Eclipsing binary systems hold a central position within astrophysics in that the fundamental para... more Eclipsing binary systems hold a central position within astrophysics in that the fundamental parameters of stars can be determined by direct observations. The simultaneous analyses of high-quality space observations, combined with ground-based photometric data, have allowed more sensitive detection of fundamental stellar parameters by multicolor photometry. In the paper, the fundamental parameters of the component stars for the V1175 Cas binary system were sensitively obtained by a simultaneous analysis of the Transiting Exoplanet Survey Satellite (TESS) light curve, and new CCD observations in BVRI filters obtained with a 60 cm robotic telescope at the TÜBİTAK National Observatory. Following the analysis, the masses and radii of the primary and secondary binary components were determined as M 1 = 1.
Eclipsing binary systems play a pivotal role in quantifying the absolute parameters of stars, suc... more Eclipsing binary systems play a pivotal role in quantifying the absolute parameters of stars, such as the mass (M), the radius (R), and the luminosity (L), offering invaluable laboratories for astronomical research and enhancing our comprehension of stellar evolution as well as galaxy dynamics. These systems provide a unique opportunity to precisely ascertain these crucial parameters. The simultaneous analyses of high-quality space observations, combined with ground-based photometric data, have allowed more sensitive detection of fundamental stellar parameters by multicolour photometry. In the paper, the absolute parameters of the component stars for the V1010 Cas binary system were sensitively obtained by a simultaneous analysis of the Transiting Exoplanet Survey Satellite (TESS) light curve, and new CCD observations in BVRI filters obtained with 60 cm Robotic telescope (T60) at the TUBITAK National Observatory. Thereby, the radii and masses of the primary and secondary components ...
Bu tez calismasinda, kromosferik aktif bir cift sistem olan V772 Her’in 3 Temmuz 2006 ile 3 Eylul... more Bu tez calismasinda, kromosferik aktif bir cift sistem olan V772 Her’in 3 Temmuz 2006 ile 3 Eylul 2007 tarihleri arasinda Ankara Universitesi Gozlemevi’ndeki (AUG) 30 cm’lik Maksutov teleskobu ve TUBITAK Ulusal Gozlemevi’ndeki (TUG) 40 cm’lik Cassegrain teleskobu kullanilarak elde edilen B, V ve R bandi isik egrileri sunulmaktadir. Isik egrisi analizleri Wilson-Devinney (WD) programi (2004 versiyonu) araciligiyla yapildi ve her bir bilesen uzerinde bir leke olmak uzere iki lekeli cozum sonucunun gozlemsel isik egrileri ile uyumlu oldugu bulundu. Bu cozum sonucunda bilesenlerin sicakliklari T1=5900 °K, T2=4500 °K, kutleleri M1=1,15 M, M2= 0,68 M, yaricaplari, R1= 0,9 R, R2= 0,61 R, q= 0,59, i= 75°,6 olarak elde edildi. V772 Her sisteminin isik egrisi analizinden elde edilen dinamik ve fiziksel parametrelerinin, daha once diger yazarlar tarafindan bulunan degerler ile yaklasik olarak uyumlu olduklari goruldu. Ek olarak sistemin 1981 yilinda alinmis uc IUE-Newsips tayfi NASA’nin IUE arsivinden elde edilerek incelendi. Tayflarda kromosfer ve gecis bolgesinde olusan salma cizgileri goruldu. Salma cizgi akilari Gauss profili fit islemine dayanarak hesaplandi. Bu tayflarda gorulen salma cizgileri sistemin morote etkinligine bagli olarak degerlendirilmeye calisildi. Ancak bu verilerin az olmasi nedeniyle, sistemin isik egrileriyle beraber, salma cizgi akilarinin zamana veya yorunge evresine bagli degisimine iliskin yorum yapilabilecek seviyede bilgi elde edinilemedi.Abstract In this thesis, B,V and R light curves of chromospherically active binary V772 Her obtained between July 3, 2006 and September 3, 2007 by using 30 cm Maksutov Telescope of Ankara University Observatory (AUG) and 40 cm Cassegrain Telescope of TUBITAK National Observatory (TUG) are presented. Light curve analyses were made by means of Wilson-Devinney (WD) program (Version of 2004) and the achieved result with two spots located on each component of the system is found to be well fitted the observational light curves. This analyses reveals that the temperatures, masses and radii of the components are T1= 5900 °K, T2= 4500 °K, M1=1,15 M, M2=0,68 M, and R1= 0,9 R, R2= 0,61 R, respectively. The mass ratio and orbital inclination are found to be q=0,59 and, i=75°,6, respectively. Dynamical and physical parameters of V772 Her, obtained by this light curve analyses, are found to be in agreement with those obtained previously by other authors. In addition, three IUE-Newsips spectra, acquired in 1981, obtained from the NASA IUE archive were analyzed. The spectra show emission lines originating in the chromosphere and transition region. The emission line fluxes were computed based on Gaussian profile fitting procedures. Emission lines seen in these spectra were tried to evaluate according to system’s ultraviolet activity. But, it could not be possible to obtain enough information on the flux variability in time or orbital phase from these spectra to evaluate with the light curves of the system.
