- ID:
- ivo://CDS.VizieR/J/ApJS/176/276
- Title:
- PTI calibrator catalog
- Short Name:
- J/ApJS/176/276
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Palomar Testbed Interferometer (PTI) archive of observations between 1998 and 2005 is examined for objects appropriate for calibration of optical long-baseline interferometer observations - stars that are predictably pointlike and single. Approximately 1400 nights of data on 1800 objects were examined for this investigation. We compare those observations to an intensively studied object that is a suitable calibrator, HD 217014, and statistically compare each candidate calibrator to that object by computing both a Mahalanobis distance and a principal component analysis. Our hypothesis is that the frequency distribution of visibility data associated with calibrator stars differs from noncalibrator stars such as binary stars. Spectroscopic binaries resolved by PTI, objects known to be unsuitable for calibrator use, are similarly tested to establish detection limits of this approach. From this investigation, we find more than 350 observed stars suitable for use as calibrators (with an additional ~140 being rejected), corresponding to >~95% sky coverage for PTI.
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- ID:
- ivo://CDS.VizieR/J/AJ/161/283
- Title:
- Radial velocity estimates of 4 stars with IGRINS
- Short Name:
- J/AJ/161/283
- Date:
- 08 Mar 2022
- Publisher:
- CDS
- Description:
- Application of the radial velocity (RV) technique in the near-infrared is valuable because of the diminished impact of stellar activity at longer wavelengths, making it particularly advantageous for the study of late-type stars but also for solar-type objects. In this paper, we present the IGRINS RV open-source python pipeline for computing infrared RV measurements from reduced spectra taken with IGRINS, an R~{lambda}/{Delta}{lambda}~45000 spectrograph with simultaneous coverage of the H-band (1.49-1.80{mu}m) and K-band (1.96-2.46{mu}m). Using a modified forward-modeling technique, we construct high-resolution telluric templates from A0 standard observations on a nightly basis to provide a source of common-path wavelength calibration while mitigating the need to mask or correct for telluric absorption. Telluric standard observations are also used to model the variations in instrumental resolution across the detector, including a yearlong period when the K-band was defocused. Without any additional instrument hardware, such as a gas cell or laser frequency comb, we are able to achieve precisions of 26.8m/s in the K-band and 31.1m/s in the H-band for narrow-line hosts. These precisions are empirically determined by a monitoring campaign of two RV standard stars, as well as the successful retrieval of planet-induced RV signals for both HD189733 and {tau}BooA; furthermore, our results affirm the presence of the Rossiter-McLaughlin effect for HD189733. The IGRINS RV pipeline extends another important science capability to IGRINS, with publicly available software designed for widespread use.
- ID:
- ivo://CDS.VizieR/J/A+A/524/A10
- Title:
- Radial Velocity standard stars
- Short Name:
- J/A+A/524/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The calibration of the Radial Velocity Spectrometer (RVS) onboard the ESA Gaia satellite (to be launched in 2012) requires a list of standard stars with a radial velocity (RV) known with an accuracy of at least 300m/s. The IAU commission 30 lists of RV standard stars are too bright and not dense enough. We describe the selection criteria due to the RVS constraints for building an adequate full-sky list of at least 1000 RV standards from catalogues already published in the literature.
- ID:
- ivo://CDS.VizieR/J/ApJ/518/859
- Title:
- Revision of MK luminosity classes
- Short Name:
- J/ApJ/518/859
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hipparcos parallaxes of cool giants are utilized in two ways in this paper. First, a plot of reduced parallaxes of stars brighter than 6.5, as a function of spectral type, for the first time separates members of the clump from stars in the main giant ridge. A slight modification of the MK luminosity standards has been made so that luminosity class IIIb defines members of the clump, and nearly all of the class III stars fall within the main giant ridge. Second, a new calibration of MK luminosity classes III and IIIb in terms of visual absolute magnitudes has been made.
- ID:
- ivo://CDS.VizieR/J/PASP/118/1656
- Title:
- Secondary velocity standards at NGP
- Short Name:
- J/PASP/118/1656
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present mean radial velocities for 143 stars in Selected Area 57 at the north Galactic pole that are suitable for use as secondary velocity standards. The stars were drawn from a magnitude-limited sample and are mostly fainter than 11th magnitude in V. They span a wide range of effective temperatures and surface gravities and thus provide a suitable source of targets for observed templates. The mean radial velocities are based on at least 10 observations spanning at least 8200 days, and are accurate typically to 0.2km/s, with no obvious signs of variable velocity or composite spectra.
