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- ID:
- ivo://CDS.VizieR/J/A+A/459/423
- Title:
- VI and [Fe/H] of Fornax dSph RGB stars
- Short Name:
- J/A+A/459/423
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the DART imaging and CaII triplet (CaT) survey of the Fornax dwarf spheroidal galaxy (dSph) at ESO. We collected hundreds of low resolution spectra of Red Giant Branch (RGB) stars in the CaT region, using VLT/FLAMES in Medusa mode, with the GIRAFFE spectrograph (grating LR8, resolving power R~6500). We list the results for the targets with a S/N per Angstrom >10 and an error in velocity <5km/s, because we found this to be the minimum for an accurate determination of velocity and equivalent width. We checked the sample to weed out any spurious object (e.g., broken fibres, background galaxies, foreground stars, spectra not consistent with RGBs). We use a 2.5sigma cut from the system velocity to derive which stars are probable velocity members of the Fornax dSph. We transform the equivalent width of the CaT lines of probable velocity members into metallicity ([Fe/H]) using the relation derived by Rutledge et al. (1997PASP..109..907R) and combining the CaT lines as in Tolstoy et al. (2001MNRAS.327..918T). The errors in [Fe/H] are based on S/N computations and adjusted to agree with repeated measurements.
- ID:
- ivo://CDS.VizieR/J/A+A/319/850
- Title:
- V, I , and Gunn z imaging of Terzan 4
- Short Name:
- J/A+A/319/850
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the globular cluster Terzan 4 projected close to the Galactic center, by means of V, I and Gunn z Colour-Magnitude Diagrams. The images were obtained under exceptional seeing conditions (0.35"-0.55") at the ESO New Technology Telescope equipped with SUSI. We derive a reddening of E(B-V)=2.35 and a distance from the Sun d_{sun}_=8.3kpc for Terzan 4. From the similarity of the VI Colour-Magnitude Diagrams of Terzan 4 and M30, in particular the presence of a blue horizontal branch, it could be as metal-poor as [Fe/H]=~-2.0. It is therefore another blue horizontal branch globular cluster located close to the Galactic center.
- ID:
- ivo://CDS.VizieR/J/A+A/572/A44
- Title:
- Vibrationally excited vinyl cyanide in Orion-KL
- Short Name:
- J/A+A/572/A44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Laboratory characterization (18-1893 GHz) and astronomical detection (IRAM-30m: 80-280GHz, Orion-KL) of CH_2_CHCN (vinyl cyanide) in its ground and vibrationally excited states. Improving the understanding of rotational spectra of vibrationally excited vinyl cyanide with new laboratory data and analysis. The laboratory results allow searching for these excited state transitions in the Orion-KL line survey. Furthermore, rotational lines of CH_2_CHCN contribute to the understanding of the physical and chemical properties of the cloud. Laboratory measurements of CH_2_CHCN made on several different frequency-modulated spectrometers were combined into a single broadband 50-1900GHz spectrum and its assignment was confirmed by Stark modulation spectra recorded in the 18-40GHz region and by ab-initio anharmonic force field calculations. For analyzing the emission lines of vinyl cyanide detected in Orion-KL we used the excitation and radiative transfer code (MADEX) at LTE conditions. Detailed characterisation of laboratory spectra of CH_2CHCN in 9 different excited vibrational states (v_11_=1, v_15_=1, v_11_=2, v_10_=1<==>(v_11_=1,v_15_=1), v_11_=3/v_15_=2/v_14_=1, (v_11_=1,v_10_=1)<==>(v_11_=2, v_15_=1), v_9_$=1, (v_11_=1,v_15_=2)<==>(v_10_=1, v_15_=1)<==>(v_11_=1,v_14_=1), and v_11_=4) and detection of transitions in the v_11_=2 and v_11_=3 states for the first time in Orion-KL, and of those in the v_10_=1<==>(v_11_=1,v_15_=1) dyad of states for the first time in space. The rotational transitions of the ground state of this molecule emerge from four cloud components of hot core nature which trace the physical and chemical conditions of high mass star forming regions in the Orion-KL Nebula. The lowest energy vibrationally excited states of vinyl cyanide such as v_11_=1 (at 328.5K), v_15_=1 (at 478.6K), v_11_=2 (at 657.8K), the v_10_=1<==>(v_11_=1,v_15_=1) dyad (at 806.4/809.9K), and v_11_=3 (at 987.9K) are populated under warm and dense conditions, so they probe the hottest parts of the Orion-KL source. The vibrational temperatures derived for the v_11_=1, v_11_=2, and v_15_=1 states are 252+/-76K, 242+/-121K, and 227+/-68K, respectively; all of them close to the mean kinetic temperature of the hot core component (210K). The total column density of CH_2_CHCN in the ground state is (3.0+/-0.9)x10^15^cm^-2^. We report the detection of methyl isocyanide (CH_3_NC) for the first time in Orion-KL and a tentative detection of vinyl isocyanide (CH_2_CHNC) and give column density ratios between the cyanide and isocyanide isomers obtaining a N(CH_3_NC)/N(CH_3_CN) ratio of 0.002. Laboratory characterisation of many previously unassigned vibrationally excited states of vinyl cyanide at microwave to THz frequencies allowed us to detect these molecular species in Orion-KL. Column density and rotational and vibrational temperatures for CH_2_CHCN in their ground and excited states, as well as for the isotopologues, have been constrained by means of a sample of more than 1000 lines in this survey.
