- ID:
- ivo://CDS.VizieR/J/other/AstBu/69.427
- Title:
- CP stars magnetic fields catalog (2007)
- Short Name:
- J/other/AstBu/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog presents the results of magnetic field measurements for 39 chemically peculiar and 3 normal main sequence stars used as standard stars. Observations were carried out with the Main Stellar Spectrograph of the Russian 6-m telescope during 2007. The accuracy analysis for the longitudinal magnetic field measurements of the stars confirms that the systematic errors do not exceed 10-20G and are within the quoted limits. The absence of significant instrumental deviations follows from the measurements of theBD CP stars with well-known B_e_ variation curves.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/other/AstBu/72.391
- Title:
- CP stars magnetic fields catalog (2010)
- Short Name:
- J/other/AstBu/72
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of measuring longitudinal magnetic fields (B_e_), rotation velocities (v_esini_), and radial velocities (V_r_) of 92 stars observed with the Main Stellar Spectrograph (MSS) of the 6-m BTA telescope of the Special Astrophysical Observatory in 2010. Observations of standard stars without magnetic fields confirm the absence of systematic errors capable of introducing distortions into the longitudinal-field measurement results.
- ID:
- ivo://CDS.VizieR/J/other/AstBu/70.444
- Title:
- CP stars magnetic fields catalog (2008)
- Short Name:
- J/other/AstBu/70
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the magnetic field measurements of 37 chemically peculiar and 4 normal main sequence stars using circularly polarized spectra obtained in 2008 with a Zeeman analyzer on the Main Stellar Spectrograph (MSS) of the Russian 6-m telescope (BTA). Four new magnetic stars have been discovered (HD25999, HD35100, HD96237, and HD279021), the presence of a field was suspected in two stars (HD2887 and BD-12 2366), 16 previously known CP stars were continued to be monitored to study their fields. The results of the longitudinal magnetic field B_e_ measurements show that in stars with narrow spectral lines, systematic errors in B_e_ determination do not exceed 10-20G, which is within the statistical error. Our study of stars with reliable phase curves of the longitudinal field B_e_ show that there are no instrumental effects which can distort the observations.
- ID:
- ivo://CDS.VizieR/J/ApJS/237/18
- Title:
- Cr, Co, and Ni abundances for metal-poor red giants
- Short Name:
- J/ApJS/237/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present measurements of the abundances of chromium, cobalt, and nickel in 4113 red giants, including 2277 stars in globular clusters (GCs), 1820 stars in the Milky Way's dwarf satellite galaxies, and 16 field stars. We measured the abundances from mostly archival Keck/DEIMOS medium-resolution spectroscopy with a resolving power of R~6500 and a wavelength range of approximately 6500-9000{AA}. The abundances were determined by fitting spectral regions that contain absorption lines of the elements under consideration. We used estimates of temperature, surface gravity, and metallicity that we previously determined from the same spectra. We estimated systematic error by examining the dispersion of abundances within mono- metallic GCs. The median uncertainties for [Cr/Fe], [Co/Fe], and [Ni/Fe] are 0.20, 0.20, and 0.13, respectively. Finally, we validated our estimations of uncertainty through duplicate measurements, and we evaluated the accuracy and precision of our measurements through comparison to high-resolution spectroscopic measurements of the same stars.
