- ID:
- ivo://CDS.VizieR/J/ApJ/890/71
- Title:
- 5100{AA} continuum & emission lines LCs of PG2130+099
- Short Name:
- J/ApJ/890/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As one of the most interesting Seyfert 1 galaxies, PG 2130+099 has been the target of several reverberation mapping (RM) campaigns over the years. However, its measured broad H{beta} line responses have been inconsistent, with time lags of ~200days, ~25days, and ~10days being reported for different epochs while its optical luminosity changed no more than 40%. To investigate this issue, we conducted a new RM-campaign with homogenous and high cadence (about ~3days) for two years during 2017-2019 to measure the kinematics and structure of the ionized gas. We successfully detected time lags of broad H{beta}, HeII, HeI, and FeII lines with respect to the varying 5100{AA} continuum, revealing a stratified structure that is likely virialized with Keplerian kinematics in the first year of observations, but an inflow kinematics of the broad-line region from the second year. With a central black hole mass of 0.97_-0.18_^+0.15^x10^7^M_{sun}_, PG2130+099 has an accretion rate of 10^2.1+/-0.5^L_Edd_c^-2^, where L_Edd_ is the Eddington luminosity and c is speed of light, implying that it is a super-Eddington accretor and likely possesses a slim, rather than thin, accretion disk. The fast changes of the ionization structures of the three broad lines remain puzzling.
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- ID:
- ivo://CDS.VizieR/J/ApJ/814/52
- Title:
- 3600-24700{AA} deep X-shooter spectrum of HH 1
- Short Name:
- J/ApJ/814/52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep spectroscopic (3600-24700{AA}) X-shooter observations of the bright Herbig-Haro object HH 1, one of the best laboratories to study the chemical and physical modifications caused by protostellar shocks on the natal cloud. We observe atomic fine structure lines, HI and HeI recombination lines and H_2_ ro-vibrational lines (more than 500 detections in total). Line emission was analyzed by means of Non-local Thermal Equilibiurm codes to derive the electron temperature and density, and for the first time we are able to accurately probe different physical regimes behind a dissociative shock. We find a temperature stratification in the range 4000K/80000K, and a significant correlation between temperature and ionization energy. Two density regimes are identified for the ionized gas, a more tenuous, spatially broad component (density ~10^3^/cm^3^), and a more compact component (density>=10^5^/cm^3^) likely associated with the hottest gas. A further neutral component is also evidenced, having a temperature <~10000K and a density >10^4^/cm^3^. The gas fractional ionization was estimated by solving the ionization equilibrium equations of atoms detected in different ionization stages. We find that neutral and fully ionized regions co-exist inside the shock. Also, indications in favor of at least partially dissociative shock as the main mechanism for molecular excitation are derived. Chemical abundances are estimated for the majority of the detected species. On average, abundances of non-refractory/refractory elements are lower than solar of about 0.15/0.5dex. This indicates the presence of dust inside the medium, with a depletion factor of iron of ~40%.
- ID:
- ivo://CDS.VizieR/J/A+AS/141/141
- Title:
- 8500-8750{AA} high resolution spectroscopy. II.
- Short Name:
- J/A+AS/141/141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a library of synthetic spectra characterized by -2.5<=[Z/Z_{sun}_]<=+0.5, 4.5<=logg<=1.0, and T_eff_<=7500K computed at the same {lambda}/{Delta}{lambda}=20000 resolving power of the observed spectra given in Paper I (Munari, 1999, Cat. <J/A+AS/137/521>) for 131 standard stars mapping the MKK spectral classification system. This range of parameters includes the majority of the galactic stars expected to dominate the GAIA target population, i.e. F-G-K-M type stars with metallicity ranging from that of the galactic globular clusters to Population I objects. Extension to T_eff_>7500K will be given later on in this series. The 254 synthetic spectra presented here are based on Kurucz's codes and line data and have been computed over a more extended wavelength interval (7650-8750{AA}) than that currently baselined for implementation on GAIA, i.e. the 8500-8750{AA}. This last range is dominated by the near-IR Ca II triplet and the head of the Paschen series. The more extended wavelength range allows us to investigate the behaviour of other strong near-IR spectral features (severely contaminated by telluric absorptions in ground-based observed spectra) as the K I doublet (7664, 7699{AA}), the Na I doublet (8183, 8194{AA}) and the lines of Fe I multiplet N.60 at 8327 and 8388{AA}. The synthetic spectra support our previous conclusions about the superior performance of the Paschen/Ca II 8500-8750{AA} region in meeting the GAIA requirements when compared to other near-IR intervals of similar {Delta}{lambda}=250{AA}.
- ID:
- ivo://CDS.VizieR/J/A+A/366/1003
- Title:
- 8500-8750{AA} high resolution spectroscopy. III.
- Short Name:
- J/A+A/366/1003
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we complete the library of synthetic spectra for the range 7650-8750{AA}, which includes the 8500-8750{AA} interval currently base-lined for the spectroscopic observations by GAIA, candidate ESA Cornerstone 5 mission. As for Paper II (Munari & Castelli, Cat. <J/A+AS/141/141>), the spectra are based on Kurucz's codes and line data. The explored metallicity, gravity and temperature ranges are -2.5<=[Z/Z_{sun}_]<=+0.5, 4.5<=logg<=2.0 and 7750<=T_eff_<=50000K, respectively. The 698 new spectra are computed at the same {lambda}/{Delta}{lambda}=20000 resolving power of the observed spectra given in Paper I (Munari & Castelli, Cat. <J/A+AS/137/521>) (131 standard stars mapping the MKK spectral classification system) and the 254 synthetic spectra of Paper II (characterized by T_eff_<=7500K).
- ID:
- ivo://CDS.VizieR/J/A+A/406/995
- Title:
- 8500-8750{AA} high resolution spectroscopy. IV.
- Short Name:
- J/A+A/406/995
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A library of high resolution spectra of MK standard and reference stars, observed in support to the GAIA mission, is presented. The aim of this paper is to integrate the MK mapping of Paper I (<J/A+AS/137/521>) of this series as well as to consider stars over a wider range of metallicities. Radial velocities are measured for all the target stars.
