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1061. Asteroseismic solutions for 77 Kepler stars
ID:
ivo://CDS.VizieR/J/ApJ/767/127
Title:
Asteroseismic solutions for 77 Kepler stars
Short Name:
J/ApJ/767/127
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have used asteroseismology to determine fundamental properties for 66 Kepler planet-candidate host stars, with typical uncertainties of 3% and 7% in radius and mass, respectively. The results include new asteroseismic solutions for four host stars with confirmed planets (Kepler-4, Kepler-14, Kepler-23 and Kepler-25) and increase the total number of Kepler host stars with asteroseismic solutions to 77. A comparison with stellar properties in the planet-candidate catalog by Batalha et al. (2013, J/ApJS/204/24) shows that radii for subgiants and giants obtained from spectroscopic follow-up are systematically too low by up to a factor of 1.5, while the properties for unevolved stars are in good agreement. We furthermore apply asteroseismology to confirm that a large majority of cool main-sequence hosts are indeed dwarfs and not misclassified giants. Using the revised stellar properties, we recalculate the radii for 107 planet candidates in our sample, and comment on candidates for which the radii change from a previously giant-planet/brown-dwarf/stellar regime to a sub-Jupiter size or vice versa. A comparison of stellar densities from asteroseismology with densities derived from transit models in Batalha et al. assuming circular orbits shows significant disagreement for more than half of the sample due to systematics in the modeled impact parameters or due to planet candidates that may be in eccentric orbits. Finally, we investigate tentative correlations between host-star masses and planet-candidate radii, orbital periods, and multiplicity, but caution that these results may be influenced by the small sample size and detection biases.
1062. Asteroseismic study of solar-type stars
ID:
ivo://CDS.VizieR/J/ApJS/210/1
Title:
Asteroseismic study of solar-type stars
Short Name:
J/ApJS/210/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use asteroseismic data obtained by the NASA Kepler mission to estimate the fundamental properties of more than 500 main-sequence and sub-giant stars. Data obtained during the first 10 months of Kepler science operations were used for this work, when these solar-type targets were observed for one month each in survey mode. Stellar properties have been estimated using two global asteroseismic parameters and complementary photometric and spectroscopic data. Homogeneous sets of effective temperatures, T_eff_, were available for the entire ensemble from complementary photometry; spectroscopic estimates of T_eff_ and [Fe/H] were available from a homogeneous analysis of ground-based data on a subset of 87 stars. We adopt a grid-based analysis, coupling six pipeline codes to 11 stellar evolutionary grids. Through use of these different grid-pipeline combinations we allow implicitly for the impact on the results of stellar model dependencies from commonly used grids, and differences in adopted pipeline methodologies. By using just two global parameters as the seismic inputs we are able to perform a homogeneous analysis of all solar-type stars in the asteroseismic cohort, including many targets for which it would not be possible to provide robust estimates of individual oscillation frequencies (due to a combination of low signal-to-noise ratio and short dataset lengths). The median final quoted uncertainties from consolidation of the grid-based analyses are for the full ensemble (spectroscopic subset) approximately 10.8% (5.4%) in mass, 4.4% (2.2%) in radius, 0.017 dex (0.010 dex) in log g, and 4.3% (2.8%) in mean density. Around 36% (57%) of the stars have final age uncertainties smaller than 1 Gyr. These ages will be useful for ensemble studies, but should be treated carefully on a star-by-star basis. Future analyses using individual oscillation frequencies will offer significant improvements on up to 150 stars, in particular for estimates of the ages, where having the individual frequency data is most important.