- ID:
- ivo://CDS.VizieR/J/A+A/539/A109
- Title:
- CRIRES-POP: high resolution IR spectra library
- Short Name:
- J/A+A/539/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New instrumental capabilities and the wealth of astrophysical information extractable from the near-infrared wavelength region have led to a growing interest in the field of high resolution spectroscopy at 1-5m. We aim to provide a library of observed high-resolution and high signal-to-noise-ratio near-infrared spectra of stars of various types throughout the Hertzsprung-Russell diagram. This is needed for the exploration of spectral features in this wavelength range and for comparison of reference targets with observations and models.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A192
- Title:
- C3R2-KMOS zsp & galaxy physical properties
- Short Name:
- J/A+A/642/A192
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Complete Calibration of the Colour-Redshift Relation survey (C3R2) is a spectroscopic effort involving ESO and Keck facilities designed specifically to empirically calibrate the galaxy colour-redshift relation - P(zjC) to the Euclid depth (i_AB_=24.5) and is intimately linked to the success of upcoming Stage IV dark energy missions based on weak lensing cosmology. The aim is to build a spectroscopic calibration sample that is as representative as possible of the galaxies of the Euclid weak lensing sample. In order to minimise the number of spectroscopic observations necessary to fill the gaps in current knowledge of the P(zjC), self-organising map (SOM) representations of the galaxy colour space have been constructed. Here we present the first results of an ESO@VLT Large Programme approved in the context of C3R2, which makes use of the two VLT optical and near-infrared multi-object spectrographs, FORS2 and KMOS. This data release paper focuses on high-quality spectroscopic redshifts of high-redshift galaxies observed with the KMOS spectrograph in the near-infrared H- and K-bands. A total of 424 highly-reliable redshifts are measured in the 1.3<=z<=2.5 range, with total success rates of 60.7% in the H-band and 32.8% in the K-band. The newly determined redshifts fill 55% of high (mainly regions with no spectroscopic measurements) and 35% of lower (regions with low-resolution/low-quality spectroscopic measurements) priority empty SOMgrid cells.We measured H fluxes in a 1.2" radius aperture from the spectra of the spectroscopically confirmed galaxies and converted them into star formation rates. In addition, we performed an SED fitting analysis on the same sample in order to derive stellar masses, E(B-V), total magnitudes, and SFRs. We combine the results obtained from the spectra with those derived via SED fitting, and we show that the spectroscopic failures come from either weakly star-forming galaxies (at z<1.7, i.e. in the H-band) or low S/N spectra (in the K-band) of z>2 galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/603/A67
- Title:
- CRL618, MWC922 and M2-9 RRL spectra
- Short Name:
- J/A+A/603/A67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results from a pilot search for radio recombination line (RRL) emission at millimeter wavelengths in a small sample of pre-planetary nebulae (pPNe) and young PNe (yPNe) with emerging central ionized regions. Observations of the H30{alpha}, H31{alpha}, H39{alpha}, H41{alpha}, H48{beta}, H49{beta}, H51{beta}, and H55{gamma} lines at ~1 and ~3mm have been performed with the IRAM 30m radio telescope. These lines are excellent probes of the dense inner (<~150 au) and heavily obscured regions of these objects, where the yet unknown agents for PN-shaping originate. We detected mm-RRLs in three objects: CRL 618, MWC922, and M2-9. For CRL 618, the only pPN with previous published detections of H41{alpha}, H35{alpha}, and H30{alpha} emission, we find significant changes in the line profiles indicating that current observations are probing regions of the ionized wind with larger expansion velocities and mass-loss rate than ~29 years ago. In the case of MWC922, we observe a drastic transition from single-peaked profiles at 3mm (H39{alpha} and H41{alpha}) to double-peaked profiles at 1mm (H31{alpha} and H30{alpha}), which is consistent with maser amplification of the highest frequency lines; the observed line profiles are compatible with rotation and expansion of the ionized gas, probably arranged in a disk+wind system around a ~5-10M_{sun}_ central mass. In M2-9, the mm-RRL emission appears to be tracing a recent mass outburst by one of the stars of the central binary system. We present the results from non-LTE line and continuum radiative transfer models, which enables us to constrain the structure, kinematics, and physical conditions (electron temperature and density) of the ionized cores of our sample. We find temperatures Te~6000-17000K, mean densities ne~10^5^-10^8^cm^-3^, radial density gradients ne{prop.to}r^-alpha_n_^ whit alpha_n_~2-3.5, and motions of velocities of ~10-30km/s in the ionized wind regions traced by these mm-wavelength observations. We deduce mass-loss rates of dM_pAGB_/dt~=10^-6^-10^-7^M_{sun}_/yr, which are significantly higher than the values adopted by stellar evolution models currently in use and would result in a transition from the asymptotic giant branch to the PN phase faster than hitherto assumed.