- ID:
- ivo://CDS.VizieR/J/ApJS/216/22
- Title:
- 3060-3700{AA} spectra analysis of early-type stars
- Short Name:
- J/ApJS/216/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive and sensitive unbiased survey of interstellar features in the near-UV range (3050-3700{AA}). We combined a large number of VLT/UVES archival observations of a sample of highly reddened early-type stars -typical diffuse interstellar band targets- and unreddened standards. We stacked the individual observations to obtain a reddened "superspectrum" in the interstellar rest frame with a signal-to-noise ratio exceeding 1500. We compared this to the analogous geocentric and stellar rest frame superspectra as well as to an unreddened superspectrum to find interstellar absorption features. We find 30 known features (11 atomic and 19 molecular) and tentatively detect up to 7 new interstellar absorption lines of unknown origin. Our survey is sensitive to narrow and weak features; telluric residuals preclude us from detecting broader features. For each sightline, we measured fundamental parameters (radial velocities, line widths, and equivalent widths) of the detected interstellar features. We also revisit upper limits for the column densities of small, neutral polycyclic aromatic hydrocarbon molecules that have strong transitions in this wavelength range.
- ID:
- ivo://CDS.VizieR/J/ApJ/850/34
- Title:
- 3000-25000{AA} spectroscopy of nearby M dwarfs
- Short Name:
- J/ApJ/850/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent studies of the stellar population in the solar neighborhood (<20pc) suggest that there are undetected white dwarfs (WDs) in multiple systems with main-sequence companions. Detecting these hidden stars and obtaining a more complete census of nearby WDs is important for our understanding of stellar and galactic evolution, as well as the study of explosive phenomena. In an attempt to uncover these hidden WDs, we present intermediate resolution spectroscopy over the wavelength range of 3000-25000{AA} of 101 nearby M dwarfs (dMs), observed with the Very Large Telescope X-Shooter spectrograph. For each star we search for a hot component superimposed on the dM spectrum. X-Shooter has excellent blue sensitivity and thus can reveal a faint hot WD despite the brightness of its red companion. Visual examination shows no clear evidence of a WD in any of the spectra. We place upper limits on the effective temperatures of WDs that may still be hiding by fitting dM templates to the spectra and modeling the WD spectra. On average our survey is sensitive to WDs hotter than about 5300K. This suggests that the frequency of WD companions of Teff>~5300K with separation of the order of <~50 au among the local dM population is <3% at the 95% confidence level.
- ID:
- ivo://CDS.VizieR/J/ApJ/470/724
- Title:
- Abell 576 galaxies magnitude and velocities
- Short Name:
- J/ApJ/470/724
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyse the galaxy population and dynamics of the galaxy cluster A576; the observational constraints include 281 redshifts (230 new), R-band CCD galaxy photometry over a 2h^-1^Mpcx2h^-1^Mpc region centered on the cluster, an Einstein IPC X-ray image, and an Einstein MPC X-ray spectrum. We focus on an 86% complete magnitude-limited sample (R_23.5_<17) of 169 cluster galaxies. The cluster galaxies with emission lines in their spectra have a larger velocity dispersion and are significantly less clustered on this 2h^-1^Mpc scale than galaxies without emission lines. We show that excluding the emission-line galaxies from the cluster sample decreases the velocity dispersion by 18% and the virial mass estimate by a factor of 2. The central cluster region contains a non-emission galaxy population and an intracluster medium which is significantly cooler ({sigma}_core_=387^+250^_-105_km/s and T_X_=1.6-0.3/+0.4keV at 90% confidence) than the global populations ({sigma}=977^+124^_-96_km/s for the non-emission population and T_X_>4keV at 90% confidence). Because (1) the low-dispersion galaxy population is no more luminous than the global population and (2) the evidence for a cooling flow is weak, we suggest that the core of A576 may contain the remnants of a lower mass subcluster. We examine the cluster mass, baryon fraction, and luminosity function. The cluster virial mass varies significantly depending on the galaxy sample used. Consistency between the hydrostatic and virial estimators can be achieved if (1) the gas temperature at r~1h^-1^Mpc is T_X_~8keV (the best-fit value) and (2) several velocity outliers are excluded from the virial calculation. Although the best-fit Schechter function parameters and the ratio of galaxy to gas mass in A576 are typical of other clusters, the baryon fraction is relatively low. Using the consistent cluster binding mass, we show that the gas mass fraction is ~3h^-3/2^% and the baryon fraction is ~4%.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A131
- Title:
- Abell 520 galaxies redshifts
- Short Name:
- J/A+A/607/A131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The mergers of galaxy clusters are the most energetic events in the universe after the Big Bang. An ever increasing fraction of local clusters exhibit signs of recent or past mergers. Our goal is to probe how these mergers affect the evolution and content of their member galaxies. We specifically aim to answer the following questions: Is the quenching of star formation in merging clusters enhanced when compared with relaxed clusters? Is the quenching accompanied by a (short lived) burst of star formation? We obtained optical spectroscopy of $>400$ galaxies in the field of the merging cluster Abell 520. We combine these observations with archival data to get a comprehensive picture of the state of star formation in the members of this merging cluster. Finally, we compare these observations with a control sample of 10 non-merging clusters at the same redshift from The Arizona Cluster Redshift Survey (ACReS). We split the member galaxies in passive, star forming or recently quenched depending on their spectra. The core of the merger shows a decreased fraction of star-forming galaxies compared to clusters in the non-merging sample. This region, dominated by passive galaxies, is extended along the axis of the merger. We find evidence of rapid quenching of the galaxies during the core passage with no signs of a star burst on the time scales of the merger. Additionally, we report the tentative discovery of an infalling group along the main filament feeding the merger, currently at ~2.5Mpc from the merger centre. This group contains a high fraction of star forming galaxies as well as ~2/3 of all the recently quenched galaxies in our survey.
- ID:
- ivo://CDS.VizieR/J/AJ/128/3053
- Title:
- Absolute flux distribution of BD +17 4708
- Short Name:
- J/AJ/128/3053
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Secondary flux standards are established by measuring their brightness relative to primary standard stars. The Hubble Space Telescope (HST) primary standards are the three pure-hydrogen white dwarf (WD) flux standards that determine the sensitivity calibration for the Space Telescope Imaging Spectrograph. STIS observations have defined the flux of the Sloan Digital Sky Survey (SDSS, http://www.sdss.org) standard BD+17 4708 from 0.17 to 1.0{mu}m with an uncertainty of less than 0.5% relative to the HST primary standards, as verified by two independent sets of photometry.
