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1281. JMMC Stellar Diameters Catalogue - JSDC
ID:
ivo://CDS.VizieR/II/300
Title:
JMMC Stellar Diameters Catalogue - JSDC
Short Name:
II/300
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue contains stellar angular diameter estimate for bright stars, complete for all stars with Hipparcos parallaxes. The JMMC Calibrator Workgroup has long developed methods to estimate the angular diameter of stars, and provides this expertise in the SearchCal software (http://www.jmmc.fr/searchcal). "SearchCal" creates a dynamical catalogue of stars suitable to calibrate Optical Long-Baseline Interferometry (OLBI) observations from on-line queries of CDS catalogues, according to observational parameters. In essence, SearchCal is limited only by the completeness of the stellar catalogues it uses, and in particular is not limited in magnitude. SearchCal being an application centered on OLBI peculiar purposes, it appeared useful to publish the estimated angular diameters of all stars with known parallaxes in a static catalogue. The present catalogue of stellar angular diameters has been obtained from an automated SearchCal results aggregation on the whole celestial sphere. For each star, the value of the limb-darkened angular diameters are computed using a surface brightness method and calibrations for (B-V), (V-R) and (V-K) color indexes. Stars whose angular diameters estimated from the various color indexes are not comparable, are rejected, and a reliable error on the estimated diameter is computed (1). For details of the method see Bonneau et al. (2006A&A...456..789B). To avoid specific confusion problems, spectroscopic binaries in the 9th Catalogue of Spectroscopic Binary Orbits (Pourbaix et al., 2009, Cat. B/sb9) or close visual binaries with a separation of less than 2 arc seconds in the Washington Visual Double Star Catalog (Mason et al., 2001, Cat. B/wds) have been filtered out.
1282. JMMC Stellar Diameters Catalogue - JSDC. Version 2
ID:
ivo://CDS.VizieR/II/346
Title:
JMMC Stellar Diameters Catalogue - JSDC. Version 2
Short Name:
II/346
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue contains stellar angular diameter estimates for nearly all the stars of the Hipparcos and Tycho catalogue that have an associated spectral type in Simbad/CDS. The median error on the diameters is around 1.5%, with possible biases of around ~2%. For each object, the limb-darkened diameter retained is the mean value of several estimates performed using different couples of photometries. The chi-square representing the dispersion between these values is also given (it is below 2 for ~400000 stars). An additional flag signals stars that could represent a risk if chosen as calibrators for Optical Long-Baseline Interferometry, independently of the correctness of their apparent diameter estimate. This catalog replaces the catalog II/300/jsdc .
1283. K and M stars photometry
ID:
ivo://CDS.VizieR/J/AJ/105/1962
Title:
K and M stars photometry
Short Name:
J/AJ/105/1962
Date:
21 Oct 2021
Publisher:
CDS
Description:
Broadband UBVRI photometry is presented for 687 stars from among the dwarf K and M stars found spectroscopically by Vyssotsky [1958AJ.....63..211V]. Of these, 211 are without previous photometry.
1284. KASI-Yonsei Deep Imaging Survey of Clusters (KYDISC)
ID:
ivo://CDS.VizieR/J/ApJS/237/14
Title:
KASI-Yonsei Deep Imaging Survey of Clusters (KYDISC)
Short Name:
J/ApJS/237/14
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the KASI-Yonsei Deep Imaging Survey of Clusters targeting 14 clusters at 0.015<~z<~0.144 using the Inamori Magellan Areal Camera and Spectrograph on the 6.5m Magellan Baade telescope and the MegaCam on the 3.6m Canada-France-Hawaii Telescope. We provide a catalog of cluster galaxies that lists magnitudes, redshifts, morphologies, bulge-to-total ratios, and local density. Based on the 1409 spectroscopically confirmed cluster galaxies brighter than -19.8 in the r band, we study galaxy morphology, color, and visual features generated by galaxy mergers. We see a clear trend between morphological content and cluster velocity dispersion, which was not presented by previous studies using local clusters. Passive spirals are preferentially found in a highly dense region (i.e., cluster center), indicating that they have gone through environmental quenching. In deep images ({mu}_r'_~27mag/arcsec^2^), 20% of our sample shows signatures of recent mergers, which is not expected from theoretical predictions and a low frequency of ongoing mergers in our sample (~4%). Such a high fraction of recent mergers in the cluster environment supports a scenario that the merger events that made the features have preceded the galaxy accretion into the cluster environment. We conclude that mergers affect a cluster population mainly through the preprocessing of recently accreted galaxies.
