- ID:
- ivo://CDS.VizieR/J/A+A/530/A50
- Title:
- Principal Component Analysis of QSO UV spectra
- Short Name:
- J/A+A/530/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From a principal component analysis (PCA) of 78 z~3 high-quality quasar spectra in the SDSS-DR7 we derive the principal components that characterize the QSO continuum over the full available wavelength range. The shape of the mean continuum is similar to that measured at low-z (z~1), but the equivalent width of the emission lines is larger at low redshift. We calculate the correlation between fluxes at different wavelengths and find that the emission line fluxes in the red part of the spectrum are correlated with those in the blue part. We construct a projection matrix to predict the continuum in the Lyman{alpha} forest from the red part of the spectrum.
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- ID:
- ivo://CDS.VizieR/J/ApJ/726/25
- Title:
- Production of the p-process nuclei in SNe Ia
- Short Name:
- J/ApJ/726/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We calculate the nucleosynthesis of proton-rich isotopes in the carbon-deflagration model for Type Ia supernovae (SNe Ia). The seed abundances are obtained by calculating the s-process nucleosynthesis that is expected to occur in the repeating helium shell flashes on the carbon-oxygen (CO) white dwarf (WD) during mass accretion from a binary companion. When the deflagration wave passes through the outer layer of the CO WD, p-nuclei are produced by photodisintegration reactions on s-nuclei in a region where the peak temperature ranges from 1.9 to 3.6x10^9^K. We confirm the sensitivity of the p-process on the initial distribution of s-nuclei. We show that the initial C/O ratio in the WD does not affect much the yield of p-nuclei. On the other hand, the abundance of ^22^Ne left after s-processing has a large influence on the p-process via the ^22^Ne({alpha},n) reaction. We find that about 50% of p-nuclides are co-produced when normalized to their solar abundances in all adopted cases of seed distribution. Mo and Ru, which are largely underproduced in Type II supernovae (SNe II), are produced more than in SNe II although they are underproduced with respect to the yield levels of other p-nuclides. The ratios between p-nuclei and iron in the ejecta are larger than the solar ratios by a factor of 1.2. We also compare the yields of oxygen, iron, and p-nuclides in SNe Ia and SNe II and suggest that SNe Ia could make a larger contribution than SNe II to the solar system content of p-nuclei.
- ID:
- ivo://CDS.VizieR/J/AJ/135/850
- Title:
- Properties of eclipsing binaries found in TrES
- Short Name:
- J/AJ/135/850
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In recent years, we have witnessed an explosion of photometric time-series data, collected for the purpose of finding a small number of rare sources, such as transiting extrasolar planets and gravitational microlenses. Once combed, these data are often set aside, and are not further searched for the many other variable sources that they undoubtedly contain. To this end, we describe a pipeline that is designed to systematically analyze such data, while requiring minimal user interaction. We ran our pipeline on a subset of the Trans-Atlantic Exoplanet Survey dataset, and used it to identify and model 773 eclipsing binary systems. For each system we conducted a joint analysis of its light curve, colors, and theoretical isochrones. This analysis provided us with estimates of the binary's absolute physical properties, including the masses and ages of their stellar components, as well as their physical separations and distances. We identified three types of eclipsing binaries that are of particular interest and merit further observations. The first category includes 11 low-mass candidates, which may assist current efforts to explain the discrepancies between the observation and the models of stars at the bottom of the main sequence. The other two categories include 34 binaries with eccentric orbits, and 20 binaries with abnormal light curves. Finally, this uniform catalog enabled us to identify a number of relations that provide further constraints on binary population models and tidal circularization theory.
- ID:
- ivo://CDS.VizieR/J/A+A/363/1051
- Title:
- Properties of He-rich stars. III.
- Short Name:
- J/A+A/363/1051
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of helium rich atmospheres in the interval He/H 0.1-1.0 as derived from fully consistent model computations for effective temperature (from 15000K up to 32000K) and surface gravity (log(g)=3.5 and 4.0).
- ID:
- ivo://CDS.VizieR/J/AJ/156/149
- Title:
- Properties of massive giant planets & brown dwarfs
- Short Name:
- J/AJ/156/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present thermodynamic material and transport properties for the extreme conditions prevalent in the interiors of massive giant planets and brown dwarfs. They are obtained from extensive ab initio simulations of hydrogen-helium mixtures along the isentropes of three representative objects. In particular, we determine the heat capacities, the thermal expansion coefficient, the isothermal compressibility, and the sound velocity. Important transport properties such as the electrical and thermal conductivity, opacity, and shear viscosity are also calculated. Further results for associated quantities, including magnetic and thermal diffusivity, kinematic shear viscosity, as well as the static Love number k_2_ and the equidistance, are presented. In comparison to Jupiter-mass planets, the behavior inside massive giant planets and brown dwarfs is stronger dominated by degenerate matter. We discuss the implications on possible dynamics and magnetic fields of those massive objects. The consistent data set compiled here may serve as a starting point to obtain material and transport properties for other substellar H-He objects with masses above one Jovian mass and finally may be used as input for dynamo simulations.