- ID:
- ivo://CDS.VizieR/J/AJ/155/213
- Title:
- Absolute reflectance & new calibration site of the Moon
- Short Name:
- J/AJ/155/213
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- How bright the Moon is forms a simple but fundamental and important question. Although numerous efforts have been made to answer this question such as use of sophisticated electro-optical measurements and suggestions for calibration sites, the answer is still debated. An in situ measurement with a calibration panel on the surface of the Moon is crucial for obtaining the accurate absolute reflectance and resolving the debate. China's Chang'E-3 (CE-3) "Yutu" rover accomplished this type of measurement using the Visible-Near Infrared Spectrometer (VNIS). The measurements of the VNIS, which were at large emission and phase angles, complement existing measurements for the range of photometric geometry. The in situ reflectance shows that the CE-3 landing site is very dark with an average reflectance of 3.86% in the visible bands. The results are compared with recent mission instruments: the Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC), the Spectral Profiler (SP) on board the SELENE, the Moon Mineralogy Mapper (M^3^) on board the Chandrayaan-1, and the Chang'E-1 Interference Imaging Spectrometer (IIM). The differences in the measurements of these instruments are very large and indicate inherent differences in their absolute calibration. The M^3^ and IIM measurements are smaller than LROC WAC and SP, and the VNIS measurement falls between these two pairs. When using the Moon as a radiance source for the on-orbit calibration of spacecraft instruments, one should be cautious about the data. We propose that the CE-3 landing site, a young and homogeneous surface, should serve as the new calibration site.
- ID:
- ivo://CDS.VizieR/J/AJ/135/2245
- Title:
- Absolute spectrum of the Sun and Vega for 0.2-30um
- Short Name:
- J/AJ/135/2245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determine an absolute calibration for the Multiband Imaging Photometer for Spitzer 24um band and recommend adjustments to the published calibrations for Two Micron All Sky Survey (2MASS), Infrared Array Camera (IRAC), and IRAS photometry to put them on the same scale. We show that consistent results are obtained by basing the calibration on either an average A0V star spectral energy distribution (SED), or by using the absolutely calibrated SED of the Sun in comparison with solar-type stellar photometry (the solar analog method).
- ID:
- ivo://CDS.VizieR/J/AJ/161/285
- Title:
- Absorption & emission lines and RVel for vA 351
- Short Name:
- J/AJ/161/285
- Date:
- 08 Mar 2022
- Publisher:
- CDS
- Description:
- We extend results first announced by Franz et al., that identified vA351=H346 in the Hyades as a multiple star system containing a white dwarf. With Hubble Space Telescope Fine Guidance Sensor fringe tracking and scanning, and more recent speckle observations, all spanning 20.7years, we establish a parallax, relative orbit, and mass fraction for two components, with a period, P=2.70yr and total mass 2.1M{sun}. With ground-based radial velocities from the McDonald Observatory Otto Struve 2.1m Telescope Sandiford Spectrograph, and Center for Astrophysics Digital Speedometers, spanning 37 years, we find that component B consists of BC, two M-dwarf stars orbiting with a very short period (P_BC_=0.749days), having a mass ratio M_C_/M_B_=0.95. We confirm that the total mass of the system can only be reconciled with the distance and component photometry by including a fainter, higher-mass component. The quadruple system consists of three M dwarfs (A, B, C) and one white dwarf (D). We determine individual M-dwarf masses M_A_=0.53{+/-}0.10M{sun}, M_B_=0.43{+/-}0.04M{sun}, and M_C_=0.41{+/-}0.04M{sun}. The white dwarf mass, 0.54{+/-}0.04M{sun}, comes from cooling models, an assumed Hyades age of 670Myr, and consistency with all previous and derived astrometric, photometric, and radial velocity results. Velocities from H{alpha} and HeI emission lines confirm the BC period derived from absorption lines, with similar (HeI) and higher (H{alpha}) velocity amplitudes. We ascribe the larger H{alpha} amplitude to emission from a region each component shadows from the other, depending on the line of sight.
- ID:
- ivo://CDS.VizieR/J/ApJS/235/11
- Title:
- Absorption features in SDSS. I. MgII abs. doublets
- Short Name:
- J/ApJS/235/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the SDSS spectra of quasars included in the DR7Q or DR12Q catalogs, we search for MgII{lambda}{lambda}2796,2803 narrow absorption doublets in the spectra data around MgII{lambda}2798 emission lines. We obtain 17316 MgII doublets, within the redshift range of 0.3299<=z_abs_<=2.5663. We find that a velocity offset of {upsilon}_r_<6000km/s is a safe boundary to constrain the vast majority of associated Mg ii systems, although we find some doublets at {upsilon}_r_>6000km/s. If associated Mg ii absorbers are defined by {upsilon}_r_<6000km/s, ~33.3% of the absorbers are supposed to be contaminants of intervening systems. Removing the 33.3% contaminants, ~4.5% of the quasars present at least one associated MgII system with W_r_^{lambda}2796^>=0.2{AA}. The fraction of associated MgII systems with high-velocity outflows correlates with the average luminosities of their central quasars, indicating a relationship between outflows and the quasar feedback power. The {upsilon}_r_ distribution of the outflow MgII absorbers is peaked at 1023km/s, which is smaller than the corresponding value of the outflow CIV absorbers. The redshift number density evolution of absorbers (dn/dz) limited by {upsilon}_r_{>}-3000km/s differs from that of absorbers constrained by {upsilon}_r_>2000km/s. Absorbers limited by {upsilon}_r_>2000km/s and higher values exhibit profiles similar to dn/dz. In addition, the dn/dz is smaller when absorbers are constrained with larger {upsilon}_r_. The distributions of equivalent widths, and the ratio of W_r_^{lambda}2796^/W_r_^{lambda}2803^, are the same for associated and intervening systems, and independent of quasar luminosity.
- ID:
- ivo://CDS.VizieR/J/ApJS/239/19
- Title:
- Absorption lines in 21 Lyn A-type star
- Short Name:
- J/ApJS/239/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of absorption lines in the z', Y, and J bands that we identified in 21 Lyn, a slowly rotating A0.5V star. We detected 155 absorption features in the high-resolution (0.90-1.35um, R=28000) spectrum obtained with the WINERED spectrograph after the telluric absorption was carefully removed using a spectrum of a B-type star as a telluric standard. With a visual comparison with synthetic spectra, we compiled a catalog of 219 atomic lines for the 155 features, some of which are composed of multiple fine structure lines. The high-quality WINERED spectrum enabled us to detect a large number of weak lines down to ~1% in depth, which are identified for an A-type star for the first time. The catalog includes the lines of H, C, N, O, Mg, Al, Si, S, Ca, Fe, and Sr. These new lines are expected to be useful for spectral classification and chemical abundance analyses, while the line catalog is useful for observers who plan to use A-type stars as telluric standards because it is necessary to distinguish between stellar lines and telluric absorption lines in high-resolution spectra. ASCII versions of the spectra are available in the online version of the journal.
- ID:
- ivo://CDS.VizieR/J/A+A/318/347
- Title:
- Absorption lines in QSO 0000-2619
- Short Name:
- J/A+A/318/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We give the list of absorption lines in the high resolution (FWHM=13 km/s) spectrum of the z=4.12 QSO 0000-2619. The first table contains the lines of the Lyman-alpha forest, while in the second table the lines of the metal systems are listed.
