- ID:
- ivo://CDS.VizieR/J/A+A/572/A108
- Title:
- 47 Tuc red giants chemical composition
- Short Name:
- J/A+A/572/A108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of chemical abundance patterns in globular clusters is of key importance to constrain the different candidates for intra-cluster pollution of light elements. We aim at deriving accurate abundances for a large range of elements in the globular cluster 47 Tucanae (NGC 104) to add new constraints to the pollution scenarios for this particular cluster, expanding the range of previously derived element abundances. Using tailored 1D LTE atmospheric models together with a combination of equivalent width measurements, LTE, and NLTE synthesis we derive stellar parameters and element abundances from high-resolution, high signal-to-noise spectra of 13 red giant stars near the tip of the RGB. We derive abundances of a total 27 elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ru, Ba, La, Ce, Pr, Nd, Eu, Dy). Departures from LTE were taken into account for Na, Al and Ba. We find a mean [Fe/H]=-0.78+/-0.07 and [alpha/Fe]=0.34+/-0.03 in good agreement with previous studies. The remaining elements show good agreement with the literature, but the inclusion of NLTE for Al has a significant impact on the behaviour of this key element. We confirm the presence of an Na-O anti-correlation in 47 Tucanae found by several other works. Our NLTE analysis of Al shifts the [Al/Fe] to lower values, indicating that this may be overestimated in earlier works. No evidence for an intrinsic variation is found in any of the remaining elements.
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- ID:
- ivo://CDS.VizieR/J/A+A/619/A51
- Title:
- Type II Cepheids in the Galactic bulge
- Short Name:
- J/A+A/619/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new Near-Infrared photometry of Type II Cepheids in the Bulge from the VISTA Variables in the Via Lactea survey (VVV) (Minniti et al., 2010NewA...15..433M; Saito et al., 2012A&A...537A.107S, Cat. II/337. We provide the largest sample (894 stars) of T2Cs with JHKs observations that have accurate periods from the OGLE catalog (Soszynski et al., 2017, Cat. J/AcA/67/297). Our analysis makes use of the Ks-band time-series observations to estimate mean-magnitudes and individual distances by means of the Period-Luminosity PL relation. To constrain the kinematic properties of our targets, we complement our analysis with proper motions based on both the VVV and Gaia Data Release 2.
- ID:
- ivo://CDS.VizieR/J/ApJS/115/271
- Title:
- UBV-beta Database for LS Stars
- Short Name:
- J/ApJS/115/271
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (Excerpt from the "intro.txt" file) Between 1959 and 1971, the Hamburg and Warner and Swasey Observatories published a seven-volume survey listing intrinsically luminous stars (hereafter "LS" objects) - mostly OB stars, as well as a number of A, F, and G supergiants and Wolf-Rayet stars - within about ten degrees of the plane of the Milky Way to a limiting photographic magnitude of approximately 13.5. Based on objective-prism surveys of dispersion 580 Angstrom per millimeter at Hydrogen-gamma, these catalogs have served as starting points for numerous investigations of galactic structure and the characteristics of massive stars. Much fundamental data on the LS stars now exists distributed throughout the astronomical literature. This work describes a compilation of published photoelectric UBV-Beta photometry and spectral classifications nominally on the MK system for the LS stars, as well as an extensive cross-identification table linking LS numbers and other commonly-used identifiers such as HD, BD, CD, CPD and HR numbers. At this writing, the UBV-Beta portion of the database covers both the Northern and Southern LS stars, whereas MK classifications have as yet only been fully compiled for the Southern stars; compilation of MK types for the Northern LS stars is as yet incomplete, but ongoing.
- ID:
- ivo://CDS.VizieR/J/MNRAS/398/221
- Title:
- UBVIJHK photometry towards (l=305{deg},b=0{deg})
- Short Name:
- J/MNRAS/398/221
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical (UBVIc) observations of a rich and complex field in the Galactic plane towards l~305{deg} and b~0{deg}.
- ID:
- ivo://CDS.VizieR/J/A+A/536/A101
- Title:
- UBVI photometry towards (l=314,b=0)
- Short Name:
- J/A+A/536/A101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spiral structure of the Milky Way is nowadays receiving renewed attention thanks to the combined efforts of observational campaigns in different wavelength regimes, from the optical to the radio. We start in the paper the exploration of a number of key sectors (line of sights) in the inner Milky Way, where the spiral structure is still poorly known. We search for density enhancements of young stars that might plausibly be associated with spiral structure. To this aim we collect sufficiently wide-field UBVI photometry to allow us to probe in statistical sense the distribution in reddening and distance of young stars in the field. The intensive usage of U-band photometry - although heavily demanding in terms of observational efforts - ensures robust determination of reddening and hence distance for stars of spectral type earlier than A0, which are well-known spiral arm tracers, even though no spectroscopic information are available. The fields we use are large enough to include in most cases well-studied Galactic clusters, which we use as bench-marks to assess the quality and standardisation of the data, and to validate our method. We focus in this paper on the line of sight to the Galactic longitude l=314{deg}, where previous surveys already detected H{alpha} emitters at different standard of rest velocities, and hence distances. The difficulty, however, to translate velocity into distance make predictions on the spiral structure quite vague. First of all, we made exhaustive tests to show that our data-set is in the standard system, and calibrated our method using the two open clusters NGC 5617 and Pismis 19 which happen to be in the field, and for which we found estimates of the basic parameters in full agreement with the literature. We then applied the method to the general field stars and detected signatures of three different groups of stars, evenly distributed across the field of view, at 1.5^+0.5^_-0.2_, 2.5^+0.3^_-0.5_, and 5.1^+1.5^_-1.1_kpc, respectively. These distances are compatible with the location of the nowadays commonly accepted description of the Carina-Sagittarius and Scutum-Crux arms, at heliocentric distance of ~2 an 5kpc, respectively. As a consequence, we consider these groups to be good candidates to trace the location of these two inner arms. In line with previous studies, this investigation demonstrates once again how powerful the use of U-band photometry is to characterize ensembles of young stars, and make predictions on the spiral structure of the Milky Way.