1063. Asteroseismology of ~16000 Kepler red giants
ID:
ivo://CDS.VizieR/J/ApJS/236/42
Title:
Asteroseismology of ~16000 Kepler red giants
Short Name:
J/ApJS/236/42
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Kepler mission has provided exquisite data to perform an ensemble asteroseismic analysis on evolved stars. In this work we systematically characterize solar-like oscillations and granulation for 16094 oscillating red giants, using end-of-mission long-cadence data. We produced a homogeneous catalog of the frequency of maximum power (typical uncertainty {sigma}_{nu}max_=1.6% ), the mean large frequency separation ({sigma}_{Delta}{nu}_=0.6%), oscillation amplitude ({sigma}_A_=4.7%), granulation power ({sigma}_gran_=8.6% ), power excess width ({sigma}_width_=8.8%), seismically derived stellar mass ({sigma}_M_=7.8%), radius ({sigma}_R_=2.9% ), and thus surface gravity ({sigma}_logg_=0.01dex). Thanks to the large red giant sample, we confirm that red-giant-branch (RGB) and helium-core-burning (HeB) stars collectively differ in the distribution of oscillation amplitude, granulation power, and width of power excess, which is mainly due to the mass difference. The distribution of oscillation amplitudes shows an extremely sharp upper edge at fixed {nu}_max_, which might hold clues for understanding the excitation and damping mechanisms of the oscillation modes. We find that both oscillation amplitude and granulation power depend on metallicity, causing a spread of 15% in oscillation amplitudes and a spread of 25% in granulation power from [Fe/H]=-0.7 to 0.5dex. Our asteroseismic stellar properties can be used as reliable distance indicators and age proxies for mapping and dating galactic stellar populations observed by Kepler. They will also provide an excellent opportunity to test asteroseismology using Gaia parallaxes, and lift degeneracies in deriving atmospheric parameters in large spectroscopic surveys such as APOGEE and LAMOST.
1064. Asteroseismology of 36 Kepler subgiants. I.
ID:
ivo://CDS.VizieR/J/MNRAS/495/2363
Title:
Asteroseismology of 36 Kepler subgiants. I.
Short Name:
J/MNRAS/495/2363
Date:
21 Oct 2021
Publisher:
CDS
Description:
The presence of mixed modes makes subgiants excellent targets for asteroseismology, providing a probe for the internal structure of stars. Here we study 36 Kepler subgiants with solar-like oscillations and report their oscillation mode parameters. We performed a so-called peakbagging exercise, i.e. estimating oscillation mode frequencies, linewidths, and amplitudes with a power spectrum model, fitted in the Bayesian framework and sampled with a Markov Chain Monte Carlo algorithm. The uncertainties of the mode frequencies have a median value of 0.180uHz. We obtained seismic parameters from the peakbagging, analysed their correlation with stellar parameters, and examined against scaling relations. The behaviour of seismic parameters (e.g. {Delta}{nu}, {nu}_max_, {epsilon}_p_) is in general consistent with theoretical predictions. We presented the observational p-g diagrams: {gamma}_1_-{Delta}u for early subgiants and {Delta}{Pi}_1_-{Delta}u for late subgiants, and demonstrate their capability to estimate stellar mass. We also found a logg dependence on the linewidths and a mass dependence on the oscillation amplitudes and the widths of oscillation excess. This sample will be valuable constraints for modelling stars and studying mode physics such as excitation and damping.
1065. Asteroseismology of 1523 misclassified red giants
ID:
ivo://CDS.VizieR/J/MNRAS/463/1297
Title:
Asteroseismology of 1523 misclassified red giants
Short Name:
J/MNRAS/463/1297
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analysed solar-like oscillations in 1523 Kepler red giants which have previously been misclassified as subgiants, with predicted {nu}_max_ values [based on the Kepler Input Catalogue (KIC)] between 280 and 700{mu}Hz. We report the discovery of 626 new oscillating red giants in our sample, in addition to 897 oscillators that were previously characterized by Hekker et al. from one quarter of Kepler data. Our sample increases the known number of oscillating low-luminosity red giants by 26 per cent (up to >=1900 stars). About three quarters of our sample are classified as ascending red giant branch stars, while the remainder are red-clump stars. A novel scheme was applied to determine {Delta}{nu} for 108 stars with {nu}_max_ close to the Nyquist frequency (387{mu}Hz>{nu}_max_>387{mu}Hz). Additionally, we identified 47 stars oscillating in the super-Nyquist frequency regime, up to 387 {mu}Hz, using long-cadence light curves. We show that the misclassifications are most likely due to large uncertainties in KIC surface gravities, and do not result from the absence of broad-band colours or from different physical properties such as reddening, spatial distribution, mass or metallicity. The sample will be valuable to study oscillations in low-luminosity red giants and to characterize planet candidates around those stars.
