Context: In our Paper I, by using statistical deconvolution methods, extended kinematics maps of Gaia-DR2 data have been produced in a range of heliocentric distances that are a factor of two to three larger than those analyzed previously by the Gaia Collaboration with the same data. It added the range of Galactocentric distances between 13 kpc and 20 kpc to the previous maps.
Aims: Here, we investigate the dynamical effects produced by different mechanisms that can explain the radial and vertical components of these extended kinematic maps, including a decomposition of bending and breathing of the vertical components. This paper as a whole tries to be a compendium of different dynamical mechanisms whose predictions can be compared to the kinematic maps.
Methods: Using analytical methods or simulations, we are able to predict the main dynamical factors and compare them to the predictions of the extended kinematic maps of Gaia-DR2.
Results: The gravitational influence of Galactic components that are different from the disk, such as the long bar or bulge, the spiral arms, or a tidal interaction with Sagittarius dwarf galaxy, may explain some features of the velocity maps, especially in the inner parts of the disk. However, they are not sufficient in explaining the most conspicuous gradients in the outer disk. Vertical motions might be dominated by external perturbations or mergers, although a minor component may be due to a warp whose amplitude evolves with time. Here, we show with two different methods, which analyze the dispersion of velocities, that the mass distribution of the disk is flared. Despite these partial explanations, the main observed features can only be explained in terms of out-of-equilibrium models, which are either due to external perturbers or to the fact that the disk has not had time to reach equilibrium since its formation.
The kinematical parameters, spatial shape and structure of the open cluster IC 2391 and the associated stellar stream are studied here using Gaia-DR2 (GDR2) astrometry data. The apex positions are determined for the open cluster IC 2391 (data taken from Cantat-Gaudin et al.) and for the kinematical streams stars mentioned in Montes et al. using both convergent point and AD-diagram methods. The values of apex coordinates identified. The results are in good agreement with the previously calculated values. The positions of the stars in the disk and the spatial dispersion velocities are determined…
Using a numerical simulation of an isolated barred disc galaxy, we first demonstrate that the resonances of the inner bar structure induce more prominent features in the action space distribution for the kinematically hotter stars, which are less sensitive to the local perturbation, such as the transient spiral arms. Then, we analyse the action distribution for the kinematically hotter stars selected from the Gaia EDR3 data as the stars with higher values of radial and vertical actions. We find several resonance features, including two new features, in the angular momentum distribution similar…
CONTEXT. The Gaia Collaboration has used Gaia-DR2 sources with six-dimensional (6D) phase space information to derive kinematical maps within 5 kpc of the Sun, which is a reachable range for stars with relative error in distance lower than 20%. AIMS. Here we aim to extend the range of distances by a factor of two to three, thus adding the range of Galactocentric distances between 13 kpc and 20 kpc to the previous maps, with their corresponding error and root mean square values. METHODS. We make use of the whole sample of stars of Gaia-DR2 including radial velocity measurements, which consists …
The work on the kinematical parameters and spatial shape structure have been performed with Gaia DR2 astrometry data of the new recently southern discovered open clusters; UFMG 1, UFMG 2, and UFMG 3 in the vicinity (1.3 degrees radius) of the rarely studied NGC 5999. The apexes positions with AD-diagram method are computed for about 107, 168, 98, and 154 members of these star clusters, respectively, our calculated values of apex coordinates, seems like: (A, D) = (102.40 +/- 1.02 & -4.60 +/- 0.47; NGC 5999), (96.69 +/- 1.10 & -0.58 +/- 0.045; UFMG 1), (97.47 +/- 1.09 & 1.56 +/- 0.051; UFMG 2), …
Recent results using radial-velocity measurements from the Gaia-ESO Survey have led to the discovery of multiple kinematic populations across the Vela OB2 association. We present here a proper-motion study of the same region. Our aim is to test whether the radial-velocity populations have a counterpart in proper-motion space, and if so, how the two sets of kinematical data complement each other. This work is based on parallaxes and proper motions from the TGAS catalog, as part of Gaia DR1. Two distinct proper-motion populations are found dispersed across ~5 degrees (or ~30 pc at their likely d…
