F3501 Scientific workflow in astrophysics

Přírodovědecká fakulta
podzim 2022
Rozsah
0/2/0. 2 kr. Ukončení: z.
Vyučující
doc. Ernst Paunzen, Dr.rer.nat (přednášející)
Garance
doc. Ernst Paunzen, Dr.rer.nat
Ústav teoretické fyziky a astrofyziky – Fyzikální sekce – Přírodovědecká fakulta
Kontaktní osoba: doc. Ernst Paunzen, Dr.rer.nat
Dodavatelské pracoviště: Ústav teoretické fyziky a astrofyziky – Fyzikální sekce – Přírodovědecká fakulta
Rozvrh
St 14:00–15:50 Fs2 6/4003
Předpoklady
The course is intended for all students after the second year of study with a basic knowledge of physics and astrophysics. The main language of the course will be English because we will execute one specific scientific project. However, questions and discussions can be also done in Czech and Slovak.
Omezení zápisu do předmětu
Předmět je nabízen i studentům mimo mateřské obory.
Mateřské obory/plány
Cíle předmětu
The Gaia data releases (GDR2 and EDR3) provide precise kinematics and photometric information for an unprecedented number of stars. They also significantly improved our knowledge about true star clusters in the solar vicinity. These structures share the same age, kinematics and original metallicity, which can be used, in conjunction with the distances, to significantly advance the understanding of not only their members but also star clusters themselves.
For this semester, we have chosen the group of chemically peculiar (CP) stars for a closer investigation. CP stars are objects with unusual metal abundances (specifically in their surface layers) compared to the standard composition of the solar photosphere. For most groups of CP stars, current theories ascribe the observed chemical peculiarities to the interplay between radiative levitation and gravitational settling (atomic diffusion): whereas most elements sink under the force of gravity, those with numerous absorption lines near the local flux maximum are radiatively accelerated towards the surface. Because CP stars are generally slow rotators and boast calm radiative atmospheres, atomic diffusion processes are able to significantly influence the chemical composition of the outer stellar layers.
CP stars are traditionally divided into the following four main groups: CP1 stars (the metallic-line or Am/Fm stars), CP2 stars (the magnetic Bp/Ap stars), CP3 stars (the Mercury-Manganese or HgMn stars), and CP4 stars (the He-weak stars).
It is obvious that the catalog of CP stars in star clusters would be beneficial to the community. We theorize that the creation of a CP cluster catalog would facilitate the exploration of several research avenues, for instance:
1) The population of cluster CPs can be studied with respect to cluster parameters, such as the age and metallicity - putting constraints on the physical processes that lead to CP formation.
2) If we can confirm the cluster membership of a CP star that has spectroscopic measurements in a suitable spectral range, we can obtain an accurate CP’s mass, age and radius. The age can be compared with that of the hosting star cluster.
3) For the magnetic CP stars, we can correlate their magnetic field strengths with age and mass.
We will use the catalog of CPs and star clusters to find the positional matches between them. Then we will compare the proper motions to find CP stars which are actual members of the star clusters. This will yield a corresponding catalog for which we will write a peer-reviewed paper that we will submit at the end of the semester.
Výstupy z učení
- advanced archival search and analysis of scientific data
- matching kinematic and astrometric data
- understanding of Gaia DR2 and EDR3 data
- understanding of star clusters
- fitting of isochrones and determination of astrophysical parameters
- working in a team on a specific scientific topic
- writing a scientific paper
- following the publication and referee process of a scientific paper
Osnova
  • The following astrophysical topics will be discussed: star clusters, white dwarfs, stellar formation and evolution
  • Techniques used: advanced search in data archives, combination of astrometric and kinematic data, isochrones fitting
  • Additional skills: working in a team, writing a scientific paper
Výukové metody
lectures, group project and paper, literature search, data analysis, class discussion
Metody hodnocení
final peer-review paper
Vyučovací jazyk
Angličtina
Informace učitele
none
Další komentáře
Studijní materiály
Předmět je dovoleno ukončit i mimo zkouškové období.
Předmět je vyučován každoročně.
Předmět je zařazen také v obdobích podzim 2019, podzim 2020, podzim 2021, podzim 2023, podzim 2024.