Doktorski seminar - Marta Fatović

O B A V I J E S T

MARTA FATOVIĆ

održat će znanstveni kolokvij (doktorski seminar) iz Astrofizike tvari pod naslovom

Variable sources in large optical sky surveys

Time domain astronomy is undergoing rapid development driven by the advent of massive all-sky astronomical surveys. These surveys provide repeated observations of the same patch of the sky, thus allowing studies of a wide variety of variable astrophysical sources.
The first part of the work in this thesis focuses on the exploration of small amplitude long-period variability (100 - 600 days). This regime of variability was inaccessible until the publication of Sloan Digital Sky Survey Stripe 82 (SDSS S82) catalog that covers 300 deg2 region outside of the galactic plane observed with the photometric precision of about 0.01 mag, the faint limit reaching to r~22 mag, and more than 10 observations per source over 9 years. Analyzing the SDSS S82 sample revealed five compelling cases of periodic optical variability in sources previously identified as quasars by the SDSS spectroscopic survey. Some intriguing explanations for the mechanisms causing this periodicity in quasars involve supermassive binary black hole systems (SMBBH). These sources hold significant scientific value, as their merging process would emit an immense amount of energy in the form of gravitational waves.
The second part of this thesis focuses on recent spectroscopic observations of the Mg II broad emission line. These observations narrow down the potential physical explanations for the periodicity of representative periodically variable quasar candidates.
The third part of the thesis centers on the development of a new distance estimation method based on luminosity, utilizing variable red giant stars (RG). It provides a comparison of period calculating methods for RGs in the Gaia Andromeda Photometric Survey (GAPS) field.

Seminar će se održati u petak 12. siječnja 2024. godine u 11:00 sati u predavaonici F-201 Fizičkog odsjeka Prirodoslovno-matematičkog fakulteta Sveučilišta u Zagrebu.

Pozivaju se studenti doktorskog studija Fizike, smjer Astrofizika, da prisustvuju seminaru, ako nisu spriječeni.

Voditeljica smjera:

Prof. dr. sc. Vernesa Smolčić, v. r.