Hot atmospheres of massive galaxies are enriched with metals. Elemental abundances measured in the X-ray band have been used to study the chemical enrichment of supernova remnants, elliptical... Show moreHot atmospheres of massive galaxies are enriched with metals. Elemental abundances measured in the X-ray band have been used to study the chemical enrichment of supernova remnants, elliptical galaxies, groups, and clusters of galaxies. Here we measure the elemental abundances of the hot atmosphere of luminous infrared galaxy Arp 299 observed with XMM-Newton. To measure the abundances in the hot atmosphere, we use a multi-temperature thermal plasma model, which provides a better fit to the Reflection Grating Spectrometer data. The observed Fe/O abundance ratio is subsolar, while those of Ne/O and Mg/O are slightly above solar. Core-collapse supernovae (SNcc) are the dominant metal factory of elements like O, Ne, and Mg. We find some deviations between the observed abundance patterns and theoretical ones from a simple chemical enrichment model. One possible explanation is that massive stars with M-star greater than or similar to 23-27 M-circle dot might not explode as SNcc and enrich the hot atmosphere. This is in accordance with the missing massive SNcc progenitors problem, where very massive progenitors M-star greater than or similar to 18 M-circle dot of SNcc have not been clearly detected. It is also possible that theoretical SNcc nucleosynthesis yields of Mg/O yields are underestimated. Show less
A remarkable population of short period transiting rocky exoplanets with equilibrium temperatures on the order of 2,000 K has recently been discovered. Their high temperatures make them very... Show moreA remarkable population of short period transiting rocky exoplanets with equilibrium temperatures on the order of 2,000 K has recently been discovered. Their high temperatures make them very different to the planets in our solar system. In particular, hot super-Earths are thought to have mineral atmospheres that are produced by the vaporisation of their surfaces, or large exospheres that are produced by sputtering of their exposed surfaces by intense stellar winds. Additionally, some smaller, low surface gravity hot rocky exoplanets have been found to be actively disintegrating and forming 'comet-like' dust tails that produce asymmetric transit light curves with forward scattering features. Since the gas and dust originates from the planetary surface, these planets offer the tantalising prospect of enabling us to probe the surface composition of rocky planets. The purpose of this thesis is to work towards this goal by searching for gas around hot rocky exoplanets with observational spectroscopy (Chapters 2 and 5), and by modelling the transit light curves produced by their 'comet-like' dust tails (Chapters 3 and 4). Show less