- 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/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/201
- Title:
- Pulkovo Spectrophotometric Catalog
- Short Name:
- III/201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A spectrophotometric catalog is presented, combining results of numerous observations by Pulkovo astronomers at different observing sites. The catalog consists of three parts: the first contains the data of 602 stars in the spectral range 320-735 nm with a resolution 5 nm; the second one contains 285 stars in the spectral range of 500-1080 nm with resolution10 nm and the third one contains 278 stars combined from the preceding catalogs in spectral range 320-1080 nm with resolution 10 nm. The data are presented in the absolute energy units W/mm, with step of 2.5 nm and with an accuracy no more than 1.5 - 2.0%.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A4
- Title:
- R CrA SPHERE and SINFONI images
- Short Name:
- J/A+A/624/A4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- R Coronae Australis (R CrA) is the brightest star of the Coronet nebula of the Corona Australis (CrA) star forming region. It has very red colors, probably due to dust absorption and it is strongly variable. High contrast instruments allow for an unprecedented direct exploration of the immediate circumstellar environment of this star. We observed R CrA with the near-IR channels (IFS and IRDIS) of SPHERE at VLT. In this paper, we used four different epochs, three of them from open time observations while one is from the SPHERE guaranteed time. The data were reduced using the DRH pipeline and the SPHERE Data Center. On the reduced data we implemented custom IDL routines with the aim to subtract the speckle halo.We have also obtained pupil-tracking H-band (1.45-1.85um) observations with the VLT/SINFONI near-infrared medium-resolution (R3000) spectrograph. A companion was found at a separation of 0.156" from the star in the first epoch and increasing to 0.184" in the final one. Furthermore, several extended structures were found around the star, the most noteworthy of which is a very bright jet-like structure North-East from the star. The astrometric measurements of the companion in the four epochs confirm that it is gravitationally bound to the star. The SPHERE photometry and the SINFONI spectrum, once corrected for extinction, point toward an early M spectral type object with a mass between 0.3 and 0.55M_{sun}_. The astrometric analysis provides constraints on the orbit paramenters: e~0.4, semi-major axis at 27-28au, inclination of ~70{deg} and a period larger than 30 years. We were also able to put constraints of few MJup on the mass of possible other companions down to separations of few tens of au.
- ID:
- ivo://CDS.VizieR/J/ApJ/703/420
- Title:
- Red supergiants in M31
- Short Name:
- J/ApJ/703/420
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Red supergiants (RSGs) are a short-lived stage in the evolution of moderately massive stars (10-25M_{sun}_), and as such their location in the H-R diagram provides an exacting test of stellar evolutionary models. Since massive star evolution is strongly affected by the amount of mass loss a star suffers, and since the mass-loss rates depend upon metallicity, it is highly desirable to study the physical properties of these stars in galaxies of various metallicities. Here we identify a sample of RSGs in M31, the most metal-rich of the Local Group galaxies. We determine the physical properties of these stars using both moderate resolution spectroscopy and broadband V-K photometry. We find that on average the RSGs of our sample are variable in V by 0.5mag, smaller but comparable to the 0.9mag found for Magellanic Cloud (MC) RSGs. No such variability is seen at K, also in accord with what we know of Galactic and MC RSGs.
- ID:
- ivo://CDS.VizieR/J/A+AS/130/285
- Title:
- Sample of starburst nucleus galaxies
- Short Name:
- J/A+AS/130/285
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents optical long-slit spectroscopic observations of 105 barred Markarian IRAS galaxies. These observations are used to determine the spectral type (starburst or Seyfert) of emission-line regions in the nucleus and along the bar of the galaxies, in order to define a homogeneous sample of Starburst Nucleus Galaxies (SBNGs). Our selection criteria (ultraviolet excess, far infrared emission and barred morphology) have been very efficient for selecting star-forming galaxies, since our sample of 221 emission-line regions includes 82% nuclear or extranuclear starbursts. The contamination by Seyferts is low (9%). The remaining galaxies (9%) are objects with ambiguous classification (HII or LINER). The dust content and H{alpha} luminosity increase towards the nuclei of the galaxies. No significant variation of the electron density is found between nuclear and bar HII regions. However, the mean H{alpha} luminosity and electron density in the bar are higher than in typical disk HII regions. We investigate different mechanisms for explaining the excess of nitrogen emission observed in our starburst nuclei. There is no evidence for the presence of a weak hidden active galactic nucleus in our starburst galaxies. The cause of this excess is probably a selective enrichment of nitrogen in the nuclei of the galaxies, following a succession of short and intense bursts of star formation. Our sample of SBNGs, located at a mean redshift of 0.015, has moderate H{alpha} (10^41^erg/s) and far infrared (10^10^L{sun}) luminosities. The types are distributed equally among early- and late-type giant spirals with a slight preference for Sbc/Sc types because of their barred morphology. The majority (62%) of SBNGs are isolated with no sign of gravitational interaction. In terms of distance, luminosity and level of interaction, SBNGs are intermediate between HII galaxies and luminous infrared galaxies.