- ID:
- ivo://CDS.VizieR/J/A+A/458/541
- Title:
- Soft X-ray standards
- Short Name:
- J/A+A/458/541
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze the Chandra LETG+HRC observations of the white dwarfs HZ43A and Sirius B and of the neutron star RX J185635-3754 with the aim of resolving current uncertainties in the soft X-ray spectral fluxes and photospheric parameters of the three stars. We apply the derived photon spectra to a cross-calibration of the LETG+HRC-S with the short-wavelength EUVE spectrometer and the ROSAT PSPC.
- ID:
- ivo://CDS.VizieR/III/179
- Title:
- Southern MK Standards 5800-10200A
- Short Name:
- III/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectra are presented for MK standards in the wavelength range 580-1020nm. The stars cover the normal spectral types O to M and luminosity types I, III, and V. In addition, a small number of peculiar stars are included. The data are in 137 FITS files, in the "fits" subdirectory. The list of the 137 stars is included in the "stars.dat" file; note that the list is not identical to the stars listed in Table1 of the paper.
- ID:
- ivo://CDS.VizieR/II/179
- Title:
- Southern Spectrophotometric Standards. I + II
- Short Name:
- II/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- M. Hamuy, et al. have compiled their observations of secondary and tertiary spectrophotometric standard stars for the southern hemisphere in the wavelength range 3300-7550 Angstroms. The observations were made using the RC spectrographs and CCD cameras on the 1.5m and 4m telescopes at CTIO. The machine-readable files contain monochromatic magnitudes vs. wavelength for 29 stars in ASCII and 31 stars in FITS format.
- ID:
- ivo://CDS.VizieR/J/AJ/112/241
- Title:
- Spectral irradiance calibration. VI.
- Short Name:
- J/AJ/112/241
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present three new absolutely calibrated continuous stellar spectra from 3 to 35um, constructed as far as possible from actual observed spectral fragments taken from the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer (LRS). These stars - alpha1 Cen, alpha TrA, and epsilon Car - augment our previous archive of complete absolutely calibrated spectra for northern K and M giants. All these spectra have a common calibration pedigree. The wavelength coverage is ideal for calibration of many existing and proposed ground-based, airborne, and satellite sensors. KAO and IRAS data in the 15-30 um range suggest that the spectra of cool giants are close to Rayleigh-Jeans slopes. Our observations of alpha1 Cen, absolutely calibrated via our adopted Sirius model, indicate an angular diameter in very good agreement with values in the literature, demonstrating "closure" of the set of spectra within our absolute framework. We compare our observed alpha1 Cen spectrum with a published grid of theoretical models from Kurucz, and adopt a plausible theoretical shape, that fits our spectrum, as a secondary reference spectrum in the southern sky.
- ID:
- ivo://CDS.VizieR/J/AJ/112/2274
- Title:
- Spectral irradiance calibration. VII.
- Short Name:
- J/AJ/112/2274
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present five new absolutely calibrated continuous stellar spectra constructed as far as possible from spectral fragments observed from the ground, the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer. These stars, alpha Boo, gamma Dra, alpha Cet, gamma Cru, and mu UMa, augment our six, published, absolutely calibrated spectra of K and early-M giants. All spectra have a common calibration pedigree. A revised composite for alpha Boo has been constructed from higher quality spectral fragments than our previously published one. The spectrum of gamma Dra was created in direct response to the needs of instruments aboard the Infrared Space Observatory (ISO); this star's location near the north ecliptic pole renders it highly visible throughout the mission. We compare all our low-resolution composite spectra with Kurucz model atmospheres and find good agreement in shape, with the obvious exception of the SiO fundamental, still lacking in current grids of model atmospheres. The CO fundamental seems slightly too deep in these models, but this could reflect our use of generic models with solar metal abundances rather than models specific to the metallicities of the individual stars. Angular diameters derived from these spectra and models are in excellent agreement with the best observed diameters. The ratio of our adopted Sirius and Vega models is vindicated by spectral observations. We compare IRAS fluxes predicted from our cool stellar spectra with those observed and conclude that, as 12 and 25um, flux densities measured by IRAS should be revised downwards by about 4.1% to 5.7%, respectively, for consistency with our absolute calibration. We have provided extrapolated continuum versions of these spectra to 300um, in direct support of ISO (PHT and LWS instruments). These spectra are consistent with IRAS flux densities at 60 and 100um.
