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14651. Star motions in the nuclear cluster of the MW
ID:
ivo://CDS.VizieR/J/ApJ/821/44
Title:
Star motions in the nuclear cluster of the MW
Short Name:
J/ApJ/821/44
Date:
21 Oct 2021
Publisher:
CDS
Description:
We obtain the basic properties of the nuclear cluster of the Milky Way. First, we investigate the structural properties by constructing a stellar density map of the central 1000" using extinction-corrected old star counts from VISTA, WFC3/IR, and VLT/NACO data. We describe the data using two components. The inner, slightly flattened (axis ratio of q=0.80+/-0.04) component is the nuclear cluster, while the outer component corresponds to the stellar component of the circumnuclear zone. For the nuclear cluster, we measure a half-light radius of 178+/-51"~7+/-2pc and a luminosity of M_Ks_=-16.0+/-0.5. Second, we measure detailed dynamics out to 4pc. We obtain 10351 proper motions from AO data, and 2513 radial velocities from VLT/SINFONI data. We determine the cluster mass by means of isotropic spherical Jeans modeling. We fix the distance to the Galactic Center and the mass of the supermassive black hole. We model the cluster either with a constant M/L or with a power law. For the latter case, we obtain a slope of 1.18+/-0.06. We get a cluster mass within 100" of M_100"_=(6.09+/-0.53|_fixR_0_+/-0.97|_R_0_)x10^6^M_{sun}_ for both modeling approaches. A model which includes the observed flattening gives a 47% larger mass (see Chatzopoulos et al. 2015MNRAS.447..948C). Our results slightly favor a core over a cusp in the mass profile. By minimizing the number of unbound stars within 8", we obtain a distance of R_0_=8.53_-0.15_^+0.21^kpc when using an R0 supermassive black hole mass relation from stellar orbits. Combining our results, we obtain M/L=0.51+/-0.12M_{sun}/L_{sun},Ks_, which is roughly consistent with a Chabrier IMF.
14652. Star polarization in the Galactic plane
ID:
ivo://CDS.VizieR/J/ApJ/749/71
Title:
Star polarization in the Galactic plane
Short Name:
J/ApJ/749/71
Date:
21 Oct 2021
Publisher:
CDS
Description:
This work combines new observations of NIR starlight linear polarimetry with previously simulated observations in order to constrain dynamo models of the Galactic magnetic field. Polarimetric observations were obtained with the Mimir instrument on the Perkins Telescope in Flagstaff, AZ, along a line of constant Galactic longitude ({ell}=150{deg}) with 17 pointings of the 10'x10' field of view between -75{deg}<b<10{deg}, with more frequent pointings toward the Galactic midplane. A total of 10962 stars were photometrically measured and 1116 had usable polarizations. The observed distribution of polarization position angles with Galactic latitude and the cumulative distribution function of the measured polarizations are compared to predicted values. While the predictions lack the effects of turbulence and are therefore idealized, this comparison allows significant rejection of A0-type magnetic field models. S0 and disk-even halo-odd magnetic field geometries are also rejected by the observations, but at lower significance. New predictions of spiral-type, axisymmetric magnetic fields, when combined with these new NIR observations, constrain the Galactic magnetic field spiral pitch angle to -6{deg}+/-2{deg}.
14653. Star positions in 14 southern galactic clusters
ID:
ivo://CDS.VizieR/J/A+AS/53/181
Title:
Star positions in 14 southern galactic clusters
Short Name:
J/A+AS/53/181
Date:
21 Oct 2021
Publisher:
CDS
Description:
Positions for a total of 3487 stars, scattered over 14 regions, have been determined using the Danish 1.5-m telescope at La Silla. The 14 regions are centred on one of the southern galactic clusters NGC 1981, 2287, 2437, 2451, 2516, 2546, 2547, 2548, 3114, 3532, IC 2391, 2395, 2602 and Trumpler 10. Combining the Ritchey-Chretien reflector optics with a single element Schmidt-type corrector, gives a considerably enlarged flat field (radius about 25 minutes of arc, or 95mm) with stellar images of excellent definition. With the exception of distortion, which can be allowed for, the effect of the primary aberrations is negligible. A frame of reference has been established for each region using ESO Schmidt plates centred on the clusters, each plate containing from 20 to 35 measurable Perth 70 stars. These objects have served for determining positions of some 200 to 400 fainter stars within a central field of 25 minutes of arc radius, covering the corresponding 1.5-m plates. The fainter stars serve as a secondary standard. Based on three 1.5-m plates for each region, taken on different nights, an internal mean error in one plate position in the range 0.030 to 0.048 seconds of arc has been derived.
