- ID:
- ivo://CDS.VizieR/J/ApJS/239/32
- Title:
- APOKASC-2 catalog of Kepler evolved stars
- Short Name:
- J/ApJS/239/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of stellar properties for a large sample of 6676 evolved stars with Apache Point Observatory Galactic Evolution Experiment spectroscopic parameters and Kepler asteroseismic data analyzed using five independent techniques. Our data include evolutionary state, surface gravity, mean density, mass, radius, age, and the spectroscopic and asteroseismic measurements used to derive them. We employ a new empirical approach for combining asteroseismic measurements from different methods, calibrating the inferred stellar parameters, and estimating uncertainties. With high statistical significance, we find that asteroseismic parameters inferred from the different pipelines have systematic offsets that are not removed by accounting for differences in their solar reference values. We include theoretically motivated corrections to the large frequency spacing ({Delta}{nu}) scaling relation, and we calibrate the zero-point of the frequency of the maximum power ({nu}max) relation to be consistent with masses and radii for members of star clusters. For most targets, the parameters returned by different pipelines are in much better agreement than would be expected from the pipeline-predicted random errors, but 22% of them had at least one method not return a result and a much larger measurement dispersion. This supports the usage of multiple analysis techniques for asteroseismic stellar population studies. The measured dispersion in mass estimates for fundamental calibrators is consistent with our error model, which yields median random and systematic mass uncertainties for RGB stars of order 4%. Median random and systematic mass uncertainties are at the 9% and 8% level, respectively, for red clump stars.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/215/19
- Title:
- APOKASC catalog of Kepler red giants
- Short Name:
- J/ApJS/215/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first APOKASC catalog of spectroscopic and asteroseismic properties of 1916 red giants observed in the Kepler fields. The spectroscopic parameters provided from the Apache Point Observatory Galactic Evolution Experiment project are complemented with asteroseismic surface gravities, masses, radii, and mean densities determined by members of the Kepler Asteroseismology Science Consortium. We assess both random and systematic sources of error and include a discussion of sample selection for giants in the Kepler fields. Total uncertainties in the main catalog properties are of the order of 80K in T_eff_, 0.06dex in [M/H], 0.014dex in logg, and 12% and 5% in mass and radius, respectively; these reflect a combination of systematic and random errors. Asteroseismic surface gravities are substantially more precise and accurate than spectroscopic ones, and we find good agreement between their mean values and the calibrated spectroscopic surface gravities. There are, however, systematic underlying trends with T_eff_ and logg. Our effective temperature scale is between 0 and 200K cooler than that expected from the infrared flux method, depending on the adopted extinction map, which provides evidence for a lower value on average than that inferred for the Kepler Input Catalog (KIC). We find a reasonable correspondence between the photometric KIC and spectroscopic APOKASC metallicity scales, with increased dispersion in KIC metallicities as the absolute metal abundance decreases, and offsets in T_eff_ and logg consistent with those derived in the literature. We present mean fitting relations between APOKASC and KIC observables and discuss future prospects, strengths, and limitations of the catalog data.
- ID:
- ivo://CDS.VizieR/J/ApJS/233/23
- Title:
- APOKASC catalog of KIC dwarfs and subgiants
- Short Name:
- J/ApJS/233/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first APOKASC catalog of spectroscopic and asteroseismic data for dwarfs and subgiants. Asteroseismic data for our sample of 415 objects have been obtained by the Kepler mission in short (58.5s) cadence, and light curves span from 30 up to more than 1000 days. The spectroscopic parameters are based on spectra taken as part of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and correspond to Data Release 13 of the Sloan Digital Sky Survey. We analyze our data using two independent T_eff_ scales, the spectroscopic values from DR13 and those derived from SDSS griz photometry. We use the differences in our results arising from these choices as a test of systematic temperature uncertainties and find that they can lead to significant differences in the derived stellar properties. Determinations of surface gravity (logg), mean density (<{rho}>), radius (R), mass (M), and age ({tau}) for the whole sample have been carried out by means of (stellar) grid-based modeling. We have thoroughly assessed random and systematic error sources in the spectroscopic and asteroseismic data, as well as in the grid-based modeling determination of the stellar quantities provided in the catalog. We provide stellar properties determined for each of the two T_eff_ scales. The median combined (random and systematic) uncertainties are 2% (0.01dex; logg), 3.4% (<{rho}>), 2.6% (R), 5.1% (M), and 19% ({tau}) for the photometric T_eff_ scale and 2% (logg), 3.5% (<{rho}>), 2.7% (R), 6.3% (M), and 23% ({tau}) for the spectroscopic scale.