- ID:
- ivo://CDS.VizieR/J/ApJ/714/1441
- Title:
- Linearity of the cosmic expansion field
- Short Name:
- J/ApJ/714/1441
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Particularly accurate relative distances are compiled and homogenized for (1) 246 Type Ia supernovae and 35 clusters with v<30000km/s, and (2) relatively nearby galaxies with 176 tip of the red-giant branch and 30 Cepheid distances. The 487 objects define a tight Hubble diagram from 300-30000km/s implying individual distance errors of <~7.5%. Here the velocities are corrected for Virgocentric steaming (locally 220km/s) and -if v_220_>3500km/s- for a 495km/s motion of the Local Supercluster toward the warm cosmic microwave background (CMB) pole at l=275, b=12; local peculiar motions are averaged out by large numbers.
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- ID:
- ivo://CDS.VizieR/J/ApJS/141/469
- Title:
- Linear polarization catalog toward HD 62542
- Short Name:
- J/ApJS/141/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained linear polarization measurements of stars along the western side of the IRAS Vela Shell toward HD 62542. From 16 CCD fields distributed along the ionization front (I-front) we have built a catalog of 856 objects with polarization signal-to-noise ratio larger than 10. We detect very significant levels of polarization and hence an appreciable magnetic field throughout the region. Composite polarization maps around the I-front are shown. In some regions the polarization vectors are parallel to the I-front, but a perpendicular trend is also evident along parts of the front. In addition, the polarization pattern seems to be affected by gas streaming inside the cloud. The observations were made using a CCD imaging polarimeter attached to the 1.5m Telescope of Cerro Tololo Inter-American Observatory (CTIO), Chile. The data were collected in 1991 December and 1992 December.
- ID:
- ivo://CDS.VizieR/II/178
- Title:
- Linear polarization measurements for 5070 stars
- Short Name:
- II/178
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The authors have collected and collated measurements of linear polarization of starlight from Hiltner, Smith, Hall, Behr, Appenzeller, Mathewson and Ford, Klare et al., and Schroeder. These are presented in a catalog for stars with reliable distances that lists the Stokes parameters Q and U. The galactic latitude and longitude and distance are also given. See the documentation by Nancy G. Roman, either in plain ascii (file adc.doc), or in LaTeX (doc.tex)
- ID:
- ivo://CDS.VizieR/J/AJ/130/1389
- Title:
- Linear polarization of AGN jets at 15GHz
- Short Name:
- J/AJ/130/1389
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present first-epoch, milliarcsecond-scale linear polarization images at 15GHz of 133 jets associated with active galactic nuclei (AGNs) from the MOJAVE (Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments) survey. MOJAVE is a long-term observational program to study the structure and evolution of relativistic outflows in AGNs. The sample consists of all known AGNs with Galactic latitude |b|>2.5{deg}, J2000.0 declination greater than -20{deg} and correlated 15GHz Very Long Baseline Array (VLBA) flux density exceeding 1.5Jy (2Jy for sources below the celestial equator) at any epoch during the period 1994-2003.
- ID:
- ivo://CDS.VizieR/J/MNRAS/405/2570
- Title:
- Linear polarization of nearby bright stars
- Short Name:
- J/MNRAS/405/2570
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report observations of the linear polarization of a sample of 49 nearby bright stars measured to sensitivities of between ~1 and ~4x10^-6^. The majority of stars in the sample show measurable polarization, but most polarizations are small with 75 per cent of the stars having P<2x10^-5^.
- ID:
- ivo://CDS.VizieR/J/A+AS/39/379
- Title:
- Linear Polarization of radio sources
- Short Name:
- J/A+AS/39/379
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue is a compilation of all the data of linear polarization of radio sources published prior to December 1978. The catalogue contained 7224 data for 1510 radio sources. Polarization parameters derived from the data are also tabulated with other physical parameters.
- ID:
- ivo://CDS.VizieR/J/ApJS/244/3
- Title:
- Linear structural param. of SDSS+UKIDSS+WISE gal.
