Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Kinematic Properties of Main-sequence Stars in the RAVE Survey

The aim of this thesis is to obtain precise results about galactic structure parameters and evolution studying the kinematic and dynamic properties of RAVE sky survey stars with different spectral types in the solar neighbourhood. A thin disc main-sequence sample of 19.649 stars was selected from the RAVE DR3 consisting of 82.850 stars via applying several constraints: stellar atmospheric parameters, photometric accuracy, absolute magnitude, the errors in space velocities and population distinction criteria.

The kinematical properties of the thin disc main-sequence sample with respect to colour indices, spectral types, metal abundance and galactic orbital parameters were investigated. The LSR values obtained from kinematic analyses are (U, V, W)LSR≈(8.8, 14.0, 6.5) km/s. The LSR corrected sample was divided according to colour indices and spectral types; and its asymmetric drift, velocity dispersions, kinematic age and vertex deviations were examined. The Parenago discontinuity, which was observed from the analyses of Hipparcos data, was detected in RAVE DR3 too. Moreover, the galactic orbital parameters of thin disc main-sequence stars were determined. The thin disc main-sequence sample, which was divided according to galactic orbital parameters and metal abundance, was compared to velocity dispersions. As a result of these comparisons, the velocity dispersions were found to be consistent with galactic orbital parameters, whereas they were inconsistent with metal abundance.

The LSR values obtained from the stellar kinematics of stars within the volume of a sphere with 1 kpc radius are almost equal to the ones calculated from the newly reduced Hipparcos catalogue. The kinematic ages obtained from the RAVE DR3 sample are consistent with the main-sequence ages obtained from Padova isochrones.

Since precise radial velocity and astrometric data were used in conjunction with one another in the thesis, the kinematic and dynamic properties of stars in the solar neighbourhood were determined more precisely. As a result, this thesis shows that the solar neighbourhood concept, which was developed from Hipparcos data, is larger than the assumed size.
DANIŞAN Gaye
Birinci Danışman :Prof. Dr. Füsun LİMBOZ

İkinci Danışman : Prof. Dr. Feza GÜNERGUN

Anabilim Dalı : Astronomi ve Uzay Bilimleri Bölümü

Mezuniyet Yılı :2009

Tez Savunma Jürisi :Prof. Dr. Füsun LİMBOZ

Prof. Dr. Mustafa KAÇAR

Prof. Dr. H. Hüseyin MENTEŞE

Prof. Dr. H. Gökmen TEKTUNALI

Prof. Dr. Atilla ÖZGÜÇ