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101. Apertif DR Bootes - Catalogue
ID:
ivo://astron.nl/apertif_dr_bootes/q/cone
Title:
Apertif DR Bootes - Catalogue
Short Name:
DR Bootes
Date:
01 Aug 2024 09:31:58
Publisher:
ASTRON
Description:
Apertif is a phased-array feed system for the Westerbork Synthesis Radio Telescope (WSRT), providing forty instantaneous beams over 300 MHz of bandwidth. This data release includes the catalogue and image observed by Apertif covering 26.5 square degree region in the Boötes constellation at 1.4 GHz. The image is a mosaic of 187 Apertif images from 8 different survey observations performed between April 2019 and November 2021. It has an angular resolution of 27×11.5 arcseconds and a median background noise of 40 μJy/beam. From this mosaic, 8994 sources were extracted and the catalogue is complete down to the 0.3 mJy level. This service queries the source catalogue of the Boötes field.
102. Apertif DR Bootes - Mosaic
ID:
ivo://astron.nl/apertif_dr_bootes/q/cutout
Title:
Apertif DR Bootes - Mosaic
Short Name:
DR Bootes
Date:
01 Aug 2024 09:31:58
Publisher:
ASTRON
Description:
Apertif is a phased-array feed system for the Westerbork Synthesis Radio Telescope (WSRT), providing forty instantaneous beams over 300 MHz of bandwidth. This data release includes the catalogue and image observed by Apertif covering 26.5 square degree region in the Boötes constellation at 1.4 GHz. The image is a mosaic of 187 Apertif images from 8 different survey observations performed between April 2019 and November 2021. It has an angular resolution of 27×11.5 arcseconds and a median background noise of 40 μJy/beam. From this mosaic, 8994 sources were extracted and the catalogue is complete down to the 0.3 mJy level. This service queries the mosaic image of the Boötes field.
103. APOGEE-2 data from DR16
ID:
ivo://CDS.VizieR/III/284
Title:
APOGEE-2 data from DR16
Short Name:
III/284
Date:
05 Jan 2022
Publisher:
CDS
Description:
The spectral analysis and data products in Data Release 16 (DR16; 2019 December) from the high-resolution near-infrared Apache Point Observatory Galactic Evolution Experiment (APOGEE)-2/Sloan Digital Sky Survey (SDSS)-IV survey are described. Compared to the previous APOGEE data release (DR14; 2017 July), APOGEE DR16 includes about 200000 new stellar spectra, of which 100000 are from a new southern APOGEE instrument mounted on the 2.5m du Pont telescope at Las Campanas Observatory in Chile. DR16 includes all data taken up to 2018 August, including data released in previous data releases. All of the data have been re-reduced and re-analyzed using the latest pipelines, resulting in a total of 473307 spectra of 437445 stars. Changes to the analysis methods for this release include, but are not limited to, the use of MARCS model atmospheres for calculation of the entire main grid of synthetic spectra used in the analysis, a new method for filling "holes" in the grids due to unconverged model atmospheres, and a new scheme for continuum normalization. Abundances of the neutron-capture element Ce are included for the first time. A new scheme for estimating uncertainties of the derived quantities using stars with multiple observations has been applied, and calibrated values of surface gravities for dwarf stars are now supplied. Compared to DR14, the radial velocities derived for this release more closely match those in the Gaia DR2 database, and a clear improvement in the spectral analysis of the coolest giants can be seen.
104. APOGEE DR14:Binary companions of evolved stars
ID:
ivo://CDS.VizieR/J/AJ/156/18
Title:
APOGEE DR14:Binary companions of evolved stars
Short Name:
J/AJ/156/18
Date:
21 Oct 2021
Publisher:
CDS
Description:
Multi-epoch radial velocity measurements of stars can be used to identify stellar, substellar, and planetary-mass companions. Even a small number of observation epochs can be informative about companions, though there can be multiple qualitatively different orbital solutions that fit the data. We have custom-built a Monte Carlo sampler (The Joker) that delivers reliable (and often highly multimodal) posterior samplings for companion orbital parameters given sparse radial velocity data. Here we use The Joker to perform a search for companions to 96231 red giant stars observed in the APOGEE survey (DR14) with >=3 spectroscopic epochs. We select stars with probable companions by making a cut on our posterior belief about the amplitude of the variation in stellar radial velocity induced by the orbit. We provide (1) a catalog of 320 companions for which the stellar companion's properties can be confidently determined, (2) a catalog of 4898 stars that likely have companions, but would require more observations to uniquely determine the orbital properties, and (3) posterior samplings for the full orbital parameters for all stars in the parent sample. We show the characteristics of systems with confidently determined companion properties and highlight interesting systems with candidate compact object companions.