Recent statistical deconvolution methods have produced extended kinematical maps in a range of heliocentric distances that are a factor of two to three larger than those analysed in the Gaia Collaboration based on the same data. In this paper, we use such maps to derive the rotation curve both in the Galactic plane and in off-plane regions and to analyse the density distribution. By assuming stationary equilibrium and axisymmetry, we used the Jeans equation to derive the rotation curve. Then we fit it with density models that include both dark matter and predictions of the MOND (Modified Newto…
We present a detailed analysis of kinematics of the Milky Way disk in solar neighborhood using GAIA DR3 catalog. To determine the local kinematics of the stellar disks of the Milky Way galaxy we use a complete sample of 278,228 red giant branch (RGB) stars distributed in a cylinder, centered at the Sun with a 1 kpc radius and half-height of 0.5 kpc. We determine separately the kinematical properties of RGB stars for each Galactic hemisphere in search for possible asymmetries. The kinematical properties of the RGB stars reveal the existence of two kinematically distinct components: the thin dis…
IC 166 is an intermediate-age open cluster ($\sim 1$ Gyr) which lies in the transition zone of the metallicity gradient in the outer disc. Its location, combined with our very limited knowledge of its salient features, make it an interesting object of study. We present the first high-resolution spectroscopic and precise kinematical analysis of IC 166, which lies in the outer disc with $R_{GC} \sim 12.7$ kpc. High resolution \textit{H}-band spectra were analyzed using observations from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. We made use of the Brussel…
High-Mass X-ray Binaries (HMXBs) are produced after the first supernova event in a massive binary. These objects are intrinsically young, and can suffer from a significant natal kick. As such, the progenitors of HMXBs are likely to have formed away from the current location of the X-ray emitting systems. We aim to find the birthplace of the known HMXBs of our Milky Way. Specifically, we want to answer the question whether the formation of HMXBs can be associated to open stellar clusters and/or Galactic spiral structures, and infer from that the time elapsed since the first supernova event. We …
We have learned recently that the inner halo of the Milky Way contains a kinematically coherent component (Gaia-Enceladus) from a significant merger 10 Gyrs ago. By contrast the inner halo (defined to exclude the Magellanic Stream) contains no similar intruder stellar population of billion year age. The tracer we use to set the corresponding upper limit is Gaia asymptotic giant branch stars, rather than Gaia kinematics. The primary sample is drawn from Gaia DR2 with SkyMapper photometry. This is supplemented with PanSTARRS and 2MASS photometry. As the Gaia mission proceeds, a star formation hi…
This study reports the first comprehensive astrometric, photometric and kinematical analysis of four newly discovered open clusters; namely QC1, QC2, QC3, and QC4, using astrometric and photometric data from the most recent Gaia EDR3 for G<17 mag. Utilizing the ASteCA code, we identified the most probable (P>=50%) star candidates and found the numbers of star members (N) to be 118 (QC1), 142(QC2), 210 (QC3), and 110 (QC4). By fitting King's density profile to the cluster's RDPs, we found the internal structural parameters of each cluster such as the cluster radii that are in the range 7.00 to …
We present a photometric and kinematical analysis of two and poorly studied open clusters; Koposov 12 (FSR 802) and Koposov 43 (FSR 848) by using cross-matched data from PPMXL and Gaia DR2 catalog. We use astrometric parameters to identify 285 and 310 cluster members for Koposov 12 and Koposov 43, respectively. Using the extracted member candidates and isochrone fitting to near-infrared (J, H, Ks) and Gaia DR2 bands (G, GBP, GRP), and Color Magnitude Diagrams (CMDs), we have estimated ages: log (age/yr) = 9.00 +/- 0.20 and 9.50 +/- 0.20, and distances d = 1850 +/- 43 pc and 2500 +/- 50 pc for …
We present a study of the membership of the Hyades open cluster, derive kinematically-modelled parallaxes of its members, and study the colour-absolute magnitude diagram of the cluster. We use Gaia DR1 Tycho-Gaia Astrometric Solution (TGAS) data complemented by Hipparcos-2 data for bright stars not contained in TGAS. We supplement the astrometric data with radial velocities collected from a dozen literature sources. By assuming that all cluster members move with the mean cluster velocity to within the velocity dispersion, we use the observed and the expected motions of the stars to determine i…