- ID:
- ivo://CDS.VizieR/J/A+AS/93/553
- Title:
- UBV photometry of stars near galactic plane
- Short Name:
- J/A+AS/93/553
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/II/316
- Title:
- UKIDSS-DR6 Galactic Plane Survey
- Short Name:
- II/316
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The UKIDSS Galactic Plane Survey (GPS) is one of the five near infrared Public Legacy Surveys that are being undertaken by the UKIDSS consortium, using the Wide Field Camera on the United Kingdom Infrared Telescope. It is surveying 1868 deg^2^ of the northern and equatorial Galactic plane at Galactic latitudes -5{deg}<b<5{deg} in the J, H and K filters and a ~300 deg^2^ area of the Taurus-Auriga-Perseus molecular cloud complex in these three filters and the 2.12{mu}m (1-0)S(1)H_2_ filter. It will provide data on ~ 3x10^9^ sources. The survey use the Wide Field Camera (WFCAM, see Casali et al. 2007A&A...467..777C) on the United Kingdom Infrared Telescope (UKIRT). The typical 90% completeness limits in uncrowded fields are K=18.0, H=18.75, J=19.5, with uncertainties of about 0.2mag.
- ID:
- ivo://CDS.VizieR/J/AJ/160/279
- Title:
- Untangling the Galaxy. II. Structure within 3kpc
- Short Name:
- J/AJ/160/279
- Date:
- 09 Mar 2022 22:00:00
- Publisher:
- CDS
- Description:
- We present the results of the hierarchical clustering analysis of the Gaia DR2 data to search for clusters, comoving groups, and other stellar structures. The current paper builds on the sample from the previous work, extending it in distance from 1 to 3kpc and increasing the number of identified structures up to 8292. To aid in the analysis of the population properties, we developed a neural network called Auriga to robustly estimate the age, extinction, and distance of a stellar group based on the input photometry and parallaxes of the individual members. We apply Auriga to derive the properties of not only the structures found in this paper, but also previously identified open clusters. Through this work, we examine the temporal structure of the spiral arms. Specifically, we find that the Sagittarius Arm has moved by >500pc in the last 100Myr and the Perseus Arm has been experiencing a relative lull in star formation activity over the last 25Myr. We confirm the findings of the previous paper on the transient nature of the spiral arms, with the timescale of transition of a few 100Myr. Finally, we find a peculiar ~1Gyr old stream of stars that appears to be heliocentric. Its origin is unclear.
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/2586
- Title:
- UWISH2 extended H2 emission line sources
- Short Name:
- J/MNRAS/454/2586
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the extended source catalogue for the UKIRT Wide Field Infrared Survey for H2 (UWISH2). The survey is unbiased along the inner Galactic Plane from l~357{deg} to l~65{deg} and |b|<=1.5{deg} and covers 209deg^2^. A further 42.0 and 35.5deg^2^ of high dust column density regions have been targeted in Cygnus and Auriga. We have identified 33200 individual extended H_2_ features. They have been classified to be associated with about 700 groups of jets and outflows, 284 individual (candidate) planetary nebulae, 30 supernova remnants and about 1300 photodissociation regions. We find a clear decline of star formation activity (traced by H_2_ emission from jets and photodissociation regions) with increasing distance from the Galactic Centre. About 60 percent of the detected candidate planetary nebulae have no known counterpart and 25 percent of all supernova remnants have detectable H_2_ emission associated with them.
- ID:
- ivo://CDS.VizieR/J/MNRAS/470/3427
- Title:
- Variable Stars in the Galactic Center
- Short Name:
- J/MNRAS/470/3427
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used four-year baseline HST/WFC3 IR observations of the Galactic Centre in the F153M band (1.53 micron) to identify variable stars in the central ~2.3'x2.3' field. We classified 3845 long-term (periods from months to years) and 76 short-term (periods of a few days or less) variables among a total sample of 33070 stars. For 36 of the latter ones, we also derived their periods (<3 days). Our catalog not only confirms bright long period variables and massive eclipsing binaries identified in previous works, but also contains many newly recognized dim variable stars. For example, we found delta Scuti and RR Lyrae stars towards the Galactic Centre for the first time, as well as one BL Her star (period < 1.3d). We cross-correlated our catalog with previous spectroscopic studies and found that 319 variables have well-defined stellar types, such as Wolf-Rayet, OB main sequence, supergiants and asymptotic giant branch stars. We used colours and magnitudes to infer the probable variable types for those stars without accurately measured periods or spectroscopic information. We conclude that the majority of unclassified variables could potentially be eclipsing/ellipsoidal binaries and Type II Cepheids. Our source catalog will be valuable for future studies aimed at constraining the distance, star formation history and massive binary fraction of the Milky Way nuclear star cluster.
