SIMBAD references

2022ApJ...932L..16D - Astrophys. J., 932, L16-L16 (2022/June-3)

The Local Stellar Halo is Not Dominated by a Single Radial Merger Event.

DONLON II T., NEWBERG H.J., KIM B. and LEPINE S.

Abstract (from CDS):

We use halo dwarf stars with photometrically determined metallicities that are located within 2 kpc of the Sun to identify local halo substructure. The kinematic properties of these stars do not indicate a single, dominant radial merger event (RME). The retrograde Virgo Radial Merger (VRM) component has [Fe/H] = -1.7. A second, nonrotating RME component we name Nereus is identified with [Fe/H] = -2.1 and has similar energy to the VRM. We identify a possible third RME, which we name Cronus, that is corotating with the disk, has lower energy than the VRM, and has [Fe/H] = -1.2. We identify the Nyx Stream in the data. In addition to these substructures, we observe metal-poor halo stars ([Fe/H] ∼ -2.0 and σv ∼ 180 km s–1) and a disk/Splash component with lower rotational velocity than the disk and lower metallicity than typically associated with the Splash. An additional excess of halo stars with low velocity and metallicity of [Fe/H] = -1.5 could be associated with the shell of a lower-energy RME or indicate that lower-energy halo stars have higher metallicity. Stars that comprise the "Gaia Sausage" velocity structure are a combination of the components identified in this work.

Abstract Copyright: © 2022. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): Milky Way Galaxy - Galaxy mergers - Galaxy accretion - Milky Way dynamics

Errata: erratum vol. 941, art. L21 (2022)

Simbad objects: 4

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2022ApJ...932L..16D and select 'bookmark this link' or equivalent in the popup menu