- ID:
- ivo://CDS.VizieR/J/MNRAS/425/2741
- Title:
- Parameters of Spiral galaxies from SDSS 7
- Short Name:
- J/MNRAS/425/2741
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have compiled a sample of 3041 spiral galaxies with multiband gri imaging from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7; Abazajian et al., 2009ApJS..182..543A) and available galaxy rotational velocities, V, derived from HI linewidths. We compare the data products provided through the SDSS imaging pipeline with our own photometry of the SDSS images, and use the velocities, V, as an independent metric to determine ideal galaxy sizes (R) and luminosities (L). Our radial and luminosity parameters improve upon the SDSS DR7 Petrosian radii and luminosities through the use of isophotal fits to the galaxy images. This improvement is gauged via VL (Vmag-Luminosity) and RV relations whose respective scatters are reduced by ~8 and ~30% with our parameters compared to similar relations built with SDSS parameters.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/135/1225
- Title:
- Parameters of the local white dwarfs
- Short Name:
- J/AJ/135/1225
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a detailed new survey of the local population of white dwarfs lying within 20pc of the Sun. A new revised catalog of local white dwarfs containing 122 entries (126 individual degenerate stars) is presented. This list contains 27 white dwarfs not included in a previous list from 2002, as well as new and recently published trigonometric parallaxes. In several cases new members of the local white dwarf population have come to light through accurate photometric distance estimates. In addition, a suspected new double degenerate system (WD 0423+120) has been identified. The 20pc sample is currently estimated to be 80% complete. Using a variety of recent spectroscopic, photometric, and trigonometric distance determinations, we re-compute a space density of 4.8+/-0.5x10^-3^pc^-3^ corresponding to a mass density of 3.2+/-0.3x10^-3^M_{sun}_pc^-3^ from the complete portion of the sample within 13pc. We find an overall mean mass for the local white dwarfs of 0.665M_{sun}_, a value larger than most other non-volume-limited estimates. Although the sample is small, we find no evidence of a correlation between mass and temperature in which white dwarfs below 13000K are systematically more massive than those above this temperature. Within 20pc 25% of the white dwarfs are in binary systems (including double degenerate systems). Approximately 6% are double degenerates and 6.5% are Sirius-like systems. The fraction of magnetic white dwarfs in the local population is found to be 13%.
- ID:
- ivo://CDS.VizieR/I/227
- Title:
- Paris AC Zone Data Reduced to ACRS
- Short Name:
- I/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Paris Zone, whose plates are centered between declinations +18 and +24 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 253,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/2295
- Title:
- 25 parsec local white dwarf population
- Short Name:
- J/MNRAS/462/2295
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have extended our detailed survey of the local white dwarf population from 20 to 25pc, effectively doubling the sample volume, which now includes 232 stars. In the process, new stars within 20 pc have been added, a more uniform set of distance estimates as well as improved spectral and binary classifications are available. The present 25pc sample is estimated to be about 68 per cent complete (the corresponding 20pc sample is now 86 per cent complete). The space density of white dwarfs is unchanged at 4.8+/-0.5x10^-3^pc^-3^. This new study includes a white dwarf mass distribution and luminosity function based on the 232 stars in the 25pc sample. We find a significant excess of single stars over systems containing one or more companions (74 per cent versus 26 per cent). This suggests mechanisms that result in the loss of companions during binary system evolution. In addition, this updated sample exhibits a pronounced deficiency of nearby 'Sirius-like' systems. 11 such systems were found within the 20pc volume versus only one additional system found in the volume between 20 and 25pc. An estimate of white dwarf birth rates during the last ~8Gyr is derived from individual remnant cooling ages. A discussion of likely ways new members of the local sample may be found is provided.
- ID:
- ivo://CDS.VizieR/J/A+A/650/A201
- Title:
- 10 parsec sample in the Gaia era
- Short Name:
- J/A+A/650/A201
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The nearest stars provide a fundamental constraint for our understanding of stellar physics and the Galaxy. The nearby sample serves as an anchor where all objects can be seen and understood with precise data. This work is triggered by the most recent data release of the astrometric space mission Gaia and uses its unprecedented high precision parallax measurements to review the census of objects within 10pc. The first aim of this work was to compile all stars and brown dwarfs within 10pc observable by Gaia and compare it with the Gaia Catalogue of Nearby Stars as a quality assurance test. We complement the list to get a full 10 pc census, including bright stars, brown dwarfs, and exoplanets. We started our compilation from a query on all objects with a parallax larger than 100 mas using the Set of Identifications, Measurements, and Bibliography for Astronomical Data database (SIMBAD). We completed the census by adding companions, brown dwarfs with recent parallax measurements not in SIMBAD yet, and vetted exoplanets. The compilation combines astrometry and photometry from the recent Gaia Early Data Release 3 with literature magnitudes, spectral types, and line-of-sight velocities. We give a description of the astrophysical content of the 10pc sample. We find a multiplicity frequency of around 27%. Among the stars and brown dwarfs, we estimate that around 61% are M stars and more than half of the M stars are within the range from M3.0 V to M5.0 V. We give an overview of the brown dwarfs and exoplanets that should be detected in the next Gaia data releases along with future developments. We provide a catalogue of 540 stars, brown dwarfs, and exoplanets in 339 systems, within 10pc from the Sun. This list is as volume-complete as possible from current knowledge and it provides benchmark stars that can be used, for instance, to define calibration samples and to test the quality of the forthcoming Gaia releases. It also has a strong outreach potential.
