Exploring Brown Dwarf Disks: A 1.3 mm Survey in Taurus

By A. Scholz, R. Jayawardhana, K. Wood. 2006

147 citations recorded by the source corpus.

We have carried out sensitive 1.3 mm observations of 20 young brown dwarfs in the Taurus star-forming region, representing the largest sample of young substellar objects targeted in a deep millimeter-continuum survey to date. Under standard assumptions, the masses of brown dwarf disks range from ≲0.4 to several Jupiter masses. Their relative disk masses are comparable to those derived for coeval low-mass stars; most of them are in the ≲1%-5% range, and there is no clear change of relative disk mass with object mass from 0.015 to 3 M☉. Specifically, we do not find evidence for disk truncation, as would be expected in the ejection scenario for brown dwarf origin, although the signature of ejection may be hidden in our nondetections. We use the millimeter fluxes, complemented by mid-infrared data from the Spitzer Space Telescope to construct spectral energy distributions (SEDs) for six of our sources, and model those SEDs with a Monte Carlo radiative transfer code. We find that the SEDs in the mid-infrared often exhibit lower flux levels than predicted by hydrostatic models, implying dust settling to the disk midplane. What is more, at least 25% of our targets are likely to have disks with radii >10 AU; models with smaller disks cannot reproduce the millimeter fluxes. This result is in contrast to the results of some simulations of the ejection scenario for brown dwarf formation that suggest only ~5% of ejected objects would harbor disks larger than 10 AU. Our findings imply that ejection is probably not the dominant formation process, but may still be relevant for some brown dwarfs.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/b38857f5e1d3e1fc8434bace3dd4ead3f6b8ffaa

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Citations in the corpus

The properties of brown dwarfs and low-mass hydrogen-burning stars formed by disc fragmentation (2008, background): “These disc masses and radii are consistent with observations, which show discs to be very common around BDs (Klein et al. 2003; Luhman 2004; Luhman et al. 2005a; Scholz et al. 2006; Guieu et al. 2007; Riaz & Gizis 2007, 2008), even around very low-mass ones (e.g. Luhman et al. 2005b).”
Planet Formation around Stars of Various Masses: The Snow Line and the Frequency of Giant Planets (2007, background): “To extend this model to a range of stellar masses requires consideration of how disk mass varies with stellar mass. Observations indicate Mdisk ∝ M⋆ (Natta et al. 2000; Scholz et al. 2006); however, there is a wide range of disk masses at any given stellar mass.”
A STEEPER THAN LINEAR DISK MASS–STELLAR MASS SCALING RELATION (2016, result): “…stellar mass, the data were consistent with a linear disk mass (Mdust)–stellar mass (M*) scaling relation (Andrews et al. 2013; Mohanty et al. 2013), as hinted earlier on by the detection of a few bright disks around substellar objects (Klein et al. 2003; Scholz et al. 2006; Harvey et al. 2012).”
Variations on Debris Disks: Icy Planet Formation at 30-150 AU for 1-3 M☉ Main-Sequence Stars (2008, result): “Consistent with observations of disks surrounding preYmain-sequence stars (e.g., Natta et al. 2000; Scholz et al. 2006), we scale the reference surface density with the stellar mass, 0(M?)”
A Decreased Probability of Habitable Planet Formation around Low-Mass Stars (2007, methodology): “Many of the data points from Scholz et al. (2006) are only upper limits, but we think extreme cases h = 0 or h > 2 would be apparent in this data.”
Dust properties of protoplanetary disks in the Taurus-Auriga star forming region from millimeter wavelengths (2009, background): “3mm <∼5−20 mJy), and from the detection of very low disk masses around sub-stellar objects in Taurus-Auriga (Klein et al. 2003, Scholz et al. 2006), it is likely that a correlation between the disk mass in dust and the mass of the central star exists.”
THE MASS DEPENDENCE BETWEEN PROTOPLANETARY DISKS AND THEIR STELLAR HOSTS (2013, methodology): “…Jensen & Akeson 2003; Duchêne et al. 2003, 2010; Corder et al. 2005; Piétu et al. 2005, 2006, 2011; Lin et al. 2006; Moriarty-Schieven et al. 2006; Scholz et al. 2006; Hamidouche et al. 2006; Andrews & Williams 8For reference, we also found σ̄v ≈ 0.4mags in U , but the 〈F(m)〉 were much more…”
On the diversity and statistical properties of protostellar discs (2018, background): “…increases with stellar mass (see the discussion in Andrews et al. 2013), and this relation seems to extend into the sub-stellar (Klein et al. 2003; Scholz et al. 2006; Schaefer et al. 2009; Mohanty et al. 2013; Daemgen et al. 2016; van der Plas et al. 2016; Testi et al. 2016) and planetary-mass…”
MAPPING THE SHORES OF THE BROWN DWARF DESERT. II. MULTIPLE STAR FORMATION IN TAURUS–AURIGA (2011, background): “…its observational predictions, particularly in the potential impact (or lack thereof) on the velocity and spatial distributions of star-forming regions (e.g. Luhman 2006; Kraus & Hillenbrand 2008) and the frequency and properties of disks (e.g. White & Basri 2003; Luhman 2004; Scholz et al. 2006).”
Direct Imaging and Spectroscopy of a Planetary-Mass Candidate Companion to a Young Solar Analog (2008, background): “Typical disks around T Tauri stars contain only 0.01–0.1 M⋆ of material (Scholz et al. 2006), but more massive disks may exist during earlier protostellar phases.”
GIANT PLANET MIGRATION, DISK EVOLUTION, AND THE ORIGIN OF TRANSITIONAL DISKS (2009, methodology): “In addition, we point out that our models apply only to stars of approximately solar mass. Disks around low-mass stars and brown dwarfs are now commonly observed (e.g. Scholz et al. 2006), but our knowledge of their evolution is limited.”