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- ID:
- ivo://CDS.VizieR/J/other/ApSS/361.126
- Title:
- NGC 6819 CCD UBV photometry
- Short Name:
- J/other/ApSS/361
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of CCD UBV observations of the open cluster NGC 6819. We calculated the stellar density profile in the cluster's field to determine the structural parameters of NGC 6819. Using the existing astrometric data, we calculated the probabilities of the stars being physical members of the cluster, and used these objects in the determination of the astrophysical parameters of NGC 6819. We inferred the reddening and metallicity of the cluster as E(B-V)=0.130+/-0.035mag and [Fe/H]=+0.051+/-0.020dex, respectively, using the U-B vs B-V two-colour diagram and UV excesses of the F-G type main-sequence stars. We fit the colour-magnitude diagrams of NGC 6819 with the PARSEC isochrones and derived the distance modula, distance and age of the cluster as mu_V=12.22+/-0.10mag, d=2309+/-106pc and t=2.4+/-0.2Gyr, respectively. The parameters of the galactic orbit estimated for NGC 6819 indicate that the cluster is orbiting in a slightly eccentric orbit of e=0.06 with a period of P_orb_=142Myr. The slope of the mass function estimated for the cluster is close to the one found for the stars in the solar neighbourhood.
- ID:
- ivo://CDS.VizieR/J/other/ApSS/355.267
- Title:
- NGC 6811 CCD UBVRI photometry
- Short Name:
- J/other/ApSS/355
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of CCD UBVRI observations of the open cluster NGC 6811 obtained on 18th July 2012 with the 1m telescope at the TIBITAK National Observatory (TUG). Using these photometric results, we determine the structural and astrophysical parameters of the cluster. The mean photometric uncertainties are better than 0.02 mag in the V magnitude and B-V, V-R, and V-I colour indices to about 0.03mag for U-B among stars brighter than magnitude V=18. Cluster member stars were separated from the field stars using the Galaxia model of Sharma et al. (2011ApJ...730....3S) together with other techniques. The core radius of the cluster is found to be r_c_=3.60arcmin. The astrophysical parameters were determined simultaneously via Bayesian statistics using the colour-magnitude diagrams V versus B-V, V versus V-I, V versus V-R, and V versus R-I of the cluster. The resulting most likely parameters were further confirmed using independent methods, removing any possible degeneracies. The colour excess, distance modulus, metallicity and the age of the cluster are determined simultaneously as E(B-V)=0.05+/-0.01mag, {mu}=10.06+/-0.08mag, [M/H]=-0.10+/-0.01dex and t=1.00+/-0.05Gyr, respectively. Distances of five red clump stars which were found to be members of the cluster further confirm our distance estimation.
- ID:
- ivo://CDS.VizieR/J/A+AS/134/525
- Title:
- NGC 6611 compiled catalog
- Short Name:
- J/A+AS/134/525
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue contains data on stars in sky area of the open cluster NGC 6611. The catalogue is based on a new reduction of positions, proper motions, and photometric data whenever published in this region and includes among others, Hipparcos, AC/GSC and Tautenburg Schmidt plate observations. The basis of compiled catalogue is made of stars distributed over a circular area with radius of 22.8arcmin centered on the cluster NGC 6611 (Kharchenko and Schilbach, 1995AN....316...91K). To construct the compiled catalogue, we used also astrometric data published by Van Schewick (1962VeUSB..62....1V), Kamp (1974A&AS...16....1K), Tucholke et al. (1986A&AS...66..311T), Bastian and Roeser (1993, Cat. <I/193>), Roeser (1996, in "An updated GSC as the astrometric reference for minor planet observations", Kluwer Dordrecht, p. 481.), Hillenbrand et al. (1993, Cat. <J/AJ/106/1906>), and photometry published by Walker (1961ApJ...133..438W), Hoag et al. (1961PUSNO..17..343H), Hiltner and Morgan (1969AJ.....74.1152H), Sagar and Joshi (1979Ap&SS..66....3S), The et al (1990A&AS...82..319T), Hillenbrand et al. (1993, Cat. <J/AJ/106/1906>) as it described by Belikov et al. (1998, A&A, in press, this paper, 1999A&AS..134..525B). The catalogue contains 2185 stars up to the limiting magnitudes V=16.78mag. It includes equatorial (equinox 2000.0 and epoch 1990.77) and rectangular coordinates, absolute proper motions with respect to the Hipparcos proper motion system, photometric data (results of UBV, HJK photometry and color excess) and cluster membership probabilities. X - and Y - directions correspond to right ascension and declination directions. The rms errors of right ascension and declination are 0.008sec and 0.14arcsec, respectively. The individual rms errors of proper motions and V-magnitudes are given in the catalogue. The membership probabilities of the cluster stars belonging to the core and corona were determined using information both on spatial and proper motion distributions of stars in the field.
