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Projecte llegit

Títol: Spectroscopic follow-up of Gaia-selected white dwarfs

Estudiants que han llegit aquest projecte:


Departament: FIS

Títol: Spectroscopic follow-up of Gaia-selected white dwarfs

Data inici oferta: 06-02-2023     Data finalització oferta: 06-10-2023

Estudis d'assignació del projecte:
Tipus: Individual
Lloc de realització: EETAC
Segon director/a (UPC): RADDI, ROBERTO
Paraules clau:
Spectroscopy, Data reduction and calibration, Gaia spacecraft and White Dwarfs
Descripció del contingut i pla d'activitats:
The Gaia satellite has provided astrometric and photometric information for hundreds of thousands of white dwarfs, the typical endpoints of stellar evolution. A large fraction of these white dwarfs are in binary systems with main sequence companions, stars like the Sun that are burning hydrogen in their interiors.

Based on the Gaia satellite data, we have identified peculiar white dwarfs in binary systems that challenge the theoretical predictions. On the one hand, we have found indications that a population of extremely low-mass white dwarfs reside in tight orbits with main sequence companions. These systems are not expected to exist since their evolutionary paths are thought to end up with the merger of the two stars. On the other hand, the photometric data of a large percentage of white dwarfs in wide orbits with main sequence companions indicate white dwarf masses that are too low for them to have evolved via standard evolutionary channels.

We have secured spectroscopic follow-up observations from the New Technology Telescope at the European Southern Observatory in La Silla, Chile, of a selected sample of white dwarfs in tight and wide orbits. This TFG will focus on the data reduction and analysis of these data for deriving independent mass estimates of these white dwarfs. The comparison of the results obtained in this TFG and those obtained from the Gaia data will allow us to confirm or disprove whether or not we have found strong observational evidence for revising the theoretical evolutionary pathways of white dwarf binaries.
Overview (resum en anglès):
Astronomy unveils the wonders of the universe, including white dwarfs. These stellar remnants, with their dense cores, offer insights into stellar evolution and the cosmos. Spectroscopy, a powerful tool in astronomy, plays a crucial role in studying their properties. By analyzing the spectra emitted by white dwarfs, astronomers can decipher their chemical composition, mass, temperature, and atmospheric conditions. This knowledge enhances our understanding of star formation, the physics of compact objects, and the fate of stars like our Sun. With advancements in telescopes and instruments like the Gaia spacecraft, the research of white dwarfs has entered a new era of discovery, opening doors to further exploration and unraveling the mysteries of these celestial objects.

One effective way to contribute to this field is through this TFG, which offers information on white dwarfs and spectroscopy. The thesis includes the analysis of spectral data obtained from the European Southern Observatory, with the primary objective of reducing and calibrating the data. Furthermore, an analytical method is presented to investigate the existence of newly discovered binary systems composed of an M-dwarf and an Extremely Low Mass (ELM) white dwarf.

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