10318

9535

كارشناسي ارشد

ذرات بنيادي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك

1393

يازده، 74ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

1396/10/03

كتابنامه

فيزيك

فيزيك

ID9535

Star Formation History and Dust Production in Low Metallicity Dwarf Galaxies NGC 147 and NGC 185 Roya Hamedani Golshan r hamedani@ph iut ac ir 17 01 2015 Department of Physics Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Pro B Mirza Dr A Javadi Supervisor Abstract We present the rst reconstruction of the star formation history for two of the most luminous M31dwarf satellite galaxies NGC 147 and NGC 185 using the Long Period Variable stars over 6 4 6 4 eld of view of each galaxy Long period variable stars were chosen from Lorenz et al 2011 Theoretically evolved stars in Asymptotic Giant Branch AGB phase achieve their maximum lu minosity in K band with the wavelength of 2 2 micrometer Maximum luminosity of a star is relatedto its birth mass therefore it is possible to construct birth mass function and drive the star formationhistory For NGC 185 we found a 9 5 Gyr old single star formation epoch at a rate of 0 14 M yr 1 followedby a relatively continuous star formation In the case of NGC 147 one peak as old as 7 Gyr withthe rate of 0 019 M yr 1 can be seen which descend to lower amount with less steep in respect toNGC 185 AGB stars are also important dust factories we t a Spectral Energy Distribution model on observednear and mid infrared data in Lorenz et al 2011 and Wide Field Infrared Survey Explorer re spectively with Dusty code Therefore we are able to estimate AGB stars dust production rates Carbon stars total rate of mass loss is 1 06 10 4 M yr 1 for NGC 147 and 2 89 10 4 M yr 1for NGC 185 Keywords stars evolution galaxies star formation galaxies stellar content galaxies structure stars AGB stars mass loss

بهروز ميرزا، عاطفه جوادي

فرهنگ لران

غلامرضا خسروي، مسلم زارعي