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1871. [O III] emission in 2 field-galaxy surveys
ID:
ivo://CDS.VizieR/J/AJ/95/1629
Title:
[O III] emission in 2 field-galaxy surveys
Short Name:
J/AJ/95/1629
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present emission-line strengths for 394 galaxies from the field-galaxy redshift surveys of Kirshner, Oemler, and Schechter (1978, Cat. <J/AJ/83/1549>, KOS) and Kirshner et al. (1983, Cat. <J/AJ/88/1285>, KOSS) as part of a study of the nature of field and void galaxies. These data are 95% complete in their coverage of the [O III]{lambda}{lambda}5007,4959 emission lines. We find that 8.8%+/-1.5% of a J magnitude-limited data set have [O III]{lambda}5007 emission equivalent widths greater than 10A. There is no evidence that the spatial distribution of emission-line galaxies in each field differs from that of galaxies without emission. However, there is a significant increase in the fraction of galaxies with strong [O III] emission in the southern fields of the Kirshner, Oemler, and Schechter (1978, Cat. <J/J/83/1549>) survey as compared with the other survey fields. Our results are consistent with the conclusion that the fraction of galaxies with emission is larger in the Bootes void than in the general field, but tighter constraints on the void normal galaxy population are needed to improve the statistics.
1872. [OII] nebular emission from MgII absorbers
ID:
ivo://CDS.VizieR/J/MNRAS/471/1910
Title:
[OII] nebular emission from MgII absorbers
Short Name:
J/MNRAS/471/1910
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present nebular emission associated with 198 strong Mg II absorbers at 0.35<=z<=1.1 in the fibre spectra of quasars from the Sloan Digital Sky Survey. Measured [OII] luminosities (L_[OII]_) are typical of sub-L* galaxies with derived star formation rate (uncorrected for fibre losses and dust reddening) in the range of 0.5-20M_{sun}_/yr. Typically less than ~3 per cent of the MgII systems with rest equivalent width, W_2796_>=2{AA}, show L_[OII]_>=0.3L*_[OII]_. The detection rate is found to increase with increasing W_2796_ and z. No significant correlation is found between W_2796_ and L_[OII]_ even when we restrict the samples to narrow z ranges. A strong correlation is seen between L_[OII]_ and z. While this is expected from the luminosity evolution of galaxies, we show that finite fibre size plays a very crucial role in this correlation. The measured nebular line ratios (like [OIII]/[OII] and [OIII]/H {beta}) and their z evolution are consistent with those of galaxies detected in deep surveys. Based on the median stacked spectra, we infer the average metallicity (logZ~8.3), ionization parameter (logq~7.5) and stellar mass (log (M/M_{sun}_)~9.3). The MgII systems with nebular emission typically have W_2796_>=2{AA}, MgII doublet ratio close to 1 and W(FeII{lambda}2600)/W_2796_~0.5 as often seen in damped Ly {alpha} and 21-cm absorbers at these redshifts. This is the biggest reported sample of [OII] emission from MgII absorbers at low-impact parameters ideally suited for probing various feedback processes at play in z<=1 galaxies.
1873. Old stellar populations. V.
ID:
ivo://CDS.VizieR/J/ApJS/94/687
Title:
Old stellar populations. V.
Short Name:
J/ApJS/94/687
Date:
21 Oct 2021
Publisher:
CDS
Description:
Twenty-one optical absorption features, 11 of which have been previously defined, are automatically measured in a sample of 460 stars. Following Gorgas et al., the indices are summarized in fitting functions that give index strengths as functions of stellar temperature, gravity, and [Fe/H]. This project was carried out with the purpose of predicting index strengths in the integrated light of stellar populations of different ages and metallicities, but the data should be valuable for stellar studies in the Galaxy as well. Several of the new indices appear to be promising indicators of metallicity for old stellar populations. A complete list of index data and atmospheric parameters is available in computer-readable form.
1874. Old Stellar Populations. VI. Absorption-Line
ID:
ivo://CDS.VizieR/J/ApJS/116/1
Title:
Old Stellar Populations. VI. Absorption-Line
Short Name:
J/ApJS/116/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present absorption-line strengths on the Lick/IDS line-strength system of 381 galaxies and 38 globular clusters in the 4000--6400 angstrom region. All galaxies were observed at Lick Observatory between 1972 and 1984 with the Cassegrain Image Dissector Scanner spectrograph, making this study one of the largest homogeneous collections of galaxy spectral line data to date. We also present a catalogue of nuclear velocity dispersions used to correct the absorption-line strengths onto the stellar Lick/IDS system. Extensive discussion of both random and systematic errors of the Lick/IDS system is provided. Indices are seen to fall into three families: alpha-element-like indices (including CN, Mg, Na D, and TiO2) that correlate positively with velocity dispersion; Fe-like indices (including Ca, the G band, TiO1, and all Fe indices) that correlate only weakly with velocity dispersion and the alpha indices; and Hbeta which anti-correlates with both velocity dispersion and the alpha indices. C2 4668 seems to be intermediate between the alpha and Fe groups. These groupings probably represent different element abundance families with different nucleosynthesis histories.