1066. Astrochemical study along M83 circumnuclear ring
ID:
ivo://CDS.VizieR/J/ApJ/884/100
Title:
Astrochemical study along M83 circumnuclear ring
Short Name:
J/ApJ/884/100
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report an astrochemical study on the evolution of interstellar molecular clouds and consequent star formation in the center of the barred spiral galaxy M83. We used the Atacama Large Millimeter/submillimeter Array (ALMA) to image molecular species indicative of shocks (SiO and CH_3_OH), dense cores (N_2_H^+^), and photodissociation regions (CN and CCH), as well as a radio recombination line (H41{alpha}) tracing active star-forming regions. M83 has a circumnuclear gas ring that is joined at two intersections by gas streams from the leading- edge gas lanes on the bar. We found elevated abundances of the shock and dense-core tracers in one of the orbit-intersecting areas, and found peaks of CN and H41{alpha} downstream. In the other orbit-intersection area, we found a similar enhancement of the shock tracers, but less variation of other tracers, and no sign of active star formation in the stream. We propose that the observed chemical variation or lack of it is due to the presence or absence of collision-induced evolution of molecular clouds and induced star formation. This work presents the clearest case of the chemical evolution in the circumnuclear rings of barred galaxies thanks to the ALMA resolution and sensitivity.
1067. ASTRODEEP Frontier Fields Catalogues
ID:
ivo://CDS.VizieR/J/A+A/590/A31
Title:
ASTRODEEP Frontier Fields Catalogues
Short Name:
J/A+A/590/A31
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present multiwavelength photometric catalogues (HST, Spitzer and Hawk-I K band) for the first two of the Frontier Fields, Abell2744 and MACSJ0416 (plus their parallel fields). To detect faint sources even in the central regions of the clusters, we develop a robust and repeatable procedure that uses the public codes Galapagos and Galfit to model and remove most of the light contribution from both the brightest cluster members as well as the ICL. We perform the detection on the HST H160 processed image to obtain a pure H-selected sample. We also add a sample of sources which are undetected in the H160 image but appear on a stacked infrared image. Photometry in the other HST bands is obtained using SExtractor, performed again on residual images after the Galfit procedure for foreground light removal. Photometry on the Hawk-I and IRAC bands has been obtained using our PSF-matching deconfusion code T-PHOT. A similar procedure, but without the need for the foreground light removal, is adopted for the Parallel fields. The procedure allows for the detection and the photometric measurements of ~2500 sources per field. We deliver and release complete photometric H-detected catalogues, with the addition of a complementary sample of infrared-detected sources. All objects have multiwavelength coverage including B to H HST bands, plus K band from Hawk-I, and 3.6 - 4.5 {\mu}m from Spitzer. Full and detailed treatment of photometric errors is included. We perform basic sanity checks on the reliability of our results. The multiwavelength catalogues are publicly available and are ready to be used for scientific purposes. Our procedures allows for the detection of outshined objects near the bright galaxies, which, coupled with the magnification effect of the clusters, can reveal extremely faint high redshift sources. Full analysis on photometric redshifts is presented in a companion Paper II. We present the first public release of photometric redshifts, galaxy rest-frame properties and associated magnification values in the cluster and parallel pointings of the first two Frontier Fields, Abell-2744 and MACS-J0416. We exploit a multi-wavelength catalogue ranging from HST to ground-based K and Spitzer IRAC which is specifically designed to enable detection and measurement of accurate fluxes in crowded cluster regions. The multi-band information is used to derive photometric redshifts and physical properties of sources detected either in the H-band image alone or from a stack of four WFC3 bands. To minimize systematics median photometric redshifts are assembled from six different approaches to photo-z estimates. Their reliability is assessed through a comparison with available spectroscopic samples. State of the art lensing models are used to derive magnification values on an object-by-object basis by taking into account sources positions and redshifts. We show that photometric redshifts reach a remarkable ~3-5% accuracy. After accounting for magnification the H band number counts are found in agreement at bright magnitudes with number counts from the CANDELS fields, while extending the presently available samples to galaxies intrinsically as faint as H160~32-33 thanks to strong gravitational lensing. The Frontier Fields allow to probe the galaxy stellar mass distribution at 0.5-1.5dex lower masses, depending on magnification, with respect to extragalactic wide fields, including sources at Mstar~10^7-10^8^M_{sun}_ at z>5. Similarly, they allow the detection of objects with intrinsic SFRs>1dex lower than in the CANDELS fields reaching 0.1-1M_{sun}_/yr at z~6-10.
