Sökning: "Gaia-ESO"

Hittade 5 uppsatser innehållade ordet Gaia-ESO.

1. 1. Machine Learning for Stellar Spectra : Anomaly Detection in stellar spectra using Unsupervised Random ForestSpectral Analysis using Variational Autoencoders

   Master-uppsats, Luleå tekniska universitet/Rymdteknik

   Författare :Mihir Paranjape; [2021]
   Nyckelord :Stellar spectra; outlier; VAE; neural network; machine learning; Gaia-ESO;

   Sammanfattning : This thesis was carried out in two parts. The stellar spectral data was used from the Gaia-ESO survey. The data used was fromthe public archive as well as data received from Dr. Recio-Blanco at Observatoire Cote D'Azure. LÄS MER

3. 2. Examining LUMBA UVES pipeline spectroscopy on giant and sub-giant stars of M67

   Master-uppsats, Uppsala universitet/Observationell astrofysik

   Författare :Nikolaos Papakonstantinou; [2021]
   Nyckelord :methods: numerical; stars:abundances; stars: atmospheres; stars: statistics; stars:giants; stars:subgiants; stars: open clusters; stars: M67;

   Sammanfattning : In this work, the efficiency of the LUMBA UVES pipeline for processing of spectroscopic observations is tested by use on 23 high-resolution spectra of the open star cluster M67. An abundance trend discovered by Gavel et al. (2019) concerning iron abundances of giant and sub-giant stars of that cluster is examined. LÄS MER

4. 3. Analysis of stellar spectra with machine learning

   Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation; Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation

   Författare :Alvaro Segovia Otero; [2020]
   Nyckelord :Galactic Archaeology; machine learning; chemical abundances; FGK stars; Physics and Astronomy;

   Sammanfattning : Researchers in the field of Galactic Archaeology have entered the era of industrial revolution. Upcoming surveys are planning on observing tens of millions of stars and high precision and accuracy must be ensured when deriving their stellar parameters and elemental abundances. LÄS MER

5. 4. Broadening of spectral lines in the Gaia-ESO survey

   Kandidat-uppsats, Uppsala universitet/Teoretisk fysik

   Författare :Kristoffer Bengtsson; [2018]
   Nyckelord :Astronomy; Hydrogen; Iron; Spectral line broadening; collisional broadening; pressure broadening; Gaia; Stellar atmosphere; spectrum; stars: abundances; Atomic data; Astronomi; tryckbreddning; kollisionsbreddning; breddning av spektrallinjer; spektrum; väte; järn; Gaia; stjärnatmosfär; atomdata;

   Sammanfattning : Analyzing stellar spectra plays a big role in understanding the evolution of our galaxy. Having good data for spectral line properties is very important when analyzing these spectra. One part of the Gaia-ESO public spectroscopic survey (GES) is to gather data for spectral line properties from stellar spectra. LÄS MER

7. 5. The status of neutron-capture elements according to Gaia-ESO.

   Kandidat-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

   Författare :Linnéa Strandell; [2017]
   Nyckelord :Neutron-capture elements; Gaia-ESO; Milky Way field stars; Physics and Astronomy;

   Sammanfattning : The aim of this thesis is to get a better understanding of the evolution of the Milky Way stellar disc by looking at the abundance ratios for neutron-capture elements in thin and thick disc stars. In this project the formation of our Galaxy’s thin and thick disc was studied by analysing 10 different neutron-capture elements in field stars measured by Gaia-ESO. LÄS MER