In this work certain concepts of the relationship, not very flowing, between the Milky Way and modern science fiction are analyzed. We focus on the scientific goals of Gaia mission: the structure and components of our Galaxy (My Stepmother is an Alien; Starship Troopers; Independence Day; The Hitchhiker's Guide to the Galaxy); the galaxy stellar component (The Black Hole); exoplanets (Interstellar; Les mondes dAldébaran; Valérian); Andromeda galaxy (Tumannost Andromedy) and others.

We report on the effect of observational errors when recovering cold streams related to the formation of our Galaxy by analysing the 10% fastest objects within 3 kpc of the “Sun” of an inner halo based on four N− body numerical simulations of the interaction between dwarf galaxies and the Milky Way. Much of the original substructure becomes visible again thanks to the superior precision that Gaia will achieve.

In this work we shed new light in the nature of spiral arm structures in galaxies. We present a disk kinematic and dynamic study of MW like galaxies using complementary approaches: analytical models, test-particle simulations, pure N-body and cosmological N-body plus hydrodynamic simulations. Using collisionless N-body data we have found that models with strong bar present a flat rotation frequency, i.e. rigid body rotation, whereas in the opposite extreme case, i.e. in unbarred systems, spiral arms are disk corotant (Roca-Fàbrega et al. 2013). Complementary to this work, we discuss how the vertex deviation parameter is a good tracer of corotation (CR) and outer Lindblad resonance radius (OLR) (Roca-Fàbrega et al. 2014). We have succeeded to produce MW like models in fully cosmological N-body plus hydrodynamic simulations with a high resolution (Roca-Fàbrega et al., in preparation). First results concerning disk phase space properties in terms of spiral arm nature using these simulations are presented (http://www.am.ub.edu/ sroca/shared/PosterRocaFabrega.pdf).

Red Clump (RC) stars are known to be good distance indicators. However the accuracy on these calculations strongly depends on the knowledge of their basic properties: a complete calibration is required.

It is in the less dense Outer Galaxy where Gaia can contribute much to stellar studies of the Galactic Plane. As O stars are by definition young objects, their positions and kinematics can still be related to their formation site and history. O star astrometry will not only be important for studies of high-mass star formation, such as triggered star-formation in shells, but also an interesting complement to the radio maser astrometry of star-forming regions and the structure of spiral arms. With the TLUSTY (Lanz & Hubeny 2013) model atmospheres and the nominal Gaia parallax uncertainty, we estimate the parallax uncertainty for all subtypes of main sequence O stars given a visual extinction. The expected extinction is an important limitation for Gaia's astrometric performance and we estimate the extinction from the column density maps calculated from the Herschel Infrared Galactic Plane survey (Molinari et al. 2010), a thermal cold dust emission survey of unprecedented angular resolution and sensitivity. In the 10∘ strip, taken to represent the first estimate of the average extinction in the Outer Galaxy, we find that most of the visual extinction is less than 10 mag. Only the most dense parts of the clouds have AV > 10 mag. Given these extinctions toward the Outer Galaxy, Gaia will provide accurate (5σ) astrometry for O stars in the Outer Galaxy up to distances of at least 4–6 kpc, which means that Gaia's O star astrometry will be able to transgress the Perseus arm and reach the less-known Outer Arm of the Milky Way (Rygl et al.https://gaia.ub.edu/Twiki/pub/GREATITNFC/ProgramFinalconference/Poster_Rygl%2cK.pdf).

Based on the Bayesian Inference (BI) method, the Multiple-modelling approach is improved to combine coordinative positions, proper motions (PM) and radial velocities (RV), to separate the motion of the open cluster from field stars, as well as to describe the intrinsic kinematic status of the cluster.