Eclipsing binary systems are significant objects for astrophysics in that direct observations can... more Eclipsing binary systems are significant objects for astrophysics in that direct observations can determine the fundamental parameters of stars. In this study, we determined precisely the fundamental parameters of the binary component stars obtained by simultaneous analysis of radial velocities and the TESS light curve using the Wilson and Devinney code. Following the analysis, the masses and radii of the primary and secondary components were determined as 1 = 1.58 ± 0.01 ⊙ , 2 = 0.48 ± 0.02 ⊙ , and 1 = 1.93 ± 0.01 ⊙ , 2 = 1.14 ± 0.01 ⊙ , respectively. Furthermore, the distance of IS CMa is calculated as 92.7 ± 6.5 pc. On the basis of the analysis of the mid-eclipse times, it was found that the variation in the orbital period is represented by an upward parabola. It has an increasing rate of ∕ = 1.09 × 10 −7 day yr −1. Using PARSEC stellar evolutionary tracks and isochrones with solar metallicity were estimated the age of IS CMa as 1.3 ± 0.1 Gyr. Kinematic and Galactic orbital parameters of IS CMa were obtained from the astrometric and spectroscopic data of the system. The Galactic orbit analysis reveals that IS CMa formed inside the solar circle and it is a member of the young thin-disc population.
We present the relation between supermassive black hole (M•) and host galaxy masses (MGal) in ter... more We present the relation between supermassive black hole (M•) and host galaxy masses (MGal) in terms of the host galaxy morphology using data taken from Nair & Abraham (2010). Since the data don’t contain the black hole masses, we calculate them using the M•–σ (σ: velocity dispersion) relation given by Gultekin et al. (2009). We find a strong linear relation between black hole and host galaxy masses. In addition, there is a finding which shows that the most massive black holes are contained by the elliptical galaxies and also these galaxies tend to be more massive than the other galaxies. Depending on these results, we discuss that these massive ellipticals could probably be formed or evaluated by mergers. Introduction Relations between the masses of supermassive black holes, located at the centre of galaxies with a mass from ∼ 103 to ∼ 109M , and properties of host galaxies, such as morphologies, masses, absolute magnitudes, etc. possess information about the evolution of galaxies. ...
We present an archival Chandra study of the O-rich supernova remnant (SNR) 1E 0102.2-7219 in the ... more We present an archival Chandra study of the O-rich supernova remnant (SNR) 1E 0102.2-7219 in the Small Magellanic Cloud. Based on the deep ∼ 265 ks archival Chandra data we performed a detailed spatially resolved spectral analysis of 1E 0102.2-7219. Our aim is to reveal the spatial and chemical structures of this remnant in unprecedented details. Radial profiles of O, Ne and Mg abundances based on our analysis of regional spectra extracted along nine different azimuthal directions of 1E 0102.2-7219 suggest the contact discontinuity at ∼ 5-5.5 pc from the geometric center of the X-ray emission of the SNR. We find that the metal-rich ejecta gas extends further outward in west and southwest than in other directions of the SNR. The average O/Ne, O/Mg and Ne/Mg abundance ratios of the ejecta are in plausible agreement with the nucleosynthesis products from the explosion of a ∼ 40M ⊙ progenitor. We estimate an upper limit on the Sedov age of ∼ 3500 yr and explosion energy of ∼ 1.8 × 10 51 erg for 1E 0102.2-7219. We discuss the implications of our results on the geometrical structure of the remnant, its circumstellar medium and the nature of the progenitor star. Our results do not fit with a simple picture of the reverse-shocked emission from a spherical shell-like ejecta gas with a uniformly-distributed metal abundance and a power-law density along the radius of the SNR.
