Presentation #203.02 in the session Mapping and Modeling the Milky Way’s Tidal Streams.
The stellar halo of the Milky Way was predominantly formed by the merging of numerous progenitor galaxies. However, our knowledge of this merging process is still incomplete, especially in regard to the total number of mergers, their global dynamical properties and their contribution to the stellar population of the Galactic halo. In this regard, I will talk about two algorithms, namely STREAMFINDER and ENLINK, and show their power in detecting and characterizing the Milky Way mergers using the ESA/Gaia dataset.
1) STREAMFINDER is specially designed to detect stellar streams of the halo. Using Gaia DR2 and EDR3, STREAMFINDER has charted more than 40 streams in our Galaxy. I will discuss some interesting dynamical and chemical properties of these streams. [This discussion will be based on our numerous STREAMFINDER-based papers, for instance, https://arxiv.org/abs/2104.09523]
2) ENLINK is a group-finding algorithm that we recently employed to analyse the Gaia EDR3 based orbits of 170 globular clusters, 41 streams and 46 satellite galaxies. We detected 7 mergers: including the previously known “Sagittarius”, “Cetus”, “Gaia-Sausage/Enceladus”, “LMS-1/Wukong”, “Sequoia+Arjuna+I'itoi” and two discoveries — “Pontus” and “Candidate”. I will discuss the properties of these massive mergers and also focus on the most metal-poor merger of our Galaxy (that possess [Fe/H]minima ~ -3.4 dex). [This discussion will be based on our ApJ paper: https://arxiv.org/abs/2202.07660]