A Brown Dwarf Census from the SIMP Survey

TL;DR

This study conducted a near-infrared proper motion survey to identify and characterize ultracool dwarfs in the solar neighborhood, discovering new brown dwarfs, peculiar objects, and unresolved binaries through spectroscopic follow-up.

Contribution

It presents a comprehensive NIR proper motion survey that expands the census of ultracool dwarfs, including new discoveries and peculiar objects, using multi-telescope observations and follow-up spectroscopy.

Findings

Discovery of 2 young field brown dwarfs

Identification of 6 unusually red and 25 unusually blue M and L dwarfs

Detection of 2 candidate unresolved L+T binaries and 24 peculiar UCDs

Abstract

We have conducted a near-infrared (NIR) proper motion survey, the Sondage Infrarouge de Mouvement Propre, in order to discover field ultracool dwarfs (UCD) in the solar neighborhood. The survey was conducted by imaging $\sim28\%$ of the sky with the Cam\'era PAnoramique Proche-InfraRouge both in the southern hemisphere at the Cerro Tololo Inter-American Observatory 1.5 m telescope, and in the northern hemisphere at the Observatoire du Mont-M\'egantic 1.6 m telescope and comparing the source positions from these observations with the Two Micron All-Sky Survey Point Source Catalog (2MASS PSC). Additional color criteria were used to further discriminate unwanted astrophysical sources. We present the results of an NIR spectroscopic follow-up of 169 M, L, and T dwarfs. Among the sources discovered are 2 young field brown dwarfs, 6 unusually red M and L dwarfs, 25 unusually blue M and L dwarfs, 2 candidate unresolved L+T binaries, and 24 peculiar UCDs. Additionally, we add 9 L/T transition dwarfs (L6--T4.5) to the already known objects.