1068. ASTRODEEP-GS43 catalogue
ID:
ivo://CDS.VizieR/J/A+A/649/A22
Title:
ASTRODEEP-GS43 catalogue
Short Name:
J/A+A/649/A22
Date:
22 Feb 2022
Publisher:
CDS
Description:
We present ASTRODEEP-GS43, a new multiwavelength photometric catalogue of the GOODS-South field, which builds and improves upon the previously released CANDELS catalogue. We provide photometric fluxes and corresponding uncertainties in 43 optical and infrared bands (25 wide and 18 medium filters), as well as photometric redshifts and physical properties of the 34930 CANDELS H-detected objects, plus an additional sample of 178 H-dropout sources, of which 173 are Ks-detected and 5 IRAC-detected. We keep the CANDELS photometry in 7 bands (CTIOU, Hubble Space Telescope WFC3 and ISAAC-K), and measure from scratch the fluxes in the other 36 (VIMOS, HST ACS, HAWK-I Ks, Spitzer IRAC, and 23 from Subaru SuprimeCAM and Magellan-Baade Fourstar) with state-of-the-art techniques of template-fitting. We then compute new photometric redshifts with three different software tools, and take the median value as best estimate. We finally evaluate new physical parameters from SED fitting, comparing them to previously published ones. Comparing to a sample of 3931 high quality spectroscopic redshifts, for the new photo-z's we obtain a normalized median absolute deviation (NMAD) of 0.015 with 3.01% of outliers (0.011, 0.22% on the bright end at I_814_<22.5), similarly to the best available published samples of photometric redshifts, such as the COSMOS UltraVISTA catalogue. The ASTRODEEP-GS43 results are in qualitative agreement with previously published catalogues of the GOODS-South field, improving on them particularly in terms of SED sampling and photometric redshift estimates. The catalogue is available for download from the Astrodeep website.
1069. Astrographic Catalog of Reference Stars
ID:
ivo://nasa.heasarc/acrs
Title:
Astrographic Catalog of Reference Stars
Short Name:
ACRS
Date:
21 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
For a number of years there has been a great demand for a high-density catalog of accurate stellar positions and proper motions that maintains a consistent system of reference over the entire sky. The Smithsonian Astrophysical Observatory Star Catalog (SAO; SAO Staff 1966) has partially met those requirements, but its positions brought to current epochs now contain errors on the order of 1 second of arc, plus the proper motions in the SAO differ systematically with one another depending on their source catalogs. With the completion of the Second Cape Photographic Catalogue (CPC2; de Vegt et al. 1989), a photographic survey comparable in density to the AGK3 (Dieckvoss 1975) was finally available for the southern hemisphere. These two catalogs were used as a base and matched against the AGK2 (Schorr &amp; Kohlschuetter 1951-58), Yale photographic zones (Yale Trans., Vols. 11-32), First Cape Photographic Catalogue (CPC1; Jackson &amp; Stoy 1954, 55, 58; Stoy 1966), Sydney Southern Star Catalogue (King &amp; Lomb 1983), Sydney Zone Catalogue -48 to -54 degrees (Eichhorn et al. 1983), 124 meridian circle catalogs, and catalogs of recent epochs, such as the Carlsberg Meridian Catalogue, La Palma (CAMC), USNO Zodiacal Zone Catalog (Douglass &amp; Harrington 1990), and the Perth 83 Catalogue (Harwood [1990]) to obtain as many input positions as possible. All positions were then reduced to the system of the FK4 (Fricke &amp; Kopff 1963) using a combination of the FK4, the FK4 Supplement as improved by H. Schwan of the Astronomisches Rechen-Institut in Heidelberg, and the International Reference Stars (IRS; Corbin 1991), then combined with the CPC2 and AGK3. The total number of input positions from which the ACRS was formed is 1,643,783. The original catalog is divided into two parts. Part 1 contains the stars having better observational histories and, therefore, more