- Short Name:
- J/ApJS/244/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate measurements of galaxy structure are prerequisites for quantitative investigation of galaxy properties or evolution. Yet galaxy inclination, through projection and varying dust effects, strongly affects many commonly used metrics of galaxy structure. Here we demonstrate that collapsing a galaxy's light distribution onto its major axis gives a "linear brightness profile" that is unaffected by projection. In analogy to widely used half-light radius and concentrations, we use two metrics to describe this light distribution: x_50_, the linear distance containing half of the galaxy's luminosity, and c_x_=x_90_/x_50_, the ratio between the 90% light distance and the 50% light distance. In order to minimize the effects of dust, we apply this technique to a diverse sample of galaxies with moderately deep and high-resolution K-band imaging from the UKIDSS Large Area Survey. Using simulated galaxy images, we find that while our measurements are primarily limited by the surface brightness in the outer parts of galaxies, most local galaxies have high enough surface brightnesses to result in reliable measurements. When applied to real data, our metrics vary from face-on to edge-on by typically ~5% in c_x_ and ~12% in x_50_, representing factors of several to 10 improvement over existing optical and some infrared catalog measures of galaxy structure. We release a sample of 23804 galaxies with inclination-independent and dust-penetrated observational proxies for stellar mass, specific star formation rate, half-light size, and concentration.
- ID:
- ivo://CDS.VizieR/J/ApJ/621/673
- Title:
- Line indices for 124 early-type galaxies
- Short Name:
- J/ApJ/621/673
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this paper is to set constraints on the epochs of early-type galaxy formation through the "archaeology" of the stellar populations in local galaxies. Using our models of absorption-line indices that account for variable abundance ratios, we derive ages, total metallicities, and element ratios of 124 early-type galaxies in high- and low-density environments. The data are analyzed by comparison with mock galaxy samples created through Monte Carlo simulations taking the typical average observational errors into account, in order to eliminate artifacts caused by correlated errors.
- ID:
- ivo://CDS.VizieR/J/MNRAS/403/896
- Title:
- Line intensities of SDSS HII regions
- Short Name:
- J/MNRAS/403/896
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectra of high-metallicity [12+log(O/H)>~8.2] HII regions, where oxygen auroral lines are measurable in both the O^+^ and O^++^ zones, have been extracted from the Data Release 6 of the Sloan Digital Sky Survey (SDSS). Our final sample consists of 181 SDSS spectra of HII regions in galaxies in the redshift range from ~0.025 to ~0.17. The t_2,O_-t_3,O_ diagram is examined. In the SDSS HII regions, the electron temperature t_2,O_ is found to have a large scatter at a given value of the electron temperature t_3,O_. The majority of the SDSS HII regions lie below the t_2,O-t3,O_ relation derived for HII regions in nearby galaxies, i.e. the positions of the SDSS HII regions show a systematic shift towards lower t_2,O_ temperatures or/and towards higher t_3,O_ temperatures. The scatter and shift of the SDSS HII regions in the t_2,O_-t_3,O_ diagram can be understood if they are composite nebulae excited by two or more ionizing sources of different temperatures.
- ID:
- ivo://CDS.VizieR/J/MNRAS/450/4301
- Title:
- Line list for red giants in open clusters
- Short Name:
- J/MNRAS/450/4301
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed high-dispersion echelle spectra of red giant members in the five open clusters (OCs) NGC 1342, NGC 1662, NGC 1912, NGC 2354 and NGC 2447 and determined their radial velocities and chemical compositions. These are the first chemical abundance measurements for all but NGC 2447. We combined our clusters from this and previous papers with a sample drawn from the literature for which we remeasured the chemical abundances to establish a common abundance scale. With this homogeneous sample of OCs, we study the relative elemental abundances of stars in OCs in comparison with field stars as a function of age and metallicity. We find a range of mild enrichment of heavy (Ba-Eu) elements in young OC giants over field stars of the same metallicity. Our analysis supports that the youngest stellar generations in cluster might be underrepresented by the solar neighbourhood field stars.