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14091. Spectroscopic observations of A3571
ID:
ivo://CDS.VizieR/J/A+AS/101/475
Title:
Spectroscopic observations of A3571
Short Name:
J/A+AS/101/475
Date:
21 Oct 2021
Publisher:
CDS
Description:
Spectroscopic data and density counts are presented for this southern cluster, which seems to belong to the outskirts of the Shapley 8 concentration (= A 3558 = SC 1326-311). Using telescopes at the Cerro Tololo Interamerican Observatory and La Silla Observatory a total of 72 galaxy velocities were measured giving a mean redshift of 0.0384 and a global velocity dispersion of 1022 (+99, -77) km/s. A preliminary analysis of velocity and density data suggests the presence of various subgroups. The central core of the cluster is dominated by a very elongated, distorded and diffuse cD galaxy. This cluster may be an example where the cD was formed early in the collapse process of a cluster which has not reached overall virialization yet. The derived X-ray luminosity of ~2x10^44^erg/s in the 2-6keV band places this cluster in the group of strong X-ray cluster sources.
14092. Spectroscopic observations of globular clusters
ID:
ivo://CDS.VizieR/J/MNRAS/405/839
Title:
Spectroscopic observations of globular clusters
Short Name:
J/MNRAS/405/839
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of medium-resolution spectroscopy of 28 globular clusters (GCs) in six nearby galaxies of different luminosities and morphological types, situated in M33 (15 objects), M31 (three), IC10 (four), UGCA86 (four), Holmberg IX (one) and DDO71 (one) obtained at the Special Astrophysical Observatory 6-m telescope. Measurements of Lick absorption line indices and comparison with Simple Stellar Population models enabled us to obtain their spectroscopic ages, metallicities and {alpha}-element to Fe abundance ratios.
14093. Spectroscopic observations of Herbig Ae/Be stars
ID:
ivo://CDS.VizieR/J/ApJ/653/657
Title:
Spectroscopic observations of Herbig Ae/Be stars
Short Name:
J/ApJ/653/657
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present optical spectra of 45 intermediate-mass Herbig Ae/Be stars. Together with the multiepoch spectroscopic and photometric data compiled for a large sample of these stars and ages estimated for individual stars by using pre-main-sequence evolutionary tracks, we have studied the evolution of emission-line activity in them. We find that, on average, the H{alpha} emission line strength decreases with increasing stellar age in Herbig Ae/Be stars, indicating that the accretion activity gradually declines during the pre-main-sequence phase.
14094. Spectroscopic observations of southern stars
ID:
ivo://CDS.VizieR/J/PAZh/32/628
Title:
Spectroscopic observations of southern stars
Short Name:
J/PAZh/32/628
Date:
21 Oct 2021
Publisher:
CDS
Description:
The results of spectrophotometric observations of 64 southern stars in the range from 320 to 730nm are presented as quasi-monochromatic luminosities from the stars on the external board of atmosphere expressed in the absolute energy units (W/m^2^/m) with spectral interval of 2.5nm.
14095. Spectroscopic obs & members of ZwCl 2341+0000
ID:
ivo://CDS.VizieR/J/ApJ/841/7
Title:
Spectroscopic obs & members of ZwCl 2341+0000
Short Name:
J/ApJ/841/7
Date:
21 Oct 2021
Publisher:
CDS
Description:
ZwCl 2341.1+0000, a merging galaxy cluster with disturbed X-ray morphology and widely separated (~3Mpc) double radio relics, was thought to be an extremely massive (10-30x10^14^M_{sun}_) and complex system, with little known about its merger history. We present JVLA 2-4GHz observations of the cluster, along with new spectroscopy from our Keck/DEIMOS survey, and apply Gaussian Mixture Modeling to the three-dimensional distribution of 227 confirmed cluster galaxies. After adopting the Bayesian Information Criterion to avoid overfitting, which we discover can bias high the total dynamical mass estimates, we find that a three-substructure model with a total dynamical mass estimate of 9.39+/-0.81x10^14^M_{sun}_ is favored. We also present deep Subaru imaging and perform the first weak lensing analysis on this system, obtaining a weak lensing mass estimate of 5.57+/-2.47x10^14^M_{sun}_. This is a more robust estimate because it does not depend on the dynamical state of the system, which is disturbed due to the merger. Our results indicate that ZwCl2341.1+0000 is a multiple merger system comprised of at least three substructures, with the main merger that produced the radio relics occurring near the plane of the sky, and a younger merger in the north occurring closer to the line of sight. Dynamical modeling of the main merger reproduces observed quantities (relic positions and polarizations, subcluster separation and radial velocity difference), if the merger axis angle of ~10_-6_^+34^ degrees and the collision speed at pericenter is ~1900_-200_^+300^km/s.
