Quantifying the Short-Period Brown Dwarf Deserts

Details Quantifying the Short-Period Brown Dwarf Deserts Quantifying the Short-Period Brown Dwarf Deserts

Dec 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005aas...207.7705l&link_type=abstract

American Astronomical Society Meeting 207, #77.05; Bulletin of the American Astronomical Society, Vol. 37, p.1292

Astronomy and Astrophysics

Astronomy

Scientific paper

Sun-like stars have stellar, brown dwarf and planetary companions. To help constrain their formation and migration scenarios, we analyse the close companions (orbital period < 5 years) of nearby Sun-like stars. By using the same sample to extract the relative numbers of stellar, brown dwarf and planetary companions, we verify the existence of a very dry brown dwarf desert and describe it quantitatively. With decreasing mass, the companion mass function drops by almost two orders of magnitude from 1 MSun stellar companions to the brown dwarf desert and then rises by more than an order of magnitude from brown dwarfs to Jupiter-mass planets. The slopes of the planetary and stellar companion mass functions are of opposite sign and are incompatible at the 3 sigma level, thus yielding a brown dwarf desert. The minimum number of companions per unit interval in log mass (the driest part of the desert) is at M = 31 +25-18 MJup. Linear fits to the companion mass function marginally suggest that the driest part of the desert scales with host mass and we predict a Jupiter-mass desert and a stellar companion desert for hosts of mass < 0.5 MSun and >2 MSun respectively. However, we find no evidence that companion mass scales with host mass in general. Approximately 16% of Sun-like stars have close (P < 5 years) companions more massive than Jupiter: 11% ± 3% are stellar, <1% are brown dwarf and 5% ± 2% are giant planets. The steep decline in the number of companions in the brown dwarf regime, compared to the initial mass function of individual stars and free-floating brown dwarfs, suggests either a different spectrum of gravitational fragmentation in the formation environment or post-formation migratory processes disinclined to leave brown dwarfs in close orbits. We acknowledge funding from ANU's Planetary Science Institute, the Australian Research Council and UNSW.

Affiliated with

Also associated with

No associations

Rating

Quantifying the Short-Period Brown Dwarf Deserts does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Quantifying the Short-Period Brown Dwarf Deserts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantifying the Short-Period Brown Dwarf Deserts will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1281839