- ID:
- ivo://CDS.VizieR/J/MNRAS/436/1343
- Title:
- Calibration of RAVE distances with Hipparcos
- Short Name:
- J/MNRAS/436/1343
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A magnitude limited population of 18808 Hipparcos stars is used to calibrate distances for 52794 RAVE stars, including dwarfs, giants, and pre-main sequence stars. I give treatments for a number of types of bias affecting calculation, including bias from the non-linear relationship between the quantity of interest (e.g., distance or distance modulus) and the measured quantity (parallax or visual magnitude), the Lutz-Kelker bias, and bias due to variation in density of the stellar population. The use of a magnitude bound minimises the Malmquist and the Lutz-Kelker bias, and avoids a measurement bias because Hipparcos parallaxes are more accurate for brighter stars. The calibration is applicable to stars in 2MASS when there is some way to determine stellar class with reasonable confidence. For RAVE this is possible for hot dwarfs and using log g. The accuracy of the calibration is tested against Hipparcos stars with better than 2% parallax errors, and by comparison of the RAVE velocity distribution with that of Hipparcos, and is found to improve upon previous estimates of luminosity distance. An estimate of the LSR from RAVE data, (U0, V0, W0) = (14.9-1.7, 15.3-0.4, 6.9-0.1)km/s shows excellent agreement with the current best estimate from XHIP. The RAVE velocity distribution confirms the alignment of stellar motions with spiral structure.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/440/2026
- Title:
- Calibration of some distance scales
- Short Name:
- J/MNRAS/440/2026
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a method for distance calibration without using standard fitting procedures. Instead, we use random resampling to reconstruct the probability density function (PDF) of calibration data points in the fitting plane. The resulting PDF is then used to estimate distance-related properties. The method is applied to samples of radio surface brightness to diameter ({Sigma}-D}) data for the Galactic supernova remnants (SNRs) and planetary nebulae (PNe), and period-luminosity (PL) data for the Large Magellanic Cloud (LMC) fundamental mode classical Cepheids. We argue that resulting density maps can provide more accurate and more reliable calibrations than those obtained by standard linear fitting procedures. For the selected sample of the Galactic SNRs, the presented PDF method of distance calibration results in a smaller average distance fractional error of up to ~16 percentage points. Similarly, the fractional error is smaller for up to ~8 and ~0.5 percentage points, for the samples of Galactic PNe and LMC Cepheids, respectively. In addition, we provide a PDF-based calibration data for each of the samples.
- ID:
- ivo://CDS.VizieR/J/A+A/339/858
- Title:
- Calibration of stellar parameters
- Short Name:
- J/A+A/339/858
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of calibration of the surface brightness, bolometric flux and effective temperature scales are presented for 537 dwarfs and giants selected as standards for the Infrared Space Observatory (ISO). Individual temperatures with small model-dependent corrections are derived at the target accuracy of 1%. The comparison with semiempirical values achieved by the Infrared Flux Method (IRFM) shows consistent results within the 1% level for F, G and K stars, but not for A-type stars.
- ID:
- ivo://CDS.VizieR/J/A+A/498/527
- Title:
- Calibration of Stromgren phot. for late-type stars
- Short Name:
- J/A+A/498/527
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The use of model atmospheres for deriving stellar fundamental parameters, such as Teff, log(g), and [Fe/H], will increase as we find and explore extreme stellar populations where empirical calibrations are not yet available. Moreover, calibrations for upcoming large satellite missions of new spectrophotometric indices, similar to the uvby-Hbeta system, will be needed. We aim to test the power of theoretical calibrations based on a new generation of MARCS models by comparisons with observational photometric data. We calculated synthetic uvby-Hbeta colour indices from synthetic spectra. A sample of 367 field stars, as well as stars in globular clusters, is used for a direct comparison of the synthetic indices versus empirical data and for scrutizing the possibilities of theoretical calibrations for temperature, metallicity, and gravity. We show that the temperature sensitivity of the synthetic (b-y) colour is very close to its empirical counterpart, whereas the temperature scale based upon Hbeta shows a slight offset. The theoretical metallicity sensitivity of the m1 index (and for G-type stars its combination with c1) is somewhat higher than the empirical one, based upon spectroscopic determinations. The gravity sensitivity of the synthetic c1 index shows satisfactory behaviour when compared to observations of F stars. For stars cooler than the sun, a deviation is significant in the c1-(b-y) diagram. The theoretical calibrations of (b-y), (v-y), and c1 seem to work well for Pop II stars and lead to effective temperatures for globular cluster stars supporting recent claims that atomic diffusion occurs in stars near the turnoff point of NGC 6397. Synthetic colours of stellar atmospheres can indeed be used, in many cases, to derive reliable fundamental stellar parameters. The deviations seen when compared to observational data could be due to incomplete linelists but are possibly also due to the effects of assuming plane-parallel or spherical geometry and LTE.
- ID:
- ivo://CDS.VizieR/J/AJ/129/1642
- Title:
- Calibration of synthetic photometry
- Short Name:
- J/AJ/129/1642
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new calibration of optical (UBV, Stroemgren uvby{beta}, and Geneva) and near-IR (Johnson RIJHK and Two Micron All Sky Survey) photometry for B and early A stars derived from Kurucz ATLAS9 model atmospheres. These models are then used to calibrate the synthetic photometry.