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A158
- Title:
- A polarimetric study of ACOs
- Short Name:
- J/A+A/658/A158
- Date:
- 22 Feb 2022 15:07:47
- Publisher:
- CDS
- Description:
- Asteroids in comet-like orbits (ACOs) consist of asteroids and dormant comets. Due to their similar appearance, it is challenging to distinguish dormant comets from ACOs via general telescopic observations. Surveys for discriminating dormant comets from the ACO population have been conducted via spectroscopy or optical and mid-infrared photometry. However, they have not been conducted through polarimetry. We conducted the first polarimetric research of ACOs. We conducted a linear polarimetric pilot survey for three ACOs: (944) Hidalgo, (3552) Don Quixote, and (331471) 1984 QY1. These objects are unambiguously classified into ACOs in terms of their orbital elements (i.e., the Tisserand parameters with respect to Jupiter TJ significantly less than 3). Three ACOs were observed by the 1.6-m Pirka Telescope from UT 2016 May 25 to UT 2019 July 22 (13 nights). We found that two ACOs, Don Quixote and Hidalgo, have polarimetric properties similar to comet nuclei and D-type asteroids (optical analogs of comet nuclei. However, 1984 QY1 exhibited a polarimetric property consistent with S-type asteroids. We conducted a backward orbital integration to determine the origin of 1984 QY1 and found that this object was transported from the main belt into the current comet-like orbit via the 3:1 mean motion resonance with Jupiter. We conclude that the origins of ACOs can be more reliably identified by adding polarimetric data to the color and spectral information. This study would be valuable for investigating how the ice-bearing small bodies distribute in the inner solar system.
- ID:
- ivo://CDS.VizieR/J/ApJ/712/585
- Title:
- Apparent velocity measurements of DA WDs
- Short Name:
- J/ApJ/712/585
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure apparent velocities (v_app_) of the H{alpha} and H{beta} Balmer line cores for 449 non-binary thin disk normal DA white dwarfs (WDs) using optical spectra taken for the European Southern Observatory SN Ia progenitor survey (SPY). Assuming these WDs are nearby and comoving, we correct our velocities to the local standard of rest so that the remaining stellar motions are random. By averaging over the sample, we are left with the mean gravitational redshift, <v_g_>: we find <v_g_>=<v_app_>=32.57+/-1.17km/s. Using the mass-radius relation from evolutionary models, this translates to a mean mass of 0.647^+0.013^_-0.014_M_{sun}_. We interpret this as the mean mass for all DAs.
- ID:
- ivo://CDS.VizieR/J/A+A/581/A126
- Title:
- Application of the D^3^PO algorithm
- Short Name:
- J/A+A/581/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze the 6.5yr all-sky data from the Fermi LAT restricted to gamma-ray photons with energies between 0.6-307.2GeV. We present a non-parametric reconstruction of the diffuse photon flux up to several hundred GeV, its all-sky spectral index map, and its angular power spectrum. We decompose the diffuse emission into a cloud-like abd a bubble-like component and analyze their spectra. Additionally, we wrote up a catalog of source candidates that includes 3106 sources. For each source we report the location in the sky, flux, spectral index, and possible associations with sources from the second and third Fermi source catalog.
- ID:
- ivo://CDS.VizieR/J/A+A/437/375
- Title:
- Approximate elements of eclipsing binaries
- Short Name:
- J/A+A/437/375
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The new data on the orbital elements, masses and luminosities have been collected for 31 pre-contact binary systems of short-periodic RS CVn type. The results of statistical treatment of the catalogue data pursue the goal of an accurate definition of the properties and evolutionary status of the given class systems. The ages of pre-contact systems have been estimated by isochrone method. Numerous comments and bibliographic references to the catalogue are accessible.