Araştırmada Büyük Macellan Bulutsusundaki süpernova kalıntısı DEM L71'in 103 ksn'lik {\it... more Araştırmada Büyük Macellan Bulutsusundaki süpernova kalıntısı DEM L71'in 103 ksn'lik {\it Chandra} arşiv verileriyle kapsamlı bir X-ışın tayf analizi gerçekleştirilmiştir. Kalıntı yedi farklı doğrultuda toplam 50 bölgeye ayrılarak incelenmiş ve plazma parametreleri ile element bollukları konumsal olarak elde edilmiştir. Öncü şokun süpürdüğü çevresel maddenin fiziksel yapısı da belirlenmiştir. Element bolluk ölçümleri, kalıntının asimetrik bir uzaysal dağılıma sahip olduğunu ortaya koymuştur. Değme süreksizliğinin konumu, batı yönü hariç, genellikle DEM L71'in geometrik merkezinden $\sim 5$ pc uzaklıktadır. Patlama ile atılan maddede Fe bolluğu fazlayken, O ve Ne bollukları genellikle ihmal edilebilir düzeydedir. Bu bulgu, DEM L71'in Tip Ia kökenli olduğunu desteklemektedir. Kalıntı için Sedov yaşı $\sim 6,660 \pm 770$ yıl ve patlama enerjisi $E_0$ $\sim 1.74 \pm 0.35 \times 10^{51}$ erg olarak hesaplanmıştır.
Eclipsing binary systems hold a central position within astrophysics in that the fundamental para... more Eclipsing binary systems hold a central position within astrophysics in that the fundamental parameters of stars can be determined by direct observations. The simultaneous analyses of high-quality space observations, combined with ground-based photometric data, have allowed more sensitive detection of fundamental stellar parameters by multicolor photometry. In the paper, the fundamental parameters of the component stars for the V1175 Cas binary system were sensitively obtained by a simultaneous analysis of the Transiting Exoplanet Survey Satellite (TESS) light curve, and new CCD observations in BVRI filters obtained with a 60 cm robotic telescope at the TÜBİTAK National Observatory. Following the analysis, the masses and radii of the primary and secondary binary components were determined as M 1 = 1.
Eclipsing binary systems play a pivotal role in quantifying the absolute parameters of stars, suc... more Eclipsing binary systems play a pivotal role in quantifying the absolute parameters of stars, such as the mass (M), the radius (R), and the luminosity (L), offering invaluable laboratories for astronomical research and enhancing our comprehension of stellar evolution as well as galaxy dynamics. These systems provide a unique opportunity to precisely ascertain these crucial parameters. The simultaneous analyses of high-quality space observations, combined with ground-based photometric data, have allowed more sensitive detection of fundamental stellar parameters by multicolour photometry. In the paper, the absolute parameters of the component stars for the V1010 Cas binary system were sensitively obtained by a simultaneous analysis of the Transiting Exoplanet Survey Satellite (TESS) light curve, and new CCD observations in BVRI filters obtained with 60 cm Robotic telescope (T60) at the TUBITAK National Observatory. Thereby, the radii and masses of the primary and secondary components ...
