Spectral characterization of newly detected young substellar binaries with SINFONI
- Author(s)
- Per Calissendorff, Markus Janson, Ruben Asensio Torres, Rainer Köhler
- Abstract
Multiplicity studies of stars and brown dwarfs have shown a decrease in multiplicity frequency as a function of primary mass and spectral type, with fewer multiple systems for primaries of lower mass and later spectral types, which stretches down all the way to the substellar mass-regime. However, at the very bottom of the stellar and substellar initial mass function, binarity and multiplicity is not very well-constrained. Recent efforts in associating low-mass members to young moving groups have provided much sought means to constrain ages for substellar objects, which otherwise prove difficult to do. As such, we are now at a point where we can compare the multiplicity rates for both older and younger samples of substellar brown dwarfs, which provide insight to their formation channels and dynamical evolution. This is of particular interest as very low-mass brown dwarfs are analogous to directly imaged exoplanets, which when resolved can be studied in high detail. We present the results from observations of 14 young low-mass substellar objects using the VLT/SINFONI integral field spectrograph with laser guide star adaptive optics, which we employ to detect and characterize 3 new binary systems. These results indicate for higher multiplicity frequencies for the younger populations of brown dwarfs,and that older systems may have undergone dynamical interactions disrupting the primordial binaries. By utilizing substellar theoretical models and the resolved brightnesses we obtain from our astrometric techniques, we discover some of these companions to be of planetary-mass. Furthermore, we find that the binary systems have small separations, which translates to orbital periods of just a few decades.As such, dynamical masses can be obtained within just a few years of astrometric monitoring, making these systems excellent benchmarks for calibrating evolutionary models in an otherwise scarcely probed mass-regime.
- Organisation(s)
- Department of Astrophysics
- Pages
- 127
- Publication date
- 08-2019
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/9ecd08d0-43a5-4a2d-a43a-e5dda527215f