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14821. Stellar population synthesis of clumps
ID:
ivo://CDS.VizieR/J/ApJS/234/35
Title:
Stellar population synthesis of clumps
Short Name:
J/ApJS/234/35
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have identified 1027 star-forming complexes in a sample of 46 galaxies from the Spirals, Bridges, and Tails (SB&T) sample of interacting galaxies, and 693 star-forming complexes in a sample of 38 non-interacting spiral (NIS) galaxies in 8{mu}m observations from the Spitzer Infrared Array Camera. We have used archival multi-wavelength UV-to IR observations to fit the observed spectral energy distribution of our clumps with the Code Investigating GALaxy Emission using a double exponentially declined star formation history. We derive the star formation rates (SFRs), stellar masses, ages and fractions of the most recent burst, dust attenuation, and fractional emission due to an active galactic nucleus for these clumps. The resolved star formation main sequence holds on 2.5kpc scales, although it does not hold on 1kpc scales. We analyzed the relation between SFR, stellar mass, and age of the recent burst in the SB&T and NIS samples, and we found that the SFR per stellar mass is higher in the SB&T galaxies, and the clumps are younger in the galaxy pairs. We analyzed the SFR radial profile and found that the SFR is enhanced through the disk and in the tidal features relative to normal spirals.
14822. Stellar population trends in S0 galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/412/423
Title:
Stellar population trends in S0 galaxies
Short Name:
J/MNRAS/412/423
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present stellar population age and metallicity trends for a sample of 59 S0 galaxies based on optical Sloan Digital Sky Survey (SDSS) and near-infrared (NIR) J and H photometry. When combined with optical g and r passband imaging data from the SDSS archive and stellar population models, we obtain radial age and metallicity trends out to at least five effective radii for most of the galaxies in our sample. The sample covers a range in stellar mass and light concentration.
14823. Stellar proper motions in the Orion Nebula Cluster
ID:
ivo://CDS.VizieR/J/AJ/157/109
Title:
Stellar proper motions in the Orion Nebula Cluster
Short Name:
J/AJ/157/109
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Orion Nebula Cluster (ONC) is the nearest site of ongoing massive star formation, which allows us to study the kinematics and dynamics of the region in detail and constrain star formation theories. Using HST ACS/WFPC2/WFC3IR and Keck II NIRC2 data, we have measured the proper motions of 701 stars within an ~6'x6' field of view around the center of the ONC. We have found more than 10 escaping star candidates, concentrated predominantly at the core of the cluster. The proper motions of the bound stars are consistent with a normal distribution, albeit elongated north-south along the Orion filament, with proper-motion dispersions of ({sigma}_{mu},{alpha}_*, {sigma}_{mu},{delta}_)=(0.83+/-0.02, 1.12+/-0.03) mas/yr or intrinsic velocity dispersions of ({sigma}_v,{alpha}_*, {sigma}_v,{delta}_)=(1.57+/-0.04, 2.12+/-0.06) km/s assuming a distance of 400 pc to the ONC. The cluster shows no evidence for tangential-to-radial anisotropy. Our velocity dispersion profile agrees with the prediction from the observed stellar + gas density profile from Da Rio et al. (2014ApJ...795...55D, 2017ApJ...845..105D), indicating that the ONC is in virial equilibrium. This finding suggests that the cluster was formed with a low star formation efficiency per dynamical timescale based on comparisons with current star formation theories. Our survey also recovered high-velocity IR sources BN, x and n in the BN/KL region. The estimated location of the first two sources ~500 yr ago agrees with that of the radio source I, consistent with their proposed common origin from a multistellar disintegration. However, source n appears to have a small proper motion and is unlikely to have been involved in the event.
14824. Stellar properties for M dwarfs in MEarth-South
ID:
ivo://CDS.VizieR/J/AJ/156/217
Title:
Stellar properties for M dwarfs in MEarth-South
Short Name:
J/AJ/156/217
Date:
21 Oct 2021
Publisher:
CDS
Description:
Stellar rotation periods are valuable both for constraining models of angular momentum loss and for understanding how magnetic features impact inferences of exoplanet parameters. Building on our previous work in the northern hemisphere, we have used long-term, ground-based photometric monitoring from the MEarth Observatory to measure 234 rotation periods for nearby, southern hemisphere M dwarfs. Notable examples include the exoplanet hosts GJ 1132, LHS 1140, and Proxima Centauri. We find excellent agreement between our data and K2 photometry for the overlapping subset. Among the sample of stars with the highest quality data sets, we recover periods in 66%; as the length of the data set increases, our recovery rate approaches 100%. The longest rotation periods we detect are around 140 days, which we suggest represent the periods that are reached when M dwarfs are as old as the local thick disk (about 9 Gyr).