1285. Keck HIRES obs. of 245 subgiants (retired A stars)
ID:
ivo://CDS.VizieR/J/ApJ/860/109
Title:
Keck HIRES obs. of 245 subgiants (retired A stars)
Short Name:
J/ApJ/860/109
Date:
21 Oct 2021
Publisher:
CDS
Description:
Exoplanet surveys of evolved stars have provided increasing evidence that the formation of giant planets depends not only on stellar metallicity ([Fe/H]) but also on the mass (M*). However, measuring accurate masses for subgiants and giants is far more challenging than it is for their main-sequence counterparts, which has led to recent concerns regarding the veracity of the correlation between stellar mass and planet occurrence. In order to address these concerns, we use HIRES spectra to perform a spectroscopic analysis on a sample of 245 subgiants and derive new atmospheric and physical parameters. We also calculate the space velocities of this sample in a homogeneous manner for the first time. When reddening corrections are considered in the calculations of stellar masses and a -0.12M_{sun}_ offset is applied to the results, the masses of the subgiants are consistent with their space velocity distributions, contrary to claims in the literature. Similarly, our measurements of their rotational velocities provide additional confirmation that the masses of subgiants with M*>=1.6M_{sun}_ (the "retired A stars") have not been overestimated in previous analyses. Using these new results for our sample of evolved stars, together with an updated sample of FGKM dwarfs, we confirm that giant planet occurrence increases with both stellar mass and metallicity up to 2.0M_{sun}_. We show that the probability of formation of a giant planet is approximately a one-to-one function of the total amount of metals in the protoplanetary disk M* 10^[Fe/H]. This correlation provides additional support for the core accretion mechanism of planet formation.
1286. Keck Lyman continuum spectroscopic survey (KLCS)
ID:
ivo://CDS.VizieR/J/ApJ/869/123
Title:
Keck Lyman continuum spectroscopic survey (KLCS)
Short Name:
J/ApJ/869/123
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results of a deep spectroscopic survey quantifying the statistics of the escape of ionizing radiation from star-forming galaxies at z~3. We measure the ratio of ionizing to non-ionizing UV flux density <f_900_/f_1500_>_obs_, where f_900_ is the mean flux density evaluated over the range [880,910]{AA}. We quantify the emergent ratio of ionizing to non-ionizing UV flux density by analyzing high signal-to-noise ratio composite spectra formed from subsamples with common observed properties and numbers sufficient to reduce the statistical uncertainty in the modeled IGM+CGM correction to obtain precise values of <f_900_/f_1500_>_out_, including a full-sample average <f_900_/f_1500>_out_=0.057{+/-}0.006. We show that <f_900_/f_1500_>_out_ increases monotonically with W_{lambda}_(Ly{alpha}), inducing an inverse correlation with UV luminosity as a by-product. We fit the composite spectra using stellar spectral synthesis together with models of the ISM in which a fraction f_c_ of the stellar continuum is covered by gas with column density N_HI_. We show that the composite spectra simultaneously constrain the intrinsic properties of the stars (L_900_/L_1500_)_int_ along with f_c_, N_HI_, E(B-V), and f_esc,abs_, the absolute escape fraction of ionizing photons. We find a sample-averaged f_esc,abs_=0.09{+/-}0.01, with subsamples falling along a linear relation <f_esc,abs_>~0.75[W_{lambda}_(Ly{alpha})/110{AA}]. Using the far-UV luminosity function, the distribution function n(W(Ly{alpha})), and the relationship between W_{lambda}_(Ly{alpha}) and <f_900_/f_1500_>_out_, we estimate the total ionizing emissivity of z~3 star-forming galaxies with M_uv_<=-19.5, which exceeds the contribution of quasi-stellar objects by a factor of ~3, and accounts for ~50% of the total {epsilon}LyC at z~3 estimated using indirect methods.
1287. Keck/MOSFIRE spectroscopy of ZFOURGE galaxies
ID:
ivo://CDS.VizieR/J/ApJ/834/101
Title:
Keck/MOSFIRE spectroscopy of ZFOURGE galaxies
Short Name:
J/ApJ/834/101
Date:
21 Oct 2021
Publisher:
CDS
Description:
We compare galaxy scaling relations as a function of environment at z~2 with our ZFIRE survey where we have measured H{alpha} fluxes for 90 star-forming galaxies selected from a mass-limited (log(M_*_/M_{sun}_)>9) sample based on ZFOURGE. The cluster galaxies (37) are part of a confirmed system at z=2.095 and the field galaxies (53) are at 1.9<z<2.4; all are in the COSMOS legacy field. There is no statistical difference between H{alpha}-emitting cluster and field populations when comparing their star formation rate (SFR), stellar mass (M_*_), galaxy size (r_eff_), SFR surface density ({Sigma}(H{alpha}_star_)), and stellar age distributions. The only difference is that at fixed stellar mass, the H{alpha}-emitting cluster galaxies are log(r_eff_)~0.1 larger than in the field. Approximately 19% of the H{alpha} emitters in the cluster and 26% in the field are IR-luminous (L_IR_>2x10^11^L_{sun}_). Because the luminous IR galaxies in our combined sample are ~5 times more massive than the low-IR galaxies, their radii are ~70% larger. To track stellar growth, we separate galaxies into those that lie above, on, or below the H{alpha} star-forming main sequence (SFMS) using {Delta}SFR(M*)=+/-0.2dex. Galaxies above the SFMS (starbursts) tend to have higher H{alpha} SFR surface densities and younger light-weighted stellar ages than galaxies below the SFMS. Our results indicate that starbursts (+SFMS) in the cluster and field at z~2 are growing their stellar cores. Lastly, we compare to the (SFR-M*) relation from Rhapsody-G cluster simulations and find that the predicted slope is nominally consistent with the observations. However, the predicted cluster SFRs tend to be too low by a factor of ~2, which seems to be a common problem for simulations across environment.
