- ID:
- ivo://CDS.VizieR/J/A+A/638/A104
- Title:
- Gaia DR2 candidate RR Lyrae of Sgr stream & dwarf
- Short Name:
- J/A+A/638/A104
- Date:
- 14 Jan 2022 08:12:04
- Publisher:
- CDS
- Description:
- The Sagittarius (Sgr) stream is one of the best tools that we currently have to estimate the mass and shape of our Galaxy. However, assigning membership and obtaining the phase-space distribution of the stars that form the tails is quite challenging. Our goal is to produce a catalogue of RR Lyrae stars of Sgr and obtain an empiric measurement of the trends along the stream in sky position, distance and tangential velocities. We generate two initial samples from the Gaia DR2 RR Lyrae catalogue: one, selecting only the stars within +/-20{deg} of the orbital plane of Sagittarius (Strip) and the other, the result of applying the Pole Count Map (nGC3) algorithm. We then use the model-independent, deterministic method developed in this work to remove most of the contamination by detecting and isolating the stream in distance and proper motions. The output is two empiric catalogues: the Strip sample (higher-completeness, lower-purity) which contains 11677 stars, and the nGC3 sample (higher-purity, lower-completeness) with 6608 stars. We characterise the changes along the stream in all the available dimensions, the 5 astrometric ones plus the metallicity, covering more than 2{pi}rad in the sky and obtain new estimates for the apocentres and the mean [Fe/H] of the RR Lyrae population. Also, we show the first map of the two components of the tangential velocity, thanks to the combination of distances and proper motions. Finally, we detect the bifurcation in the leading arm and report no significant difference between the two branches, either in metallicity, kinematics or distance. We provide the largest sample of RR Lyrae candidates of Sgr, which can be used as an input for a spectroscopic follow-up or as a reference for the new generation of models of the stream through the interpolators in distance and velocity that we have constructed.
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Search Results
4912. GAIA DR2 ConeSearch
- ID:
- ivo://archive.stsci.edu/catalogs/GAIADR2
- Title:
- GAIA DR2 ConeSearch
- Short Name:
- GAIADR2 CS
- Date:
- 23 Jul 2020 20:18:57
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- All MAST catalog holdings are available via Cone Search endpoints. This service provides access to the MAST mirror of the GAIA catalog data release 2. All available missions are listed at http://archive.stsci.edu/vo/mast_services.html.
4913. GAIA DR1 ConeSearch
- ID:
- ivo://archive.stsci.edu/catalogs/GAIADR1
- Title:
- GAIA DR1 ConeSearch
- Short Name:
- GAIADR1 CS
- Date:
- 23 Jul 2020 20:18:44
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- All MAST catalog holdings are available via Cone Search endpoints. This service provides access to the MAST mirror of the GAIA catalog data release 1. All available missions are listed at http://archive.stsci.edu/vo/mast_services.html.
4914. GAIA DR3 ConeSearch
- ID:
- ivo://archive.stsci.edu/catalogs/GAIADR3
- Title:
- GAIA DR3 ConeSearch
- Short Name:
- GAIADR3 CS
- Date:
- 02 Aug 2024 14:20:04
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- All MAST catalog holdings are available via Cone Search endpoints. This service provides access to the MAST mirror of the GAIA catalog data release 3. All available missions are listed at http://archive.stsci.edu/vo/mast_services.html.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A59
- Title:
- Gaia DR2 confirmed new nearby open clusters
- Short Name:
- J/A+A/618/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The publication of the Gaia Data Release 2 (Gaia DR2) opens a new era in astronomy. It includes precise astrometric data (positions, proper motions, and parallaxes) for more than 1.3 billion sources, mostly stars. To analyse such a vast amount of new data, the use of data-mining techniques and machine-learning algorithms is mandatory. A great example of the application of such techniques and algorithms is the search for open clusters (OCs), groups of stars that were born and move together, located in the disc. Our aim is to develop a method to automatically explore the data space, requiring minimal manual intervention. We explore the performance of a density-based clustering algorithm, DBSCAN, to find clusters in the data together with a supervised learning method such as an artificial neural network (ANN) to automatically distinguish between real OCs and statistical clusters. The development and implementation of this method in a five-dimensional space (l, b, p, {mu}_{alpha}_^*^, {mu}_{delta}_) with the Tycho-Gaia Astrometric Solution (TGAS) data, and a posterior validation using Gaia DR2 data, lead to the proposal of a set of new nearby OCs. We have developed a method to find OCs in astrometric data, designed to be applied to the full Gaia DR2 archive.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A119