Bu tez calismasinda, kromosferik aktif bir cift sistem olan V772 Her’in 3 Temmuz 2006 ile 3 Eylul... more Bu tez calismasinda, kromosferik aktif bir cift sistem olan V772 Her’in 3 Temmuz 2006 ile 3 Eylul 2007 tarihleri arasinda Ankara Universitesi Gozlemevi’ndeki (AUG) 30 cm’lik Maksutov teleskobu ve TUBITAK Ulusal Gozlemevi’ndeki (TUG) 40 cm’lik Cassegrain teleskobu kullanilarak elde edilen B, V ve R bandi isik egrileri sunulmaktadir. Isik egrisi analizleri Wilson-Devinney (WD) programi (2004 versiyonu) araciligiyla yapildi ve her bir bilesen uzerinde bir leke olmak uzere iki lekeli cozum sonucunun gozlemsel isik egrileri ile uyumlu oldugu bulundu. Bu cozum sonucunda bilesenlerin sicakliklari T1=5900 °K, T2=4500 °K, kutleleri M1=1,15 M, M2= 0,68 M, yaricaplari, R1= 0,9 R, R2= 0,61 R, q= 0,59, i= 75°,6 olarak elde edildi. V772 Her sisteminin isik egrisi analizinden elde edilen dinamik ve fiziksel parametrelerinin, daha once diger yazarlar tarafindan bulunan degerler ile yaklasik olarak uyumlu olduklari goruldu. Ek olarak sistemin 1981 yilinda alinmis uc IUE-Newsips tayfi NASA’nin IUE arsivinden elde edilerek incelendi. Tayflarda kromosfer ve gecis bolgesinde olusan salma cizgileri goruldu. Salma cizgi akilari Gauss profili fit islemine dayanarak hesaplandi. Bu tayflarda gorulen salma cizgileri sistemin morote etkinligine bagli olarak degerlendirilmeye calisildi. Ancak bu verilerin az olmasi nedeniyle, sistemin isik egrileriyle beraber, salma cizgi akilarinin zamana veya yorunge evresine bagli degisimine iliskin yorum yapilabilecek seviyede bilgi elde edinilemedi.Abstract In this thesis, B,V and R light curves of chromospherically active binary V772 Her obtained between July 3, 2006 and September 3, 2007 by using 30 cm Maksutov Telescope of Ankara University Observatory (AUG) and 40 cm Cassegrain Telescope of TUBITAK National Observatory (TUG) are presented. Light curve analyses were made by means of Wilson-Devinney (WD) program (Version of 2004) and the achieved result with two spots located on each component of the system is found to be well fitted the observational light curves. This analyses reveals that the temperatures, masses and radii of the components are T1= 5900 °K, T2= 4500 °K, M1=1,15 M, M2=0,68 M, and R1= 0,9 R, R2= 0,61 R, respectively. The mass ratio and orbital inclination are found to be q=0,59 and, i=75°,6, respectively. Dynamical and physical parameters of V772 Her, obtained by this light curve analyses, are found to be in agreement with those obtained previously by other authors. In addition, three IUE-Newsips spectra, acquired in 1981, obtained from the NASA IUE archive were analyzed. The spectra show emission lines originating in the chromosphere and transition region. The emission line fluxes were computed based on Gaussian profile fitting procedures. Emission lines seen in these spectra were tried to evaluate according to system’s ultraviolet activity. But, it could not be possible to obtain enough information on the flux variability in time or orbital phase from these spectra to evaluate with the light curves of the system.
Eclipsing binary systems are significant objects for astrophysics in that direct observations can... more Eclipsing binary systems are significant objects for astrophysics in that direct observations can determine the fundamental parameters of stars. In this study, we determined precisely the fundamental parameters of the binary component stars obtained by simultaneous analysis of radial velocities and the TESS light curve using the Wilson and Devinney code. Following the analysis, the masses and radii of the primary and secondary components were determined as 1 = 1.58 ± 0.01 ⊙ , 2 = 0.48 ± 0.02 ⊙ , and 1 = 1.93 ± 0.01 ⊙ , 2 = 1.14 ± 0.01 ⊙ , respectively. Furthermore, the distance of IS CMa is calculated as 92.7 ± 6.5 pc. On the basis of the analysis of the mid-eclipse times, it was found that the variation in the orbital period is represented by an upward parabola. It has an increasing rate of ∕ = 1.09 × 10 −7 day yr −1. Using PARSEC stellar evolutionary tracks and isochrones with solar metallicity were estimated the age of IS CMa as 1.3 ± 0.1 Gyr. Kinematic and Galactic orbital parameters of IS CMa were obtained from the astrometric and spectroscopic data of the system. The Galactic orbit analysis reveals that IS CMa formed inside the solar circle and it is a member of the young thin-disc population.
