- ID:
- ivo://CDS.VizieR/J/ApJ/751/46
- Title:
- Spectroscopic observations in VV124 (UGC 4879)
- Short Name:
- J/ApJ/751/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- VV124 (UGC 4879) is an isolated, dwarf irregular/dwarf spheroidal (dIrr/dSph) transition-type galaxy at a distance of 1.36 Mpc. Previous low-resolution spectroscopy yielded inconsistent radial velocities for different components of the galaxy, and photometry hinted at the presence of a stellar disk. In order to quantify the stellar dynamics, we observed individual red giants in VV124 with the Keck/Deep Extragalactic Imaging Multi-Object Spectrograph (DEIMOS). We validated members based on their positions in the color-magnitude diagram, radial velocities, and spectral features. Our sample contains 67 members. The average radial velocity is <v_r_>=-29.1+/-1.3km/s in agreement with the previous radio measurements of H I gas. The velocity distribution is Gaussian, indicating that VV124 is supported primarily by velocity dispersion inside a radius of 1.5 kpc. Outside that radius, our measurements provide only an upper limit of 8.6km/s on any rotation in the photometric disk-like feature. The velocity dispersion is {sigma}_v_=9.4+/-1.0km/s, from which we inferred a mass of M_1/2_=(2.1 +/-0.2)x10^7^M_{sun}_ and a mass-to-light ratio of (M/L_V_)_1/2_=5.2+/-1.1M_{sun}_/L_{sun}_, both measured within the half-light radius. Thus, VV124 contains dark matter. We also measured the metallicity distribution from neutral iron lines. The average metallicity, <[Fe/H]>=-1.14+/-0.06, is consistent with the mass-metallicity relation defined by dSph galaxies. The dynamics and metallicity distribution of VV124 appear similar to dSphs of similar stellar mass.
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- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/408/305
- Title:
- Spectroscopic observations of delta Sco
- Short Name:
- J/A+A/408/305
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a spectroscopic monitoring program of the binary system Scorpii, whose primary became a Be star after the last periastron encounter in the Summer of 2000. The observations cover a period of 2 years (March 2001-June 2003) and are a continuation of our previous campaign reported in Miroshnichenko et al. (2001A&A...377..485M). We found that the emission-line spectrum was gradually strengthening over the whole monitoring period. Several short-term increases of the line emission, possibly due to outbursts of matter ejected from the stellar surface, were detected. The outbursts seem to be responsible for the brightness fadings, seen afterwards. We attempt to explain the overall observed line and continuum behaviour in terms of a circumstellar disk, growing in density and size. The disk is most likely Keplerian with an outer radius of and a mean expansion speed of ~0.4km/s.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/501/291
- Title:
- Spectroscopic observations of HD 152219
- Short Name:
- J/A+A/501/291
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- HD 152219 is a massive binary system with O9.5 III + B1-2 V/III components and a short orbital period of 4.2d. Its primary component further displays clear line profile variability (LPV). The primary component being located within the pulsational instability domain predicted for high-luminosity stars, we previously suggested that the observed LPV could be associated with non-radial pulsations. The aim of the present work is to determine the nature of the observed LPV in the spectrum of the primary component of HD 152219. During a 4-night FEROS monitoring campaign, we collected a new set of 134 high signal-to-noise spectra. These new observations were then used to re-investigate the variability of different line profiles in the spectrum of HD~152219. Based on the present analysis, we discard the non-radial pulsations and point out the Rossiter-McLaughlin effect as the cause of the LPV in HD 152219. The upper limit on the amplitude of possible weak pulsations is set at a few parts per thousand of the continuum level.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/AZh/71/572
- Title:
- Spectroscopic observations of V380 Ori
- Short Name:
- J/AZh/71/572
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of spectral observations of the Ae/Be star V380 Ori in the optical and near-IR ranges for 1976 to 1991, are presented. The spectra were obtained on various telescopes and spectrographs including the Main Stellar Spectrograph of the BTA six-meter telescope. For 270 bright emission lines, the intensities, equivalent widths, half-widths, radial velocities, and variability amplitudes are given.
- 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.
- 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.