Context. The origin and dynamical evolution of star clusters is an important topic in stellar astrophysics. Several models have been proposed to understand the formation of bound and unbound clusters and their evolution, and these can be tested by examining the kinematical and dynamical properties of clusters over a wide range of ages and masses. Aims. We use the Gaia-ESO Survey products to study four open clusters (IC 2602, IC 2391, IC 4665, and NGC 2547) that lie in the age range between 20 and 50 Myr. Methods. We employ the gravity index $γ$ and the equivalent width of the lithium line at 6…
We propose an extension of the GC3 streamer finding method of Johnston et al. 1996 that can be applied to the future Gaia database. The original method looks for streamers along great circles in the sky, our extension adds the kinematical restriction that velocity vectors should also be constrained to lie along these great circles, as seen by a Galactocentric observer. We show how to use these combined criteria starting from heliocentric observables. We test it by using the mock Gaia catalogue of Brown et al. 2005, which includes a realistic Galactic background and observational errors, but wi…
Our location in the Milky Way provides an exceptional opportunity to gain insight on the galactic evolution processes, and complement the information inferred from observations of external galaxies. Since the Milky Way is a barred galaxy, the study of motions of individual stars in the bulge and disc is useful to understand the role of the bar. The Gaia mission enables such study by providing the most precise parallaxes and proper motions to date. In this theoretical work, we explore the effects of the bar on the distribution of higher-order moments --the skewness and kurtosis-- of the proper …
This article discusses the physical and kinematical characteristics of planetary nebulae accompanying PG1159 central stars. The study is based on the parallax and proper motion measurements recently offered by Gaia space mission. Two approaches were used to investigate the kinematical properties of the sample. The results revealed that most of the studied nebulae arise from progenitor stars of mass range; $0.9-1.75$\,M$_{\odot}$. Furthermore, they tend to live within the Galactic thick-disk and moving with an average peculiar velocity of $61.7\pm19.2$\,km\,s$^{-1}$ at a mean vertical height of…
We have derived accurate distances to Galactic globular clusters by combining data from the Gaia Early Data Release 3 with distances based on Hubble Space telescope HST data and literature based distances. We determine distances either directly from the Gaia EDR3 parallaxes, or kinematically by combining line-of-sight velocity dispersion profiles with Gaia EDR3 and HST based proper motion velocity dispersion profiles. We furthermore calculate cluster distances from fitting nearby subdwarfs, whose absolute luminosities we determine from their Gaia EDR3 parallaxes, to globular cluster main-seque…
We identify members of 65 open clusters in the solar neighborhood using the machine-learning algorithm StarGO based on Gaia EDR3 data. After adding members of twenty clusters from previous studies (Pang et al. 2021a,b; Li et al. 2021) we obtain 85 clusters, and study their morphology and kinematics. We classify the substructures outside the tidal radius into four categories: filamentary (f1) and fractal (f2) for clusters $<100$ Myr, and halo (h) and tidal-tail (t) for clusters $>100$ Myr. The kinematical substructures of f1-type clusters are elongated; these resemble the disrupted cluster Grou…
We explore the phase-space structure of nearby halo stars identified kinematically from Gaia DR2 data. We focus on their distribution in velocity and in "integrals of motion" space as well as on their photometric properties. Our sample of stars selected to be moving at a relative velocity of at least 210 km/s with respect to the Local Standard of Rest, contains an important contribution from the low rotational velocity tail of the disk(s). The $V_R$-distribution of these stars depicts a small asymmetry similar to that seen for the faster rotating thin disk stars near the Sun. We also identify …
Gaia-ESO Survey observations of the young Gamma Velorum cluster led to the discovery of two kinematically-distinct populations, Gamma Vel A and B, respectively, with population B extended over several square degrees in the Vela OB2 association. Using the Gaia DR2 data for a sample of high-probability cluster members, we find that the two populations differ not only kinematically, but are also located at different distances along the line of sight, with the main cluster Gamma Vel A being closer. A combined fit of the two populations yields $\varpi_A = 2.895 \pm 0.008$ mas and $\varpi_B = 2.608 …
