Globular Clusters contain very old metal-poor stars in different evolutionary stages evolved from the same primordial cloud. Signatures of atomic in stellar interiors are studied in the metal-poor GC M30. Furthermore, traces of cluster internal pollution depleting alpha elements e.g. Mg & O are also found through high precision spectroscopy, which favors the existence of multiple stellar populations within a Globular Cluster. In this work, I use spectroscopic observations of 177 sample stars using the multi object spectrograph GIRAFFE and increasing the initial size of 12 of Scheutwinkel (2018) by 13 new UVES spectrograph sample stars of the Globular Cluster M30 ([Fe/H] = -2.3). The abundances of Fe, Ti, Mg & Ba (GIRAFFE) and Fe, Na, Al & Mg (UVES) are derived through the graphical spectrum analysis program SIU with VI broadband photometric stellar input parameters. The underlying line-formation theory is in LTE and uses 1-dimensional hydrostatic plan-parallel MAFAGS atmospheres with mixing length convection. We confirm an Al-Mg anti-correlation (Spearman ϱs= -0.583) and a correlation (Spearman ϱs= 0.641) between Al-Na in RGB stars as a direct result of being the partner elements of the depleted alpha elements Mg & O caused through NeNa, ON and MgAl cycles. We find similar element ratios [X/Fe] as Carretta et al. (2018) & O‘Malley et al. (2018) favoring the prior existence of multiple stellar populations within M30. Furthermore, we detected a signifcant restoration of abundances in the elements Fe, Mg & Ba towards RGB stars. Fe, Mg and Ti are matching the predictions of the diffusion model T5.8 (Richard et al. 2005) reasonably well. For Ba, we have no current atomic diffusion modeling, so the validation of the results is not possible. The trend of Ti is v-shaped presumably due to stronger radiative accelaration effects for this element. Overall our relative abundance trends are consistent with other Globular Cluster studies by Gruyters et al. (2013&2016), Korn et al. (2007) & Lind (2007).
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-381507 |
| Date | January 2019 |
| Creators | Scheutwinkel, Kilian Hikaru |
| Publisher | Uppsala universitet, Observationell astrofysik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | FYSAST ; FYSMAS1090 |
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