1875. OMC-2 FIR 3 and FIR 4 [OI] maps
ID:
ivo://CDS.VizieR/J/A+A/596/A26
Title:
OMC-2 FIR 3 and FIR 4 [OI] maps
Short Name:
J/A+A/596/A26
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first detection of a jet in the far-IR [OI] lines from an intermediate mass protostar. We have carried out a Herschel/PACS spectral mapping study in the [OI] lines of OMC-2 FIR 3 and FIR 4, two of the most luminous protostars in Orion outside of the Orion Nebula. The spatial morphology of the fine structure line emission reveals the presence of an extended photodissociation region (PDR) and a narrow, but intense jet emission connecting the two protostars. The jet seen in [OI] emission is spatially aligned with the Spitzer/IRAC 4.5um jet and the CO (6-5) molecular outflow centered on FIR 3. The mass loss rate derived from the total [OI] 63um line luminosity of the jet is 7.7*10^-6^M_{sun}_/yr, which is more than an order of magnitude higher than that measured for typical low mass class 0 protostars. The implied accretion luminosity is significantly higher than the observed bolometric luminosity of FIR 4, indicating that the [OI] jet is unlikely to be associated with FIR 4. We argue that the peak line emission seen toward FIR 4 originates in the terminal shock produced by the jet driven by FIR 3. The higher mass loss rate that we find for FIR 3 is consistent with the idea that intermediate mass protostars drive more powerful jets than their low-mass counterparts. Our results also call into question the nature of FIR 4.
1876. On the metallicity of open clusters. II.
ID:
ivo://CDS.VizieR/J/A+A/561/A93
Title:
On the metallicity of open clusters. II.
Short Name:
J/A+A/561/A93
Date:
21 Oct 2021
Publisher:
CDS
Description:
The literature was searched for [Fe/H] estimates of individual member stars of open clusters (OCs) based on the analysis of high-resolution spectra. The lower limit for spectral resolving power (R={lambda}/{Delta}{lambda}) was set to 25000, and the lower limit for signal-to-noise ratio was set to 50. We searched the PASTEL database (2010A&A...515A.111S, Cat. B/pastel) and the recent literature for such metallicity determinations in references posterior to 1990 and until June 2013. Only stars with an effective temperature lower than 7000K were included to avoid rapid rotators and chemical peculiarities. We eliminated confirmed non-members, spectroscopic binaries, and chemically peculiar stars and kept only stars with a high probability of membership. This resulted in a list of 571 stars in 86 OCs, with 830 metallicity determinations from 94 papers, which we call the starting sample.
1877. On the multiplicity of the O star Herschel 36
ID:
ivo://CDS.VizieR/J/ApJ/710/L30
Title:
On the multiplicity of the O star Herschel 36
Short Name:
J/ApJ/710/L30
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the analysis of high-resolution optical spectroscopic observations of the zero-age main-sequence O star Herschel 36 spanning six years. This star is definitely a multiple system, with at least three components detected in its spectrum. Based on our radial-velocity (RV) study, we propose a picture of a close massive binary and a more distant companion, most probably in wide orbit about each other. The orbital solution for the binary, whose components we identify as O9V and B0.5V, is characterized by a period of 1.5415+/-0.0006 days. With a spectral type O7.5V, the third body is the most luminous component of the system and also presents RV variations with a period close to 498 days. Some possible hypotheses to explain the variability are briefly addressed and further observations are suggested.
1878. OP Survey of Halo early-type stars
ID:
ivo://CDS.VizieR/J/AJ/106/591
Title:
OP Survey of Halo early-type stars
Short Name:
J/AJ/106/591
Date:
21 Oct 2021
Publisher:
CDS
Description:
The results are reported of an objective-prism survey of stars, mostly earlier than spectral type F5, for two fields at (l;b) = (90 deg and 270 deg; -45 deg). The fields, each of approximately 70 square degrees, are examined on plates taken with the Schmidt Telescope of the Anglo-Australian Observatory. The brightness range of the stars classified is 10 < V < 15. The prism combination used provides a dispersion of 600 A/mm at Hgamma. The spectral classification presented is defined by the equality of equivalent widths of Ca II K and Hdelta at type "F0" and the absence of Ca II K in stars with significant Balmer lines at type "A0". Positions listed in the catalog were measured on the Stromlo PDS microdensitometer. Most stars were subsequently identified with objects in the ST ScI-NASA-ESO Hubble Space Telescope Guide Star Catalog in which positions have an accuracy of near +/- 1.0 arcsec.