- ID:
- ivo://CDS.VizieR/J/MNRAS/386/715
- Title:
- Absorption-line strengths in Coma galaxies
- Short Name:
- J/MNRAS/386/715
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present stellar population parameters of 12 elliptical and S0 galaxies in the Coma cluster around and including the cD galaxy NGC 4874, based on spectra obtained using the Low Resolution Imaging Spectrograph on the Keck II Telescope. Our data are among the most precise and accurate absorption-line strengths yet obtained for cluster galaxies, allowing us to examine in detail the zero-point and scatter in the stellar population properties of Coma cluster early-type galaxies (ETGs).
- ID:
- ivo://CDS.VizieR/J/A+A/412/707
- Title:
- Absorption-line systems in QSO spectra - CoALS
- Short Name:
- J/A+A/412/707
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Absorption lines and absorption-line systems (ALSs) observed in the spectra of QSOs contain fundamental information on distribution of matter between the observer and the QSO, and on physical processes in the Universe in different epochs of the cosmological evolution. The presented catalog contains a compilation of basic information on absorption-line systems (ALSs) in QSO spectra. The data are taken from publications available to the authors up to January 2002. The catalog includes, in particular, all the data of the catalogs by Junkkarinen et al. (1991ApJS...77..203J) and York et al. (1991MNRAS.250...24Y ). The catalog consists of table1.dat, table2.txt and the list of references in refs.dat file. The present catalog is also available at the site of the Dept. of Theor. Astrophys. of the Ioffe Physical Technical Institute: <www.ioffe.ru/astro/QC>
- ID:
- ivo://CDS.VizieR/J/A+AS/127/217
- Title:
- Absorption spectrum of the QSO PKS2126-158
- Short Name:
- J/A+AS/127/217
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectra of the z_em_=3.268 quasar PKS 2126-158 have been obtained in the wavelength range 430-662nm with a resolution R=27000 and an average signal to noise ratio s/n=25 per resolution element. 12 metal absorption systems have been identified, two of which were previously unknown. All the lines shortward of the Lyman{alpha} emission not identified as due to metals have been fitted as Lyman{alpha} and Lyman{beta}. We reported statistical analysis of this sample of lines. In particular, the two-point correlation function for metal systems has been computed.
- ID:
- ivo://CDS.VizieR/J/A+A/294/377
- Title:
- Absorption systems of HS 1700+6416
- Short Name:
- J/A+A/294/377
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ultraviolet observations of the high-redshift quasat HS 1700+6416 were obtained with the Faint Object Spectrograph (FOS) onboard the Hubble Space Telescope (HST) in the range 115-328nm, on 1991-12-13/14 and 1992-02-13/14 at a resolution R=1300. The identification of the numerous absoprtion lines provides evidence for 15 heavy-element absorption systems, among them 7 Lyman Limit systems (LLS).
- ID:
- ivo://CDS.VizieR/J/ApJS/155/351
- Title:
- Absorption toward PG 1116+215
- Short Name:
- J/ApJS/155/351
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Hubble Space Telescope (HST) and Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the intergalactic absorption toward QSO PG 1116+215 in the 900-3000{AA} spectral region.
- ID:
- ivo://CDS.VizieR/J/ApJ/845/85
- Title:
- Absorption velocities for 21 super-luminous SNe Ic
- Short Name:
- J/ApJ/845/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Super-luminous supernovae (SLSNe) are tremendously luminous explosions whose power sources and progenitors are highly debated. Broad-lined SNe Ic (SNe Ic-bl) are the only type of SNe that are connected with long-duration gamma-ray bursts (GRBs). Studying the spectral similarity and difference between the populations of hydrogen-poor SLSNe (SLSNe Ic) and of hydrogen-poor stripped-envelope core-collapse SNe, in particular SNe Ic and SNe Ic-bl, can provide crucial observations to test predictions of theories based on various power source models and progenitor models. In this paper, we collected all of the published optical spectra of 32 SLSNe Ic, 21 SNe Ic-bl, as well as 17 SNe Ic, quantified their spectral features, constructed average spectra, and compared them in a systematic way using new tools we have developed. We find that SLSNe Ic and SNe Ic-bl, including those connected with GRBs, have comparable widths for their spectral features and average absorption velocities at all phases. Thus, our findings strengthen the connection between SLSNe Ic and GRBs. In particular, SLSNe Ic have average FeII{lambda}5169 absorption velocities of -15000+/-2600km/s at 10 days after peak, which are higher than those of SNe Ic by ~7000km/s on average. SLSNe Ic also have significantly broader FeII{lambda}5169 lines than SNe Ic. Moreover, we find that such high absorption and width velocities of SLSNe Ic may be hard to explain with the interaction model, and none of the 13 SLSNe Ic with measured absorption velocities spanning over 10 days has a convincing flat velocity evolution, which is inconsistent with the magnetar model in one dimension. Lastly, we compare SN 2011kl, the first SN connected with an ultra-long GRB, with the mean spectrum of SLSNe Ic and of SNe Ic-bl.
- ID:
- ivo://CDS.VizieR/J/ApJ/847/127
- Title:
- Abundance analyses of V652 Her and HD 144941
- Short Name:
- J/ApJ/847/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical high-resolution spectra of V652 Her and HD 144941, the two extreme helium stars with exceptionally low C/He ratios, have been subjected to a non-LTE abundance analysis using the tools TLUSTY and SYNSPEC. Defining atmospheric parameters were obtained from a grid of non-LTE atmospheres and a variety of spectroscopic indicators including HeI and HeII line profiles, and the ionization equilibrium of ion pairs such as CII/CIII and NII/NIII. The various indicators provide a consistent set of atmospheric parameters: Teff=25000+/-300K, logg=3.10+/-0.12(cgs), and {xi}=13+/-2km/s are provided for V652 Her, and Teff=22000+/-600K, logg=3.45+/-0.15(cgs), and {xi}=10km/s are provided for HD 144941. In contrast to the non-LTE analyses, the LTE analyses-LTE atmospheres and an LTE line analysis-with the available indicators do not provide a consistent set of atmospheric parameters. The principal non-LTE effect on the elemental abundances is on the neon abundance. It is generally considered that these extreme helium stars with their very low C/He ratio result from the merger of two helium white dwarfs. Indeed, the derived composition of V652 Her is in excellent agreement with predictions by Zhang & Jeffery (2012MNRAS.419..452Z), who model the slow merger of helium white dwarfs; a slow merger results in the merged star having the composition of the accreted white dwarf. In the case of HD 144941, which appears to have evolved from metal-poor stars, a slow merger is incompatible with the observed composition but variations of the merger rate may account for the observed composition. More detailed theoretical studies of the merger of a pair of helium white dwarfs are to be encouraged.