14825. Stellar properties of KIC stars
ID:
ivo://CDS.VizieR/J/MNRAS/475/5487
Title:
Stellar properties of KIC stars
Short Name:
J/MNRAS/475/5487
Date:
21 Oct 2021
Publisher:
CDS
Description:
Investigations of the origin and evolution of the Milky Way disc have long relied on chemical and kinematic identifications of its components to reconstruct our Galactic past. Difficulties in determining precise stellar ages have restricted most studies to small samples, normally confined to the solar neighbourhood. Here, we break this impasse with the help of asteroseismic inference and perform a chronology of the evolution of the disc throughout the age of the Galaxy. We chemically dissect the Milky Way disc population using a sample of red giant stars spanning out to 2 kpc in the solar annulus observed by the Kepler satellite, with the added dimension of asteroseismic ages. Our results reveal a clear difference in age between the low- and high-{alpha} populations, which also show distinct velocity dispersions in the V and W components. We find no tight correlation between age and metallicity nor [{alpha}/Fe] for the high-{alpha} disc stars. Our results indicate that this component formed over a period of more than 2 Gyr with a wide range of [M/H] and [{alpha}/Fe] independent of time. Our findings show that the kinematic properties of young {alpha}-rich stars are consistent with the rest of the high-{alpha} population and different from the low-{alpha} stars of similar age, rendering support to their origin being old stars that went through a mass transfer or stellar merger event, making them appear younger, instead of migration of truly young stars formed close to the Galactic bar.
14826. Stellar properties of Kron 3 stars
ID:
ivo://CDS.VizieR/J/MNRAS/476/114
Title:
Stellar properties of Kron 3 stars
Short Name:
J/MNRAS/476/114
Date:
02 Nov 2021 11:26:14
Publisher:
CDS
Description:
We present the results of a spectroscopic study of the intermediate age (~=6.5Gyr) massive cluster Kron 3 in the Small Magellanic Cloud. We measure CN and CH band strengths (at ~=3839 and 4300{AA}, respectively) using VLT FORS2 spectra of 16 cluster members and find a sub-population of five stars enriched in nitrogen. We conclude that this is evidence for multiple populations in Kron 3, the fourth intermediate age cluster, after Lindsay 1, NGC 416 and NGC 339 (ages 6-8Gyr), to display this phenomenon originally thought to be a unique characteristic of old globular clusters. At ~=6.5Gyr this is one of the youngest clusters with multiple populations, indicating that the mechanism responsible for their onset must operate until a redshift of at least 0.75, much later than the peak of globular cluster formation at redshift ~3.
14827. Stellar properties of M dwarfs
ID:
ivo://CDS.VizieR/J/A+A/620/A180
Title:
Stellar properties of M dwarfs
Short Name:
J/A+A/620/A180
Date:
21 Oct 2021
Publisher:
CDS
Description:
Being the most numerous and oldest stars in the galaxy, M dwarfs are objects of great interest for exoplanet searches. The presence of molecules in their atmosphere complicates our understanding of their atmospheric properties. But great advances have recently been made in the modeling of M dwarfs due to the revision of solar abundances. We aim to determine stellar parameters of M dwarfs using high resolution spectra (R~90000) simultaneously in the visible and the near-infrared. The high resolution spectra and broad wavelength coverage provide an unique opportunity to understand the onset of dust and cloud formation at cool temperatures. Furthermore, this study will help in understanding the physical processes which occur in a cool atmospheres, particularly, the redistribution of energy from the optical to the near-infrared. The stellar parameters of M dwarfs in our sample have been determined by comparing the high resolution spectra both in the optical and in the near-infrared simultaneously observed by CARMENES with the synthetic spectra obtained from the BT-Settl model atmosphere. The detailed spectral synthesis of these observed spectra both in the optical and in the near-infrared helps to understand the missing continuum opacity. For the first time, we derive fundamental stellar parameters of M dwarfs using the high resolution optical and near-infrared spectra simultaneously. We determine Teff, logg and [M/H] for 292 M dwarfs of spectral type M0 to M9, where the formation of dust and clouds are important. The derived Teff for the sample ranges from 2300 to 4000K, values of log g ranges from 4.5<=logg<=5.5 and the resulting metallicity ranges from -0.5<=[M/H]<=+0.5. We have also explored the possible differences in Teff, logg and [M/H] by comparing them with other studies of the same sample of M dwarfs.