1879. Opt. follow-up of galaxies within S190814bv region
ID:
ivo://CDS.VizieR/J/ApJ/884/L55
Title:
Opt. follow-up of galaxies within S190814bv region
Short Name:
J/ApJ/884/L55
Date:
21 Oct 2021
Publisher:
CDS
Description:
On 2019 August 14 the Laser Interferometer Gravitational Wave Observatory (LIGO) and the Virgo gravitational wave interferometer announced the detection of a binary merger, S190814bv, with a low false alarm rate of about 1 in 1.6x10^25^yr, a distance of 267+/-52Mpc, a 90% (50%) localization region of about 23 (5) deg^2^, and a probability of being a neutron star-black hole (NS-BH) merger of >99%. The LIGO/Virgo Collaboration (LVC) defines NS-BH such that the lighter binary member has a mass of <3M_{sun}_ and the more massive one has >5M_{sun}_, and this classification is in principle consistent with a BH-BH merger depending on the actual upper mass cutoff for neutron stars. Additionally, the LVC designated a probability that the merger led to matter outside the final BH remnant of <1%, suggesting that an electromagnetic (EM) counterpart is unlikely. Here we report our optical follow-up observations of S190814bv using the Magellan Baade 6.5m telescope to target all 96 galaxies in the Galaxy List for the Advanced Detector Era catalog within the 50% localization volume (representing about 70% of the integrated luminosity within this region). No counterpart was identified to a median 3{sigma} limiting magnitude of i=22.2 (M_i_~-14.9mag), comparable to the brightness of the optical counterpart of the binary neutron star merger GW170817 at the distance of S190814bv; similarly, we can rule out an on-axis jet typical of short GRBs. However, we cannot rule out other realistic models, such as a kilonova with only ~0.01M_{sun}_ of lanthanide-rich material, or an off-axis jet with a viewing angle of {theta}_obs_>~15{deg}.
1880. Optical activity indicators
ID:
ivo://CDS.VizieR/J/A+A/627/A118
Title:
Optical activity indicators
Short Name:
J/A+A/627/A118
Date:
21 Oct 2021
Publisher:
CDS
Description:
Understanding stellar activity in solar-type stars is crucial for the physics of stellar atmospheres as well as for ongoing exoplanet programmes. We aim to test how well we understand stellar activity using our own star, the Sun, as a test case. We perform a detailed study of the main optical activity indicators (CaII H & K, Balmer lines, NaI D1, D2, and HeI D3 measured for the Sun using the data provided by the HARPS-N solar-telescope feed at the Telescopio Nazionale Galileo. We make use of periodogram analyses to study solar rotation, and we use the pool variance technique to study the temporal evolution of active regions. The correlations between the different activity indicators as well as the correlations between activity indexes and the derived parameters from the cross-correlation technique are analysed. We also study the temporal evolution of these correlations and their possible relationship with indicators of inhomogeneities in the solar photosphere like sunspot number or radio flux values. The value of the solar rotation period is found in all the activity indicators, with the only exception being H{delta}. The derived values vary from 26.29 days (H{gamma} line) to 31.23 days (HeI). From an analysis of sliding periodograms we find that in most of the activity indicators the spectral power is split into several "bands" of periods around 26 and 30 days, that might be explained by the migration of active regions between the equator and a latitude of ~30{deg}, spot evolution or a combination of both effects. In agreement with previous works a typical lifetime of active regions of ~ ten rotation periods is inferred from the pooled variance diagrams. We find that H{alpha}, H{beta}, H{gamma}, H{epsilon}, and HeI show a significant correlation with the S index. Significant correlations between the contrast, bisector span, and the heliocentric radial velocity with the activity indexes are also found. We show that the full width at half maximum, the bisector, and the disc-integrated magnetic field correlate with the radial velocity variations. The correlation of the S index and H{alpha} changes with time, increasing with larger sun spot numbers and solar irradiance. A similar tendency with the S index - radial velocity correlation is also present in the data. Our results are consistent with a scenario in which higher activity favours the correlation between the S index and the H{alpha} activity indicators and between the S index and radial velocity variations.

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