105. APOGEE/Kepler sample stars abundances
ID:
ivo://CDS.VizieR/J/A+A/594/A43
Title:
APOGEE/Kepler sample stars abundances
Short Name:
J/A+A/594/A43
Date:
21 Oct 2021
Publisher:
CDS
Description:
The APOGEE survey has obtained high-resolution infrared spectra of more than 100,000 stars. Deriving chemical abundances patterns of these stars is paramount to piecing together the structure of the MilkyWay. While the derived chemical abundances have been shown to be precise for most stars, some calibration problems have been reported, in particular for more metal-poor stars. In this paper, we aim to (1) re-determine the chemical abundances of the APOGEE+Kepler stellar sample (APOKASC) with an independent procedure, line list and line selection, and high-quality surface gravity information from asteroseismology, and (2) extend the abundance catalogue by including abundances that are not currently reported in the most recent APOGEE release (DR12). We fixed the Teff and logg to those determined using spectrophotometric and asteroseismic techniques, respectively. We made use of the Brussels Automatic Stellar Parameter (BACCHUS) code to derive the metallicity and broadening parameters for the APOKASC sample. In addition, we derived differential abundances with respect to Arcturus.
106. APOGEE kinematics. I. Galactic bulge overview
ID:
ivo://CDS.VizieR/J/ApJ/819/2
Title:
APOGEE kinematics. I. Galactic bulge overview
Short Name:
J/ApJ/819/2
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the stellar kinematics across the Galactic bulge and into the disk at positive longitudes from the SDSS-III APOGEE spectroscopic survey of the Milky Way. APOGEE includes extensive coverage of the stellar populations of the bulge along the midplane and near-plane regions. From these data, we have produced kinematic maps of 10000 stars across longitudes of 0{deg}<l<65{deg}, and primarily across latitudes of |b|<5{deg} in the bulge region. The APOGEE data reveal that the bulge is cylindrically rotating across all latitudes and is kinematically hottest at the very center of the bulge, with the smallest gradients in both kinematic and chemical space inside the innermost region (|l,b|)<(5{deg},5{deg}). The results from APOGEE show good agreement with data from other surveys at higher latitudes and a remarkable similarity to the rotation and dispersion maps of barred galaxies viewed edge-on. The thin bar that is reported to be present in the inner disk within a narrow latitude range of |b|<2{deg} appears to have a corresponding signature in [Fe/H] and [{alpha}/Fe]. Stars with [Fe/H]>-0.5 have dispersion and rotation profiles that are similar to that of N-body models of boxy/peanut bulges. There is a smooth kinematic transition from the thin bar and boxy bulge (|l,b|)<(15{deg},12{deg}) out to the disk for stars with [Fe/H]>-1.0, and the chemodynamics across (l,b) suggests that the stars in the inner Galaxy with [Fe/H]>-1.0 originate in the disk.
107. APOGEE M-dwarf survey. I. First year velocities
ID:
ivo://CDS.VizieR/J/AJ/146/156
Title:
APOGEE M-dwarf survey. I. First year velocities
Short Name:
J/AJ/146/156
Date:
21 Oct 2021
Publisher:
CDS
Description:
We are carrying out a large ancillary program with the Sloan Digital Sky Survey, SDSS-III, using the fiber-fed multi-object near-infrared APOGEE spectrograph, to obtain high-resolution H-band spectra of more than 1200 M dwarfs. These observations will be used to measure spectroscopic rotational velocities, radial velocities, physical stellar parameters, and variability of the target stars. Here, we describe the target selection for this survey, as well as results from the first year of scientific observations based on spectra that will be publicly available in the SDSS-III DR10 data release. As part of this paper we present radial velocities and rotational velocities of over 200 M dwarfs, with a vsini precision of ~2km/s and a measurement floor at vsini=4km/s. This survey significantly increases the number of M dwarfs studied for rotational velocities and radial velocity variability (at ~100-200m/s), and will inform and advance the target selection for planned radial velocity and photometric searches for low-mass exoplanets around M dwarfs, such as the Habitable Zone Planet Finder, CARMENES, and TESS. Multiple epochs of radial velocity observations enable us to identify short period binaries, and adaptive optics imaging of a subset of stars enables the detection of possible stellar companions at larger separations. The high-resolution APOGEE spectra, covering the entire H band, provide the opportunity to measure physical stellar parameters such as effective temperatures and metallicities for many of these stars. At the culmination of this survey, we will have obtained multi-epoch spectra and radial velocities for over 1400 stars spanning the spectral range M0-L0, providing the largest set of near-infrared M dwarf spectra at high resolution, and more than doubling the number of known spectroscopic vsini values for M dwarfs. Furthermore, by modeling telluric lines to correct for small instrumental radial velocity shifts, we hope to achieve a relative velocity precision floor of 50m/s for bright M dwarfs. With three or more epochs, this precision is adequate to detect substellar companions, including giant planets with short orbital periods, and flag them for higher-cadence followup. We present preliminary, and promising, results of this telluric modeling technique in this paper.
