A Spitzer Search For Planetary-Mass Brown Dwarfs With Circumstellar Disks: Candidate Selection

TL;DR

This study uses Spitzer infrared data to identify and analyze very low-mass brown dwarf candidates with circumstellar disks in Ophiuchus, aiming to understand their properties and formation.

Contribution

It extends previous work by applying deep IRAC photometry to find new brown dwarf candidates with disks, potentially down to planetary masses.

Findings

18 new brown dwarf candidates identified

Candidates have luminosities down to 10^-4 L_sun

Potential masses as low as ~2 Jupiter masses

Abstract

We report on initial results from a Spitzer program to search for very low-mass brown dwarfs in Ophiuchus. This program is an extension of an earlier study by Allers et al. which had resulted in an extraordinary success rate, 18 confirmed out of 19 candidates. Their program combined near-infrared and Spitzer photom- etry to identify objects with very cool photospheres together with circumstellar disk emission to indicate youth. Our new program has obtained deep IRAC pho- tometry of a 0.5 deg2 field that was part of the original Allers et al. study. We report 18 new candidates whose luminosities extend down to 10-4 L\cdot which sug- gests masses down to ~ 2 MJ if confirmed. We describe our selection techniques, likely contamination issues, and follow-on photometry and spectroscopy that are in progress.