- ID:
- ivo://CDS.VizieR/J/MNRAS/405/783
- Title:
- Passive red spirals in Galaxy Zoo
- Short Name:
- J/MNRAS/405/783
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the spectroscopic properties and environments of red (or passive) spiral galaxies found by the Galaxy Zoo project. By carefully selecting face-on disc-dominated spirals, we construct a sample of truly passive discs (i.e. they are not dust reddened spirals, nor are they dominated by old stellar populations in a bulge). As such, our red spirals represent an interesting set of possible transition objects between normal blue spiral galaxies and red early types, making up ~6 per cent of late-type spirals. We use optical images and spectra from Sloan Digital Sky Survey to investigate the physical processes which could have turned these objects red without disturbing their morphology.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/L11
- Title:
- Passive spiral galaxy cand. multi-phot.
- Short Name:
- J/MNRAS/462/L11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified a population of passive spiral galaxies from photometry and integral field spectroscopy. We selected z<0.035 spiral galaxies that have WISE colours consistent with little mid-infrared emission from warm dust. Matched aperture photometry of 51 spiral galaxies in ultraviolet, optical and mid-infrared show these galaxies have colours consistent with passive galaxies. Six galaxies form a spectroscopic pilot study and were observed using the Wide-Field Spectrograph (WiFeS) to check for signs of nebular emission from star formation. We see no evidence of substantial nebular emission found in previous red spiral samples. These six galaxies possess absorption line spectra with 4000{AA} breaks consistent with an average luminosity-weighted age of 2.3Gyr. Our photometric and IFU spectroscopic observations confirm the existence of a population of local passive spiral galaxies, implying that transformation into early-type morphologies is not required for the quenching of star formation.
- ID:
- ivo://CDS.VizieR/J/AJ/162/100
- Title:
- PAST. II. LAMOST-Gaia-Kepler catalog of 35835 stars
- Short Name:
- J/AJ/162/100
- Date:
- 14 Mar 2022 06:40:51
- Publisher:
- CDS
- Description:
- The Kepler telescope has discovered over 4000 planets (candidates) by searching ~200000 stars over a wide range of distance (order of kpc) in our Galaxy. Characterizing the kinematic properties (e.g., Galactic component membership and kinematic age) of these Kepler targets (including the planet candidate hosts) is the first step toward studying Kepler planets in the Galactic context, which will reveal fresh insights into planet formation and evolution. In this paper, the second part of the Planets Across the Space and Time (PAST) series, by combining the data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and Gaia and then applying the revised kinematic methods from PAST I, we present a catalog of kinematic properties (i.e., Galactic positions, velocities, and the relative membership probabilities among the thin disk, thick disk, Hercules stream, and the halo) as well as other basic stellar parameters for 35835 Kepler stars. Further analyses of the LAMOST-Gaia-Kepler catalog demonstrate that our derived kinematic age reveals the expected stellar activity-age trend. Furthermore, we find that the fraction of thin (thick) disk stars increases (decreases) with the transiting planet multiplicity (N_p_=0,1,2 and3+) and the kinematic age decreases with N_p_, which could be a consequence of the dynamical evolution of planetary architecture with age. The LAMOST-Gaia-Kepler catalog will be useful for future studies on the correlations between the exoplanet distributions and the stellar Galactic environments as well as ages.
- ID:
- ivo://CDS.VizieR/J/A+A/480/495
- Title:
- Patterns of color variations in close binaries
- Short Name:
- J/A+A/480/495
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first of a series of papers in which we present the results of a long-term photometric monitoring project carried out at Catania Astrophysical Observatory aimed at studying magnetic activity in late-type components of close binary systems, its dependence on global stellar parameters, and its evolution on different time scales from days to years. In this first paper, we present the complete observation dataset and new results of an investigation into the origin of brightness and color variations observed in the well-known magnetically active close binary stars: AR Psc, VY Ari, UX Ari, V711 Tau, EI Eri, V1149 Ori, DH Leo, HU Vir, RS CVn, V775 Her, AR Lac, SZ Psc, II Peg and BY Dra . About 38000 high-precision photoelectric nightly observations in the U, B and V filters are analysed. Correlation and regression analyses of the V magnitude vs. U-B and B-V color variations are carried out and a comparison with model variations for a grid of active region temperature and filling factor values is also performed. We find the existence of two different patterns of color variation. Eight stars in our sample: BY Dr, VY Ari, V775 Her, II Peg, V1149 Ori, HU Vir, EI Eri and DH Leo become redder when they become fainter, as is expected from the presence of active regions consisting of cool spots. The other six stars show the opposite behaviour, i.e. they become bluer when they become fainter. For V711 Tau this behaviour could be explained by the increased relative U- and B- flux contribution by the earlier-type component of the binary system when the cooler component becomes fainter. On the other hand, for AR Psc, UX Ari, RS CVn, SZ Psc and AR Lac the existence of hot photospheric faculae must be invoked. We also found that in single-lined and double-lined binary stars in which the fainter component is inactive or much less active the V magnitude is correlated to B-V and U-B color variations in more than 60% of observation seasons. The correlation is found in less than 40% of observation seasons when the fainter component has a non-negligible level of activity and/or hot faculae are present but they are either spatially or temporally uncorrelated to spots.
- ID:
- ivo://CDS.VizieR/J/AJ/139/2269
- Title:
- P Cyg H{alpha} squared visibility
- Short Name:
- J/AJ/139/2269
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High spatial resolution observations of the H{alpha}-emitting wind structure associated with the luminous blue variable star P Cygni were obtained with the Navy Prototype Optical Interferometer. These observations represent the most comprehensive interferometric data set on P Cyg to date. We demonstrate how the apparent size of the H{alpha}-emitting region of the wind structure of P Cyg compares between the 2005, 2007, and 2008 observing seasons and how this relates to the H{alpha} line spectroscopy. Using the data sets from 2005, 2007, and 2008 observing seasons, we fit a circularly symmetric Gaussian model to the interferometric signature from the H#-emitting wind structure of P Cyg.