reliable positions and proper motions. This part constitutes 78 percent of the catalog; the mean errors of the proper motions are +/-0.47 arcsec per century and +/-0.46 arcsec per century in right ascension and declination, respectively. The stars in Part 2 have poor observational histories and consist mostly of objects for which only two catalog positions in one or both coordinates were available for computing the proper motions. Where accuracy is the primary consideration, only the stars in Part 1 should be used, while if the highest possible density is desired, the two parts should be combined. The ACRS was compiled at the U. S. Naval Observatory with the intention that it be used for new reductions of the Astrographic Catalogue (AC) plates. These plates are small in area (2 x 2 deg) and the IRS is not dense enough. Whereas the ACRS was compiled using the same techniques developed to produce the IRS, it became clear as the work progressed that the ACRS would have applications far beyond its original purpose. With accurate positions and proper motions rigorously reduced to both the FK4 and FK5 (Fricke et al. 1988) systems, it does more than simply replace the SAO. Rather, it provides the uniform system of reference stars that has been needed for many years by those who require densities greater than the IRS and with high accuracy over a wide range of epochs. It is intended that, as additional observations become available, stars will be migrated from Part 2 to Part 1, with the hope that eventually the ACRS will be complete in one part. Additional details concerning the compilation and properties of the ACRS can be found in Corbin &amp; Urban (1989) except that the star counts and errors given here supersede the ones given in 1989. The HEASARC revised this database table in August, 2005, in order to add Galactic coordinates. This is a service provided by NASA HEASARC .
1070. Astrographic Catalog Reference Stars (ACRS)
ID:
ivo://CDS.VizieR/I/171
Title:
Astrographic Catalog Reference Stars (ACRS)
Short Name:
I/171
Date:
21 Oct 2021
Publisher:
CDS
Description:
The ACRS is an all-sky catalog of positions and proper motions that is based on the AGK3 in the north and on the newly completed second Cape Photographic Catalogue (CPC2, de Vegt et al. 1989) in the south. The astrometric data are on the system of the International Reference Stars (IRS, catalog <I/172>), compiled on B1950.0 FK4 and then transformed to J2000.0 FK5. The ACRS contains 320,111 stars, the mean positions for which were derived from a total of 1,643,783 individual input positions. The catalog is divided into two parts. Part 1 contains stars having better observational histories and, therefore, more reliable positions and proper motions, while the stars in Part 2 have poor histories and consist mostly of objects for which only two catalog positions in one or both coordinates were available for computing proper motions. For Part 1, which consists of 78 percent of the catalog, the mean errors of the proper motions in right ascension and declination are 0.47 and 0.46 seconds of arc/century (4.7 and 4.6 mas/yr), respectively. It is intended that, as more observations are accumulated for stars in Part 2, they will be migrated to Part 1. The catalog was compiled at the U.S. Naval Observatory, Washington, D.C., for purposes of performing new reductions of the Astrographic Catalogue plates. Additional details about the construction of the ACRS may be found in Corbin and Urban (1989). The data included are catalog part, ACRS number, equatorial coordinates (equinox, equator, epoch B1950.0 and J2000.0), proper motions (B1950.0 and J2000.0), original epochs, weights for right ascension and declination, and reference data such as DM numbers (BD, CD, CPD), AGK3 and CPC2 designations, and an IAU recommended ACRS identifier (based on coordinates).

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