We present a comprehensive analysis (photometric and kinematical) of poorly studied open cluster NGC 4337 using 2MASS, WISE, APASS, and Gaia~DR2 database. By determining the membership probabilities of stars, we identified 624 most probable members with membership probability higher than $50\%$ by using proper motion and parallax data taken from Gaia~DR2. The mean proper motion of the cluster is obtained as $μ_{x}=-8.83\pm0.01$ and $μ_{y}=1.49\pm0.006$ mas yr$^{-1}$. We find the normal interstellar extinction towards the cluster region. The radial distribution of members provides a cluster rad…
Based on the first Gaia data release and spectroscopy from the LAMOST Data Release 4, we study the kinematics and chemistry of the local halo stars. The halo stars are identified kinematically with a relative speed of at least 220 km s$^{-1}$ with respect to the local standard of rest. In total, 436 halo stars are identified. From this halo sample, 16 high velocity (HiVel) stars are identified. We studied the metallicity and [$α$/Fe] distribution of these HiVel stars. Though most of HiVel stars are metal-poor, there are several stars that have metallicity above $-0.5$ dex. To understand the or…
Context. We have compiled a catalogue of central stars of planetary nebulae (CSPN) with reliable distances and positions obtained from Gaia Data Release 2 (DR2) astrometry. Distances derived from parallaxes allow us to analyse the galactic distribution and estimate other parameters such as sizes, kinematical ages, bolometric magnitudes, and luminosities. Aims. Our objective is to analyse the information regarding distances together with other available literature data about photometric properties, nebular kinematics, and stellar effective temperatures to throw new light on this rapid and rathe…
Stars form in spatially and temporarily correlated star formation events (CSFEs) and the dynamical processes within these "embedded clusters" leave imprints in the stellar populations in galactic fields. Such imprints are correlations in phase space (e.g. gravitationally bound star clusters, tidal streams), in the binary properties of stars and in the present-day stellar mass functions in the surviving clusters. The dynamical processes include expulsion of massive stars from cluster cores, disruption of CSFEs due to residual gas expulsion and energy-equipartition driven evaporation of stars fr…
While the precise relationship between the Milky Way disk and the symmetry planes of the dark matter halo remains somewhat uncertain, a time-varying disk orientation with respect to an inertial reference frame seems probable. Hierarchical structure formation models predict that the dark matter halo is triaxial and tumbles with a characteristic rate of ~2 rad/Hubble time (~30 muas/yr). These models also predict a time-dependent accretion of gas, such that the angular momentum vector of the disk should be misaligned with that of the halo. These effects, as well as tidal effects of the LMC, will …
We use the first Gaia data release, combined with RAVE and APOGEE spectroscopic surveys, to investigate the origin of halo stars within <~3 kpc from the Sun. We identify halo stars kinematically, as moving with a relative speed of at least 220 km/s with respect to the local standard of rest. These stars are in general more metal-poor than the disk, but surprisingly, half of our halo sample is comprised of stars with [Fe/H]>-1. The orbital directions of these metal-rich halo stars are preferentially aligned with the disk rotation, in sharp contrast with the isotropic orbital distribution of the…
The second release of Gaia data (Gaia DR2) contains the astrometric parameters for more than half a million quasars. This set defines a kinematically non-rotating reference frame in the optical domain referred to as the Gaia-CRF2. The Gaia-CRF2 is the first realisation of a non-rotating global optical reference frame that meets the ICRS prescriptions, meaning that it is built only on extragalactic sources. It consists of the positions of a sample of 556 869 sources in Gaia DR2, obtained from a positional cross-match with the ICRF3-prototype and AllWISE AGN catalogues. The sample constitutes a …
We employ Gaia DR2 proper motions for 151 Milky Way globular clusters from Vasiliev (2019) in tandem with distances and line-of-sight velocities to derive their kinematical properties. To assign clusters to the Milky Way thick disk, bulge, and halo we follow the approach of Posti et al. (2018) who distinguished among different Galactic stellar components using stars's orbits. In particular, we use the ratio $L_{z}/e$, the $Z$ projection of the angular momentum to the eccentricity, as population tracer, which we complement with chemical abundances extracted from the literature and Monte-Carlo s…
