Kinematics of Very Metal-Poor Stars in the Inner Regions of Aurigaia Galaxies

Sipma, Sten (2022) Kinematics of Very Metal-Poor Stars in the Inner Regions of Aurigaia Galaxies. Bachelor's Thesis, Astronomy.

Preview	Text bsc_thesis_sten_sipma.pdf Download (17MB) | Preview
	Text toestemming.pdf Restricted to Registered users only Download (94kB)

Abstract

The bulge in the Milky Way is known to be a Boxy/Peanut bulge, however recent observations show that a spherical, non-rotating component might be hiding in the metal-poor populations. These observations show that the strength of the rotational signal decreases with metallicity, to almost no rotation for very metal-poor stars ([Fe/H] < −2). In this thesis we reproduce the-pattern using a Gaia DR2 mock of a subset of the auriga cosmological magneto-hydrodynamical simulated galaxies, showing that the rotational fall-off is not unique to the Milky Way. Moreover, we show that observations of this pattern are roboust against a range of selection effects, and therefore are representative of what most likely is the underlying reality. Finally, we look at a connection with the merger history of the galaxies, qualitatively showing that bulge rotation decreases in galaxies with an active merger history until populations with metallicity −1 < [Fe/H] < −0.5, or ages between 8 − 9 Gyr. For galaxies with a more quiescent merger history, the decrease in rotation continues until metallicities −1.5 < [Fe/H] < −1 (or ages > 12 Gyr). The latter results suggest that by measuring rotational fall-off, we can put constraints on major merger events in the Milky Way

Item Type:	Thesis (Bachelor's Thesis)
Supervisor name:	Starkenburg, E.
Degree programme:	Astronomy
Thesis type:	Bachelor's Thesis
Language:	English
Date Deposited:	03 Aug 2022 14:11
Last Modified:	11 Aug 2022 12:41
URI:	https://fse.studenttheses.ub.rug.nl/id/eprint/28009

Actions (login required)

View Item