14654. Star positions in the region of alpha Per
ID:
ivo://CDS.VizieR/J/AN/283/109
Title:
Star positions in the region of alpha Per
Short Name:
J/AN/283/109
Date:
21 Oct 2021
Publisher:
CDS
Description:
This file contains 1221 stars observed for spectral type in the field of the alpha Persei cluster. The types were published in the well known proper-motion survey by Heckmann et al. (1956AN....283..109H), and were determined by Wachmann with the equipment and methods used for the Bergedorf selected areas surveys (BSD). In general the brighter HD stars were not observed for spectral type, but most of these have been classified on the MK system by Roman & Morgan (1950ApJ...111..426R) and in later work. Nearly all the stars are included in SIMBAD with the source positions, and most also appear in WEBDA with these data as well. The positions below are nearly all from UCAC2 (for both epoch and equinox J2000), and thus differ by a few arcsec mainly from proper motion, but also from the systematic shift between the FK3 to the ICRS. In general the spectral types are not present in SIMBAD or WEBDA. I worked from Alain Fresneau's compilation for the field, which is based largely on the Heckmann data (Cat. <I/68>). I ran those coordinates into VizieR looking at UCAC2, Tycho-2, and the Fabricius Tycho double-star catalogue (Cat. <I/276>). Coordinates for two crowded stars were obtained from 2MASS. With one exception all the stars were found quite close to the predicted positions. Close pairs are indicated in the notes, as are stars with substantial proper motion (>>0.1"/year).
14655. Stars and globulars in NGC4494
ID:
ivo://CDS.VizieR/J/MNRAS/415/3393
Title:
Stars and globulars in NGC4494
Short Name:
J/MNRAS/415/3393
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a comprehensive analysis of the spatial, kinematic and chemical properties of stars and globular clusters (GCs) in the 'ordinary' elliptical galaxy NGC 4494 using data from the Keck and Subaru telescopes. We derive galaxy surface brightness and colour profiles out to large galactocentric radii. We compare the latter to metallicities derived using the near-infrared Calcium Triplet. We obtain stellar kinematics out to ~3.5 effective radii.
14656. Stars associated to Eagle Nebula (M16=NGC6611)
ID:
ivo://CDS.VizieR/J/A+A/521/A61
Title:
Stars associated to Eagle Nebula (M16=NGC6611)
Short Name:
J/A+A/521/A61
Date:
21 Oct 2021
Publisher:
CDS
Description:
Massive star-forming regions are characterized by intense ionizing fluxes, strong stellar winds and, occasionally, supernovae explosions, all of which have important effects on the surrounding media, on the star-formation process and on the evolution of young stars and their circumstellar disks. We present a multiband study of the massive young cluster NGC 6611 and its parental cloud (the Eagle Nebula) with the aim of studying how OB stars affect the early stellar evolution and the formation of other stars. We search for evidence of triggering of star formation by the massive stars inside NGC 6611 on a large spatial scale (~10 parsec) and ongoing disk photoevaporation in NGC 6611 and how its efficiency depends on the mass of the central stars.
14657. Stars classified from S2/68 UV line features
ID:
ivo://CDS.VizieR/III/53
Title:
Stars classified from S2/68 UV line features
Short Name:
III/53
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog provides the spectral classifications of 1900 stars from the papers listed in References. The classifications were made from spectra obtained by the S2/68 sky survey telescope experiment aboard the TD1 satellite.