- ID:
- ivo://CDS.VizieR/J/A+AS/111/17
- Title:
- Abundance analysis of stars in NGC 6522
- Short Name:
- J/A+AS/111/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CASPEC echelle spectrograph at the ESO 3.6 m telescope was used to obtain high resolution spectra of Arp 1145 and Arp 2240, two stars of the Baade Window, near the globular cluster NGC 6522. From a detailed analysis using equivalent widths and spectrum synthesis we derive the stellar parameters (T_eff_, log g and [M/H])=(4750,1.2,-0.9) and (5000,2.15,+0.2), respectively for Arp 1145 and Arp 2240.
- ID:
- ivo://CDS.VizieR/J/ApJS/162/346
- Title:
- Abundance gradients in the Galaxy
- Short Name:
- J/ApJS/162/346
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Six HII regions at galactocentric distances of R=10-15kpc have been observed in the far-IR emission lines of [OIII] (52{mu}m, 88{mu}m), [NIII] (57{mu}m), and [SIII] (19{mu}m) using the Kuiper Airborne Observatory. These observations have been combined with Very Large Array radio continuum observations of these sources to determine the abundances of O++, N++, and S++ relative to hydrogen. In addition, eight of the most recent sets of measurements of ionic line strengths in HII regions have been reanalyzed in order to attempt to reconcile differences in optical versus far-IR abundance determinations. We have in total 168 sets of observations of 117 HII regions in our analysis.
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/1976
- Title:
- Abundance ratio for 5 local stellar associations
- Short Name:
- J/MNRAS/454/1976
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have observed high-dispersion echelle spectra of main-sequence stars in five nearby young associations - Argus, Carina-Near, Hercules-Lyra, Orion and Subgroup B4 - and derived abundances for elements ranging from Na to Eu. These are the first chemical abundance measurements for two of the five associations, while the remaining three associations are analysed more extensively in our study. Our results support the presence of chemical homogeneity among association members with a typical star-to-star abundance scatter of about 0.06dex or less over many elements. The five associations show log {epsilon}(Li) consistent with their age and share a solar chemical composition for all elements with the exception of Ba. We find that all the heavy elements (Y, Zr, La, Ce, Nd, Sm and Eu) exhibit solar ratios, i.e. [X/Fe]=~0, while Ba is overabundant by about 0.2-0.3dex. The origin of the overabundance of Ba is a puzzle. Within the formulation of the s-process, it is difficult to create a higher Ba abundance without a similar increase in the s-process contributions to other heavy elements (La-Sm). Given that Ba is represented by strong lines of Ba II and La-Sm are represented by rather weak ionized lines, the suggestion, as previously made by other studies, is that the Ba abundance may be systematically overestimated by standard methods of abundance analysis perhaps because the upper reaches of the stellar atmospheres are poorly represented by standard model atmospheres. A novel attempt to analyse the Ba I line at 5535{AA} gives a solar Ba abundance for stars with effective temperatures hotter than about 5800K but increasingly subsolar Ba abundances for cooler stars with apparent Ba deficiencies of 0.5dex at 5100K. This trend with temperature may signal a serious non-local thermodynamical equilibrium effect on the Ba I line.
- ID:
- ivo://CDS.VizieR/J/A+A/617/A132
- Title:
- Abundances and distributions of CS and SiS
- Short Name:
- J/A+A/617/A132
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Sulphur has long been known to form different molecules depending on the chemical composition of its environment. More recently, the sulphur-bearing molecules SO and H2S have been shown to behave differently in oxygen-rich asymptotic giant branch (AGB) circumstellar envelopes of different densities. By surveying a diverse sample of AGB stars for CS and SiS emission, we aim to determine in which environments these sulphur-bearing molecules most readily occur. We include sources with a range of mass-loss rates and carbon-rich, oxygen-rich, and mixed S-type chemistries. Where these molecules are detected, we aim to determine their CS and SiS abundances. We surveyed 20 AGB stars of different chemical types using the APEX telescope, and combined this with an IRAM 30m and APEX survey of CS and SiS emission towards over 30 S-type stars. For those stars with detections, we performed radiative transfer modelling to determine abundances and abundance distributions. We detect CS towards all the surveyed carbon stars, some S-type stars, and the highest mass-loss rate oxygen-rich stars, (dM/dt>=5x10^-6^M_[sun}_/yr). SiS is detected towards the highest mass-loss rate sources of all chemical types (dM/dt>=8x10^-7^M_{sun}_/yr). We find CS peak fractional abundances ranging from ~4x10^-7^ to ~2x10^-5^ for the carbon stars, from ~3x10^-8^ to ~1x10^-7^ for the oxygen-rich stars, and from ~1x10^-7^ to ~8x10^-6^ for the S-type stars. We find SiS peak fractional abundances ranging from ~9x10^-6^ to ~2x10^-5^ for the carbon stars, from ~5x10^-7^ to ~2x10^-6^ for the oxygen-rich stars, and from ~2x10^-7^ to ~2x10^-^6 for the S-type stars. Overall, we find that wind density plays an important role in determining the chemical composition of AGB circumstellar envelopes. It is seen that for oxygen-rich AGB stars both CS and SiS are detected only in the highest density circumstellar envelopes and their abundances are generally lower than for carbon-rich AGB stars by around an order of magnitude. For carbon-rich and S-type stars SiS was also only detected in the highest density circumstellar envelopes, while CS was detected consistently in all surveyed carbon stars and sporadically among the S-type stars.
- ID:
- ivo://CDS.VizieR/J/A+A/569/A55
- Title:
- Abundances and vsini for 348 red giants
- Short Name:
- J/A+A/569/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Li and alpha-elements abundances, as well as rotational velocities for 348 stars. Li has been detected in 92 stars, of which 82 are giants. Those data ware used to investigate various channels of Li enrichment in giants.
