Brown Dwarf Disks new MIR observations

1
Brown Dwarf Disks new MIR observations

• M. Sterzik w/ Daniel Apai, Ilaria Pascucci,
  Thomas Henning (MPIA)
• Gwendolyn Meeus (AIP), Caes Dullemond (MPIA)
• Nicole v. der Bliek (CTIO)

2
BD disks

• Are there disks around BDs?
• How do they compare to cTTS disks?
• Lifetime, masses, grain properties can they
  form planets?
• NIR not adequate cold BD photosphere!

3
SED

• ISOCAM 6.714.3µm excess detected for 10 young
  BD
• 10-30mJy rel. faint!
• Standard flared disk
• BD have disks and form like stars
• However MIR cannot probe disk radius and mass.

Natta Testi (2001)
4
TIMMI2 1st groundbased observations

• T2 photometry favors flat disk and/or (rapid?)
  grain growth
• MIR spectroscopy and/or sampling of the Si
  feature needed

Apai et al. (2002)
5
TRecS_at_Gemini S SV and 2003/B
6
BD TWH1 aka 2M1207-3932

• old BD 10Mio year
• No L excess, no disk (Jayawardhana 2002)
• Magellan echelle spectra show strong Ha and HeI
  accretion (Mohanty 2003)
• Our 8.8µ and 10.4µ photometry confirm disk

7
Outlook

• BD disk spectra pending T2 and TRecS underway.
  Compare disk physics and grain growth timescales
  w/ cTTS.
• VISIR might help (?)
• SPITZER/Sofia will do LOTS of BDs ?
• Disk masses/radii ONLY in submm/mm chance for
  APEX? Certainly ALMA. ?