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Document Type |
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Thesis |
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Document Title |
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PHOTOMETRIC AND SPECTRAL ENERGY DISTRIBUTION (SED) STUDIES OF TWO YOUNG OPEN CLUSTERS (YOCS): NGC 1545 AND NGC 2099 دراسات توزيع الطاقة الضوئية والطيفية لاثنين من الحشود النجمية المفتوحة حديثة العمر: NGC 1545 و NGC 2099 |
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Subject |
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Faculty of Science |
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Document Language |
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Arabic |
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Abstract |
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The significance of the studies of galactic star agglomeration stems from the fact that they provide us with valuable information related to the processes of star formation, stellar evolution and the properties of the galactic disk. This thesis determines the fundamental characteristics of six galactic star clusters using both GAIA DR2 Survey observations in BP, RP and G passbands and Two Micron All Sky Survey (2MASS) photometry in J, H, and Ks passbands. The six clusters are: NGC 188, NGC 3680, IC 4651, NGC 1545, NGC 2099 and BLANCO 1. The structural parameters (core radius, limiting radius, etc) and the astrophysical parameters (reddening, distance and age) of the six clusters have been investigated. The star coordinates as well as the proper motion data (GAIA DR2 survey) are extracted from TOPCAT for the clusters. The equatorial coordinates of six clusters are re-determined and the distribution of star number density as a function of the radius far away from the center is derived for each cluster. We used a series of axisymmetric young stellar objects (YSOs) radiation transfer models covering a wide range of stellar masses (from 0.1Mʘ to 50Mʘ) and developmental phases (from the early envelope infall phase to the late disk-only phase). The grid consists of 20,000 YSO models, with spectral energy distributions (SEDs) and polarization spectra calculated for each model at 10 viewing angles, resulting in a total of 200,000 SEDs (Robitaille et al. (2006)). Although near-IR (such as JHK) and mid-IR (such as IRAC) fluxes are helpful in separating stars from YSOs and are useful in detecting very young origins, incorporating longer wavelength information such as MIPS 24 µm is extremely valuable in evaluating the developmental stage of YSOs. |
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Supervisor |
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Prof. Abdulrahman Ali Malawi |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1442 AH
2020 AD |
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Co-Supervisor |
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Prof. Aied Sulaiman Alruhaili |
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Added Date |
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Sunday, August 23, 2020 |
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Researchers
| امال تركي الغامدي | Alghamdi, Amaal Turki | Researcher | Master | |
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