- ID:
- ivo://CDS.VizieR/J/ApJ/765/L41
- Title:
- Asteroseismic classification of KIC objects
- Short Name:
- J/ApJ/765/L41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Of the more than 150000 targets followed by the Kepler Mission, about 10% were selected as red giants. Due to their high scientific value, in particular for Galaxy population studies and stellar structure and evolution, their Kepler light curves were made public in late 2011. More than 13000 (over 85%) of these stars show intrinsic flux variability caused by solar-like oscillations making them ideal for large-scale asteroseismic investigations. We automatically extracted individual frequencies and measured the period spacings of the dipole modes in nearly every red giant. These measurements naturally classify the stars into various populations, such as the red giant branch, the low-mass (M/M_{sun}_<~1.8) helium-core-burning red clump, and the higher-mass (M/M_{sun}_>~1.8) secondary clump. The period spacings also reveal that a large fraction of the stars show rotationally induced frequency splittings. This sample of stars will undoubtedly provide an extremely valuable source for studying the stellar population in the direction of the Kepler field, in particular when combined with complementary spectroscopic surveys.
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- ID:
- ivo://CDS.VizieR/J/ApJ/871/13
- Title:
- Asteroseismology of the WD GD358, 1982-2016
- Short Name:
- J/ApJ/871/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the analysis of 34 years of photometric observations of the pulsating helium atmosphere white dwarf GD358. The complete data set includes archival data from 1982 to 2006, and 1195.2hr of new observations from 2007 to 2016. From this data set, we extract 15 frequencies representing g-mode pulsation modes, adding 4 modes to the 11 modes known previously. We present evidence that these 15 modes are l=1 modes, 13 of which belong to a consecutive sequence in radial overtone k. We perform a detailed asteroseismic analysis using models that include parameterized, complex, carbon and oxygen core composition profiles to fit the periods. Recent spectroscopic analyses place GD358 near the red edge of the DBV instability strip, at 24000{+/-}500K and a logg of 7.8{+/-}0.08dex. The surface gravity translates to a mass range of 0.455-0.540M_{sun}_. Our best-fit model has a temperature of 23650K and a mass of 0.5706M_{sun}_. That is slightly more massive than what is suggested by the most recent spectroscopy. We find a pure helium layer mass of 10^-5.50^, consistent with the result of previous studies and the outward diffusion of helium over time.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A145
- Title:
- Astrometric Catalogue 5, LQAC-5
- Short Name:
- J/A+A/624/A145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In addition to their great astrophysical interest, quasars represent quasi-ideal reference objects in the celestial sphere with, a priori, a lack of significant proper motion. Since the fourth release of the Large Quasar Astrometric Catalogue (LQAC-4), a large number of quasars have been discovered, in particular those coming from the DR14Q release of the SDSS. With the advent of the Gaia Data Release 2 (DR2), it is now also possible to fold in extremely accurate quasar positions. Following the same procedure as in the previous releases of the LQAC, our aim is to compile the large majority of the recorded quasars, with their best estimated coordinates and substantial information about their physical properties such as the redshift, multi-bands apparent, and absolute magnitudes. Emphasis is given to the results of the cross-matches with the Gaia DR2 catalogue, which considerably increases the positional accuracy. New quasars from the SDSS DR14Q release were cross-matched with the precedent LQAC-4 compilation with a 1" search radius, which leads to 149084 objects not present in the previous LQAC-4 release. Another cross-match was done with the Gaia DR2 catalogue, which enables us to considerably improve the positioning of these objects. For the first time, parallaxes and proper motions from the DR2, when available, are added to our compilation. Furthermore, a cross-identification of the LQAC-5 with the AllWISE survey gives additional mid-infrared information for an important percentage of objects. Our final catalogue, namely the LQAC-5, contains 592 809 quasars. This represents roughly a 34% increase with respect to the number of objects recorded in the LQAC-4. Among them, 398 697 objects were found in common with the Gaia DR2, within a 1" search radius. That corresponds to 67.26% of the whole population of the compilation. The LQAC-5 delivers a nearly complete catalogue of spectroscopically confirmed quasars (including a small proportion of 14126 compact AGN's) to the astronomical community, with the aim of giving their best equatorial coordinates with respect to the ICRF2 and with exhaustive additional information. For more than 50% of the sample, these coordinates are extracted from the very recent Gaia DR2.
