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771. Equivalent widths of 8 DIBs for 186 O & B stars
ID:
ivo://CDS.VizieR/J/ApJ/850/194
Title:
Equivalent widths of 8 DIBs for 186 O & B stars
Short Name:
J/ApJ/850/194
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the behavior of eight diffuse interstellar bands (DIBs) in different interstellar environments, as characterized by the fraction of hydrogen in molecular form (f_H2_), with comparisons to the corresponding behavior of various known atomic and molecular species. The equivalent widths of the five "normal" DIBs ({lambda}{lambda}5780.5, 5797.1, 6196.0, 6283.8, and 6613.6), normalized to E_B-V_, show a "lambda-shaped" behavior: they increase at low f_H2_, peak at f_H2_~0.3, and then decrease. The similarly normalized column densities of Ca, Ca+, Ti+, and CH+ also decline for f_H2_>0.3. In contrast, the normalized column densities of Na, K, CH, CN, and CO increase monotonically with fH2, and the trends exhibited by the three C_2_ DIBs ({lambda}{lambda}4726.8, 4963.9, and 4984.8) lie between those two general behaviors. These trends with f_H2_ are accompanied by cosmic scatter, the dispersion at any given f_H2_ being significantly larger than the individual errors of measurement. The lambda-shaped trends suggest the balance between creation and destruction of the DIB carriers differs dramatically between diffuse atomic and diffuse molecular clouds; additional processes aside from ionization and shielding are needed to explain those observed trends. Except for several special cases, the highest W{lambda}(5780)/W{lambda}(5797) ratios, characterizing the so-called "sigma-zeta effect," occur only at f_H2_<0.2. We propose a sequence of DIBs based on trends in their pair-wise strength ratios with increasing f_H2_. In order of increasing environmental density, we find the {lambda}6283.8 and {lambda}5780.5 DIBs, the {lambda}6196.0 DIB, the {lambda}6613.6 DIB, the {lambda}5797.1 DIB, and the C_2_ DIBs.
772. Equivalent widths of giants in the GC NGC3201
ID:
ivo://CDS.VizieR/J/ApJ/887/91
Title:
Equivalent widths of giants in the GC NGC3201
Short Name:
J/ApJ/887/91
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Hubble Space Telescope (HST) UV Legacy Survey of Galactic Globular Clusters (GCs) has investigated multiple stellar populations by means of the "chromosome map" (ChM) diagnostic tool that maximizes the separation between stars with different chemical compositions. One of the most challenging features revealed by ChM analysis is the apparent inhomogeneity among stars belonging to the first population, a phenomenon largely attributed to He variations. However, this explanation is not supported by uniformity in the p-capture elements of these stars. The HST survey has revealed that the GC NGC 3201 shows exceptionally wide coverage in the {Delta}_F275W,F814W_ parameter of the ChM. We present a chemical abundance analysis of 24 elements in 18 giants belonging to the first population of this GC and having a wide range in {Delta}_F275W,F814W_. As far as the p-capture elements are concerned, the chemical abundances are typical of first-generation (1G) stars, as expected from the location of our targets in the ChM. Based on radial velocities and chemical abundance arguments, we find that the three stars with the lowest {Delta}_F275W,F814W_ values are binary candidates. This suggests that at least those stars could be explained with binarity. These results are consistent with evidence inferred from multiband photometry that evolved blue stragglers (BSs) populate the bluest part of the 1G sequence in the ChM. The remaining 15 spectroscopic targets show a small range in the overall metallicity by ~0.10dex, with stars at higher {Delta}_F275W,F814W_ values having higher absolute abundances. We suggest that a small variation in metals and binarity governs the color spread of the 1G in the ChM and that evolved BSs contribute to the bluest tail of the 1G sequence.
773. Equivalent widths of 9 RGB in Carina dSph
ID:
ivo://CDS.VizieR/J/ApJ/751/102
Title:
Equivalent widths of 9 RGB in Carina dSph
Short Name:
J/ApJ/751/102
Date:
21 Oct 2021
Publisher:
CDS
Description:
The detailed abundances of 23 chemical elements in nine bright red giant branch stars in the Carina dwarf spheroidal galaxy are presented based on high-resolution spectra gathered at the Very Large Telescope (VLT) and Magellan telescopes. A spherical model atmospheres analysis is applied using standard methods (local thermodynamic equilibrium and plane-parallel radiative transfer) to spectra ranging from 380 to 680nm. Stellar parameters are found to be consistent between photometric and spectroscopic analyses, both at moderate and high resolution. The stars in this analysis range in metallicity from -2.9<[Fe/H]<-1.3, and adopting the ages determined by Lemasle et al. (Cat. J/A+A/538/A100), we are able to examine the chemical evolution of Carina's old and intermediate-aged populations.
