Leader: Jesse van de Sande

Email: jesse.vandesande@sydney.edu.au

Collaborators: This project is open for everyone who wants to collaborate.

Topic: The kinematic properties of Milky Way analogues

Status: under review by Science Committee

Abstract: Despite the wealth of data from our own Galaxy, the origin of its different components – the thin and thick disks, the bulge and bar – remain elusive. Milky Way Analogues (MWAs) offer a unique insight into how our own Milky Way might have formed and bridge the gap between the detailed measurements in our own Galaxy and the predictions from (zoom-in) cosmological simulations. While a number of Milky Way-like galaxies were already identified within the SAMI Galaxy Survey sample [scott2021], the lack of spectral resolution limited a detailed study of the higher order kinematic signatures and orbital distribution within the disks of these galaxies. Hector’s higher spectral resolution is ideally suited to determine the kinematic disk properties of Milky Way analogues. Based on the final SAMI Galaxy Survey sample of ∼ 3000 galaxies, with Hector we will be able to determine the kinematic properties of ∼ 50 galaxies with stellar mass between 10.4 < log(M∗/M⊙) < 10.8 with Milky Way disk-like morphology. We will employ Hector repeat observations to reach the required depth in the disk beyond one Re to measure the higher-order kinematic signatures and link these to their assembly history. Few kinematic studies of Milky Way analogues exist and even with a relatively small sample (N ∼ 50), Hector will be able to make a significant impact in this rapidly growing field.

Needed data products: This project requires deep exposures (3 complete repeats, 9 hrs) on at least 50 Milky Way Analogues. The paper will require stellar mass estimates, colours (g-i), structural parameters (e.g., Sersic profiles, or MGE fits). The stellar kinematics will be derived using the Hector Stellar Kinematic Pipeline, but the paper would also require stellar population estimates (age, metallicity, alpha/Fe).

Publication date: 02/06/2023