CRIRES observations of CO emission from disks around embedded young stars Gregory Herczeg (MPE)...
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Transcript of CRIRES observations of CO emission from disks around embedded young stars Gregory Herczeg (MPE)...
CRIRES observations of CO emission from disks around
embedded young stars
Gregory Herczeg (MPE)
Collaborators: Ewine van DishoeckKlaus Pontoppidan
Joanna BrownJeanette Bast
CRIRES Observations
• 10 sources:– IRS 43, IRS 44, IRS 63, Elias 23, Elias 29,
Elias 32, HH 100, WL 6, WL 12, CrA IRS 2– Several observed in multiple epochs– Usually a few wavelength settings– Need to add a few more (mostly non-
detections)
• NGS AO not possible– Limited spatial information
Goals:
• Do young disks emit in CO?– What else is CO probing?– Why do some disks show no CO?
• Does inner disk structure differ from CTTS disks?– Luminosity– Temperature/Excitation
Red: CRIRES black: ISAAC
IRS 44: resolved emission• 0.3 arcsec binary• 0.69 mag difference in M• Equal brightness in L
– (Duchêne et al. 2007)
• Primary is barely (or not) detected in K, never in J– Ratzka et al. 2005,
Terebey et al. 2001, Allen et al. 2002
• CO and H2 emission: only detected from secondary
• 13CO emission: blueshifted, offset from 12CO emission
H2 S(9) Emission
Variability?
• Seeing in Aug.: 0.33 arcsec• Seeing in Apr.: 0.56 arcsec
• Blueshifted CO emission from IRS 44 also variable in EW
Conclusions: CO emission from embedded objects
• CO absorption can make analysis difficult– Sometimes impossible, sometimes not so bad– Better than H2, which often probes extended material
• Most emission consistent with a disk origin– Double-peaked profile from Elias 23– Winds can also play a role (IRS 44)
• Two components– Narrow, colder, optically-thick– Hot, vibrationally excited broad component
• TO DO: Add a few sources, temps, luminosities, optical depths