- Title:
- Gaia DR2 distances to two clusters
- Short Name:
- J/A+A/630/A119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- On the one hand, the second data release of the Gaia mission (GaiaDR2, Cat. I/345) has opened a trove of astrometric and photometric data for Galactic clusters within a few kpc of the Sun. On the other hand, lucky imaging has been an operational technique to measure the relative positions of visual binary systems for a decade and a half, a time sufficient to apply its results to the calculation of orbits of some massive multiple systems within ~1kpc of the Sun. As part of an ambitious research program to measure distances to Galactic stellar groups (including clusters) containing O stars,I start with two of the nearest examples: Collinder 419 in Cygnus and NGC 2264 in Monoceros. The main ionizing source for both clusters is a multiple system with an O-type primary: HD 193322 and 15 Mon, respectively. For each of those two multiple systemsI aim to derive new astrometric orbits for the Aa,Ab components. First, I present a method that usesGaiaDR2 G+G_BP_+G_RP_ photometry, positions, proper motions, and parallaxes to obtain the membership and distance of a stellar group and apply it to Collinder 419 and NGC 2264. Second, I present a new code that calculates astrometric orbits by searching the whole seven-parameter orbit space and apply it to HD 193 322 Aa,Ab and 15 Mon Aa,Abusing as input literature data from the Washington Double Star Catalog (WDS) and the AstraLux measurements recently presented by Maiz Apellaniz et al. (2019, Cat. J/A+A/626/A20) I obtain GaiaDR2 distances of 1006^+37^_-34_pc for Collinder 419 and 719+/-16pc for NGC 2264, with the main contribution to the uncertainties coming from the spatial covariance of the parallaxes. The two NGC 2264 subclusters are at the same distance (within the uncertainties) and they show a significant relative proper motion. The distances are shown to be robust. HD 193322 Aa,Ab follows an eccentric (e=0.58^+0.03^_-0.04_) orbit with a period of 44+/-1 a and the three stars it contains have a total mass of 76.1^+9.9^_-7.4_M_{sun}_. The orbit of 15 Mon Aa,Ab is even more eccentric (e=0.770^+0.023^_-0.030_), with a period of 108+/-12 a and a total mass of 45.1^+3.6^_-3.3_M_{sun}_ for its two stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/487/2771
- Title:
- Gaia-DR2 distance to the W3 Complex
- Short Name:
- J/MNRAS/487/2771
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Perseus Arm is the closest Galactic spiral arm from the Sun, offering an excellent opportunity to study in detail its stellar population. However, its distance has been controversial with discrepancies by a factor of two. Kinematic distances are in the range 3.9-4.2kpc as compared to 1.9-2.3kpc from spectrophotometric and trigonometric parallaxes, reinforcing previous claims that this arm exhibits peculiar velocities. We used the astrometric information of a sample of 31 OB stars from the star-forming W3Complex to identify another 37 W3 members and to derive its distance from their Gaia-DR2 parallaxes with improved accuracy. The Gaia-DR2 distance to the W3Complex, 2.14^+0.08^_-0.07_kpc, coincides with the previous stellar distances of ~2kpc. The Gaia-DR2 parallaxes tentatively show differential distances for different parts of the W3 Complex: W3 Main, located to the NE direction, is at 2.30^+0.19^_-0.16_kpc, the W3 Cluster (IC1795), in the central region of the complex, is at 2.17^+0.12^_-0.11_kpc, and W3(OH) is at 2.00^+0.29^_-0.23_kpc to the SW direction. The W3 Cluster is the oldest region, indicating that it triggered the formation of the other two star-forming regions located at the edges of an expanding shell around the cluster.