- ID:
- ivo://CDS.VizieR/J/A+A/287/927
- Title:
- Abundances for lines of n-capture in 19 stars
- Short Name:
- J/A+A/287/927
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJS/245/34
- Title:
- Abundances for 6 million stars from LAMOST DR5
- Short Name:
- J/ApJS/245/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the determination of stellar parameters and individual elemental abundances for 6 million stars from ~8 million low-resolution (R~1800) spectra from LAMOST DR5. This is based on a modeling approach that we dub the data-driven Payne (DD-Payne), which inherits essential ingredients from both the Payne and the Cannon. It is a data-driven model that incorporates constraints from theoretical spectral models to ensure the derived abundance estimates are physically sensible. Stars in LAMOST DR5 that are in common with either GALAH DR2 or APOGEE DR14 are used to train a model that delivers stellar parameters (Teff, log g, Vmic) and abundances for 16 elements (C, N, O, Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, and Ba) over a metallicity range of -4dex<[Fe/H]<0.6dex when applied to the LAMOST spectra. Cross-validation and repeat observations suggest that, for S/N_pixel_>=50, the typical internal abundance precision is 0.03-0.1dex for the majority of these elements, with 0.2-0.3dex for Cu and Ba, and the internal precision of Teff and logg is better than 30K and 0.07dex, respectively. Abundance systematics at the ~0.1dex level are present in these estimates but are inherited from the high-resolution surveys' training labels. For some elements, GALAH provides more robust training labels, for others, APOGEE. We provide flags to guide the quality of the label determination and identify binary/multiple stars in LAMOST DR5.
- ID:
- ivo://CDS.VizieR/J/ApJ/865/68
- Title:
- Abundances for 79 Sun-like stars within 100pc
- Short Name:
- J/ApJ/865/68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large intrinsic variation in the elemental abundance patterns of stars with similar overall metal content. However, systematic errors arising from inaccuracies in stellar models are known to be a limiting factor in such studies, and thus it is uncertain to what extent the observed diversity of stellar abundance patterns is real. Here we report the abundances of 30 elements with precisions of 2% for 79 Sun-like stars within 100pc. Systematic errors are minimized in this study by focusing on solar twin stars and performing a line-by-line differential analysis using high-resolution, high-signal-to-noise spectra. We resolve [X/Fe] abundance trends in galactic chemical evolution at precisions of 10^-3^dex/Gyr and reveal that stars with similar ages and metallicities have nearly identical abundance patterns. Contrary to previous results, we find that the ratios of carbon-to-oxygen and magnesium-to-silicon in solar-metallicity stars are homogeneous to within 10% throughout the solar neighborhood, implying that exoplanets may exhibit much less compositional diversity than previously thought. Finally, we demonstrate that the Sun has a subtle deficiency in refractory material relative to >80% of solar twins (at 2{sigma} confidence), suggesting a possible signpost for planetary systems like our own.
- ID:
- ivo://CDS.VizieR/J/A+A/572/A33
- Title:
- Abundances from Gaia-ESO Survey
- Short Name:
- J/A+A/572/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most high-resolution spectroscopic studies of the Galactic discs were mostly confined to objects in the solar vicinity. Here we aim at enlarging the volume in which individual chemical abundances are used to characterise both discs, using the first internal data release of the Gaia-ESO survey. We derive and discuss the abundances of eight elements (Mg, Al, Si, Ca, Ti, Fe, Cr, Ni, and Y). The trends of these elemental abundances with iron are very similar to those in the solar neighbourhood. We find a natural division between {alpha}-rich and {alpha}-poor stars, best seen in the bimodality of the [Mg/M] distributions in bins of metallicity, which we attribute to thick- and thin-disc sequences, respectively. With the possible exception of Al, the observed dispersion around the trends is well described by the expected errors, leaving little room for astrophysical dispersion. Using previously derived distances from Recio-Blanco et al. (2014A&A...567A...5R), we further find that the thick-disc is more extended vertically and is more centrally concentrated towards the inner Galaxy than the thin-disc, which indicates a shorter scale-length. We derive the radial and vertical gradients in metallicity, iron, four {alpha}-element abundances, and Al for the two populations, taking into account the identified correlation between R_GC_ and |Z|. Radial metallicity gradient is found in the thin disc. The positive radial individual [{alpha}/M] gradients found are at variance from the gradients observed in the RAVE survey. The thin disc also hosts a negative vertical metallicity gradient, accompanied by positive individual [{alpha}/M] and [Al/M] gradients. The thick-disc, presents no radial metallicity gradient, a shallower vertical metallicity gradient than the thin-disc, an {alpha}-elements-to-iron radial gradient in the opposite sense than that of the thin disc, and positive vertical individual [{alpha}/M] and [Al/M] gradients.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A68
- Title:
- Abundance signature of M dwarf stars
- Short Name:
- J/A+A/644/A68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most of our current knowledge on planet formation is still based on the analysis of main-sequence, solar-type stars. Conversely, detailed chemical studies of large samples of M-dwarf planet hosts are still missing. We aim to test whether the correlations between the metallicity, individual chemical abundances, and mass of the star and the presence of different type of planets found for FGK stars still holds for the less massive M dwarf stars. Methods to determine in a consistent way stellar abundances of M dwarfs from high-resolution optical spectra are still missing. The present work is a first attempt to fill this gap. We analyse in a coherent and homogeneous way a large sample of M dwarfs with and without known planetary companions. We develop for the first time a methodology to determine stellar abundances of elements others than iron for M dwarf stars from high-resolution, optical spectra. Our methodology is based on the use of principal component analysis and sparse Bayesian's methods. We made use of a set of M dwarfs orbiting around an FGK primary with known abundances to train our methods. We applied our methods to derive stellar metallicities and abundances of a large sample of M dwarfs observed within the framework of current radial velocity surveys. We then used a sample of nearby FGK stars to cross-validate our technique by comparing the derived abundance trends in the M dwarf sample with those found on the FGK stars. The metallicity distribution of the different subsamples shows that M dwarfs hosting giant planets show a planet-metallicity correlation as well as a correlation with the stellar mass. M dwarfs hosting low-mass planets do not seem to follow the planet-metallicity correlation. We also found that the frequency of low-mass planets does not depend on the mass of the stellar host. These results seem in agreement with previous works. However, we note that for giant planet hosts our metallicities predict a weaker planet metallicity correlation but a stronger mass-dependency than photometric values. We show, for the first time, that there seems to be no differences in the abundance distribution of elements different from iron between M dwarfs with and without known planets. Our data shows that low-mass stars with planets follow the same metallicity, mass, and abundance trends than their FGK counterparts, which are usually explained within the framework of core-accretion models.