- ID:
- ivo://CDS.VizieR/J/A+A/575/A26
- Title:
- Properties of the Population II star HD 140283
- Short Name:
- J/A+A/575/A26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Metal-poor halo stars are important astrophysical laboratories that allow us to unravel details about many aspects of astrophysics, including the chemical conditions at the formation of our Galaxy, understanding the processes of diffusion in stellar interiors, and determining precise effective temperatures and calibration of colour-effective temperature relations. To address any of these issues the fundamental properties of the stars must first be determined. HD 140283 is the closest and brightest metal-poor Population II halo star (distance = 58pc and V=7.21), an ideal target that allows us to approach these questions, and one of a list of 34 benchmark stars defined for Gaia astrophysical parameter calibration. In the framework of characterizing these benchmark stars, we determined the fundamental properties of HD 140283 (radius, mass, age, and effective temperature) by obtaining new interferometric and spectroscopic measurements and combining them with photometry from the literature. The interferometric measurements were obtained using the visible interferometer VEGA on the CHARA array and we determined a 1D limb-darkened angular diameter of {theta}_1D_=0.353+/-0.013-milliarcsec.
- ID:
- ivo://CDS.VizieR/J/AJ/154/228
- Title:
- Properties of transiting planet's host stars
- Short Name:
- J/AJ/154/228
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The properties of a transiting planet's host star are written in its transit light curve. The light curve can reveal the stellar density ({rho}_*_) and the limb-darkening profile in addition to the characteristics of the planet and its orbit. For planets with strong prior constraints on orbital eccentricity, we may measure these stellar properties directly from the light curve; this method promises to aid greatly in the characterization of transiting planet host stars targeted by the upcoming NASA Transiting Exoplanet Survey Satellite mission and any long-period, singly transiting planets discovered in the same systems. Using Bayesian inference, we fit a transit model, including a nonlinear limb-darkening law, to 66 Kepler transiting planet hosts to measure their stellar properties. We present posterior distributions of {rho}*, limb-darkening coefficients, and other system parameters for these stars. We measure densities to within 5% for the majority of our target stars, with the dominant precision-limiting factor being the signal-to-noise ratio of the transits. Of our measured stellar densities, 95% are in 3{sigma} or better agreement with previously published literature values. We make posterior distributions for all of our target Kepler objects of interest available online at 10.5281/zenodo.1028515.
- ID:
- ivo://CDS.VizieR/J/ApJ/792/118
- Title:
- Protonated oxirane characterization
- Short Name:
- J/ApJ/792/118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An accurate spectroscopic characterization of protonated oxirane has been carried out by means of state-of-the-art computational methods and approaches. The calculated spectroscopic parameters from our recent computational investigation of oxirane together with the corresponding experimental data available were used to assess the accuracy of our predicted rotational and IR spectra of protonated oxirane. We found an accuracy of about 10cm^-1^ for vibrational transitions (fundamentals as well as overtones and combination bands) and, in relative terms, of 0.1% for rotational transitions. We are therefore confident that the spectroscopic data provided herein are a valuable support for the detection of protonated oxirane not only in Titan's atmosphere but also in the interstellar medium.
509. PSF models fits maps
- ID:
- ivo://CDS.VizieR/J/A+A/601/A86
- Title:
- PSF models fits maps
- Short Name:
- J/A+A/601/A86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep imaging of the diffuse light that is emitted by stellar fine structures and outer halos around galaxies is often now used to probe their past mass assembly. Because the extended halos survive longer than the relatively fragile tidal features, they trace more ancient mergers. We use images that reach surface brightness limits as low as 28.5-29mag/arcsec^2^ (g-band) to obtain light and color profiles up to 5-10 effective radii of a sample of nearby early-type galaxies. These were acquired with MegaCam as part of the CFHT MATLAS large programme. These profiles may be compared to those produced using simulations of galaxy formation and evolution, once corrected for instrumental effects. Indeed they can be heavily contaminated by the scattered light caused by internal reflections within the instrument. In particular, the nucleus of galaxies generates artificial flux in the outer halo, which has to be precisely subtracted. We present a deconvolution technique to remove the artificial halos that makes use of very large kernels. The technique, which is based on PyOperators, is more time efficient than the model-convolution methods that are also used for that purpose. This is especially the case for galaxies with complex structures that are hard to model. Having a good knowledge of the point spread function (PSF), including its outer wings, is critical for the method. A database of MegaCam PSF models corresponding to different seeing conditions and bands was generated directly from the deep images. We show that the difference in the PSFs in different bands causes artificial changes in the color profiles, in particular a reddening of the outskirts of galaxies having a bright nucleus. The method is validated with a set of simulated images and applied to three representative test cases: NGC 3599, NGC 3489, and NGC 4274, which exhibits a prominent ghost halo for two of them. This method successfully removes this.
- ID:
- ivo://CDS.VizieR/J/A+A/339/123
- Title:
- PSR J1012+5307 evolutionary tracks
- Short Name:
- J/A+A/339/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a set of evolutionary tracks for white dwarfs with helium cores in the mass range from 0.179 to 0.414M_{sun}_. The tracks are based on a 1M_{sun}_ model sequence extending from the pre-main sequence stage up to the tip of the red-giant branch. Applying large mass loss rates at appropriate positions forced the models to move off the giant branch.The further evolution was then followed across the Hertzsprung-Russell diagram and down the cooling branch.