14658. Stars earlier than F2 in a NGP region
ID:
ivo://CDS.VizieR/III/14
Title:
Stars earlier than F2 in a NGP region
Short Name:
III/14
Date:
21 Oct 2021
Publisher:
CDS
Description:
An objective prism survey for stars of spectral type F2 and earlier in a North Galactic Pole region was made with the Hamburg 80-120cm Schmidt telescope (dispersion 590{AA}/mm at H{gamma}). The accurate positions of these stars were recovered from the finding charts for stars without BD identification (table II) by B. Skiff (Lowell Obs.) in 2009.
14659. Stars in Alessi-Teutsch 9 (ASCC 10)
ID:
ivo://CDS.VizieR/J/other/ApSS/366.92
Title:
Stars in Alessi-Teutsch 9 (ASCC 10)
Short Name:
J/other/ApSS/366
Date:
19 Jan 2022 08:27:34
Publisher:
CDS
Description:
There is a growing interest in the automated characterization of open clusters using data from the Gaia mission. This work evidences the importance of choosing an appropriate sampling radius (the radius of the circular region around the cluster used to extract the data) and the usefulness of additional multiband photometry in order to achieve accurate results. We address this issue using as a case study the cluster Alessi-Teutsch 9. The optimal sampling is determined by counting the number of assigned members at different sampling radii. By using this strategy with data from Gaia EDR3 and with observed photometry in 12 bands spanning the optical range from 3000 to 10000{AA}, approximately, we are able to obtain reliable members and to determine the properties of the cluster. The spatial distribution of stars show a two-component structure with a central core of radius 12-13 arcmin and an outer halo extending out to 35 arcmin. With the derived cluster distance (654pc) we obtain that the number density of stars 0.06star/pc^3^, making Alessi-Teutsch 9 one of the less dense known open clusters. The short relaxation time reveals that it is a dynamically relaxed and gravitationally bound system.
14660. Stars in M13 core
ID:
ivo://CDS.VizieR/J/AJ/113/669
Title:
Stars in M13 core
Short Name:
J/AJ/113/669
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the dense core of the globular cluster Messier 13 (NGC 6205) using pre-refurbishment Planetary Camera-I images obtained with the Hubble Space Telescope. Short exposures (60s) through the F555W and F785LP filters (similar to Johnson V and I, respectively) have been used to obtain V and I photometry of 2877 stars brighter than V~20 in a 1.25arcmin^2^ region of the cluster including its core and extending out to r~66arcsec (2.3pc) from its center. The sample is complete to V~=18.3 (the main sequence turnoff) and the 1{sigma} photometric error is about 0.1mag. We find 15 blue straggler star candidates and 10 other possible blue stragglers in this region of M13. Their specific frequency is in the range F_(BSS)=0.04-0.07, comparable to what is observed near the centers of other dense clusters. A comparison between M13's observed V band stellar luminosity function and a theoretical model (Bergbusch & Vandenberg, 1992ApJS...81..163B) for the luminosity function of an old, metal-poor cluster shows that the model predicts too few of the brightest red giants (V~12.5-15) by a factor of two relative to subgiants/turnoff stars (>6{sigma} effect). The radial distributions of red giants, blue stragglers, and subgiants are consistent with one another, and are well fit by a King profile of core radius r_(core)_=38+/-6arcsec (90% confidence limits) or 1.3pc. Stars in the blue horizontal branch of M13, however, appear to be centrally depleted relative to other stellar types. We combine data from three dense ``King model clusters,'' M13, M3, and 47 Tuc, and two post core collapse clusters, M30 and M15, and compare the distributions of various stellar types as a function of (r/r_(half light)_) and (r/r_(core)_). The horizontal branch stars in the combined sample appear to be centrally depleted relative to the giants (97% significance), this depletion is only a 1-2{sigma} effect in each of the clusters taken individually. The blue stragglers in the combined sample are centrally concentrated relative to the giants. (Copyright) 1997 American Astronomical Society.

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