774. Equivalent widths of VMF73 and VMF74 galaxies
ID:
ivo://CDS.VizieR/J/A+A/421/59
Title:
Equivalent widths of VMF73 and VMF74 galaxies
Short Name:
J/A+A/421/59
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a spectroscopic analysis of two galaxy clusters out to ~4Mpc at z~0.2. The two clusters VMF73 and VMF74 identified by Vikhlinin et al. (1998, Cat. <J/ApJ/502/558>) were observed with MOSCA at the Calar Alto 3.5m telescope. Both clusters lie in the ROSAT PSPC field R285 and were selected from the X-ray Dark Cluster Survey (Gilbank et al., 2004MNRAS.348..551G) that provides optical V- and I-band data. VMF73 and VMF74 are located at respective redshifts of z=0.25 and z=0.18 with velocity dispersions of 671km/s and 442km/s, respectively. The spectroscopic observations reach out to ~2.5 virial radii. Line strength measurements of the emission lines H_alpha and [OII]3727 are used to assess the star formation activity of cluster galaxies which show radial and density dependences. The mean and median of both line strength distributions as well as the fraction of star forming galaxies increase with increasing clustercentric distance and decreasing local galaxy density. Except for two galaxies with strong H_alpha and [OII] emission, all of the cluster galaxies are normal star forming or passive galaxies. Our results are consistent with other studies that show the truncation in star formation occurs far from the cluster centre.
775. EREBOS project. I.
ID:
ivo://CDS.VizieR/J/A+A/630/A80
Title:
EREBOS project. I.
Short Name:
J/A+A/630/A80
Date:
21 Oct 2021
Publisher:
CDS
Description:
Eclipsing post-common-envelope binaries are highly important for resolving the poorly understood, very short-lived common-envelope phase of stellar evolution. Most hot subdwarfs (sdO/Bs) are the bare helium-burning cores of red giants that have lost almost all of their hydrogen envelope. This mass loss is often triggered by common-envelope interactions with close stellar or even substellar companions. Cool companions to hot subdwarf stars such as late-type stars and brown dwarfs are detectable from characteristic light-curve variations - reflection effects and often eclipses. In the recently published catalog of eclipsing binaries in the Galactic Bulge and in the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey, we discovered 125 new eclipsing systems showing a reflection effect seen by visual inspection of the light curves and using a machine-learning algorithm, in addition to the 36 systems previously discovered by the Optical Gravitational Lesing Experiment (OGLE) team. The Eclipsing Reflection Effect Binaries from Optical Surveys (EREBOS) project aims at analyzing all newly discovered eclipsing binaries of the HW Vir type (hot subdwarf + close, cool companion) based on a spectroscopic and photometric follow up to derive the mass distribution of the companions, constrain the fraction of substellar companions, and determine the minimum mass needed to strip off the red-giant envelope. To constrain the nature of the primary we derived the absolute magnitude and the reduced proper motion of all our targets with the help of the parallaxes and proper motions measured by the Gaia mission and compared those to the Gaia white-dwarf candidate catalog. It was possible to derive the nature of a subset of our targets, for which observed spectra are available, by measuring the atmospheric parameter of the primary, confirming that less than 10% of our systems are not sdO/Bs with cool companions but are white dwarfs or central stars of planetary nebula. This large sample of eclipsing hot subdwarfs with cool companions allowed us to derive a significant period distribution for hot subdwarfs with cool companions for the first time showing that the period distribution is much broader than previously thought and is ideally suited to finding the lowest-mass companions to hot subdwarf stars. The comparison with related binary populations shows that the period distribution of HW Vir systems is very similar to WD+dM systems and central stars of planetary nebula with cool companions. In the future, several new photometric surveys will be carried out, which will further increase the sample of this project, providing the potential to test many aspects of common-envelope theory and binary evolution.
776. EROS-2 Long Period Variables in LMC
ID:
ivo://CDS.VizieR/J/A+A/536/A60
Title:
EROS-2 Long Period Variables in LMC
Short Name:
J/A+A/536/A60
Date:
21 Oct 2021
Publisher:
CDS
Description:
The EROS-2 survey has produced a database of millions of time series from stars monitored for more than six years, allowing us to classify some of their sources into different variable star types. Among the so-called, long period variables (LPVs), which are known to follow particular sequences in the period-luminosity diagram, we find long secondary period variables whose variability origin remains a matter of debate. We analyze data for the 856864 variable stars that have been discovered in the Large Magellanic Cloud (LMC) that are present in the EROS-2 database, to detect, classify, and characterize LPVs.
