Radiative processes in astrophysics

Code:

AST3010

Acronym:

AST3010

Keywords
Classification	Keyword
OFICIAL	Astronomy

Instance: 2021/2022 - 2S

Active?	Yes
Responsible unit:	Department of Physics and Astronomy
Course/CS Responsible:	Bachelor in Physics

Cycles of Study/Courses

Acronym	No. of Students	Study Plan	Curricular Years	Credits UCN	Credits ECTS	Contact hours	Total Time
L:B	0	Official Study Plan	3	-	6	56	162
L:CC	0	study plan from 2021/22	2	-	6	56	162
			3
L:F	9	Official Study Plan	2	-	6	56	162
			3
L:G	0	study plan from 2017/18	3	-	6	56	162
L:M	0	Official Study Plan	3	-	6	56	162
L:Q	0	study plan from 2016/17	3	-	6	56	162

Teaching language

Suitable for English-speaking students

Objectives

In this lecture course it is intended that students acquire the knowledge to understand the radiative processes and their applications to astrophysical phenomena and space science. It is given particular focus to the non-thermal radiative processes, which are very common in high energy astrophysics. The applications and methods for calculating results will develop in the student the ability to distinguish different radiative processes from observation and get the resources for the analysis.

Learning outcomes and competences

The program covers the topic of the radiative processes and their applications in the astrophysics field. The fundamental physical concepts are reviewed at the beginning of the course, with emphasis on the thermal radiation, radiative transfer and the stellar spectra formation. The first part of the course focus on the main thermal processes operating in a star and the astrophysical phenomena associated. In the second part of the course, the non-thermal radiation processes are introduced and the applications in high-energy astrophysics phenomena. The student will develop the skills to distinguish these two types of processes and the means available to make their analysis.

Working method

Presencial

Pre-requirements (prior knowledge) and co-requirements (common knowledge)

Basic skills in Astronomy and electromagnetism

Program

1) Fundamentals of radiative transfer: The specific intensity and its moments. Radiative transfer. Thermal radiation. Local and non-local Thermodynamic equilibrium (LTE and NLTE).

2) Atoms and molecules: Line profiles. Spectral line formation. Line diagnostics of temperature and density.

3) Radiative transfer in astrophysical applications: Stellar atmosphere models. The interstellar/circumstellar medium. 

4) Basic theory of radiation fields: Review of Maxwell' equations. Plane Electromagnetic Waves. Polarization. Electromagnetic radiation from moving charges.

5) Bremsstrahlung: Thermal Bremsstrahlung. Free-free absorption. Applications to astrophysical situations.

6) Synchrotron Radiation: Emission by relativistic particles. Spectrum and polarization of synchrotron radiation. Synchrotron self-absorption. Astrophysical synchrotron sources.

 

Mandatory literature

Rybicki George B.; Radiative processes in astrophysics. ISBN: 0-471-04815-1
Osterbrock Donald E.; Astrophysics of gaseous nebulae and active galactic nuclei. ISBN: 0-935702-22-9
Rutten R.J.; Radiative transfer in stellar atmospheres, 2003 (Lecture notes )

Teaching methods and learning activities

Expository methods in theoretical lectures, where examples are given to present the concepts. The theoretical-practical classes are for discussion and help in solving exercises.

Evaluation Type

Distributed evaluation with final exam

Assessment Components

designation	Weight (%)
Exame	70,00
Trabalho prático ou de projeto	30,00
Total:	100,00

Amount of time allocated to each course unit

designation	Time (hours)
Estudo autónomo	106,00
Frequência das aulas	56,00
Total:	162,00

Eligibility for exams

The student has frequency to the course if he/she misses no more than 1/3 of the planned TP classes.

Calculation formula of final grade

- The weekly resolution of exercises and practical works proposed in the TP classes - 30%
- Final exam - 50%
The minimum grade for the exam is 7/20.

Classification improvement

May improve grades in the 2nd epoch exam (época de  recurso). Only the component exam can be improved (70% of the total)

Observations

Jury:
Nuno Santos
Catarina Lobo
João Lima