Calibration of the period-luminosity relation (PLR) for Cepheids has always been one of the biggest goals of stellar astronomy. Among a considerable number of different approaches, the Baade-Becker-Wesselink (BBW) method stands in the foreground as one of the most universal and precise methods. We present a new realization of the BBW method which is considered to be the generalization of surface brightness (\citealt{Barnes+Evans+1976}) and \cite{Balona+1977} approaches first proposed by \cite{Rastorguev+Dambis+2010} and described in \cite{Paper1}. One of the main features of this method is usi…
We present an analysis of the kinematics of Galactic disc white dwarf stars in the Solar neighbourhood using data from Gaia Data Release 2. Selection of white dwarfs based on parallax provides the first large, kinematically unbiased sample of Solar neighbourhood white dwarfs to date. Various classical properties of the Solar neighbourhood kinematics have been detected for the first time in the WD population. The disc white dwarf population exhibits a correlation between absolute magnitude and mean age, which we exploit to obtain an independent estimate of the Solar motion with respect to the L…
Sco OB2 is the nearest OB association, extending over approximately 2000 sq.deg. on the sky. Only its brightest members are already known (from Hipparcos) across its entire size, while studies of its lower-mass population refer only to small portions of its extent. In this work we exploit the capabilities of Gaia DR2 measurements to search for Sco OB2 members across its entire size and down to the lowest stellar masses. We use both Gaia astrometric and photometric data to select association members, using minimal assumptions derived mostly from the Hipparcos studies. Gaia resolves small detail…
Although the stellar halo accounts for just ~1% of the total stellar mass of the Milky Way, the kinematics of halo stars encode valuable information about the origins and evolution of our Galaxy. It has been shown that the high transverse velocity stars in Gaia DR2 reveal a double sequence in the Hertzsprung-Russell (HR) diagram, indicating a bifurcation in the local stellar halo within 1 kpc. We fit these stars by updating the popular Besançon/Galaxia model, incorporating the latest observational results for the stellar halo and an improved kinematic description for the thick-disk from Schönr…
We present a detailed photometric and kinematical analysis of poorly studied open cluster IC 1434 using CCD VRI, APASS, and Gaia DR2 database for the first time. BY determining the membership probability of stars, we identified the 238 most probable members with a probability higher than 60% by using proper motion and parallax data as taken from the Gaia DR2 catalog. The mean proper motion of the cluster is obtained as emu_x= - 3.89 +/- 0.19 and emu_y= - 3.34 +/- 0.19 mas/yr in both the directions of right ascension and declination. The radial distribution of member stars provides cluster exte…
Explaining the internal distribution and motions of stars and gas in galaxies is a key aspect in understanding their evolution. In previous work we identified five well resolved galaxies with atypical kinematics from a cosmological simulation; two had kinematically distinct cores (KDCs), and three had counter-rotating gas and stars (CRGD). In this paper, we show that i) the KDC galaxies have flattening of stellar [O/Fe] at large galacto-centric radii due to the minor mergers that gave rise to the KDCs, and ii) the CRGD galaxies have an abrupt transition in the gas metallicity maps, from high m…
Stellar streams are ubiquitous in the Galactic halo and they can be used to improve our understanding of the formation and evolution of the Milky Way as a whole. The so-called Monoceros Ring might have been the result of satellite accretion. Guglielmo et al. have used N-body simulations to search for the progenitor of this structure. Their analysis shows that, if the Ring has a dwarf galaxy progenitor, it might be found in the background of one out of eight specific areas in the sky. Here, we use Gaia DR2 data to perform a systematic exploration aimed at confirming or rejecting this remarkable…
(Abridged) We have used the atmospheric parameters, [alpha/Fe] abundances and radial velocities, determined from the Gaia-ESO Survey GIRAFFE spectra of FGK-type stars (iDR1), to provide a chemo-kinematical characterisation of the disc stellar populations. We focuss on a subsample of 1016 stars with high quality parameters, covering the volume |Z|<4.5kpc and R in the range 2-13kpc. We have identified a thin to thick disc separation in the [alpha/Fe] vs [M/H] plane, thanks to the presence of a low-density region in the number density distribution. The thick disc stars seem to lie in progressivel…