1288. K2 Ecliptic Plane Input Catalog (EPIC)
ID:
ivo://CDS.VizieR/IV/34
Title:
K2 Ecliptic Plane Input Catalog (EPIC)
Short Name:
IV/34
Date:
21 Oct 2021
Publisher:
CDS
Description:
The K2 Mission (Howell+, 2014PASP..126..398H) uses the Kepler spacecraft to obtain high-precision photometry over ~80 day campaigns in the ecliptic plane. The Ecliptic Plane Input Catalog (EPIC) provides coordinates, photometry, and kinematics based on a federation of all-sky catalogs to support target selection and target management for the K2 mission.
1289. Kepler-278 and Kepler-391 spectra
ID:
ivo://CDS.VizieR/J/A+A/634/A29
Title:
Kepler-278 and Kepler-391 spectra
Short Name:
J/A+A/634/A29
Date:
21 Oct 2021
Publisher:
CDS
Description:
Kepler-278 and Kepler-391 are two of the three evolved stars on the red giant branch (RGB) known to date, to host multiple short-period transiting planets. Moreover, these planets are among the smallest discovered around RGB stars. Here, we present a detailed stellar and planetary characterization of these remarkable systems. Methods. Based on high-quality spectra from Gemini-GRACES of Kepler-278 and Kepler-391, we obtained refined stellar parameters and precise chemical abundances of 25 elements. Nine of these elements and the carbon isotopic ratios, ^12^C/^13^C, were not previously measured. Also, combining our new stellar parameters with a photodynamical analysis of the Kepler light curves, we determined accurate planetary properties of both systems. Results. Our revised stellar parameters agree reasonably well with most of the previous results, although we find that Kepler-278 is ~15% less massive than previously reported. The abundances of C, N, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, and Ce, in both stars, are consistent with those of evolved nearby thin disk stars. Kepler-391 presents a relatively high abundance of lithium (A(Li)NLTE=1.29+/-0.09dex), which is likely a remnant from the main-sequence phase. The precise spectroscopic parameters of Kepler-278 and Kepler-391 along with their high 12 C/13 C ratios show that both stars are just starting their ascent on the RGB. The planets Kepler-278b, Kepler-278c, and Kepler-391c are warm sub-Neptunes, whilst Kepler-391b is a hot sub-Neptune that falls in the Hot Super-Earth desert and therefore it might be undergoing photo-evaporation of its outer envelope. The high-precision obtained in the transit times allowed us not only to confirm Kepler-278c's TTV signal but also to find evidence of a previously undetected TTV signal for the inner planet Kepler-278b. From the presence of gravitational interaction between these bodies we constrain, for the first time, the mass of Kepler-278b (Mp=56M_Earth_) and Kepler-278c (Mp=35M_Earth_). The mass limits, coupled with our precise determinations of the planetary radii, suggest that their bulk compositions are consistent with a significant amount of water content and the presence of H2 gaseous envelopes. Finally, our photodynamical analysis also shows that the orbits of both planets around Kepler-278 are highly eccentric (e~0.7) and, surprisingly, coplanar. Further observations (e.g., precise radial velocities) of this system are needed to confirm the eccentricity values presented here.
1290. Kepler cycle 1 observations of low-mass stars
ID:
ivo://CDS.VizieR/J/AJ/143/4
Title:
Kepler cycle 1 observations of low-mass stars
Short Name:
J/AJ/143/4
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have analyzed Kepler light curves for 849 stars with Teff<=5200K from our Cycle 1 Guest Observer program. We identify six new eclipsing binaries, one of which has an orbital period of 29.91 days and two of which are probably W UMa variables. In addition, we identify a candidate "warm Jupiter" exoplanet. We further examine a subset of 670 sources for variability. Of these objects, 265 stars clearly show periodic variability that we assign to rotation of the low-mass star. At the photometric precision level provided by Kepler, 251 of our objects showed no evidence for variability. We were unable to determine periods for 154 variable objects. We find that 79% of stars with Teff<=5200K are variable. The rotation periods we derive for the periodic variables span the range 0.31days<=Prot<=126.5days. A considerable number of stars with rotation periods similar to the solar value show activity levels that are 100 times higher than the Sun.