- ID:
- ivo://CDS.VizieR/J/A+A/580/A24
- Title:
- Abundances in dwarfs, subgiants, and giants
- Short Name:
- J/A+A/580/A24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analyzed high-resolution and high signal-to-noise ratio optical spectra of nearby FGK stars with and without detected giant planets in order to homogeneously measure their photospheric parameters, mass, age, and the abundances of volatile (C, N, and O) and refractory (Na, Mg, Si, Ca, Ti, V, Mn, Fe, Ni, Cu, and Ba) elements. Our sample contains 309 stars from the solar neighborhood (up to the distance of 100pc), out of which 140 are dwarfs, 29 are subgiants, and 140 are giants. The photospheric parameters are derived from the equivalent widths (EWs) of FeI and FeII lines. Masses and ages come from the interpolation in evolutionary tracks and isochrones on the HR diagram. The abundance determination is based on the equivalent widths of selected atomic lines of the refractory elements and on the spectral synthesis of C_2_, CN, CI, OI, and NaI features. We apply a set of statistical methods to analyze the abundances derived for the three subsamples. Our results show that: i) giant stars systematically exhibit underabundance in [C/Fe] and overabundance in [N/Fe] and [Na/Fe] in comparison with dwarfs, a result that is normally attributed to evolution-induced mixing processes in the envelope of evolved stars; ii) for solar analogs only, the abundance trends with the condensation temperature of the elements are correlated with age and anticorrelated with the surface gravity, which is in agreement with recent studies; iii) as in the case of [Fe/H], dwarf stars with giant planets are systematically enriched in [X/H] for all the analyzed elements, except for O and Ba (the former due to limitations of statistics), confirming previous findings in the literature that not only iron has an important relation with the planetary formation; and iv) giant planet hosts are also significantly overabundant for the same metallicity when the elements from Mg to Cu are combined together.
- ID:
- ivo://CDS.VizieR/J/AZh/72/855
- Title:
- Abundances in eta Psc
- Short Name:
- J/AZh/72/855
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD observations are used to analyse the atmosphere of the G7 IIIa giant Eta Piscium. The following atmospheric parameters were obtained: T(eff)=4930K, logg=2.1, and microturbulence v(t)=1.7km/s. The abundances of 21 elements in the atmosphere of eta Psc were determined.
- ID:
- ivo://CDS.VizieR/J/AZh/72/864
- Title:
- Abundances in gamma Sge
- Short Name:
- J/AZh/72/864
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD spectra are used to analyse the abundances of chemical elements in the atmosphere of the MOIII giant gamma Sagittae. Its atmospheric atmospheric parameters were determined to be T(eff)=3970K, logg=1.3, and microturbulence v(t)=1.65km/s.
- ID:
- ivo://CDS.VizieR/J/AZh/77/96
- Title:
- Abundances in Hyades red giants
- Short Name:
- J/AZh/77/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD spectra are obtained in 1994-1997 on the 2.6-m telescope of the Crimean Astrophysical observatory in the first chamber of the Coude focus. The dispersion was 3{AA}/mm and the signal-to-noise ratios were 100-300.
- ID:
- ivo://CDS.VizieR/J/MNRAS/234/583
- Title:
- Abundances in Magellanic Cloud planetary nebulae
- Short Name:
- J/MNRAS/234/583
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical spectroscopic data for 71 Planetary Nebulae (PN) in the Large and Small Magellanic Clouds have been analysed. The line fluxes have been used to determine nebular temperatures, densities, and the abundances of He, N, O, Ne and Ar, relative to H. In our sample there are 12 nebulae with N/O>=0.5, resembling Peimbert's Type I PN; six low-excitation objects [1<=I(5007)/I(H{beat})<=4], and four very-low excitation (VLE) nebulae [I(H{beta})>I(5007)], similar to the Galactic VLE class. Mean abundances have been calculated for the nebulae not in these special groups. After correction for collisional excitation contributions to the nebular He I lines, PN in the SMC and LMC yield mass fractions of Y=0.249+/-0.025 and Y=0.258+/-0.012, respectively.
- ID:
- ivo://CDS.VizieR/J/ApJ/857/2
- Title:
- Abundances in 6 metal-poor stars
- Short Name:
- J/ApJ/857/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new abundances derived from CuI, CuII, ZnI, and ZnII lines in six warm (5766<=T_eff_<=6427K), metal-poor (-2.50<=[Fe/H]<=-0.95) dwarf and subgiant (3.64<=logg<=4.44) stars. These abundances are derived from archival high-resolution ultraviolet spectra from the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope and ground-based optical spectra from several observatories. Ionized Cu and Zn are the majority species, and abundances derived from CuII and ZnII lines should be largely insensitive to departures from local thermodynamic equilibrium (LTE). We find good agreement between the [Zn/H] ratios derived separately from ZnI and ZnII lines, suggesting that departures from LTE are, at most, minimal (<~0.1dex). We find that the [Cu/H] ratios derived from CuII lines are 0.36+/-0.06dex larger than those derived from CuI lines in the most metal-poor stars ([Fe/H]{<}-1.8), suggesting that LTE underestimates the Cu abundance derived from CuI lines. The deviations decrease in more metal-rich stars. Our results validate previous theoretical non-LTE calculations for both Cu and Zn, supporting earlier conclusions that the enhancement of [Zn/Fe] in metal-poor stars is legitimate, and the deficiency of [Cu/Fe] in metal-poor stars may not be as large as previously thought.
- ID:
- ivo://CDS.VizieR/J/A+A/283/911
- Title:
- Abundances in NGC 2243 and Mel 66
- Short Name:
- J/A+A/283/911
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/579/A104
- Title:
- Abundances in NGC 5053 and NGC 5634
- Short Name:
- J/A+A/579/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The tidal disruption of the Sagittarius dwarf Spheroidal galaxy (Sgr dSph) is producing the most prominent substructure in the Milky Way (MW) halo, the Sagittarius Stream. Aside from field stars, the Sgr dSph is suspected to have lost a number of globular clusters (GC). Many Galactic GC are suspected to have originated in the Sgr dSph. While for some candidates an origin in the Sgr dSph has been confirmed due to chemical similarities, others exist whose chemical composition has never been investigated. NGC 5053 and NGC 5634 are two among these scarcely studied Sgr dSph candidate-member clusters. To characterize their composition we analyzed one giant star in NGC 5053, and two in NGC 5634. We analize high-resolution and signal-to-noise spectra by means of the MyGIsFOS code, determining atmospheric parameters and abundances for up to 21 species between O and Eu. The abundances are compared with those of MW halo field stars, of "unassociated" MW halo globulars, and of the metal poor Sgr dSph main body population. We derive a metallicity of [FeII/H]=-2.26+/-0.10 for NGC 5053, and of [FeI/H]=-1.99+/-0.075 and -1.97+/-0.076 for the two stars in NGC 5634. This makes NGC 5053 one of the most metal poor globular clusters in the MW. Both clusters display an alpha enhancement similar to the one of the halo at comparable metallicity. The two stars in NGC 5634 clearly display the Na-O anticorrelation widespread among MW globulars. Most other abundances are in good agreement with standard MW halo trends. The chemistry of the Sgr dSph main body populations is similar to the one of the halo at low metallicity. It is thus difficult to discriminate between an origin of NGC 5053 and NGC 5634 in the Sgr dSph, and one in the MW. However, the abundances of these clusters do appear closer to that of Sgr dSph than of the halo, favoring an origin in the Sgr dSph system.
