- ID:
- ivo://CDS.VizieR/J/A+A/653/A133
- Title:
- GALACTICNUCLEUS IV. JHKs imaging survey
- Short Name:
- J/A+A/653/A133
- Date:
- 10 Mar 2022 11:26:04
- Publisher:
- CDS
- Description:
- The extreme extinction (A_V_~30mag) and its variation on arc-second scales towards the Galactic centre hamper the study of its stars. Their analysis is restricted to the near infrared (NIR) regime, where the extinction curve can be approximated by a broken power law for the JHKs bands. Therefore, correcting for extinction at these wavelengths is fundamental to analyse the structure and stellar population of the central regions of our Galaxy. We aim at: (1) Discussing different strategies to de-redden the photometry and checking the usefulness of extinction maps to deal with variable stars. (2) Building and making publicly available extinction maps for the NIR bands JHKs. (3) Creating a de-reddened catalogue of the GALACTICNUCLEUS (GNS) survey, identifying foreground stars. (4) Performing a preliminary analysis of the de-reddened $K_s$ luminosity functions (KLFs). We use photometry from the GNS survey to create extinction maps for the whole catalogue. We take red clump (RC) and red giant stars of similar brightness as a reference to build the maps, and de-redden the GNS photometry. We discuss the limitations of the process and analyse non-linear effects of the de-reddening. We create high resolution (~3'') extinction maps with low statistical and systematics uncertainties (<~5%), and compute average extinctions for each of the regions covered by the GNS. We check that our maps effectively correct the differential extinction reducing the spread of the RC features by a factor of ~2. We assess the validity of the broken power law approach computing two equivalent extinction maps A_H_ using either JH and HKs photometry for the same reference stars, and obtain compatible average extinctions within the uncertainties. Finally, we analyse de-reddened KLFs for different line-of-sights and find that the regions belonging to the NSD contain a homogeneous stellar population that is significantly different from the one in the innermost bulge regions.
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- ID:
- ivo://CDS.VizieR/J/A+A/610/A83
- Title:
- GALACTICNUCLEUS: JHKs imaging survey
- Short Name:
- J/A+A/610/A83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic Centre is of fundamental astrophysical interest, but existing near-infrared surveys fall short covering it adequately, either in terms of angular resolution, multi-wavelength coverage, or both. Here we introduce the GALACTICNUCLEUS survey, a JHKs imaging survey of the centre of the Milky Way with a 0.2" angular resolution. The purpose of this paper is to present the observations of Field 1 of our survey, centred approximately on SgrA* with an approximate size of 7.95'x3.43'. We describe the observational set-up and data reduction pipeline and discuss the quality of the data. Finally, we present the analysis of the data. The data were acquired with the near-infrared camera HAWK-I (High Acuity Wide field K-band Imager) at the ESO VLT (Very Large Telescope). Short readout times in combination with the speckle holography algorithm allowed us to produce final images with a stable, Gaussian PSF (point spread function) of 0.2" FWHM (full width at half maximum). Astrometric calibration is achieved via the VVV (VISTA Variables in the Via Lactea) survey and photometric calibration is based on the SIRIUS/IRSF (Infrared Survey Facility telescope) survey. The quality of the data is assessed by comparison between observations of the same field with different detectors of HAWK-I and at different times. We reach 5{sigma} uncertainties are less than 0.05" at J<=20, H<=17, and Ks<=16. We can distinguish five stellar populations in the colour-magnitude diagrams; three of them appear to belong to foreground spiral arms, and the other two correspond to high- and low-extinction star groups at the Galactic Centre. We use our data to analyse the near-infrared extinction curve and find some evidence for a possible difference between the extinction index between J-H and H-Ks. However, we conclude that it can be described very well by a power law with an index of JHKs=2.30+.-0.08. We do not find any evidence that this index depends on the position along the line of sight, or on the absolute value of the extinction. We produce extinction maps that show the clumpiness of the ISM (interstellar medium) at the Galactic Centre. Finally, we estimate that the majority of the stars have solar or super-solar metallicity by comparing our extinction-corrected colour-magnitude diagrams with isochrones with different metallicities and a synthetic stellar model with a constant star formation.
- ID:
- ivo://CDS.VizieR/J/A+A/631/A20
- Title:
- GALACTICNUCLEUS JHKs imaging survey. II.
- Short Name:
- J/A+A/631/A20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The high extinction and extreme source crowding of the central regions of the Milky Way are serious obstacles to the study of the structure and stellar population of the Galactic centre (GC). Surveys that cover the GC region (2MASS, UKIDSS, VVV, SIRIUS) do not have the necessary high angular resolution. Therefore, a high angular resolution survey in the near infrared is crucial to improve the state of the art. Here, we present the GALACTICNUCLEUS catalogue, a near infrared JHKs high angular resolution (0.2") survey of the nuclear bulge of the Milky Way. We explain in detail the data reduction, data analysis, calibration, and uncertainty estimation of the GALACTICNUCLEUS survey. We assess the data quality comparing our results with previous surveys. We obtained accurate JHKs photometry ~3.3x10^6^ stars in the GC detecting around 20% in J, 65% in H and 90% in Ks. The survey covers a total area of ~0.3 square degrees, which corresponds to ~6000pc^2^. The GALACTICNUCLEUS survey reaches 5 sigma detections for J~22mag, H~21mag and Ks~21mag. The uncertainties are below 0.05mag at J~21mag, H~19mag and Ks~18mag. The zero point systematic uncertainty is <~0.04mag in all three bands. We present colour-magnitude diagrams for the different regions covered by the survey.