777. ESIS BVR catalog, ELAIS-S1
ID:
ivo://CDS.VizieR/J/A+A/451/881
Title:
ESIS BVR catalog, ELAIS-S1
Short Name:
J/A+A/451/881
Date:
21 Oct 2021
Publisher:
CDS
Description:
The ESO-Spitzer extragalactic Imaging Survey (ESIS) is the optical follow up of the Spitzer Wide-Area InfraRed Extragalactic (SWIRE) survey in the ELAIS-S1 area. The multiwavelength study of galaxy emission is the key to understand the interplay of the various components of galaxies and to trace their role in cosmic evolution. ESIS provides optical identification and colors of Spitzer IR galaxies and builds the bases for photometric redshift estimates. This paper presents B, V, R Wide Field Imager observations of the first 1.5 square degree of the ESIS survey. Data reduction includes astrometric calibration, illumination and color corrections. Synthetic sources are simulated in scientific and super-sky-flat images, with the purpose of estimating completeness and photometric accuracy for the survey. Number counts and color distributions are compared to literature observational and theoretical data, including non-evolutionary, PLE, evolutionary and semi-analytic Lambda-CDM galaxy models, as well as Milky Way stellar predictions. Object coordinates are defined with an accuracy as good as ~0.15" rms with respect to GSC 2.2; flux uncertainties are ~2, 10, 20% at mag. 20, 23, 24 respectively (Vega); we reach 95% completeness at B, V~25 and R~24.5. ESIS galaxy number counts are in good agreement with previous works and are best reproduced by evolutionary and hierarchical Lambda-CDM scenarios.
778. ESO Distant Cluster Survey, EDisCS
ID:
ivo://CDS.VizieR/J/A+A/444/365
Title:
ESO Distant Cluster Survey, EDisCS
Short Name:
J/A+A/444/365
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the ESO Distant Cluster Survey (EDisCS) a survey of 20 distant galaxy clusters with redshifts ranging from 0.4 to 0.8. Candidate clusters were chosen from among the brightest objects identified in the Las Campanas Distant Cluster Survey (LCDCS), half with estimated redshift z_est_~0.5 and half with z_est_~0.8. They were confirmed by identifying red sequences in moderately deep two colour data from VLT/FORS2. For confirmed candidates we have assembled deep three-band optical photometry using VLT/FORS2, deep near-infrared photometry in one or two bands using NTT/SOFI, deep optical spectroscopy using VLT/FORS2, wide field imaging in two or three bands using the ESO Wide Field Imager, and HST/ACS mosaic images for 10 of the most distant clusters. This first paper presents our sample and the VLT photometry we have obtained. We present images, colour magnitude diagrams and richness estimates for our clusters, as well as giving redshifts and positions for the brightest cluster members. Subsequent papers will present our infrared photometry, spectroscopy, HST and wide-field imaging, as well as a wealth of further analysis and science results. Our reduced data become publicly available as these papers are accepted.
779. ESO 362-G18 datacube
ID:
ivo://CDS.VizieR/J/A+A/614/A94
Title:
ESO 362-G18 datacube
Short Name:
J/A+A/614/A94
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present two-dimensional stellar and gaseous kinematics of the inner 0.7x1.2kpc^2^ of the Seyfert 1.5 galaxy ESO 362-G18, derived from optical (4092-7338{AA}) spectra obtained with the GMOS integral field spectrograph on the Gemini South telescope at a spatial resolution of 170 pc and spectral resolution of 36km/s. ESO 362-G18 is a strongly perturbed galaxy of morphological type Sa or S0/a, with a minor merger approaching along the NE direction. Previous studies have shown that the [OIII] emission shows a fan-shaped extension of ~10" to the SE. We detect the [OIII] doublet, [NII] and H{alpha} emission lines throughout our FOV. The stellar kinematics is dominated by circular motions in the galaxy plane, with a kinematic position angle of ~137{deg} and is centred approximately on the continuum peak. The gas kinematics is also dominated by rotation, with kinematic position angles ranging from 122{deg} to 139{deg}, projected velocity amplitudes of the order of 100km/s, and a mean velocity dispersion of 100km/s. A double-Gaussian fit to the [OIII]{lambda}5007 and H{alpha} lines, which have the highest signal to noise ratios of the emission lines, reveal two kinematic components: (1) a component at lower radial velocities which we interpret as gas rotating in the galactic disk; and (2) a component with line of sight (LOS) velocities 100-250km/s higher than the systemic velocity, interpreted as originating in the outflowing gas within the AGN ionization cone. We estimate a mass outflow rate of 7.4x10^-2^M_{sun}_/yr in the SE ionization cone (this rate doubles if we assume a biconical configuration), and a mass accretion rate on the supermassive black hole (SMBH) of 2.2x10^-2^M_{sun}_/yr. The total ionized gas mass within 84pc of the nucleus is 3.3x10^5^M_{sun}_; infall velocities of ~34km/s in this gas would be required to feed both the outflow and SMBH accretion.
780. ESO Imaging Survey. CDF-S point sources
ID:
ivo://CDS.VizieR/J/A+A/384/81
Title:
ESO Imaging Survey. CDF-S point sources
Short Name:
J/A+A/384/81
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper describes the methodology currently being implemented in the EIS pipeline for analysing optical/infrared multi-colour data. The aim is to identify different classes of objects as well as possible undesirable features associated with the construction of colour catalogues. The tools developed are used for a preliminary analysis of the multi-colour point source catalogue constructed from the optical/infrared imaging data obtained for the Chandra Deep Field South (CDF-S). These data are publicly available, representing the first installment of the ongoing EIS Deep Public Survey.