PENENTUAN POPULASI BINTANG PADA GALAKSI NGC 3522 DAN NGC 5164 MENGGUNAKAN PENALIZED PIXEL-FITTING
Galaxies are composed of different astronomical objects, all held together by gravity, one of the dominant component that can be observed directly are stars. Based on the age and the chemical composition of the stars, there are two stellar populations: population I and population II.. Study of st...
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| Format: | Final Project |
| Language: | Indonesia |
| Subjects: | |
| Online Access: | https://digilib.itb.ac.id/gdl/view/66013 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Galaxies are composed of different astronomical objects, all held together by
gravity, one of the dominant component that can be observed directly are stars.
Based on the age and the chemical composition of the stars, there are two stellar
populations: population I and population II.. Study of stellar population on a
galaxy will provide an important hint to understand the galaxies evolution. In this
Final Project, I will identify stellar population on elliptical galaxy NGC 3522 and
spiral galaxy NGC 5164 by using full-spectrum fitting method. Spectra of the
galaxies are obtained from Sloan Digital Sky Survey (SDSS) Science Archive and
the spectra of stellar population synthesis model in form of Simple Stellar
Population (SSP) model are obtained from MILES library. The full spectrum
fitting will be performed by using Penalized PiXel-Fitting (pPXF) by weighting
the synthetic templates to study the stellar population of galaxies. Using pPXF, it
is obtained that NGC 3522 composed of stellar population within two age ranges:
old population (> 10 Gyr), and young population (< 5 Gyr); Old population have a
metalicity of 0.0, and young population have a metalicity of 0.0 and 0.22. The
presence of a young stellar population in an elliptical galaxy can indicate
uncommon characteristic that can be found on NGC 3522, that is a rotating gas
disc and presence of satellite galaxy. Meanwhile, NGC 5164 composed by stellar
population within three age ranges: old population, young population, and
intermediate population (5 - 10 Gyr); old population’s metalicity in this galaxy is
0.22, intermediate population’s is 0.0, and young population’s are -0.40, 0.0, and
0.20. Stellar population in NGC5164 can indicate that stellar formation occured at
different time frame within NGC 5164 lifetime. |
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