- ID:
- ivo://CDS.VizieR/J/A+A/447/921
- Title:
- Galactic Open Cluster Candidates
- Short Name:
- J/A+A/447/921
- Date:
- 14 Jan 2022 07:59:11
- Publisher:
- CDS
- Description:
- An inspection of DSS and 2MASS images of selected Milky Way regions led to the discovery of 66 stellar groupings whose morphologies, color-magnitude diagrams and stellar density distributions suggest that these objects are possible open clusters that are not yet listed in any catalogue. For 24 of these, which we consider to be the most likely candidates, we provide extensive descriptions on the basis of 2MASS photometry and their visual impression on DSS and 2MASS. Of those cluster candidates, 9 have fundamental parameters determined by fitting the color-magnitude diagrams with solar metallicity Padova isochrones. Additional 10 cluster candidates have distance moduli and reddenings derived from K magnitudes and (J-K) color indices of helium-burning red clump stars. As an addendum, we provide a list of a number of apparently yet unknown galactic and extragalactic objects which were also discovered during the survey.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A54
- Title:
- Galactic open clusters in RAVE
- Short Name:
- J/A+A/562/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galactic open clusters (OCs) mainly belong to the young stellar population in the Milky Way disk, but are there groups and complexes of OCs that possibly define an additional level in hierarchical star formation? Current compilations are too incomplete to address this question, especially regarding radial velocities (RVs) and metallicities ([M/H]). Here we provide and discuss newly obtained RV and [M/H] data, which will enable us to reinvestigate potential groupings of open clusters and associations.
- ID:
- ivo://CDS.VizieR/J/AZh/79/510
- Title:
- Galactic orbits of RR Lyrae variable stars
- Short Name:
- J/AZh/79/510
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used published, high-accuracy, ground-based and satellite proper-motion measurements, a compilation of radial velocities, and photometric distances to compute the spatial velocities and Galactic orbital elements for 174 RR Lyrae (ab) variable stars in the solar neighborhood. The computed orbital elements and published heavy-element abundances are used to study relationships between the chemical, spatial, and kinematic characteristics of nearby RR Lyrae variables. We observe abrupt changes of the spatial and kinematic characteristics at the metallicity [Fe/H]~-0.95 and also when the residual spatial velocities relative to the LSR cross the critical value V_res_~290km/s.
- ID:
- ivo://CDS.VizieR/J/A+A/384/879
- Title:
- Galactic orbits of stars with planets
- Short Name:
- J/A+A/384/879
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have reconstructed the galactic orbits of the parent stars of exoplanets. For comparison, we have recalculated the galactic orbits of stars from the Edvardsson et al. (1993, Cat. <J/A+A/275/101>) catalog. A comparison between the two samples indicates that stars with planets are not kinematically peculiar. At each perigalactic distance stars with planets have a metallicity systematically larger than the average for the comparison sample. We argue that this result favors scenarios where the presence of planets is the cause of the higher metallicity of stars with planets.
5078. Galactic O star catalog
- ID:
- ivo://CDS.VizieR/V/116
- Title:
- Galactic O star catalog
- Short Name:
- V/116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have produced a catalog of 378 Galactic O stars with accurate spectral classifications that is complete for V<8 but includes many fainter stars. The catalog provides cross-identifications with other sources; coordinates (obtained in most cases from Tycho-2 data); astrometric distances for 24 of the nearest stars; optical (Tycho-2, Johnson, and Stroemgren) and NIR photometry; group membership, runaway character, and multiplicity information; and a Web-based version with links to on-line services.
5079. Galactic O Stars
- ID:
- ivo://CDS.VizieR/III/84B
- Title:
- Galactic O Stars
- Short Name:
- III/84B
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a compilation of published data for 644 galactic O stars of luminosity class V. The catalog is intended to be useful to O-type star observers by providing a reference list for general studies on O-type stars. The catalog includes cross identifications, equatorial and galactic coordinates, visual or photographic magnitudes, B-V, spectral types, distances to the stars, radial velocities, HII region identifications, remarks, and notes.
5080. Galactic O Stars Catalog
- ID:
- ivo://nasa.heasarc/ostars
- Title:
- Galactic O Stars Catalog
- Short Name:
- OStars
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table is based upon the information contained in the Catalog of Galactic O-Type Stars (Garmany, Conti, and Chiosi 1982), which is a compilation from the literature of all O-type stars for which spectral types, luminosity classes, and UBV photometry exist. Most of the entries come from Cruz-Gonzalez, et al. (1974) and Humphreys (1978), with additional stars from Garrison and Kormendy (1976); Garrison, Hiltner, and Schild (1977); Garrison and Schild (1979); Feinstein, Marraco, and Muzzio (1973); Feinstein, Marraco, and Forte (1976); and Moffat, Fitzgerald, and Jackson (1979). As discussed below, the HEASARC has deleted 5 of the original 765 entries which we believe to be erroneous and/or redundant, and modified the names and/or positions of 14 other entries. As part of the checking process, the HEASARC created new, more accurate positions for all the entries using the SIMBAD database. The catalog contains 760 stars, for each of which designations (HD, DM, etc.), spectral types, V magnitudes, B-V magnitudes, cluster memberships, positional information, and source references are given. In addition, the authors have included derived values of absolute visual and bolometric magnitudes, and distances. The source reference should be consulted for additional details concerning the derived quantities. This is a service provided by NASA HEASARC .