OFFSTAGE: Osservatorio Astronomico di Padova

PROGETTI DI TIROCINIO PRESSO L’OSSERVATORIO ASTRONOMICO DI PADOVA – INAF
vicolo dell'Osservatorio 5 - 35122 Padova


I progetti di tirocinio sono rivolti a studenti o neolaureati - durata 150-250 ore o 6 mesi


Per avviare il tirocinio e chiedere la modulistica: contattare l’ufficio stage
Per candidarsi e avere maggiori informazioni sulle attività dei progetti di tirocinio contattare il singolo referente presso l’INAF


1) I parametri fondamentali dell’evoluzione delle galassie
Le proprietà delle galassie dipendono fortemente dalla loro massa, ma alcuni studi recenti hanno suggerito che altri parametri, quali la densità o la dispersione di velocità delle galassie, siano fattori ancora più fondamentali nel determinare la storia evolutiva delle galassie.
Il/la tirocinante utilizzerà un database di galassie in diversi ambienti per studiare le correlazioni tra le principali proprietà galattiche (formazione stellare, morfologia, dimensioni) e i loro parametri fisici fondamentali (massa, densità, dispersione di velocità), confrontandosi anche con i risultati di letteratura ottenuti finora.
Proponente: Dr. Bianca Maria Poggianti, Ricercatrice DELL’INAF bianca.poggianti@oapd.inaf.it
 

2) La survey XXL: l'evoluzione delle galassie nei gruppi
La maggior parte delle galassie oggi non è isolata, ma si trova in un gruppo e quindi subisce l'interazione con altre galassie vicine e con il gas caldo intra-gruppo.
All'interno della collaborazione internazionale XXL (http://irfu.cea.fr/en/Phocea/Vie_des_labos/Ast/ast_technique.php?id_ast=3015), si studieranno i gruppi di
galassie e in particolare le caratteristiche delle galassie in funzione della componente gassosa che emette a raggi X.
Il/la tirocinante avrà modo di partecipare al processo di acquisizione, riduzione e analisi di dati spettroscopici presi con telescopi da 4 e 8 metri, che consentono l'identificazione dei gruppi e lo studio delle loro galassie.
Proponente: Dr. Bianca Maria Poggianti, Ricercatrice DELL’INAF bianca.poggianti@oapd.inaf.it


3) Evolved stars in Magellanic Cloud star clusters imaged with the Hubble Space Telescope
We have recently obtained high-quality Hubble Space Telescope imaging of 16 intermediate-age star clusters in the Large and Small Magellanic Clouds. The data is being used mainly to investigate the presence of multiple generations of stars in these clusters, which appear as dramatic features in the mainsequence
part of their colour-magnitude diagrams. The same data presents extremely well-defined sequences of evolved stars, in the evolutionary phases of subgiants, first-ascent red giants, core He-burning (red clump), and asymptotic giant branches. We offer the possibility to analyze these data with the aid of stellar evolutionary tracks and isochrones computed with the Padova-Trieste stellar evolution code. The most important aspect to be tested is the presence and amount of extra-mixing processes during the stages of core H and He-burning, which appear as changes in the lifetimes of these evolved stages, and hence as variations in the star counts along the color-magnitude diagram. The HST data can also be complemented with near-infrared imaging from the ESO's VISTA Survey of the Magellanic Cloud, which offers a complete
sampling of the reddest stars. This project offers a good opportunity to get in touch with the basic stellar evolution theory and with the observational data used to calibrate stellar evolution models.
References:
- An extended main-sequence turn-off in the Small Magellanic Cloud star cluster NGC 411, Girardi et al. 2013, MNRAS, 431, 3501, http://adsabs.harvard.edu/abs/2013MNRAS.431.3501G
- The star formation history of the Large Magellanic Cloud star clusters NGC 1846 and NGC 1783, Rubele et al. 2013, MNRAS, 430, 2774, http://adsabs.harvard.edu/abs/2013MNRAS.430.2774R
- PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code, Bressan et al. 2012, MNRAS, 427, 127, http://adsabs.harvard.edu/abs/2012MNRAS.427..127B
- The VMC survey. I. Strategy and first data, Cioni et al. 2011, A&A 527, 116,
http://adsabs.harvard.edu/abs/2011A%26A...527A.116C
Durata: 150 ore
Responsabile: Leo Girardi (leo.girardi@oapd.inaf.it)


4) Project Title: Simulating the nursery of stars
Project advisor: Michela Mapelli (http://web.pd.astro.it/mapelli/)
SCIENTIFIC RATIONALE:
Young (<100 Million year) star clusters (SCs) are the nursery of stars: more than 70 per cent of stars in the nearby Universe were born in such places.
Figure 1shows the RCW 38 young SC.
Dramatic dynamical processes take place during the early evolution of SCs, such as core collapse (i.e. the contraction of the central parts of the SC, where
very high densities can be reached), 3-body encounters (i.e. strong dynamical interactions between a binary stellar system and a single star), stellar
collisions (i.e. the physical collision between stars). Thus, direct N-body simulations, which can follow these processes with high integration-accuracy,
are needed to understand the evolution of SCs and the fate of the young stars.
AIMS:
The aim of this project is to simulate a young
star cluster, investigating its dynamical evolution.
METHODOLOGY:
The student will learn how to use the C++ code STARLAB
(http://www.sns.ias.edu/~starlab/).
Among the available direct N-body codes, STARLAB is particularly fascinating because it couples a high-precision Nbody integrator with some
accurate recipes for stellar and binary evolution: each N-body particle in STARLAB is a 'real' star with its physical radius, luminosity and temperature.
Furthermore, STARLAB is optimized to run on graphics processing units (GPUs): the graphics accelerators included in the graphic cards that are normally used for the video games (Figure 2). The student will run a SC model with STARLAB, using GPUs. The student will analyze the main features of the simulations and write a short report.
EXPERTISES:
Students with curiosity in (1) dynamics, analytical mechanics (meccanica razionale), and/or (2) highperformance computing might be particularly interested in this project.
By the end of this project, the student will acquire some basic experience in N-body simulations and in collisional stellar dynamics.
DURATION: The expected duration is 150 hours, but even longer durations are possible.
CONTACT: Michela Mapelli, Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, 35122 Padova
Email: michela.mapelli@oapd.inaf.it, Phone: +39 049 8293527, Web: http://web.pd.astro.it/mapelli/

[Ultimo aggiornamento: 29/04/2016 10:13:32]