Dissipative phenomena in extended-body interactions

Pasetto, Stefano; Bertelli, G.; Grebel, E. K.; Chiosi, C.; Fujita, Yutaka

doi:10.1051/0004-6361/201117612

Cited by 10 publications

(11 citation statements)

References 117 publications

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“…The method based on the concept of star frequencies per elemental cell of the CMD can easily simulate observational CMDs that contain huge numbers of stars. This study extends and completes other similar studies in literature that dealt with synthetic CMDs such as those presented by in Carraro et al (2001); Pasetto et al (2012). This technique aims to interface N-body simulations to photometric observations and is developed with the perspective of the ever improving capabilities of the N-body simulations in the future.…”

Section: Discussionsupporting

confidence: 82%

Theory of stellar population synthesis with an application toN-body simulations

Pasetto

Chiosi

Kawata

2012

A&A

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Aims. We present here a new theoretical approach to population synthesis. The aim is to predict colour magnitude diagrams (CMDs) for huge numbers of stars. With this method we generate synthetic CMDs for N-body simulations of galaxies. Sophisticated hydrodynamic N-body models of galaxies require equal quality simulations of the photometric properties of their stellar content. The only prerequisite for the method to work is very little information on the star formation and chemical enrichment histories, i.e. the age and metallicity of all star-particles as a function of time. The method takes into account the gap between the mass of real stars and that of the star-particles in N-body simulations, which best correspond to the mass of star clusters with different age and metallicity, i.e. a manifold of single stellar sopulations (SSP). Methods. The theory extends the concept of SSP to include the phase-space (position and velocity) of each star. Furthermore, it accelerates the building up of simulated CMD by using a database of theoretical SSPs that extends to all ages and metallicities of interest. Finally, it uses the concept of distribution functions to build up the CMD. The technique is independent of the mass resolution and the way the N-body simulation has been calculated. This allows us to generate CMDs for simulated stellar systems of any kind: from open clusters to globular clusters, dwarf galaxies, or spiral and elliptical galaxies. Results. The new theory is applied to an N-body simulation of a disc galaxy to test its performance and highlight its flexibility.

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Section: Discussionsupporting

confidence: 82%

Theory of stellar population synthesis with an application toN-body simulations

Pasetto

Chiosi

Kawata

2012

A&A

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“…This model gathered the heritage of the Padua model that stems from the early studies of the stellar content of the Palomar-Groeningen survey towards the Galactic Centre by Ng et al (1995); Bertelli et al (1995), followed by studies of specific groups of stars and interstellar extinction by Bertelli et al (1995Bertelli et al ( , 1996; Ng & Schultheis (1996); to mention a few, the studies of the stellar content towards the Galactic Pole (Ng et al 1997), the development of a new minimization technique for the diagnostics of stellar population synthesis (Ng 1998b), the study of the Galactic Disc Age-Metallicity relation (Carraro, Ng & Portinari 1998), the possible relationship between the bulge C-stars and the Sagittarius dwarf galaxy (Ng 1998a), the developments of AMORE (Automatic Observation Rendering) of a synthetic stellar population's colour-magnitude diagram based on the genetic algorithm (Ng et al 2002), the study of 3-D structure of the Galaxy from star-counts in view of the Gaia mission (Vallenari et al 2003) and of the kinematics of the Galactic populations towards the North Pole with mock Gaia data (Vallenari et al 2004;Pasetto 2005;Vallenari et al 2006).…”

Section: Discussionmentioning

confidence: 99%

“…We complete the review by mentioning that optionally we can include axisymmetric components adding a hot coronal gas. This does not influence the closest stellar dynamics of the MW stars but in mass it is thought to contribute up to ∼ 5 × 10 10 M⊙ within ∼ 200 kpc from the MW galaxy centre (see, e.g., Pasetto et al 2012a, and reference therein for a model including it).…”

Section: Dark Matter and Hot-coronal Gasmentioning

confidence: 99%

Spiral arm kinematics for Milky Way stellar populations

Pasetto

Natale

Kawata

et al. 2016

Mon. Not. R. Astron. Soc.

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We present a new theoretical population synthesis model (the Galaxy Model) to examine and deal with large amounts of data from surveys of the Milky Way and to decipher the present and past structure and history of our own Galaxy.We assume the Galaxy to consist of a superposition of many composite stellar populations belonging to the thin and thick disks, the stellar halo and the bulge, and to be surrounded by a single dark matter halo component. A global model for the Milky Way's gravitational potential is built up self-consistently with the density profiles from the Poisson equation. In turn, these density profiles are used to generate synthetic probability distribution functions (PDFs) for the distribution of stars in colour-magnitude diagrams (CMDs). Finally, the gravitational potential is used to constrain the stellar kinematics by means of the moment method on a (perturbed)-distribution function. Spiral arms perturb the axisymmetric disk distribution functions in the linear response framework of density-wave theory where we present an analytical formula of the so-called 'reduction factor' using Hypergeometric functions.Finally, we consider an analytical non-axisymmetric model of extinction and an algorithm based on the concept of probability distribution function to handle colour magnitude diagrams with a large number of stars. A genetic algorithm is presented to investigate both the photometric and kinematic parameter space.This galaxy model represents the natural framework to reconstruct the structure of the Milky Way from the heterogeneous data set of surveys such as Gaia-ESO, SEGUE, APOGEE2, RAVE and the Gaia mission.

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“…There have been several very recent determinations of the solar peculiar velocity, including some using RAdial Velocity Experiment (RAVE; Steinmetz et al 2006, see also ) data as we use here (e.g. Pasetto, Grebel & Bienaymé 2010). A summarized list of recent determinations of the space velocity components of the Sun appearing in the literature is given in Table 1, while Francis & Anderson (2009) provide an even longer list of references.…”

Section: Introductionmentioning

confidence: 99%

Local stellar kinematics from RAVE data - I. Local standard of rest

Coşkunoğlu

Bilir

et al. 2011

Monthly Notices of the Royal Astronomical Society

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107

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We analyse a sample of 82 850 stars from the RAdial Velocity Experiment (RAVE) survey, with well‐determined velocities and stellar parameters, to isolate a sample of 18 026 high‐probability thin‐disc dwarfs within 600 pc of the Sun. We derive space motions for these stars, and deduce the solar space velocity with respect to the local standard of rest. The peculiar solar motion we derive is in excellent agreement in radial U⊙ and vertical W⊙ peculiar motions with other recent determinations. Our derived tangential peculiar velocity, V⊙, agrees with very recent determinations, which favour values near 13 km s−1, in disagreement with earlier studies. The derived values are not significantly dependent on the comparison sample chosen, or on the method of analysis. The local Galaxy seems very well dynamically relaxed, in a near symmetric potential.

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Dissipative phenomena in extended-body interactions

Cited by 10 publications

References 117 publications

Theory of stellar population synthesis with an application toN-body simulations

Theory of stellar population synthesis with an application toN-body simulations

Spiral arm kinematics for Milky Way stellar populations

Local stellar kinematics from RAVE data - I. Local standard of rest

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