14096. Spectroscopic obs. of 413 HII regions in M33
ID:
ivo://CDS.VizieR/J/ApJ/842/97
Title:
Spectroscopic obs. of 413 HII regions in M33
Short Name:
J/ApJ/842/97
Date:
21 Oct 2021
Publisher:
CDS
Description:
The spectra of 413 star-forming (or H II) regions in M33 (NGC 598) were observed using the multifiber spectrograph of Hectospec at the 6.5m Multiple Mirror Telescope. Using this homogeneous spectra sample, we measured the intensities of emission lines and some physical parameters, such as electron temperatures, electron densities, and metallicities. Oxygen abundances were derived via the direct method (when available) and two empirical strong-line methods, namely, O3N2 and N2. At the high-metallicity end, oxygen abundances derived from the O3N2 calibration were higher than those derived from the N2 index, indicating an inconsistency between O3N2 and N2 calibrations. We present a detailed analysis of the spatial distribution of gas-phase oxygen abundances in M33 and confirm the existence of the axisymmetric global metallicity distribution that is widely assumed in the literature. Local variations were also observed and subsequently associated with spiral structures to provide evidence of radial migration driven by arms. Our O/H gradient fitted out to 1.1 R_25_ resulted in slopes of -0.17+/-0.03, -0.19+/-0.01, and -0.16+/-0.17dex R_25_^-1^, utilizing abundances from O3N2, N2 diagnostics, and a direct method, respectively.
14097. Spectroscopic obs. of 2 red giant stars in omega Cen
ID:
ivo://CDS.VizieR/J/ApJ/837/176
Title:
Spectroscopic obs. of 2 red giant stars in omega Cen
Short Name:
J/ApJ/837/176
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a chemical abundance analysis of a metal-poor star, ROA276, in the stellar system {omega} Centauri. We confirm that this star has an unusually high [Sr/Ba] abundance ratio. Additionally, ROA 276 exhibits remarkably high abundance ratios, [X/Fe], for all elements from Cu to Mo along with normal abundance ratios for the elements from Ba to Pb. The chemical abundance pattern of ROA 276, relative to a primordial {omega} Cen star ROA 46, is best fit by a fast-rotating low-metallicity massive stellar model of 20M_{sun}_, [Fe/H]=-1.8, and an initial rotation 0.4 times the critical value; no other nucleosynthetic source can match the neutron-capture element distribution. ROA 276 arguably offers the most definitive proof to date that fast-rotating massive stars contributed to the production of heavy elements in the early universe.
14098. Spectroscopic obs. of RR Lyrae in NGC5139
ID:
ivo://CDS.VizieR/J/ApJ/881/104
Title:
Spectroscopic obs. of RR Lyrae in NGC5139
Short Name:
J/ApJ/881/104
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a detailed spectroscopic analysis of RR Lyrae (RRL) variables in the globular cluster NGC5139 ({omega} Cen). We collected optical (4580-5330{AA}), high-resolution (R~34000), high signal-to-noise ratio (~200) spectra for 113 RRLs with the multifiber spectrograph M2FS at the Magellan/Clay Telescope at Las Campanas Observatory. We also analyzed high- resolution (R~26000) spectra for 122 RRLs collected with FLAMES/GIRAFFE at the Very Large Telescope, available in the ESO archive. The current sample doubles the literature abundances of cluster and field RRLs in the Milky Way based on high-resolution spectra. Equivalent-width measurements were used to estimate atmospheric parameters, iron, and abundance ratios for {alpha} (Mg, Ca, Ti), iron peak (Sc, Cr, Ni, Zn), and s-process (Y) elements. We confirm that {omega}Cen is a complex cluster, characterized by a large spread in the iron content: -2.58<~[Fe/H]<~-0.85. We estimated the average cluster abundance as <[Fe/H]>=-1.80{+/-}0.03, with {sigma}=0.33dex. Our findings also suggest that two different RRL populations coexist in the cluster. The former is more metal-poor ([Fe/H]<~-1.5), with almost solar abundance of Y. The latter is less numerous, more metal-rich, and yttrium enhanced ([Y/Fe]>~0.4). This peculiar bimodal enrichment only shows up in the s-process element, and it is not observed among lighter elements, whose [X/Fe] ratios are typical for Galactic globular clusters.
14099. Spectroscopic obs. of 3 spiral galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/412/1741
Title:
Spectroscopic obs. of 3 spiral galaxies
Short Name:
J/MNRAS/412/1741
Date:
21 Oct 2021
Publisher:
CDS
Description:
The correlation between the breaks in the metallicity distribution and the corotation radius of spiral galaxies has been already advocated in the past and is predicted by a chemodynamical model of our Galaxy that effectively introduces the role of spiral arms in the star formation rate. In this work, we present photometric and spectroscopic observations made with the Gemini Telescope for three of the best candidates of spiral galaxies to have the corotation inside the optical disc: IC 0167, NGC 1042 and NGC 6907. We observed the most intense and well-distributed HII regions of these galaxies, deriving reliable galactocentric distances and oxygen abundances by applying different statistical methods. From these results, we confirm the presence of variations in the gradients of metallicity of these galaxies that are possibly correlated with the corotation resonance.
14100. Spectroscopic orbits for 15 late-type stars
ID:
ivo://CDS.VizieR/J/AJ/152/46
Title:
Spectroscopic orbits for 15 late-type stars
Short Name:
J/AJ/152/46
Date:
21 Oct 2021
Publisher:
CDS
Description:
Spectroscopic orbital elements are determined for 15 stars with periods from 8 to 6528days with six orbits computed for the first time. Improved astrometric orbits are computed for two stars and one new orbit is derived. Visual orbits were previously determined for four stars, four stars are members of multiple systems, and five stars have Hipparcos "G" designations or have been resolved by speckle interferometry. For the nine binaries with previous spectroscopic orbits, we determine improved or comparable elements. For HD28271 and HD200790, our spectroscopic results support the conclusions of previous authors that the large values of their mass functions and lack of detectable secondary spectrum argue for the secondary in each case being a pair of low-mass dwarfs. The orbits given here may be useful in combination with future interferometric and Gaia satellite observations.

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