- ID:
- ivo://CDS.VizieR/J/PASP/121/827
- Title:
- NIR fluxes for 35 HR late-type stars
- Short Name:
- J/PASP/121/827
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New semicontinuous scans (with nearly contiguous passbands) are presented for alpha CMi and for 24 G and K giants. In addition, 12 such scans published in 1984 are reduced to an up-to-date standard-star system and adopted. The collected scans range from 3288{AA} to at least 6940{AA}, and they have been standardized to a system defined by alpha Lyr. They are supplemented by measurements of 23 of the program giants using six near-infrared passbands. Tests of the consistency and accuracy of the data yield encouraging results.
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- ID:
- ivo://CDS.VizieR/J/A+A/568/A9
- Title:
- 300-2500nm flux calibration reference spectra
- Short Name:
- J/A+A/568/A9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- While the near-infrared wavelength regime is becoming more and more important for astrophysics there is a marked lack of spectrophotometric standard star data that allow to flux calibrate such data. Furthermore flux calibrating medium to high resolution echelle spectroscopy data is challenging even in the optical wavelength range, because the available flux standard data are often too coarsely sampled. We will provide standard star reference data that allow users to derive response curves from 300nm to 2500nm for spectroscopic data of medium to high resolution, including those taken with echelle spectrographs. In addition we describe a method to correct for moderate telluric absorption without the need of observing telluric standard stars. As reference data for the flux standard we use theoretical spectra derived from stellar model atmospheres. We verify that they provide an appropriate description of the observed standard star spectra by checking for residuals in line cores and line overlap regions in the ratios of observed (X-shooter) spectra to model spectra. The finally selected model spectra are then corrected for remaining mismatches and photometrically calibrated using independent observations. The correction of telluric absorption is performed with the help of telluric model spectra. We provide new, finely sampled reference spectra without telluric absorption for six southern flux standard stars that allow the users to flux calibrate their data from 300nm to 2500nm, and a method to correct for telluric absorption using atmospheric models.
- ID:
- ivo://CDS.VizieR/J/AJ/148/1
- Title:
- Optical and ultraviolet photometry of SN 2012fr
- Short Name:
- J/AJ/148/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extensive optical and UltraViolet (UV) observations of the type Ia supernova (SN Ia) 2012fr are presented in this paper. It has a relatively high luminosity, with an absolute B-band peak magnitude of about -19.5mag and a smaller post-maximum decline rate than normal SNe Ia (e.g., {Delta}m_15_(B)=0.85+/-0.05mag). Based on the UV and optical light curves, we derived that a ^56^Ni mass of about 0.88M_{sun}_ was synthesized in the explosion. The earlier spectra are characterized by noticeable high-velocity features of Si II {lambda}6355 and Ca II with velocities in the range of ~22000-25000km/s. At around the maximum light, these spectral features are dominated by the photospheric components which are noticeably narrower than normal SNe Ia. The post-maximum velocity of the photosphere remains almost constant at ~12000km/s for about one month, reminiscent of the behavior of some luminous SNe Ia like SN 1991T. We propose that SN 2012fr may represent a subset of the SN 1991T-like SNe Ia viewed in a direction with a clumpy or shell-like structure of ejecta, in terms of a significant level of polarization reported in Maund et al. (2013MNRAS.433L..20M).
- ID:
- ivo://CDS.VizieR/III/136
- Title:
- Optical spectrophotometry of WR C and O Stars
- Short Name:
- III/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains a homogeneous set of optical spectrophotometric observations (3300-7300 angstroms) at moderate resolution (about 10 angstroms) of 86 Wolf-Rayet carbon and oxygen stars in this galaxy, the Large Magellanic Cloud, and the Small Magellanic Cloud. The observations were made with the Intensified Reticon Scanner on the white spectrograph of the 0.9 m telescope at Kitt Peak and with the SIT-Vidicon detector on the Cassegrain spectrograph of the 1.5-m telescope at Cerro Tololo Inter-American Observatory.
