The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Taurus

TL;DR

This study measures the Initial Mass Function in Taurus, revealing fewer brown dwarfs and a different stellar mass distribution compared to the Trapezium Cluster, providing insights into star formation processes.

Contribution

It presents the first detailed IMF measurement for Taurus, highlighting differences from other regions and testing star formation theories.

Findings

Taurus has a steeper slope in the IMF above 1 solar mass.

Significant deficit of brown dwarfs in Taurus compared to expectations.

IMF differences support environmental influence on star formation.

Abstract

By combining deep optical imaging and infrared spectroscopy with data from the Two-Micron All-Sky Survey (2MASS) and from previous studies (e.g., Briceno et al.), I have measured the Initial Mass Function (IMF) for a reddening-limited sample in four fields in the Taurus star forming region. This IMF is representative of the young populations within these fields for masses above 0.02 Msun. Relative to the similarly derived IMF for the Trapezium Cluster (Luhman et al.), the IMF for Taurus exhibits a modest deficit of stars above one solar mass (i.e., steeper slope), the same turnover mass (~0.8 Msun), and a significant deficit of brown dwarfs. If the IMF in Taurus were the same as that in the Trapezium, 12.8+/-1.8 brown dwarfs (>0.02 Msun) are expected in these Taurus fields where only one brown dwarf candidate is found. These results are used to test theories of the IMF.