The Metal-weak Thick Disc Population

Home

Discover

Bookmarks

Keep Up With Latest Trending Papers. Computer Science, AI and Machine Learning and more.Subscribe

CC 0

Source arXiv

Astrophysics of Galaxies

The Metal-weak Thick Disc Population

The Atari Disk, a Metal-Poor Stellar Population in the Disk System of the Milky Way

We have developed a chemo-dynamical approach to assign 36,010 metal-poor skymapper stars to various galactic stellar populations.

Using two independent techniques (velocity and action space behavior, and photometric metallicities), we selected stars with the characteristics of the"metal-weak"thick disk population by minimizing contamination by the canonical thick disk or other galactic structures.

This sample comprises 7,127 stars, spans a metallicity range of and has a systematic rotationational velocity of that lags that of the thick disk.

Orbital eccentricities have intermediate values between typical thick disk and halo values.

The scale length is and the scale height is.

The metallicity distribution function is well fit by an exponential with a slope of.

Overall, we find a significant metal-poor component consisting of 261 stars with.

Our sample contains only eleven stars with investigating the jinabase compilation of metal-poor stars reveals another 18 such stars that kinematically belong to our sample.

These distinct spatial, kinematic and chemical characteristics strongly suggest this metal-poor, phase-mixed kinematic sample to represent an independent diskcomponent with an accretion origin in which a massive dwarf galaxy radially plunged into the early galactic disk.

Going forward, we propose to call the metal-weak thick disk population as the atari disk, given its likely accretion origin, and in reference to it sharing space with the galactic thin and thick disks.

Authors

Mohammad K. Mardini, Anna Frebel, Anirudh Chiti, Yohai Meiron, Kaley V. Brauer, Xiaowei Ou

◐ Recommended Follows

◐ Latest Activity