The Minimum Jeans Mass, Brown Dwarf Companion IMF, and Predictions for Detection of Y-type Dwarfs
Ben Zuckerman, Inseok Song

TL;DR
This paper discusses the minimum mass for brown dwarf formation, predicts the rarity of Y-type dwarf companions at large distances, and estimates the brown dwarf initial mass function based on observational data.
Contribution
It introduces a theoretical minimum Jeans mass cutoff, predicts the scarcity of Y-type companions at large semi-major axes, and provides an initial estimate of the brown dwarf IMF from companion observations.
Findings
Y-type dwarf companions are expected to be rare at large semi-major axes.
The brown dwarf IMF follows a power law proportional to mass^-1.2.
Substellar companions below 13.5 Mj are uncommon at large orbital distances.
Abstract
Cool L- and T-type objects were discovered first as companions to stars in 1988 and 1995, respectively. A certain example of the yet cooler Y-type spectral class (Teff <~ 500K?) has not been seen. Recent infrared imaging observations of stars and brown dwarfs indicate that substellar companions with large semi-major axes and with masses less than the brown dwarf/giant planet dividing line (~13.5 Mj) are rare. Theoretical considerations of Jeans mass fragmentation of molecular clouds are consistent with this minimum mass cutoff and also with the semi-major axis (hundreds of AU) characteristic of the lowest mass imaged companions. As a consequence, Y-class companions with large semi-major axes should be scarce around stars <2Gyr old, and also around substellar primaries of all ages. By focusing on brown dwarf companions to young stellar primaries, it is possible to derive a first estimate…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