We study the dynamical properties of halo stars located in the Solar Neighbourhood. Our goal is to explore how the properties of the halo depend on the selection criteria used for defining a sample of halo stars. Once this is understood we proceed to measure the shape and orientation of the halo's velocity ellipsoid and we use this information to put constraints on the gravitational potential of the Galaxy. We use the recently released Gaia DR1 catalogue cross-matched to the RAVE dataset for our analysis. We develop a dynamical criterion based on the distribution function of stars in various G…
The ongoing Gaia mission of ESA will provide accurate spatial and kinematical information for a large fraction of stars in the Galaxy. Interstellar extinction and line absorption studies toward a large number of stars at different distances and directions can give a 3-dimensional distribution map of interstellar absorbers, and thus reach a similar spatial perfection. Under certain morphologies (e.g. geometrically thin absorption curtains) one can infer a complete velocity vector from its radial velocity component and so obtain a dynamical information comparable to stars. But observations of a …
We search for metal-rich Sausage-kinematic (MRSK) stars with [Fe/H]> -0.8 and -100<Vphi<50 km/s in LAMOST DR5 in order to investigate the influence of the Gaia-Sausage-Enceladus (GSE) merger event on the Galactic disk. For the first time, we find a group of low-alpha MRSK stars, and classify it as a metal-rich tail of the GSE galaxy based on the chemical and kinematical properties. This group has slightly larger Rapo, Zmax and Etot distributions than a previously-reported high-alpha group. Its low-alpha ratio does not allow for an origin resulting from the splash process of the GSE merger even…
The low-metallicity, kinematically interesting dwarf stars studied by Stephens \& Boesgaard (2002, SB02) are re-examined using Gaia DR2 astrometry, and updated model atmospheres and atomic line data. New stellar parameters are determined based on the Gaia DR2 parallactic distances and Dartmouth Stellar Evolution Database isochrones. These are in excellent agreement with spectroscopically determined stellar parameters for stars with [Fe/H]$>-2$; however, large disagreements are found for stars with [Fe/H]$\le-2$, with offsets as large as $Δ$T$_{\rm eff}\sim+500$ K and $Δ$log\,$g\sim+1.0$. A sub…
We cross-match the Alma catalog of OB stars with Gaia DR2 astrometry and photometry as a first step towards producing a clean sample of massive stars in the solar neighbourhood with a high degree of completeness. We analyze the resulting colour-absolute magnitude diagram to divide our sample into categories and compare extinction estimates from two sources, finding problems with both of them. The distances obtained with three different priors are found to have few differences among them, indicating that Gaia DR2 distances are robust. An analysis of the 3-D distribution of massive stars in the …
Three-dimensional (3D) maps of Galactic interstellar dust are a tool for a wide range of uses. We aim to construct 3D maps of dust extinction in the Local Arm and surrounding regions. Gaia EDR3 photometric data were combined with 2MASS measurements to derive extinction towards stars with accurate photometry and relative uncertainties on parallaxes of less than 20%. We applied our hierarchical inversion algorithm adapted to inhomogeneous spatial distributions of target stars to this catalogue of extinctions. We present the updated 3D dust extinction distribution and provide an estimate of the e…
The Blanco DECam Bulge Survey (BDBS) has imaged more than 200 square degrees of the southern Galactic bulge, providing photometry in the ugrizy filters for $\sim 250$ million unique stars. The presence of a strong foreground disk population, along with complex reddening and extreme image crowding, has made it difficult to constrain the presence of young and intermediate age stars in the bulge population. We employed an accurate cross-match of BDBS with the latest data release (EDR3) from the Gaia mission, matching more than 140 million sources with BDBS photometry and Gaia EDR3 photometry and …
Kinematics of the System of Young Open Clusters based on Gaia DR3 Data
Sternberg Astronomical Institute, Lomonosov Moscow State University（列昂尼德·莫索科夫国立莫斯科大学斯腾伯格天体物理研究所）；Lomonosov Moscow State University, Faculty of Physics（列昂尼德·莫索科夫国立莫斯科大学物理系）
We use accurate estimates of aluminium abundance provided as part of the APOGEE Data Release 17 and Gaia Early Data Release 3 astrometry to select a highly pure sample of stars with metallicity $-1.5\lesssim {\rm [Fe/H]}\lesssim 0.5$ born in-situ in the Milky Way proper. We show that the low-metallicity ([Fe/H]$\lesssim -1.3$) in-situ component that we dub Aurora is kinematically hot with an approximately isotropic velocity ellipsoid and a modest net rotation. Aurora stars exhibit large scatter in metallicity and in a number of element abundance ratios. The median tangential velocity of the in…
