Güneş benzeri titreşim yapan evrimleşmiş yıldızların asterosismik incelenmesi
Küçük Resim Yok
Tarih
2023
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Yıldızların temel parametlerini hassas bir şekilde belirlemek son derece önemlidir. Titreşim yapan yıldızların frekans analizinden sismik özelliklere ulaşabiliriz. Böylece kütle (M) ve yarıçapı (R) belirleyebiliriz. Bu bakımdan Kepler teleskobu özellikle güneş benzeri titreşim yapan yıldızların asterosismolojisine çok önemli katkılar sağlamıştır. Bu tez kapsamında, modelden elde edilen ölçekleme ilişkilerinin model bağımlı olup olmadığı araştırıldı. Bu amaçla literatürden anakol (AK) ve anakol sonrası (AKS) CESAM ve MESA modelleri derlendi. CESAM modellerinin titreşim frekanslarından büyük ayrılma, küçük ayrılma ve referans frekansları belirlendi. CESAM AK ve AKS (alt dev) modellerinden referans frekanslarına dayanan yarıçap için karecil (kuadratik) ve logaritmik yaklaşımla çözümler türetildi. MESA AK ve AKS modelleri için logaritmik yaklaşımla kütle için ilişki elde edildi. Kütlenin belirlenmesi için kütleçekim ivmesi ve yarıçap için çözüm türetildi. AKS modellerinin kütle ve yarıçapı için açıklama ilk kez bu çalışmada elde edildi. Hem CESAM hem de MESA modellerinden elde edilen çözümler Kepler Miras yıldızlarına uygulandı. Belirlenen M, R sonuçları literatür çalışmalarıyla birlikte ele alındı. Referans frekanslarına dayanan çözümlerin Kepler Miras yıldızlarıyla uyumu çok başarılıdır. Anahtar sözcükler: Asterosismoloji, güneş benzeri titreşimler, evrimleşmiş yıldızlar, yıldız iç yapı ve evrimi, referans frekansları.
It is extremely important to precisely determine the fundemantal parameters of the stars. From frequency analysis of oscillating stars, we can derive seismic properties. So, we can determine the mass (M) and radius (R) of these stars. In this respect, Kepler telescope made a significant contribution to the asteroseismology of solar-like oscillating stars. In this study, we investigated if the scaling relations obtained from the interior models are model dependent. For this purpose, the main squence (MS) and post-main squence (postMS) CESAM and MESA models were compiled from the literature. Large seperation, small seperation and reference frequencies of the CESAM models were determined. A quadratic and logarithmic solution was derived for the radius based on the reference frequencies from the CESAM MS and postMS (subgiant) models. Relation for mass was obtained by logarithmic method for MESA MS and postMS models. For the determination of mass, the solution for gravitational acceleration and radius is derived. The explanation for M and R from postMS models was obtained for the first time in this study. Solutions obtained from both CESAM and MESA models are applied to the Kepler target stars. The results for M and R are compared with the results in the literature. The compatibility of solutions based on reference frequencies with Kepler stars is very successful. Keywords: Asteroseismology, solar-like oscillations, evolved stars, stellar internal structure and evolution, reference frequencies.
It is extremely important to precisely determine the fundemantal parameters of the stars. From frequency analysis of oscillating stars, we can derive seismic properties. So, we can determine the mass (M) and radius (R) of these stars. In this respect, Kepler telescope made a significant contribution to the asteroseismology of solar-like oscillating stars. In this study, we investigated if the scaling relations obtained from the interior models are model dependent. For this purpose, the main squence (MS) and post-main squence (postMS) CESAM and MESA models were compiled from the literature. Large seperation, small seperation and reference frequencies of the CESAM models were determined. A quadratic and logarithmic solution was derived for the radius based on the reference frequencies from the CESAM MS and postMS (subgiant) models. Relation for mass was obtained by logarithmic method for MESA MS and postMS models. For the determination of mass, the solution for gravitational acceleration and radius is derived. The explanation for M and R from postMS models was obtained for the first time in this study. Solutions obtained from both CESAM and MESA models are applied to the Kepler target stars. The results for M and R are compared with the results in the literature. The compatibility of solutions based on reference frequencies with Kepler stars is very successful. Keywords: Asteroseismology, solar-like oscillations, evolved stars, stellar internal structure and evolution, reference frequencies.
Açıklama
Anahtar Kelimeler
Astronomi ve Uzay Bilimleri, Astronomy and Space Sciences, Asteroseismology, solar-like oscillations, evolved stars, stellar internal structure and evolution, reference frequencies.