- ID:
- ivo://CDS.VizieR/V/124
- Title:
- Approximate elements of eclipsing binaries
- Short Name:
- V/124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In 1986 Svechnikov M.A. had published the "Catalogue of orbital elements, masses and luminosities" [1] of 246 eclipsing binary systems with known photometric and spectroscopic elements on comparatively early stages of their evolution (on the stage of the main sequence and during or after the "first change of mass") and belonging to DM, SD, DS, KE, KW, DW and AR evolutionary types (see lower) according to Svechnikov's classification [2,3,4]. However the representative eclipsing systems in this catalogue make up only a small share (about 5%) from discovered ones to all eclipsing variable stars of mentioned types (the general catalogue of variable stars [5] (which is called further GCVS IV) contains the information approximately of about 5000 eclipsing binary stars of different types). It is of a great interest for statistic research to give if only the approximate estimations of relative and absolute elements of those systems for which elements of the spectroscopic orbits are unknown and the direct calculation of their absolute characteristics is impossible. For this approximate estimation the statistic relations (mass - luminosity, mass - radius, mass - spectrum etc.) obtained for the components of different type systems [6-9] and a number of other statistic dependences which have been found from study of 246 eclipsing systems mentioned (for example, the dependence of orbital inclination I on the depth of main minimum A1, the dependence of the main component spectral classes for the KE- and KW-systems on the period P etc.) were used. For definition of the approximate elements it was used the information from GCVS IV about the morphological type of systems (EA, EB, EW), its period, the spectral classes of systems, amplitudes A1 and A2 of the main and second minima, duration of eclipse D1 and duration of constant light phase D2 in the main minimum etc., it was made the classification of eclipsing variable stars with the help of a simple test, worked out in [4], and the statistic dependences obtained for the stars of a given type was used later on the question about reliability of approximate relative and absolute elements which have been founded by this way was studied earlier in [8]. The accuracy of these elements is essentially higher for systems with certain spectra of main components (SP1). This fact was taken into account in catalogue by giving the essentially a higher weights to elements of those systems. There are about 1200 systems with the certain meaning SP1 in our catalogue, it is about 1/3 from all eclipsing systems in it. On the whole the elements (with different reability) for about 3800 eclipsing variable stars of DM, SD, DS, KE, KW and DW types are given in catalogue which makes up the overwhelming majority of eclipsing variable stars with the certain period from GCVS IV. Because of the possible mistakes in our classification wrong or incomplete data given in GCVS IV and also because of the fact that used statistic dependences for definition of elements have an approximate character, it should be expect that founded in catalogue the approximate elements for many systems are inaccurate and even wrong. By our estimation, elements will be grossly wrong for about 10-15% of systems given in this catalogue (which principally have a small weights), for about 20- 25% of systems the founded elements will turn out essentially different from veritable, however, we hope that for 60-70% of systems the photometric and absolute elements will turn out quite similar to elements which will be received the more exact methods later on. The elements, given in catalogue, may be used in the different statistic researches and also as an initial approximation for the calculation of photometric and absolute elements of these eclipsing stars with more exact methods.
- ID:
- ivo://CDS.VizieR/J/AJ/128/463
- Title:
- A preliminary 20pc census from the NLTT catalogue
- Short Name:
- J/AJ/128/463
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Continuing our census of late-type dwarfs in the solar neighborhood, we present BVRI photometry and optical spectroscopy of 800 mid-type M dwarfs drawn from the NLTT proper-motion catalog. The targets are taken both from our own cross-referencing of the NLTT Catalogue and the 2MASS Second Incremental Data Release, and from the revised NLTT compiled recently by Salim & Gould (Cat. <J/ApJ/582/1011>). All are identified as nearby-star candidates based on their location in the (m_r_, m_r_-K_s_) diagram. Three hundred stars discussed here have previous astrometric, photometric, or spectroscopic observations. We present new BVRI photometry for 101 stars, together with low-resolution spectroscopy of a further 400 dwarfs.
- ID:
- ivo://CDS.VizieR/J/ApJ/473/822
- Title:
- APS Catalog of Galaxies behind Virgo
- Short Name:
- J/ApJ/473/822
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 1268 galaxies, essentially complete to B<=17.0, found by scanning glass copies of several fields of the original Palomar Sky Survey using the Minnesota Automated Plate Scanner in its isodensitometric mode (as opposed to the threshold densitometric mode used in the APS Catalog of the POSS I). In addition to the different scanning mode, we have employed a different star-galaxy separation method and have visually inspected POSS prints to verify that each image remaining in the catalog is non-stellar. The scanned fields are distributed generally in two areas, one around the outskirts of the Virgo Cluster, the other toward the antipode of the cluster (but still in the northern celestial hemisphere). The catalog gives the position of the center of each galaxy; estimates of the blue and red magnitudes within the outermost threshold crossing and of the blue magnitude extrapolated to zero surface brightness; blue and red diameters of four ellipses fit to the four threshold crossings (approximately 23.8, 23.6, 23.2, and 22.7 mag per square arcsec in blue, and 22.5, 22.4, 21.5 and 21.2 mag per square arcsec in red), and the ellipticities of those four ellipses. The catalog has served as a base from which to draw targets for a Tully-Fisher study of the Virgocentric infall velocity of the Local Group.