- ID:
- ivo://CDS.VizieR/J/A+A/274/335
- Title:
- Abundances in normal late-B and HgMn stars
- Short Name:
- J/A+A/274/335
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/500/1089
- Title:
- Abundances in planetary nebulae
- Short Name:
- J/A+A/500/1089
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new spectroscopic data (90 objects) and derived plasma diagnostics and abundances of a sample of planetary nebulae in the direction of the Galactic center. The spectra were obtained in 2001/2002 with the 4-m class telescope at the Cerro Tololo Interamerican Observatory and the European Southern Observatory.
- ID:
- ivo://CDS.VizieR/J/A+A/427/231
- Title:
- Abundances in planetary nebulae
- Short Name:
- J/A+A/427/231
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new spectroscopic data (43 objects) and derived plasma diagnostics and abundances (164 objects) of a sample of planetary nebulae in the direction of the Galactic center. The spectra were obtained in July 2000 with the 1.9-m telescope at the South African Astronomical Observatory. The spectral coverage was 3500-7000{AA} with an average resolution of 1000.
- ID:
- ivo://CDS.VizieR/J/A+A/494/591
- Title:
- Abundances in planetary nebulae
- Short Name:
- J/A+A/494/591
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new plasma diagnostics and abundances of a sample of planetary nebulae located in the Galactic bulge (168 objects), the Galactic inner disk (61 objects) and in the LMC (110 objects).
- ID:
- ivo://CDS.VizieR/J/ApJ/682/1217
- Title:
- Abundances in red giants in 7 globular clusters
- Short Name:
- J/ApJ/682/1217
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a technique that applies spectral synthesis to medium-resolution spectroscopy (MRS; R~6000) in the red (6300{AA}<{lambda}<9100{AA}) to measure [Fe/H] and [{alpha}/Fe] of individual red giant stars over a wide metallicity range. We apply our technique to 264 red giant stars in seven Galactic globular clusters and demonstrate that it reproduces the metallicities and {alpha}-enhancements derived from high-resolution spectroscopy (HRS). The MRS technique excludes the three CaII triplet lines and instead relies on a plethora of weaker lines. Unlike empirical metallicity estimators, such as the equivalent width of the CaII triplet, the synthetic method presented here is applicable over an arbitrarily wide metallicity range and is independent of assumptions about the {alpha}-enhancement.
- ID:
- ivo://CDS.VizieR/J/AZh/75/586
- Title:
- Abundances in solar atmosphere
- Short Name:
- J/AZh/75/586
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An analysis of the chemical composition of the solar atmosphere is performed using spectrograms of the daylight sky obtained on the ZTS telescope (dispersion 3{AA}/mm, signal-to-noise ration, S/N>100). The chemical composition derived in the framework of a Holweger-Muller atmosphere model are in excellent agreement with the generally accepted values. Analysis based on the models of Bell et al. (1976A&AS...23...37B) and Kurucz (1992RMxAA..23..181K) with Teff=5770K and logg=4.44 failed to give satisfactory results.
- ID:
- ivo://CDS.VizieR/J/ApJS/191/352
- Title:
- Abundances in stars of Milky Way dwarf satellites
- Short Name:
- J/ApJS/191/352
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of Fe, Mg, Si, Ca, and Ti abundances for 2961 stars in eight dwarf satellite galaxies of the Milky Way (MW): Sculptor, Fornax, Leo I, Sextans, Leo II, Canes Venatici I, Ursa Minor, and Draco. For the purposes of validating our measurements, we also observed 445 red giants in MW globular clusters and 21 field red giants in the MW halo. The measurements are based on Keck/DEIMOS medium-resolution spectroscopy (MRS) combined with spectral synthesis. We estimate uncertainties in [Fe/H] by quantifying the dispersion of [Fe/H] measurements in a sample of stars in monometallic globular clusters (GCs). We estimate uncertainties in Mg, Si, Ca, and Ti abundances by comparing to high-resolution spectroscopic abundances of the same stars. For this purpose, a sample of 132 stars with published high-resolution spectroscopy in GCs, the MW halo field, and dwarf galaxies has been observed with MRS. The standard deviations of the differences in [Fe/H] and <[{alpha}/Fe]> (the average of [Mg/Fe], [Si/Fe], [Ca/Fe], and [Ti/Fe]) between the two samples is 0.15 and 0.16, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/419/469
- Title:
- Abundances in the galaxy HS 0837+4717
- Short Name:
- J/A+A/419/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of high S/N long-slit spectroscopy with the Multiple Mirror (MMT) and the SAO 6-m (BTA) telescopes, optical imaging with the Wise 1-m telescope and HI observations with the Nancay Radio Telescope of the very metal-deficient (12+log(O/H)=7.64) luminous (M_B_=-18.1mag) blue compact galaxy (BCG) HS 0837+4717.
- ID:
- ivo://CDS.VizieR/J/ApJ/870/83
- Title:
- Abundances in the ultra-faint dwarf gal. GruI & TriII
- Short Name:
- J/ApJ/870/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-resolution spectroscopy of four stars in two candidate ultra-faint dwarf galaxies (UFDs), GrusI (GruI) and TriangulumII (TriII). Neither object currently has a clearly determined velocity dispersion, placing them in an ambiguous region of parameter space between dwarf galaxies and globular clusters (GCs). No significant metallicity difference is found for the two GruI stars, but both stars are deficient in neutron-capture elements. We verify previous results that TriII displays significant spreads in metallicity and [{alpha}/Fe]. Neutron-capture elements are not detected in our TriII data, but we place upper limits at the lower envelope of Galactic halo stars, consistent with previous very low detections. Stars with similarly low neutron-capture element abundances are common in UFDs but rare in other environments. This signature of low neutron-capture element abundances traces chemical enrichment in the least massive star-forming dark matter halos and further shows that the dominant sources of neutron-capture elements in metal-poor stars are rare. In contrast, all known GCs have similar ratios of neutron-capture elements to those of halo stars, suggesting that GCs do not form at the centers of their own dark matter halos. The low neutron-capture element abundances may be the strongest evidence that GruI and TriII are (or once were) galaxies rather than GCs, and we expect future observations of these systems to robustly find nonzero velocity dispersions or signs of tidal disruption. However, the nucleosynthetic origin of this low neutron-capture element floor remains unknown.