- ID:
- ivo://CDS.VizieR/J/MNRAS/485/2312
- Title:
- Outer Galactic disk A and F stars space motions
- Short Name:
- J/MNRAS/485/2312
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A and F stars can be used as probes of outer Galactic disk kinematics: here we extend the work of Harris et al. (2018, Cat. J/MNRAS/475/1680) by crossmatching their A/F sample with Gaia DR2 to bring in proper motions. These are combined with the already measured radial velocities and spectro-photometric distances to obtain full space motions. We use this sample of 1173 stars, located in two pencil-beam sightlines (l=178{deg} and l=118{deg}), to sample the Galactocentric velocity field out to almost R_G_=15kpc. We find there are significant differences in all three (radial, azimuthal and vertical) kinematic components between the two directions. The rotation curve is roughly flat in the anticentre direction, confirming and extending the result of Kawata et al. (2018MNRAS.479L.108K) thanks to the greater reach of our spectro-photometric distance scale. However at l=118{deg} the circular velocity rises outwards from R_G_=10.5kpc and there is a more pronounced gradient in radial motion than is seen at l=178{deg}. Furthermore, the A star radial motion differs from the F stars by ~10km/s. We discuss our findings in the context of perturbers potentially responsible for the trends, such as the central bar, spiral arms, the warp and external satellites. Our results at l=178{deg} are broadly consistent with previous work on K giants in the anticentre, but the kinematics at l=118{deg} in the Perseus region do not yet reconcile easily with bar or spiral arm perturbation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/475/1680
- Title:
- Parameters of 1183 A and F stars
- Short Name:
- J/MNRAS/475/1680
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Previous studies of the rotation law in the outer Galactic disc have mainly used gas tracers or clump giants. Here, we explore A and F stars as alternatives: these provide a much denser sampling in the outer disc than gas tracers and have experienced significantly less velocity scattering than older clump giants. This first investigation confirms the suitability of A stars in this role. Our work is based on spectroscopy of roughly 1300 photometrically selected stars in the red calcium-triplet region, chosen to mitigate against the effects of interstellar extinction. The stars are located in two low Galactic latitude sightlines, at longitudes l=118{deg}, sampling strong Galactic rotation shear, and l=178{deg}, near the anticentre. With the use of Markov Chain Monte Carlo parameter fitting, stellar parameters and radial velocities are measured, and distances computed. The obtained trend of radial velocity with distance is inconsistent with existing flat or slowly rising rotation laws from gas tracers (Brand & Blitz, 1993A&A...275...67B, Cat J/A+A/275/67; Reid et al., 2014ApJ...783..130R, Cat. J/ApJ/783/130). Instead, our results fit in with those obtained by Huang et al. (2016MNRAS.463.2623H) from disc clump giants that favoured rising circular speeds. An alternative interpretation in terms of spiral arm perturbation is not straight forward. We assess the role that undetected binaries in the sample and distance error may have in introducing bias, and show that the former is a minor factor. The random errors in our trend of circular velocity are within +/-5km/s.
- ID:
- ivo://CDS.VizieR/II/120
- Title:
- Phot and Spectrophot Investigation, South Gal Pole
- Short Name:
- II/120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric magnitudes and colors in the Johnson-Morgan UBV system for 477 stars in 6 square degrees near Kapteyn Selected Area 141 (l=245, b=-86; 00 43 < RA < 01 11, -33.7 < Dec < -26.9, B1950.0) are given in the first data file. The estimated rms accuracies are 0.02 (V), 0.03 (B-V), 0.07 (U-B) for stars in the magnitude range 15 to 16. Table 2 of the source reference gives the mean errors for intervals of magnitude. Photographic V magnitudes and B-V colors are given for 2835 stars to magnitude 17 (in the same region as above) in the second data file. The estimated rms accuracies are 0.05 (V) and 0.08 (B-V). The mean errors of the computed right ascensions and declinations are 0.15s and 2", respectively.
- ID:
- ivo://CDS.VizieR/III/169A
- Title:
- Photometric Atlas of Procyon for 314-747 nm
- Short Name:
- III/169A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This atlas contains intensities, expressed in terms of the continuum as 100, in steps of 5 milli Angstroem of the F5 star Procyon. The spectral range is from 3140 to 7469.995 Angstroems.
- ID:
- ivo://CDS.VizieR/J/AJ/142/153
- Title:
- Precision spectrophotometry at the level of 0.1%
- Short Name:
- J/AJ/142/153
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate relative spectrophotometry is critical for many science applications. Small wavelength-scale residuals in the flux calibration can significantly impact the measurements of weak emission and absorption features in the spectra. Using Sloan Digital Sky Survey data, we demonstrate that the average spectra of carefully selected red-sequence galaxies can be used as a spectroscopic standard to improve the relative spectrophotometry precision to 0.1% on small wavelength scales (from a few to hundreds of Angstroms). We achieve this precision by comparing stacked spectra across tiny redshift intervals. The redshift intervals must be small enough that any systematic stellar population evolution is minimized and is less than the spectrophotometric uncertainty. This purely empirical technique does not require any theoretical knowledge of true galaxy spectra. It can be applied to all large spectroscopic galaxy redshift surveys that sample a large number of galaxies in a uniform population.
- ID:
- ivo://CDS.VizieR/J/AZh/72/80
- Title:
- Primary Spectrophotometric Standards
- Short Name:
- J/AZh/72/80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A spectrophotometric catalog of 238 bright stars was compared with the Tyan Shan photometric catalog in the WBVR system. An analysis of the photometry of ten stars in four photometric systems led to new, corrected energy distributions in their spectra, which substantially improved the agreement between the observed and synthetic magnitudes.