- ID:
- ivo://CDS.VizieR/J/ApJ/841/111
- Title:
- C3R2 survey: high-confidence redshifts from DR1
- Short Name:
- J/ApJ/841/111
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A key goal of the Stage IV dark energy experiments Euclid, LSST, and WFIRST is to measure the growth of structure with cosmic time from weak lensing analysis over large regions of the sky. Weak lensing cosmology will be challenging: in addition to highly accurate galaxy shape measurements, statistically robust and accurate photometric redshift (photo-z) estimates for billions of faint galaxies will be needed in order to reconstruct the three-dimensional matter distribution. Here we present an overview of and initial results from the Complete Calibration of the Color-Redshift Relation (C3R2) survey, which is designed specifically to calibrate the empirical galaxy color-redshift relation to the Euclid depth. These redshifts will also be important for the calibrations of LSST and WFIRST. The C3R2 survey is obtaining multiplexed observations with Keck (DEIMOS, LRIS, and MOSFIRE), the Gran Telescopio Canarias (GTC; OSIRIS), and the Very Large Telescope (VLT; FORS2 and KMOS) of a targeted sample of galaxies that are most important for the redshift calibration. We focus spectroscopic efforts on undersampled regions of galaxy color space identified in previous work in order to minimize the number of spectroscopic redshifts needed to map the color-redshift relation to the required accuracy. We present the C3R2 survey strategy and initial results, including the 1283 high-confidence redshifts obtained in the 2016A semester and released as Data Release 1.
- ID:
- ivo://CDS.VizieR/J/A+A/382/184
- Title:
- Crystalline silicates around evolved stars
- Short Name:
- J/A+A/382/184
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first paper in a series of three where we present the first comprehensive inventory of solid state emission bands observed in a sample of 17 oxygen-rich circumstellar dust shells surrounding evolved stars. The data were taken with the Short and Long Wavelength Spectrographs on board of the Infrared Space Observatory (ISO) and cover the 2.4 to 195{mu}m wavelength range. The spectra show the presence of broad 10 and 18{mu}m bands that can be attributed to amorphous silicates. In addition, at least 49 narrow bands are found whose position and width indicate they can be attributed to crystalline silicates. Almost all of these bands were not known before ISO.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A91
- Title:
- CS 29497-004 abundances
- Short Name:
- J/A+A/607/A91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report an abundance analysis for the highly r-process-enhanced (r-II) star CS 29497-004, a very metal-poor giant with solar system Teff=5013K and [Fe/H]=-2.85, whose nature was initially discovered in the course of the HERES project. Our analysis is based on high signal-to-noise ratio, high-resolution (R~75000) VLT/UVES spectra and MARCS model atmospheres under the assumption of local thermodynamic equilibrium, and obtains abundance measurements for a total of 46 elements, 31 of which are neutron-capture elements. As is the case for the other ~25 r-II stars currently known, the heavy-element abundance pattern of CS 29497-004 well-matches a scaled solar system second peak r-process-element abundance pattern. We confirm our previous detection of Th, and demonstrate that this star does not exhibit an "actinide boost". Uranium is also detected (log{epsilon}(U)=-2.20+/-0.30), albeit with a large measurement error that hampers its use as a precision cosmochronometer. Combining the various elemental chronometer pairs that are available for this star, we derive a mean age of 12.2+/-3.7Gyr using the theoretical production ratios from published waiting-point approximation models. We further explore the high-entropy wind model (Farouqi et al., 2010ApJ...712.1359F) production ratios arising from different neutron richness of the ejecta (Ye), and derive an age of 13.7+/-4.4Gyr for a best-fitting Ye=0.447. The U/Th nuclei-chronometer is confirmed to be the most resilient to theoretical production ratios and yields an age of 16.5+/-6.6Gyr. Lead (Pb) is also tentatively detected in CS 29497-004, at a level compatible with a scaled solar r-process, or with the theoretical expectations for a pure r-process in this star.