14828. Stellar pulsators in the eclipsing binaries
ID:
ivo://CDS.VizieR/J/A+A/630/A106
Title:
Stellar pulsators in the eclipsing binaries
Short Name:
J/A+A/630/A106
Date:
21 Oct 2021
Publisher:
CDS
Description:
Eclipsing binaries (EBs) are unique targets for measuring precise stellar properties and can be used to constrain stellar evolution models. In particular, it is possible to measure masses and radii of both components of a double-lined spectroscopic EB at the percent level. Since the advent of high-precision photometric space missions (MOST, CoRoT, Kepler, BRITE, TESS), the use of stellar pulsation properties to infer stellar interiors and dynamics constitutes a revolution for studies of low-mass stars. The Kepler mission has led to the discovery of thousands of classical pulsators such as {delta} Scuti and solar-like oscillators (main sequence and evolved), but also almost 3000 EBs with orbital periods shorter than 1100 days. We report the first systematic search for stellar pulsators in the entire Kepler EB catalog. The focus is mainly aimed at discovering {delta} Scuti, {gamma} Doradus, red giant, and tidally excited pulsators. We developed a data inspection tool (DIT) that automatically produces a series of plots from the Kepler light curves that allows us to visually identify whether stellar oscillations are present in a given time series. We applied the DIT to the whole Kepler EB database and identified 303 systems whose light curves display oscillations, including 163 new discoveries. A total of 149 stars are flagged as {delta} Scuti (100 from this paper), 115 as {gamma} Doradus (69 new), 85 as red giants (27 new), and 59 as tidally excited oscillators (29 new). There is some overlap among these groups, as some display several types of oscillations. Despite the likelihood that many of these systems are false positives, for example, when an EB light curve is blended with a pulsator, this catalog gathers a vast sample of systems that are valuable for a better understanding of stellar evolution.
14829. Stellar Radial Velocities 1991-1998
ID:
ivo://CDS.VizieR/III/216
Title:
Stellar Radial Velocities 1991-1998
Short Name:
III/216
Date:
21 Oct 2021
Publisher:
CDS
Description:
The present catalogue is the third version and supersedes the first one (1991-1994) published by Malaroda et al. (2000A&AS..144....1M, Cat. <III/204>). We have revised the issues of the journals listed in Table 1, for the period 1991-1998. It is not a complete list of all journals devoted to astronomical literature, but they are the most important ones and those available at our libraries. We prepared a plain ASCII file with the object identifications as provided by the authors. This file was transferred to the SIMBAD database, and, using the proper formats and filters, we have retrieved the identification for each object according to the rules of SIMBAD. In the same way we have also retrieved: the J2000 coordinates, the V magnitude, and the spectral classification for each object.
14830. Stellar radial velocities bibliographic catalog
ID:
ivo://CDS.VizieR/III/249
Title:
Stellar radial velocities bibliographic catalog
Short Name:
III/249
Date:
22 Feb 2022
Publisher:
CDS
Description:
The present catalogue is the twelfth version and the continuation of the first one (1991-1994) published by Malaroda et al. (2000A&AS..144....1M). Since the 2005 version, we present the catalogue in a database for helping the search. We have revised the issues of the journals listed in Table 1, for the period 1991-2006June. It is not a complete list of all journals devoted to astronomical literature, but they are the most important ones and those available at our libraries. We prepared a plain ASCII file with the object identifications as provided by the authors. This file was transferred to the SIMBAD database, and, using the proper for mats and filters, we have retrieved the identification for each object according to the rules of SIMBAD. In the same way we have also retrieved: the J2000 coordinates, the V magnitude, and the spectral classification for each object.

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