- ID:
- ivo://CDS.VizieR/J/other/BASI/29.519
- Title:
- VI CCD photometry in NGC 6631
- Short Name:
- J/other/BASI/29.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present VI CCD photometric observations of about 5500 stars up to a limiting magnitude of V~20 in an area of ~16'x16' around the cluster NGC 6631. The cluster parameters determined for the first time by fitting the theoretical isochrones in the V, (V-I) diagram of the cluster stars are E(V-I)=0.60+/-0.05mag, distance=2.6+/-0.5kpc, age=400+/-100Myr and metallicity, Z=0.05. The cluster diameter determined from the radial density profile is 4.8+-0.5pc. The mass function of the cluster has a slope of 2.1+/-05.
- ID:
- ivo://CDS.VizieR/J/A+AS/127/167
- Title:
- V,I CCD photometry of NGC 6528
- Short Name:
- J/A+AS/127/167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD photometry in V and I for the metal-rich globular cluster NGC 6528. A comparison with previous photometry reveals discrepancies of the order 0.1 to 0.2mag in V, emphasizing the need for independent photometry. As found previously, the giant branch (or the asymptotic giant branch, which cannot be distinguished) of the cluster extends to V-I=7. Population synthesis in V-I must take these red stars into account in order to understand integrated red colours of bulge populations. Currently available theoretical isochrones do not reproduce the shape of the RGB/AGB. The derivation of reliable values for reddening, distance and metallicity of NGC 6528 is hampered by uncertainties in the extrapolation to high metallicity, which dominate the absolute error rather than the photo metric uncertainty does. Together with other properties (old age derived from HST data, high radial velocity), this object is more likely a member of the bulge than of the disk population.
- ID:
- ivo://CDS.VizieR/J/A+AS/135/391
- Title:
- VI CCD photometry of NGC 6553
- Short Name:
- J/A+AS/135/391
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- X, Y pixel coordinates and V, I CCD photometric magnitudes of stars in cluster region NGC 6553. DAOPHOT photometric errors in V and (V-I) are also given.
- ID:
- ivo://CDS.VizieR/J/MNRAS/349/641
- Title:
- VIc, CT1 magnitudes in Trumpler 5
- Short Name:
- J/MNRAS/349/641
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD observations in the Johnson V, Kron-Cousins I and the Washington system C and T_1_ passbands have been used to generate colour-magnitude diagrams (CMDs) reaching down to V~21.0mag and T_1_~19.0 for Trumpler 5, an old open cluster located towards the Galactic anticentre. Our data analysis confirms the existence of non-uniform extinction over the face of the cluster, the mean E(V-I) and E(C-T_1_) values being 0.80+/-0.05 and 1.17+/-0.15, respectively. Through comparison of the cluster CMDs with theoretical isochrones of the Geneva group, Washington Standard Giant Branches and measures of V and T_1_ indices, we derive the following values for the cluster apparent distance modulus, age, and metallicity: V-M_V_=13.80+/-0.30 (corresponding to a distance from the Sun of 2.4+/-0.5 kpc and 0.04kpc above the Galactic plane), t=5.0+/-0.5Gyr and [Fe/H]=-0.30+/-0.15. We estimate the cluster angular radius to be about 7.7 arcmin (=5.4pc) from star counts carried out within and outside the cluster field.
- ID:
- ivo://CDS.VizieR/J/MNRAS/379/1237
- Title:
- VIcJHK photometry of NGC 1893 Halpha sources
- Short Name:
- J/MNRAS/379/1237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using H{alpha} grism spectroscopy and optical and Two-Micron All-Sky Survey photometry of the fields containing NGC 1893 and two emission nebulae, Sim 129 and Sim 130, we show the presence of a number of H{alpha} and near-infrared excess sources towards the region between HD 242935 and the two emission nebulae. Among them a large majority of these pre-main-sequence candidate sources are concentrated towards regions closer to Sim 129 and Sim 130.
- ID:
- ivo://CDS.VizieR/J/A+A/492/171
- Title:
- VIc light curves of NGC 6791 V20
- Short Name:
- J/A+A/492/171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We wish to determine accurate ages for open clusters and use this, in conjunction with colour-magnitude diagrams, to constrain models of stellar structure and evolution. The detached eclipsing binary V20 in the old, metal-rich ([Fe/H]=+0.40) open cluster NGC6791 is studied in order to determine highly accurate masses and radii of its components. This allows the cluster age to be established with high precision, using isochrones in the mass-radius diagram. Methods. We employ high-resolution UVES spectroscopy of V20 to determine the spectroscopic orbit and time-series V, Ic photometry to obtain the photometric elements.