The Gaia-ESO Survey (GES) observed many open clusters as part of its programme to spectroscopically characterise the various Milky Way populations. GES spectroscopy and Gaia astrometry from its second data release are used here to assign membership probabilities to targets towards 32 open clusters with ages from 1-3800 Myr, based on maximum likelihood modelling of the 3D kinematics of the cluster and field populations. From a parent catalogue of 14398 individual targets, 5033 stars with uniformly determined 3D velocities, $T_{\rm eff}$, $\log g$ and chemistry are assigned cluster membership wi…
Open Clusters are born and evolve along the Milky Way plane, on them is imprinted the history of the Galactic disc, including the chemical and dynamical evolution. Chemical and dynamical properties of open clusters can be derived from photometric, spectroscopic, and astrometric data of their member stars. Based on the photometric and astrometric data from the Gaia mission, the membership of stars in more than 2000 Galactic clusters has been identified in the literature. The chemical and kinematical properties, however, are still poorly known for many of these clusters. In synergy with the larg…
We present analysis of the proper-motion (PM) field of the red clump stars in the Large Magellanic Cloud (LMC) disk using the Gaia Early Data Release 3 catalog. Using a kinematic model based on old stars with 3D velocity measurements, we construct the residual PM field by subtracting the center-of-mass motion and internal rotation motion components. The residual PM field reveals asymmetric patterns, including larger residual PMs in the southern disk. Comparisons between the observed residual PM field with those of five numerical simulations of an LMC analog that is subject to the tidal fields …
Previous studies based on the analysis of Gaia DR2 data have revealed that accreted stars, possibly originating from a single progenitor satellite, are a significant component of the halo of our Galaxy, potentially constituting most of the halo stars at $\rm [Fe/H] < -1$ within a few kpc from the Sun and beyond. In this paper, we couple astrometric data from Gaia DR2 with elemental abundances from APOGEE DR14 to characterize the kinematics and chemistry of in-situ and accreted populations up to $\rm [Fe/H] \sim -2$. Accreted stars appear to significantly impact the Galactic chemo-kinematic rel…
We perform analysis of the three-dimensional kinematics of Milky Way disk stars in mono-age populations. We focus on stars between Galactocentric distances of $R=6$ and 14 \,kpc, selected from the combined LAMOST DR4 red clump giant stars and Gaia DR2 proper motion catalogue. We confirm the 3D asymmetrical motions of recent works and provide time tagging of the Galactic outer disk asymmetrical motions near the anticenter direction out to Galactocentric distances of 14\,kpc. Radial Galactocentric motions reach values up to 10 km s$^{-1}$, depending on the age of the population, and present a no…
We report an analysis of the metal-rich tail ([Fe/H] $> -0.75$) of halo stars located at distances from the Galactic plane $z$ up to $|z| \sim 10$ kpc, observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). We examine the chemistry, kinematics, and dynamics of this metal-rich halo sample using chemical abundances and radial velocities provided by the fourteenth APOGEE data release (DR14) and proper motions from the second Gaia data release (DR2). The analysis reveals three chemically different stellar populations in the [Mg/Fe] vs. [Fe/H] space -- the two distinct hal…
A comprehensive kinematic model of the LMC disk from star clusters and field stars using Gaia DR3: Tracing the disk characteristics, rotation, bar, and the outliers
We aim to quantify the chemical and kinematical properties of the Galactic disks with a sample of 119,558 giant stars having abundances and 3D velocities taken or derived from the APOGEE DR17 and Gaia EDR3 catalogs. The Gaussian Mixture Model is employed to distinguish the high-$α$ and low-$α$ sequences along the metallicity by simutaneously using the chemical and kinematical data. Four disk components are identified and quantified that named as h$α$mp, h$α$mr, l$α$mp, and l$α$mr disks, which correspond to the features of high-$α$ or low-$α$, and metal-poor or metal-rich. Combined with the spa…
The $Λ$CDM cosmological scenario predicts that our Galaxy should contain hundreds of stellar streams at the solar vicinity, fossil relics of the merging history of the Milky Way and more generally of the hierarchical growth of galaxies. Because of the mixing time scales in the inner Galaxy, it has been claimed that these streams should be difficult to detect in configuration space but can still be identifiable in kinematic-related spaces like the energy/angular momenta spaces, E-Lz and Lperp-Lz, or spaces of orbital/velocity parameters. By means of high-resolution, dissipationless N-body simul…
