# Exploring the Brown Dwarf Desert: New Substellar Companions from the SDSS-III MARVELS Survey

## TL;DR

This study reports 10 new brown dwarf companions and 2 low-mass stellar companions around solar-type stars, providing new data to understand the brown dwarf desert phenomenon and its implications for substellar object formation.

## Contribution

The paper introduces new substellar companions discovered via the MARVELS survey, utilizing an improved data pipeline to reduce errors and enhance detection of brown dwarfs.

## Key findings

- 10 brown dwarf companions with masses 13-76 M_Jup within 1 AU
- Estimated brown dwarf occurrence rate of 0.56% around solar-type stars
- Improved detection pipeline reduces systematic errors in radial velocity data

## Abstract

Planet searches using the radial velocity technique show a paucity of companions to solar-type stars within ~5 AU in the mass range of ~10 - 80 M$_{\text{Jup}}$. This deficit, known as the brown dwarf desert, currently has no conclusive explanation. New substellar companions in this region help asses the reality of the desert and provide insight to the formation and evolution of these objects. Here we present 10 new brown dwarf and two low-mass stellar companion candidates around solar-type stars from the Multi-object APO Radial-Velocity Exoplanet Large-Area Survey (MARVELS) of the Sloan Digital Sky Survey III (SDSS-III). These companions were selected from processed MARVELS data using the latest University of Florida Two Dimensional (UF2D) pipeline, which shows significant improvement and reduction of systematic errors over previous pipelines. The 10 brown dwarf companions range in mass from ~13 to 76 M$_{\text{Jup}}$ and have orbital radii of less than 1 AU. The two stellar companions have minimum masses of ~98 and 100 M$_{\text{Jup}}$. The host stars of the MARVELS brown dwarf sample have a mean metallicity of [Fe/H] = 0.03 $\pm$ 0.08 dex. Given our stellar sample we estimate the brown dwarf occurrence rate around solar-type stars with periods less than ~300 days to be ~0.56%.