- ID:
- ivo://CDS.VizieR/I/338
- Title:
- Astrometric catalogue of stars KMAC3
- Short Name:
- I/338
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of astrometric observations of faint V<17mag stars obtained with the Kyiv meridian axial circle. Observations were carried out in 2010-2015 in a declination zone of +2 +5.5 degrees and with use of Johnson V-band filter. The catalogue contains data for about 2 million of stars.
- ID:
- ivo://CDS.VizieR/I/332
- Title:
- Astrometric catalogue of stars KMAC2
- Short Name:
- I/332
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of astrometric observations of faint V<17mag stars obtained with the Kyiv meridian axial circle. Observations were carried out in 2001-2005 in a declination zone of 0+2 degrees and with use of Johnson V-band filter. The catalogue contains data for about a million of stars.
- ID:
- ivo://CDS.VizieR/J/ApJS/231/15
- Title:
- Astrometric monitoring of ultracool dwarf binaries
- Short Name:
- J/ApJS/231/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the full results of our decade-long astrometric monitoring programs targeting 31 ultracool binaries with component spectral types M7-T5. Joint analysis of resolved imaging from Keck Observatory and Hubble Space Telescope and unresolved astrometry from CFHT/WIRCam yields parallactic distances for all systems, robust orbit determinations for 23 systems, and photocenter orbits for 19 systems. As a result, we measure 38 precise individual masses spanning 30-115M_Jup_. We determine a model-independent substellar boundary that is ~70M_Jup_ in mass (~L4 in spectral type), and we validate Baraffe et al. evolutionary model predictions for the lithium-depletion boundary (60M_Jup_ at field ages). Assuming each binary is coeval, we test models of the substellar mass-luminosity relation and find that in the L/T transition, only the Saumon & Marley (2008ApJ...689.1327S) "hybrid" models accounting for cloud clearing match our data. We derive a precise, mass-calibrated spectral type-effective temperature relation covering 1100-2800K. Our masses enable a novel direct determination of the age distribution of field brown dwarfs spanning L4-T5 and 30-70M_Jup_. We determine a median age of 1.3Gyr, and our population synthesis modeling indicates our sample is consistent with a constant star formation history modulated by dynamical heating in the Galactic disk. We discover two triple-brown-dwarf systems, the first with directly measured masses and eccentricities. We examine the eccentricity distribution, carefully considering biases and completeness, and find that low-eccentricity orbits are significantly more common among ultracool binaries than solar-type binaries, possibly indicating the early influence of long-lived dissipative gas disks. Overall, this work represents a major advance in the empirical view of very low-mass stars and brown dwarfs.
- ID:
- ivo://CDS.VizieR/J/AJ/126/2922
- Title:
- Astrometry and membership in NGC 188
- Short Name:
- J/AJ/126/2922
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present techniques for obtaining precision astrometry using old photographic plates from assorted large-aperture reflectors in combination with recent CCD Mosaic Imager frames. At the core of this approach is a transformation of plate/CCD coordinates into a previously constructed astrometric reference frame around the open cluster NGC 188.
- ID:
- ivo://CDS.VizieR/J/ApJ/718/810
- Title:
- Astrometry and Photometry in the Arches cluster
- Short Name:
- J/ApJ/718/810
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep Keck/NIRC2 HK'L' observations of the Arches cluster near the Galactic center reveal a significant population of near-infrared excess sources. We combine the L'-band excess observations with K'-band proper motions, which allow us to confirm cluster membership of excess sources in a starburst cluster for the first time. The robust removal of field contamination provides a reliable disk fraction down to our completeness limit of H=19mag, or ~5M_{sun}_ at the distance of the Arches. Of the 24 identified sources with K'-L'>2.0mag, 21 have reliable proper motion measurements, all of which are proper motion members of the Arches cluster. VLT/SINFONI K'-band spectroscopy of 3 excess sources reveals strong CO bandhead emission, which we interpret as the signature of dense circumstellar disks. The detection of strong disk emission from the Arches stars is surprising in view of the high mass of the B-type main sequence host stars of the disks and the intense starburst environment. We find a disk fraction of 6%+/-2% among B-type stars in the Arches cluster. A radial increase in the disk fraction from 3% to 10% suggests rapid disk destruction in the immediate vicinity of numerous O-type stars in the cluster core. A comparison between the Arches and other high- and low-mass star-forming regions provides strong indication that disk depletion is significantly more rapid in compact starburst clusters than in moderate star-forming environments.