- ID:
- ivo://CDS.VizieR/J/A+A/601/A56
- Title:
- NGC 6802 dwarf cluster members and non-members
- Short Name:
- J/A+A/601/A56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Milky Way open clusters are very diverse in terms of age, chemical composition, and kinematic properties. Intermediate-age and old open clusters are less common, and it is even harder to find them inside the solar Galactocentric radius, due to the high mortality rate and strong extinction inside this region. NGC 6802 is one of the inner disk open clusters (IOCs) observed by the $Gaia$-ESO survey (GES). This cluster is an important target for calibrating the abundances derived in the survey due to the kinematic and chemical homogeneity of the cluster members in open clusters. Using the measurements from $Gaia$-ESO internal data release 4 (iDR4), we identify 95 dwarf main-sequence stars as cluster members from the GIRAFFE target list, and 8 red giants as cluster members from the UVES target list. The dwarf cluster members have a median radial velocity of 13.6+/-1.9km/s, while the giant cluster members have a median radial velocity of 12.0+/-0.9km/s and a median [Fe/H] of 0.10+/-0.02dex. The color-magnitude diagram of these cluster members suggests an age of $0.9+/-0.1Gyr, with (m-M)_0_=11.4 and E(B-V)=0.86. We perform the first chemical abundance analysis of NGC 6802, including 27 element species. To gain a more general picture about IOCs, the measurements of NGC6802 are compared with those of other IOCs previously studied by GES, i.e., NGC 4815, Trumpler 20, NGC 6705, and Berkeley 81. NGC 6802 shows similar C, N, Na, and Al abundances as other IOCs. The abundance versus cluster turn-off mass for these elements in the five GES IOCs cannot firmly exclude any one of the competing nucleosynthetic models, including: standard models; models with rotation induced mixing and/or thermohaline mixing. The five GES IOCs, particularly NGC 6802, seem to have higher s-process element abundances than that of the inner disk field stars.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A40
- Title:
- NGC1042 g and r deep final images
- Short Name:
- J/A+A/654/A40
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present the first results of the LBT Imaging of Galaxy Haloes and Tidal Structures (LIGHTS) survey. LIGHTS is an ongoing observational campaign with the 2x8.4m Large Binocular Telescope (LBT) aiming to explore the stellar haloes and the low surface brightness population of satellites down to a depth of mu_V_~31mag/arcsec^2^ (3s in 10"x10" boxes) of nearby galaxies. We simultaneously collected deep imaging in the g and r Sloan filters using the Large Binocular Cameras (LBCs). The resulting images are 60 times (i.e. 4.5mag) deeper than those from the Sloan Digital Sky Survey (SDSS), and they have characteristics comparable (in depth and spatial resolution) to the ones expected from the future Legacy Survey of Space and Time (LSST). Here we show the first results of our pilot programme targeting NGC1042 (an M33 analogue at a distance of 13.5Mpc) and its surroundings. The depth of the images allowed us to detect an asymmetric stellar halo in the outskirts of this galaxy whose mass (1.4+/-0.4x10^8^M_{sun}_) is in agreement with the Lambda Cold Dark Matter (LambdaCDM) expectations. Additionally, we show that deep imaging from the LBT reveals low mass satellites (a few times 10^5^M_{sun}_) with very faint central surface brightness mu_V(0)_~27mag/arcsec^2^(i.e. similar to Local Group dwarf spheroidals, such as Andromeda XIV or Sextans, but at distances well beyond the local volume). The depth and spatial resolution provided by the LIGHTS survey open up a unique opportunity to explore the `missing satellites' problem in a large variety of galaxies beyond our Local Group down to masses where the difference between the theory and observation (if any) should be significant.
