The chemical composition of an extrasolar planet is fundamental to its formation, evolution and habitability. In this study, we explore a new way to measure the chemical composition of the building blocks of extrasolar planets, by measuring the gas composition of the disrupted planetesimals around white dwarf stars. As a first attempt, we used the photo-ionization code Cloudy to model the circumstellar gas emission around a white dwarf Gaia J0611−6931 under some simplified assumptions. We found most of the emission lines are saturated and the line ratios approaching the ratios of thermal emission; therefore only lower limits to the number density can be derived. Silicon is the best constrained element in the circumstellar gas and we derived a lower limit of 1010.3 cm−3. In addition, we placed a lower limit on the total amount of gas to be 1.8 × 1019 g. Further study is needed to better constrain the parameters of the gas disk and connect it to other white dwarfs with circumstellar gas absorption.
@article{arxiv.2403.15794,
title = {Modeling Circumstellar Gas Emission around a White Dwarf Using Cloudy},
author = {Siyi Xu and Sherry Yeh and Laura. K. Rogers and Amy Steele and Erik Dennihy and Alexandra E. Doyle and P. Dufour and Beth L. Klein and Christopher J. Manser and Carl Melis and Tinggui Wang and Alycia J. Weinberger},
journal= {arXiv preprint arXiv:2403.15794},
year = {2024}
}
Comments
14 pages, 10 figures, 4 table, accepted for publication in AJ