We present the relation between supermassive black hole (M•) and host galaxy masses (MGal) in ter... more We present the relation between supermassive black hole (M•) and host galaxy masses (MGal) in terms of the host galaxy morphology using data taken from Nair & Abraham (2010). Since the data don’t contain the black hole masses, we calculate them using the M•–σ (σ: velocity dispersion) relation given by Gultekin et al. (2009). We find a strong linear relation between black hole and host galaxy masses. In addition, there is a finding which shows that the most massive black holes are contained by the elliptical galaxies and also these galaxies tend to be more massive than the other galaxies. Depending on these results, we discuss that these massive ellipticals could probably be formed or evaluated by mergers. Introduction Relations between the masses of supermassive black holes, located at the centre of galaxies with a mass from ∼ 103 to ∼ 109M , and properties of host galaxies, such as morphologies, masses, absolute magnitudes, etc. possess information about the evolution of galaxies. ...
We present an archival Chandra study of the O-rich supernova remnant (SNR) 1E 0102.2-7219 in the ... more We present an archival Chandra study of the O-rich supernova remnant (SNR) 1E 0102.2-7219 in the Small Magellanic Cloud. Based on the deep ∼ 265 ks archival Chandra data we performed a detailed spatially resolved spectral analysis of 1E 0102.2-7219. Our aim is to reveal the spatial and chemical structures of this remnant in unprecedented details. Radial profiles of O, Ne and Mg abundances based on our analysis of regional spectra extracted along nine different azimuthal directions of 1E 0102.2-7219 suggest the contact discontinuity at ∼ 5-5.5 pc from the geometric center of the X-ray emission of the SNR. We find that the metal-rich ejecta gas extends further outward in west and southwest than in other directions of the SNR. The average O/Ne, O/Mg and Ne/Mg abundance ratios of the ejecta are in plausible agreement with the nucleosynthesis products from the explosion of a ∼ 40M ⊙ progenitor. We estimate an upper limit on the Sedov age of ∼ 3500 yr and explosion energy of ∼ 1.8 × 10 51 erg for 1E 0102.2-7219. We discuss the implications of our results on the geometrical structure of the remnant, its circumstellar medium and the nature of the progenitor star. Our results do not fit with a simple picture of the reverse-shocked emission from a spherical shell-like ejecta gas with a uniformly-distributed metal abundance and a power-law density along the radius of the SNR.
Araştırmada Büyük Macellan Bulutsusundaki süpernova kalıntısı DEM L71'in 103 ksn'lik {\it... more Araştırmada Büyük Macellan Bulutsusundaki süpernova kalıntısı DEM L71'in 103 ksn'lik {\it Chandra} arşiv verileriyle kapsamlı bir X-ışın tayf analizi gerçekleştirilmiştir. Kalıntı yedi farklı doğrultuda toplam 50 bölgeye ayrılarak incelenmiş ve plazma parametreleri ile element bollukları konumsal olarak elde edilmiştir. Öncü şokun süpürdüğü çevresel maddenin fiziksel yapısı da belirlenmiştir. Element bolluk ölçümleri, kalıntının asimetrik bir uzaysal dağılıma sahip olduğunu ortaya koymuştur. Değme süreksizliğinin konumu, batı yönü hariç, genellikle DEM L71'in geometrik merkezinden $\sim 5$ pc uzaklıktadır. Patlama ile atılan maddede Fe bolluğu fazlayken, O ve Ne bollukları genellikle ihmal edilebilir düzeydedir. Bu bulgu, DEM L71'in Tip Ia kökenli olduğunu desteklemektedir. Kalıntı için Sedov yaşı $\sim 6,660 \pm 770$ yıl ve patlama enerjisi $E_0$ $\sim 1.74 \pm 0.35 \times 10^{51}$ erg olarak hesaplanmıştır.
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