAP3 catalogue
ID:
ivo://CDS.VizieR/J/A+A/508/107
Title:
WMAP3 catalogue
Short Name:
J/A+A/508/107
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an extensive search to identify the counterparts of all the microwave foreground sources listed in the WMAP 3-year catalogue using literature and archival data. Our work has led to the identification of 309 WMAP sources, 98% of which are blazars, radio quasars, or radio galaxies. Only 7 WMAP detections were identified with other types of cosmic sources (3 starburst galaxies and 4 planetary/LBN nebulae). At present, 15 objects (<5%) still remain without identification because of the unavailability of optical spectroscopic data or a clear radio counterpart. Our results allow us to define a flux-limited sample of 203 high Galactic latitude microwave sources (f_41GHz_>=1Jy, |b_II_|>15{deg} that is virtually completely identified (99%).
497. WMAP five-year source catalog
ID:
ivo://CDS.VizieR/J/ApJS/180/283
Title:
WMAP five-year source catalog
Short Name:
J/ApJS/180/283
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the list of point sources found in the Wilkinson Microwave Anisotropy Probe (WMAP) five-year maps. The technique used in the first-year and three-year analyses now finds 390 point sources, and the five-year source catalog is complete for regions of the sky away from the Galactic plane to a 2Jy limit, with SNR>4.7 in all bands in the least covered parts of the sky. The noise at high frequencies is still mainly radiometer noise, but at low frequencies the cosmic microwave background (CMB) anisotropy is the largest uncertainty. A separate search of CMB-free V-W maps finds 99 sources of which all but one can be identified with known radio sources. The sources seen by WMAP are not strongly polarized. Many of the WMAP sources show significant variability from year to year, with more than a 2:1 range between the minimum and maximum fluxes.
498. WSRT HI data cubes of the dwarf galaxy UGCA 105
ID:
ivo://CDS.VizieR/J/A+A/561/A28
Title:
WSRT HI data cubes of the dwarf galaxy UGCA 105
Short Name:
J/A+A/561/A28
Date:
21 Oct 2021
Publisher:
CDS
Description:
Owing to their shallow stellar potential, dwarf galaxies possess thick gas disks, which makes them good candidates for studies of the galactic vertical kinematical structure. We present 21cm line observations of the isolated nearby dwarf irregular galaxy UGCA 105, taken with the Westerbork Synthesis Radio Telescope (WSRT), and analyse the geometry of its neutral hydrogen (HI) disk and its kinematics. The galaxy shows a fragmented HI distribution. It is more extended than the optical disk, and hence allows one to determine its kinematics out to very large galacto- centric distances. The HI kinematics and morphology are well-ordered and symmetric for an irregular galaxy. The HI is sufficiently extended to observe a substantial amount of differential rotation. Moreover, UGCA 105 shows strong signatures for the presence of a kinematically anomalous gas component. Performing tilted-ring modelling by use of the least-squares fitting routine TiRiFiC, we found that the HI disk of UGCA 105 has a moderately warped and diffuse outermost part. Probing a wide range of parameter combinations, we succeeded in modelling the data cube as a disk with a strong vertical gradient in rotation velocity (~-60km/s/kpc), as well as vertically increasing inwards motion (~-70km/s/kpc) within the radius of the stellar disk. The inferred radial gas inflow amounts to 0.06M_{sun}_/yr, which is similar to the star formation rate of the galaxy. The observed kinematics are hence compatible with direct or indirect accretion from the intergalactic medium, an extreme backflow of material that has formerly been expelled from the disk, or a combination of both.
499. WSRT Virgo HI filament survey
ID:
ivo://CDS.VizieR/J/A+A/527/A90
Title:
WSRT Virgo HI filament survey
Short Name:
J/A+A/527/A90
Date:
21 Oct 2021
Publisher:
CDS
Description:
Observations of neutral hydrogen can provide a wealth of information about the kinematics of galaxies. To learn more about the large-scale structures and accretion processes, the extended environment of galaxies have to be observed. Numerical simulations predict a cosmic web of extended structures and gaseous filaments. To observe the direct vicinity of galaxies, column densities have to be achieved that probe the regime of Lyman limit systems. Typically, HI observations are limited to a brightness sensitivity of N_HI_~10^19^cm^-2^, but this has to be improved by ~2 orders of magnitude. With the Westerbork Synthesis Radio Telescope (WSRT), we mapped the galaxy filament connecting the Virgo Cluster with the Local Group. About 1500 square degrees on the sky was surveyed with Nyquist sampled pointings. By using the WSRT antennas as single-dish telescopes instead of the more conventional interferometer, we were very sensitive to extended emission. The survey consists of a total of 22000 pointings, and each pointing was observed for two minutes with 14 antennas.
500. WSRT Virgo HI filament survey. II.
ID:
ivo://CDS.VizieR/J/A+A/528/A28
Title:
WSRT Virgo HI filament survey. II.
Short Name:
J/A+A/528/A28
Date:
21 Oct 2021
Publisher:
CDS
Description:
The extended environment of galaxies contains a wealth of information about the formation and life cycle of galaxies which are regulated by accretion and feedback processes. Observations of neutral hydrogen are routinely used to image the high brightness disks of galaxies and to study their kinematics. Deeper observations will give more insight into the distribution of diffuse gas in the extended halo of the galaxies and the inter-galactic medium, where numerical simulations predict a cosmic web of extended structures and gaseous filaments. To observe the extended environment of galaxies, column density sensitivities have to be achieved that probe the regime of Lyman limit systems. HI observations are typically limited to a brightness sensitivity of NHI~10^19^cm^-2^, but this must be improved upon by ~2 orders of magnitude.