69058 - POPOLAZIONI STELLARI RISOLTE

Scheda insegnamento

Anno Accademico 2021/2022

Conoscenze e abilità da conseguire

Al termine del corso, lo studente acquisisce il quadro generale delle proprietà osservate delle popolazioni stellari risolte. In particolare, è in grado di discutere le caratteristiche osservative di popolazioni stellari semplici (come gli ammassi stellari) e complesse (come le galassie). Inoltre acquisisce familiarità con le problematiche astrofisiche osservative e teoriche legate alle popolazioni stellari, identifica e comprende i principali indicatori delle caratteristiche fisiche delle popolazioni stellari (età, metallicità e distanza). E' in grado di discutere in maniera critica le problematiche connesse alle popolazioni stellari attraverso brevi elaborati scritti e presentazioni multimediali.

Contenuti

Evolutive sequences in the HR diagram: isochrones and evolutionary tracks. Connection between theory and observations: reddening, distance, bolometric corrections.

Metallicity/age/distance indicators in resolved stellar populations. Galactic Globular clusters and their properties. The Main Sequence Turn-Off as age indicator. The color position and the shape of the Red Giant Branch. Distance indicators: the HB level, the RR-Lyrae luminosity, the RGB-tip, the RGB-Bump properties. The WD cooling sequences as age and distance indicator. The complex morphology of the Horizontal Branch. Properties of Simple Stellar Populations (SSP). Spectral Energy Distribution (SED). Fuel Consumption theorem. Phase transitions in SSP. Contribution to the integrated light of each evolutionary sequence. The stellar population in the Magellanic Clouds. Complex stellar populations. Multiple stellar populations in globular clusters. "Exotic" stellar populations and their link with globular cluster internal dynamics: blue straggler stars, optical companions to millisecond pulsars, intermediate-mass black holes. Note about collisional dynamics (mass segregation, energy equipartition, core collapse, gravothermic catastrophe) and King models.

Testi/Bibliografia

The final exam can be prepared using the notes taken during the lessons and the Lecture Notes made available by the teacher every year at the site "Virtuale UniBO" of the Bologna University.

During the classes, the reading of several scientific papers is suggested. These can be downloaded at the dedicated web sites. For instance: http://cdsads.u-strasbg.fr/abstract_service.html

Additional text books useful for further detailed study are:

Evolution of stars and stellar populations - Salaris & Cassisi

An Introduction to modern Astrophysics - Carroll & Ostlie

Astrofisica stellare - V. Castellani

Astrophysics I. stars - Bowers& Deeming

Metodi didattici

The course is made of 6 CFU, corresponding to 48 hours of front lectures. These are made with the support of power-point presentations and at the blackboard. The lessons include the explanation of astrophysical concepts specific to resolved stellar populations and observational astronomy, helped with images and graphs aimed at improving the comprehension.

Modalità di verifica e valutazione dell'apprendimento

The final examination aims at verifying and evaluating the acquisition of the teaching goals. It consist in an oral assessment on all arguments discussed in the lectures, usually lasting 40-45min.

Strumenti a supporto della didattica

Lectures are supported by power-point presentations, which are updated and made available to the students every year on the dedicates web site "Virtuale uniBO" of the Bologna University

Orario di ricevimento

Consulta il sito web di Barbara Lanzoni