3 research outputs found
A Dust Trap in the Young Multiple System HD 34700
This is the author accepted manuscript. The final version is available from the American Astronomical Society via the DOI in this recordMillimeter observations of disks around young stars reveal substructures indicative of gas pressure
traps that may aid grain growth and planet formation. We present Submillimeter Array observations
of HD 34700- two Herbig Ae stars in a close binary system (Aa/Ab, ∼0.25 AU), surrounded by a
disk presenting a large cavity and spiral arms seen in scattered light, and two distant, lower mass
companions. These observations include 1.3 mm continuum emission and the 12CO 2-1 line at ∼ 0.
005
(178 AU) resolution. They resolve a prominent azimuthal asymmetry in the continuum, and Keplerian
rotation of a circumbinary disk in the 12CO line. The asymmetry is located at a radius of 155+11
−7
AU, consistent with the edge of the scattered light cavity, being resolved in both radius (72+14
−15 AU)
and azimuth (FWHM = 64â—¦+8
−7
). The strong asymmetry in millimeter continuum emission could be
evidence for a dust trap, together with the more symmetric morphology of 12CO emission and small
grains. We hypothesize an unseen circumbinary companion, responsible for the cavity in scattered
light and creating a vortex at the cavity edge that manifests in dust trapping. The disk mass has
limitations imposed by the detection of 12CO and non-detection of 13CO. We discuss its consequences
for the potential past gravitational instability of this system, likely accounting for the rapid formation
of a circumbinary companion. We also report the discovery of resolved continuum emission associated
with HD 34700B (projected separation ∼ 1850AU), which we explain through a circumstellar disk.National Science Foundation (NSF