Gaia will see little of the Galactic mid-plane and nuclear bulge due to high extinction at optical wavelengths. To study the structure and kinematics of the inner Galaxy we must look to longer wavelengths. The Vista Variables in the Via Lactea (VVV, Minniti et al. 2010) survey currently provides just over 4 years of observations covering approximately 560 square degrees of the Galactic bulge and plane. Typically each source is observed 50–150 times in the Ks band over this period. Using these data we provide relative proper motions for approximately 200 million unique sources down to Ks∼16 with uncertainties approaching 1 mas yr−1. In addition, we fit a solution of the parallactic motion of all sources with significant proper motion and discover a number of new nearby brown dwarfs. These results will allow us to identify faint common proper motion companions to stars with Gaia parallaxes, increasing the number of brown dwarf benchmark objects. Our absolute astrometric calibration precision is currently ∼ 2 mas yr−1, based on PPMXL. The Gaia absolute astrometric reference grid will allow us to precisely anchor our results and measure the streaming motions of stars in the bulge. Finally, we anticipate that the catalogue could provide kinematic distances to the numerous optically invisible high amplitude variable stars that VVV is discovering.

VOSA (http://svo2.cab.inta-csic.es/theory/vosa/), is a web-based tool designed to combine private photometric measurements with data available in VO services distributed worldwide to build the observational spectral energy distributions (SEDs) of hundreds of objects. VOSA also accesses various collections of models to simulate the equivalent theoretical SEDs, allows the user to decide the range of physical parameters to explore, performs the SED comparison, provides the best fitting models to the user following two different approaches (chi square and Bayesian fitting), and, for stellar sources, compares these parameters with isochrones and evolutionary tracks to estimate masses and ages. In particular, VOSA offers the advantage of deriving physical parameters using all the available photometric information instead of a restricted subset of colors. VOSA was firstly released in 2008 and its functionalities are described in Bayo et al. (2008). At the time of writing there are more than 300 active users in VOSA who have published more than 60 refereed papers. In the framework of the GENIUS (https://gaia.am.ub.es/Twiki/bin/view/GENIUS) project we are upgrading VOSA to, on one hand, provide a seamless access to Gaia data and, on the other hand, handle thousands of objects at a time.

In this poster, the main functionalities to be implemented in the Gaia context will be described. The poster can be found at: http://svo.cab.inta-csic.es/files/svo//Public/SVOPapers/posters/vosa-poster3.pdf.

Although the thick disk in our Galaxy was revealed more than thirty years ago, its formation scenario is still unclear. Here, we analyze a chemo-dynamical simulation of a primordial disk population representative of the Galactic thick disk and investigate how the spatial, kinematic, and chemical properties are affected by the presence of a central bar.

One of the primary objectives of Gaia is to survey billions stars and build the most precise 3D map of the Milky Way. Automated techniques of spectral analysis are needed to perform a rapid and homogeneous processing of the data to provide precise and accurate stellar parameters, such as for the GAIA-ESO survey. In this context, our recent work is based on the spectral synthesis technique to derive parameters for both slowly and fast rotating stars (Tsantaki et al. 2014).

The spectroscopic analysis was performed using the package Spectroscopy Made Easy (SME; Valenti & Piskunov 1996) and a specific methodology to deal with fast rotators (υsini up to 50 km/s). The spectral regions, including the atomic data of all the lines in our analysis are available online in SME readable format http://mariatsantaki.weebly.com.

A comparison between the parameters derived with our methodology and with the iron ionization and excitation method (e.g. Sousa et al. 2008; Tsantaki et al. 2013) shows that both results are on the same scale. Additionally, for fast rotating stars, our results are in good agreement with literature values when comparing to other methods. We are now able to provide parameters for a very wide group of stars: from giants to dwarfs and from slowly to fast rotating stars.

Except for galactic studies, stellar parameters are important for the planetary characterization. We provided updated stellar and planetary properties for ten systems. The stellar parameters were compiled in the SWEET-Catalogue (https://www.astro.up.pt/resources/sweet-cat/).

We have successfully assembled a set of M giant templates from M0 to M6 by using the LAMOST DR1 spectra. After combining the M giant templates and M dwarf/subdwarf templates as a new M-type spectral library, we re-run the updated classification pipeline to identify and classify M-type stars in the LAMOST DR1. The 8639 M giants and the 107193 M dwarfs/subdwarfs are cataloged.