96393 - HIGH ENERGY ASTROPHYSICS

Conoscenze e abilità da conseguire

This course focuses on the description of mechanisms and physical processes responsible for the emission observed from populations of Galactic and extra-galactic sources in the high-energy portion of the electromagnetic spectrum (mostly X-ray and Gamma-ray). All the phenomena will be illustrated using results from state-of-the-art X-ray and Gamma ray observatories. Students will be able to critically comprehend and discuss the high-energy emission properties of different classes of cosmic sources (e.g. compact X-ray sources such as X-ray binaries and Active Galactic Nuclei, clusters of galaxies, exploding stars such as Supernovae and Gamma Ray Burst, the Galactic Center). Through a multi-wavelength (and multi-messenger) approach, students will be able relate the X-ray properties of the observed sources with their emission at other wavelengths (and other messengers). The student is expected also to attain a basic knowledge of the techniques related to the detection of X-ray and Gamma-ray photons and on the properties of past, present, and future X-ray telescopes.

Contenuti

INTRODUCTION TO HIGH-ENERGY ASTROPHYSICS

• Recap on emission mechanisms: blackbody/bremsstrahlung/synchrotron/Compton scattering and Inverse Compton scattering, and some examples in the field of high-energy Astrophysics. Line production. Plasma physics (collisional and ionization equilibrium)

• History of the high-energy Astronomy. Excursus on the properties of the main X-ray/Gamma-ray satellites of the 'golden age'.

• Detection techniques for high-energy photons. X-ray and Gamma-ray detectors; CCDs in X-rays. Wolter-type telescopes and coded-aperture masks. Cerenkov radiation.

ACCRETION PHYSICS:

• Theory, Eddington limit, accretion discs. Accretion and ejection processes (jets, winds)

• Physics of compact objects: white dwarfs, Chandrasekhar limit, neutron stars, pulsars, black holes (with some mentions on relativistic astrophysics)

HIGH-ENERGY ASTROPHYSICS: GALACTIC

• X-ray binaries: phenomenology, classification and physical properties. Cataclysmic variables,Low- and High-mass X-ray binaries, candidates black holes.
  

• The Galactic Center: a multi-wavelength perspective. Emission from point-like and extended X-ray/Gamma-ray sources. Properties of the Fermi bubbles and other extended features. Matter infalling onto SgrA*.

• X-ray emission from Solar System objects, including the Sun. Basics on stellar X-ray Astronomy.
  

HIGH-ENERGY ASTROPHYSICS: EXTRA-GALACTIC

• Clusters of galaxies and cooling flows
  

• Active Galactic Nuclei (AGN): spectral components in X-rays, models vs. observations.

• X-ray surveys in the last decade. AGN contribution to the cosmic X-ray background. Open issues.
  
  
• Gamma ray bursts: phenomenologies, origin and emission mechanisms.

• High Energy sources of Gravitational waves and multi-messenger astrophysics

Testi/Bibliografia

MAIN/REFERENCE TEXT:

• Malcolm S. Longair: "High-Energy Astrophysics", Cambridge University Press

OTHER KEY RESOURCES (optional):

• George B. Rybicky, Alan P. Lightman: "Radiative Processes in Astrophysics", Wiley

• J. Frank, A. King & D. Raine: "Accretion Power in Astrophysics", Cambridge University Press

For each lecture, few selected resources (papers, slides of seminars, web-pages) will be given to complement the material on the Longair's book. The material is given to the students to trigger their interest in the specific topics and enlarge their knowledge on state-of-the-art high energy astrophysics results.


The slides used during the lectures will be made available, at the end of the lecture.

All the material (slides and additional resources) are made available in the Virtuale space

Metodi didattici

Lectures with the aid of slides and blackboard. From time to time, during the lecture we will critically analyze recent publications and/or reviews on the lecture topics. Time will also be devoted to "questions and answer" sessions at the end of the macro-topics.

During the course few lectures will be devoted to specialistic seminars (2 hours each) given by colleagues of INAF and CTA, on future perspectives on high-energy astrophysics studies and synergies with theory/modelling and/or multifrequencies.

 

Modalità di verifica e valutazione dell'apprendimento

Oral exam lasting between 40 and 60 minutes, where the candidate should demonstrate the ability to apply their knowledge and to make the necessary logical-deductive connections, in order to demonstrate a comprehensive and critical view of the discipline.

The exam starts with a topic chosen by the student. Few questions will be addressed on this chosen topic. After the first question, there will be another couple of questions concerning different subjects to verify the overall student knowledge of the subjects addressed in the full course. The candidate should be able to deduce relations among physical quantities related to high-energy astrophysics, and connect the different topics, in a non mnemonic way.

 

Grade of the marks:

The grade scale is 18/30-30/30.

Preparation on a very limited number of topics covered in the course and analytical ability that emerges only with the help of the teacher, expression in generally correct language → 18-21;

preparation on a large number of topics covered in the course but  analytical ability autonomous only in a limited way, and/or only on purely executive questions, expression in correct language → 22-25;

Preparation on a large number of topics covered in the course, ability to make autonomous choices of critical analysis, mastery of specific terminology → 26-29;

Preparation complete and excellent ability to independently carry out critical analysis and connection between the various topics covered in the course, with full mastery of the terminology and argumentation ability, → 30 or 30L

Strumenti a supporto della didattica

Video Projector and PC. The slides used during the lectures will be also made available on Virtuale, at the end of the lecture.

Students with specific needs based on disabilities can contact the teacher and will be given access to the slides in advance. 

Orario di ricevimento

Consulta il sito web di Marcella Brusa