108. APOGEE stars distance and extinction
ID:
ivo://CDS.VizieR/J/MNRAS/460/3179
Title:
APOGEE stars distance and extinction
Short Name:
J/MNRAS/460/3179
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using a Bayesian technology, we derived distances and extinctions for over 100000 red giant stars observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey by taking into account spectroscopic constraints from the APOGEE stellar parameters and photometric constraints from Two Micron All-Sky Survey, as well as a prior knowledge on the Milky Way. Derived distances are compared with those from four other independent methods, the Hipparcos parallaxes, star clusters, APOGEE red clump stars, and asteroseismic distances from APOKASC and Stromgren survey for Asteroseismology and Galactic Archaeology catalogues. These comparisons covers four orders of magnitude in the distance scale from 0.02 to 20kpc. The results show that our distances agree very well with those from other methods: the mean relative difference between our Bayesian distances and those derived from other methods ranges from -4.2 per cent to +3.6 per cent, and the dispersion ranges from 15 per cent to 25 per cent. The extinctions towards all stars are also derived and compared with those from several other independent methods: the Rayleigh-Jeans Colour Excess (RJCE) method, Gonzalez's 2D extinction map, as well as 3D extinction maps and models. The comparisons reveal that, overall, estimated extinctions agree very well, but RJCE tends to overestimate extinctions for cool stars and objects with low logg.
109. APOGEE-2 survey of Orion Complex. II.
ID:
ivo://CDS.VizieR/J/AJ/156/84
Title:
APOGEE-2 survey of Orion Complex. II.
Short Name:
J/AJ/156/84
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis of spectroscopic and astrometric data from APOGEE-2 and Gaia DR2 (Cat. I/345) to identify structures toward the Orion Complex. By applying a hierarchical clustering algorithm to the six-dimensional stellar data, we identify spatially and/or kinematically distinct groups of young stellar objects with ages ranging from 1 to 12 Myr. We also investigate the star-forming history within the Orion Complex and identify peculiar subclusters. With this method we reconstruct the older populations in the regions that are currently largely devoid of molecular gas, such as Orion C (which includes the {sigma} Ori cluster) and Orion D (the population that traces Ori OB1a, OB1b, and Orion X). We report on the distances, kinematics, and ages of the groups within the Complex. The Orion D group is in the process of expanding. On the other hand, Orion B is still in the process of contraction. In {lambda} Ori the proper motions are consistent with a radial expansion due to an explosion from a supernova; the traceback age from the expansion exceeds the age of the youngest stars formed near the outer edges of the region, and their formation would have been triggered when they were halfway from the cluster center to their current positions. We also present a comparison between the parallax and proper-motion solutions obtained by Gaia DR2 and those obtained toward star-forming regions by the Very Long Baseline Array.
110. APOGEE-2 survey of Orion Complex (OSFC). I.
ID:
ivo://CDS.VizieR/J/ApJS/236/27
Title:
APOGEE-2 survey of Orion Complex (OSFC). I.
Short Name:
J/ApJS/236/27
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Orion Star-forming Complex (OSFC) is a central target for the APOGEE-2 Young Cluster Survey. Existing membership catalogs span limited portions of the OSFC, reflecting the difficulty of selecting targets homogeneously across this extended, highly structured region. We have used data from wide-field photometric surveys to produce a less biased parent sample of young stellar objects (YSOs) with infrared (IR) excesses indicative of warm circumstellar material or photometric variability at optical wavelengths across the full 420deg^2^ extent of the OSFC. When restricted to YSO candidates with H<12.4, to ensure S/N~100 for a six-visit source, this uniformly selected sample includes 1307 IR excess sources selected using criteria vetted by Koenig & Leisawitz (2014ApJ...791..131K) and 990 optical variables identified in the Pan-STARRS1 3{pi} survey: 319 sources exhibit both optical variability and evidence of circumstellar disks through IR excess. Objects from this uniformly selected sample received the highest priority for targeting, but required fewer than half of the fibers on each APOGEE-2 plate. We filled the remaining fibers with previously confirmed and new color-magnitude selected candidate OSFC members. Radial velocity measurements from APOGEE-1 and new APOGEE-2 observations taken in the survey's first year indicate that ~90% of the uniformly selected targets have radial velocities consistent with Orion membership. The APOGEE-2 Orion survey will include >1100 bona fide YSOs whose uniform selection function will provide a robust sample for comparative analyses of the stellar populations and properties across all sub-regions of Orion.

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