- ID:
- ivo://CDS.VizieR/J/ApJ/765/94
- Title:
- Calibration of the mid-IR Tully-Fisher relation
- Short Name:
- J/ApJ/765/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Distance measures on a coherent scale around the sky are required to address the outstanding cosmological problems of the Hubble constant and of departures from the mean cosmic flow. The correlation between galaxy luminosities and rotation rates can be used to determine the distances to many thousands of galaxies in a wide range of environments potentially out to 200Mpc. Mid-infrared (3.6{mu}m) photometry with the Spitzer Space Telescope is particularly valuable as a source of luminosities because it provides products of uniform quality across the sky. From a perch above the atmosphere, essentially the total magnitude of targets can be registered in exposures of a few minutes. Extinction is minimal and the flux is dominated by the light from old stars, which is expected to correlate with the mass of the targets. In spite of the superior photometry, the correlation between mid-infrared luminosities and rotation rates extracted from neutral hydrogen profiles is slightly degraded from the correlation found with I-band luminosities. A color correction recovers a correlation that provides comparable accuracy to that available at the I band (~20% 1{sigma} in an individual distance) while retaining the advantages identified above. Without color correction, the relation between linewidth and [3.6] magnitudes is M^b,i,k,a^_[3.6]_=-20.34-9.74(logW^i^_mx_-2.5). This description is found with a sample of 213 galaxies in 13 clusters that define the slope and 26 galaxies with Cepheid or tip of the red giant branch distances that define the zero point. A color-corrected parameter M_c[3.6]_ is constructed that has reduced scatter: M_c[3.6]_=-20.34-9.13(logW_mx_^i^-2.5). Consideration of the seven calibration clusters beyond 50Mpc, outside the domain of obvious peculiar velocities, provides a preliminary Hubble constant estimate of H_0_=74+/-4km/s.M/pc.
- ID:
- ivo://CDS.VizieR/J/ApJ/533/744
- Title:
- Calibration of the Tully-Fischer relation
- Short Name:
- J/ApJ/533/744
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The correlation between the luminosities and rotation velocities of galaxies can be used to estimate distances to late-type galaxies. It is an appropriate moment to reevaluate this method given the great deal of new information available. The major improvements described here include: (1) the template relations can now be defined by large, complete samples, (3) the samples are drawn from a wide range of environments, (3) the relations are defined by photometric information at the B, R, I, and K' bands, (4) the multiband information clarifies problems associated with internal reddening, (5) the template zero points are defined by 24 galaxies with accurately known distances, and (6) the relations are applied to 12 clusters scattered across the sky and out to velocities of 8000km/s.
- ID:
- ivo://CDS.VizieR/J/other/PASA/37.22
- Title:
- Calibration sample UBV and GALEX photometry
- Short Name:
- J/other/PASA/37.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive transformation equations between GALEX and UBV colours by using the reliable data of 556 stars. We present two sets of equations: as a function of (only) luminosity class and as a function of both luminosity class and metallicity. The metallicities are provided from the literature, while the luminosity classes are determined by using the PARSEC mass tracks in this study. Small colour residuals and high squared correlation coefficients promise accurate derived colours. The application of the transformation equations to 70 stars with reliable data shows that the metallicity plays an important role in estimation of more accurate colours.
- ID:
- ivo://CDS.VizieR/J/AJ/162/191
- Title:
- 2011-2021 calibrator observations of SCUBA-2
- Short Name:
- J/AJ/162/191
- Date:
- 14 Mar 2022 06:52:03
- Publisher:
- CDS
- Description:
- The Submillimetre Common User Bolometer Array 2 (SCUBA-2) is the James Clerk Maxwell Telescope's continuum imager, operating simultaneously at 450 and 850{mu}m. SCUBA-2 was commissioned in 2009-2011, and since that time, regular observations of point-like standard sources have been performed whenever the instrument is in use. Expanding the calibrator observation sample by an order of magnitude compared to previous work, in this paper we derive updated opacity relations at each wavelength for a new atmospheric extinction correction, analyze the Flux Conversion Factors used to convert instrumental units to physical flux units as a function of date and observation time, present information on the beam profiles for each wavelength, and update secondary calibrator source fluxes. Between 07:00 and 17:00 UTC, the portion of the night that is most stable to temperature gradients that cause dish deformation, the total flux uncertainty and the peak flux uncertainty measured at 450{mu}m are found to be 14% and 17%, respectively. Measured at 850{mu}m, the total flux and peak flux uncertainties are 6% and 7%, respectively. The analysis presented in this work is applicable to all SCUBA-2 projects observed since 2011.
- ID:
- ivo://CDS.VizieR/J/MNRAS/414/108
- Title:
- Calibrator of exoplanet-host stars
- Short Name:
- J/MNRAS/414/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Phase-referenced interferometric astrometry offers the possibility to look for exoplanets around bright stars. Instruments like PRIMA (Phase-Referenced Imaging and Micro-arcsecond Astrometry) will measure the astrometric wobble of a candidate star due to an exoplanet relative to a close-by 'calibrator' star, located within the instrument's observing field (1-arcmin in the PRIMA case). Stars with already known exoplanets will constitute the first targets for this technique, as it will provide a way to further specify the characteristics of the known exoplanets, such as the inclinations. The main requirement is to have a calibrator in the vicinity of the star. We provide here a list of calibrators for all stars with known exoplanets obtained using data mining and Virtual Observatory techniques. This list is available online and revised regularly. The calibrators are found from catalogues available at Centre de Donnees astronomiques de Strasbourg (CDS) using the SearchCal software developed at Jean-Marie Mariotti Center (JMMC). In our test case, the calibrators are found within 1 arcmin angular distance for approximately 50 per cent of the stars tested, and often closer. They are all faint objects from the Two Micron All Sky Survey (2MASS) with K magnitudes between 13 and 15. A list of the most promising targets is also given.