2024 #5

Stellar Spectra from the DESI Milky Way Survey

Andrew Cooper (NTHU)

※Keywords:
Milky Way, DESI, Stars, Spectroscopy, Stellar Populations

※Description:
The spectra of a star reveals a wealth of information about its structure, its composition, and ultimately its origin. This project will explore the classification and analysis of stellar spectra from the ongoing DESI Milky Way Survey (https://doi.org/10.3847/1538-4357/acb3c0), the largest database of moderate-resolution optical stellar spectroscopy ever assembled.

Within the theme of DESI spectroscopy and Milky Way stellar populations, there is a lot of flexibility to find a topic that interests you. We’ll start (hopefully, a bit before the summer) by discussing the nature of the data and how to work with it, and find a topic of mutual interest. Potential projects include:
●searching for rare and unusual types of star;
identifying and fitting models to spectra that are not handled well by the DESI MWS analysis pipelines;
●testing and optimising the design of the DESI “twilight time” observations of bright stars.
●assembling a detailed “spectral atlas” of stellar types.
●understanding what kinds of stellar targets are found ‘accidentally’ by other DESI programs.

Regardless of the topic, you will be the first person to look at most of the spectra you examine. Perhaps you could find something no-one has ever seen before!

Note: This project would best suit undergraduate students, who will have a unique opportunity to work on the full DESI catalog, including unreleased data. For unavoidable reasons related to proprietary data rights in the DESI collaboration, students already at MS level or above will only be able to work with the subset of DESI data that are already public.

※Required Background:
●Experience with Unix(MacOs)/Linux, Python and Jupyter notebooks or equivalent. The project will involve searching, manipulating and plotting large amounts of data. It will also involve remote work on the NTHU CICA computing cluster.
●Basic familiarity with astrophysical concepts related to stars and spectroscopy, at the level of an undergraduate “introduction to astronomy” course (for example, how stars evolve, and why they have different colors and brightnesses). More detailed knowledge of stellar astrophysics is desirable, but not required.