- ID:
- ivo://CDS.VizieR/J/ApJ/859/75
- Title:
- NGC 5824 giant star members from VLT obs.
- Short Name:
- J/ApJ/859/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 5824 is a massive Galactic globular cluster suspected to have an intrinsic spread in its iron content, according to the strength of the calcium triplet lines. We present chemical abundances of 117 cluster giant stars using high-resolution spectra acquired with the multi-object spectrograph FLAMES. The metallicity distribution of 87 red giant branch stars is peaked at [Fe/H]=-2.11+/-0.01dex, while that derived from 30 asymptotic giant branch stars is peaked at [Fe/H]=-2.20+/-0.01dex. Both the distributions are compatible with a null spread, indicating that this cluster did not retain the ejecta of supernovae. The small iron abundance offset between the two groups of stars is similar to the abundances already observed among red and asymptotic giant branch stars in other clusters. The lack of intrinsic iron spread rules out the possibility that NGC 5824 is the remnant of a disrupted dwarf galaxy, as previously suggested. We also find evidence of the chemical anomalies usually observed in globular clusters, namely the Na-O and the Mg-Al anticorrelations. In particular, NGC 5824 exhibits a huge range of [Mg/Fe] abundance, observed in only a few metal-poor and/or massive clusters. We conclude that NGC 5824 is a normal globular cluster, without spread in [Fe/H] but with an unusually large spread in [Mg/Fe], possibly due to an efficient self-enrichment driven by massive asymptotic giant branch stars.
- ID:
- ivo://CDS.VizieR/J/AJ/140/2101
- Title:
- NGC 5128 globular clusters photometry
- Short Name:
- J/AJ/140/2101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new photometry for 323 of the globular clusters in NGC 5128 (Centaurus A), measured for the first time in the g'r'i'z' filter system. The color indices are calibrated directly to standard stars in the g'r'i'z' system and are used to establish the fiducial mean colors for the blue and red (low and high metallicity) globular cluster sequences. We also use previously published spectroscopically measured abundances to establish the conversion between the most metallicity-sensitive colors ((g'-r')_0_,(g'-i')_0_) and metallicity, [Fe/H].
- ID:
- ivo://CDS.VizieR/J/AJ/134/494
- Title:
- NGC 5128 globular clusters UBVRICMT1 phot. & RV
- Short Name:
- J/AJ/134/494
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new kinematic and dynamic study of the halo of the giant elliptical galaxy NGC 5128 is presented. From a spectroscopically confirmed sample of 340 globular clusters and 780 planetary nebulae, the rotation amplitude, rotation axis, velocity dispersion, and total dynamical mass are determined for the halo of NGC 5128.
- ID:
- ivo://CDS.VizieR/J/AJ/146/57
- Title:
- NGC 6402. I. BV photometry
- Short Name:
- J/AJ/146/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present BV photometry of the Galactic globular cluster NGC 6402 (M14), based on 65 V frames and 67 B frames, reaching two magnitudes below the turnoff level. This represents, to the best of our knowledge, the deepest color-magnitude diagram (CMD) of NGC 6402 available in the literature. Statistical decontamination of field stars as well as differential reddening corrections are performed in order to derive a precise ridgeline and hence physical parameters of the cluster. We discuss previous attempts at deriving a reddening value for the cluster, and argue in favor of a value E(B-V)=0.57+/-0.02, which is significantly higher than indicated by either the Burstein & Heiles or Schlegel et al. (corrected according to Bonifacio et al.) interstellar dust maps. Differential reddening across the face of the cluster, which we find to be present at the level of {Delta}E(B-V){approx}0.17mag, is taken into account in our analysis. We measure several metallicity indicators based on the position of the red giant branch (RGB) in the cluster CMD. These give a metallicity of [Fe/H]=-1.38+/-0.07 on the Zinn & West scale and [Fe/H]=-1.28+/-0.08 on the new Carretta et al. (UVES) scale. We also provide measurements of other important photometric parameters for this cluster, including the position of the RGB luminosity function "bump" and the horizontal branch morphology. We compare the NGC 6402 ridgeline with that of NGC 5904 (M5) derived by Sandquist et al., and find evidence that NGC 6402 and M5 have approximately the same age to within the uncertainties, although the possibility that M14 may be slightly older cannot be ruled out.