- ID:
- ivo://astronet.ru/cas/gaiadr2-gaia_source
- Title:
- Gaia DR2 (Gaia Collaboration, 2018)
- Short Name:
- gaiadr2-gaia_sou
- Date:
- 17 Jun 2006 18:44:05
- Publisher:
- Sternberg Astronomical Institute Virtual Observatory Project
- Description:
- </pre><p>Gaia is an ambitious mission to chart a three-dimensional map of our Galaxy, the Milky Way, in the process revealing the composition, formation and evolution of the Galaxy. Gaia will provide unprecedented positional and radial velocity measurements with the accuracies needed to produce a stereoscopic and kinematic census of about one billion stars in our Galaxy and throughout the Local Group. This amounts to about 1 per cent of the Galactic stellar population. <p>The data collected during the first 22 months of the nominal, five-year mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC), resulting into this second data release. A summary of the release properties is provided in Gaia Collaboration et al. (2018b). The overall scientific validation of the data is described in Arenou et al. (2018). Background information on the mission and the spacecraft can be found in Gaia Collaboration et al. (2016), with a more detailed presentation of the Radial Velocity Spectrometer (RVS) in Cropper et al. (2018). In addition, Gaia DR2 is accompanied by various, dedicated papers that describe the processing and validation of the various data products: Lindegren et al. (2018) for the Gaia DR2 astrometry, Riello et al. (2018) and Evans et al. (2018) for the Gaia DR2 photometry, Sartoretti et al. (2018), Soubiran et al. (2018), and Katz et al. (2018) for the Gaia DR2 spectroscopy (radial velocities), Holl et al. (2018) for the Gaia DR2 variability, Andrae et al. (2018) for the Gaia DR2 astrophysical parameters, Gaia Collaboration et al. (2018g) for the Solar-system objects, and Gaia Collaboration et al. (2018f) for the celestial reference frame. Four more papers present a glimpse of the scientific richness of the data in the areas of the Hertzsprung-Russell diagram (Gaia Collaboration et al. 2018a), the mapping of the kinematics and large-scale structure of the Milky Way (Gaia Collaboration et al. 2018e), parallaxes and proper motions of Milky Way satellite galaxies (Gaia Collaboration et al. 2018d), and variable stars in the colour-magnitude diagram (Gaia Collaboration et al. 2018c). In addition to the set of references mentioned above, this documentation provides a detailed, complete overview of the processing and validation of the Gaia DR2 data.
- ID:
- ivo://CDS.VizieR/J/MNRAS/502/L90
- Title:
- Gaia DR2 Galactic bulge new star clusters
- Short Name:
- J/MNRAS/502/L90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of 34 new open clusters and candidates as a result of a systematic search carried out in 200 adjacent fields of 1x1 square degrees area projected towards the Galactic bulge, using Gaia DR2 data. The objects were identified and characterized by a joint analysis of their photometric, kinematic and spatial distribution, which has been consistently used and proved to be effective in our previous works. The discoveries were validated by cross-referencing the objects position and astrometric parameters with the available literature. Besides their coordinates and astrometric parameters, we also provide sizes, ages, distances and reddening for the discovered objects. In particular, 32 clusters are closer than 2kpc from the Sun, which represents an increment of nearly 39% of objects with astrophysical parameters determined in the nearby inner disk. Although these objects fill an important gap in the open clusters distribution along the Sagittarius arm, this arm, traced by known clusters, appears to be interrupted, which may be an artifact due to the incompleteness of the cluster census.
- ID:
- ivo://org.gavo.dc/gaia/q2/dr2lcone
- Title:
- Gaia DR2-light Cone Search
- Short Name:
- GDR2light SCS
- Date:
- 15 Aug 2024 15:16:59
- Publisher:
- The GAVO DC team
- Description:
- This schema contains data re-published from the official Gaia mirrors (such as ivo://uni-heidelberg.de/gaia/tap) either to support combining its data with local tables (the various Xlite tables) or to make the data more accessible to VO clients (e.g., epoch fluxes). Other Gaia-related data is found in, among others, the gdr2dist, gdr3mock, gdr3spec, gedr3auto, gedr3dist, gedr3mock, and gedr3spur schemas.