Preparatory observations VLT

- VLT-ISAAC survey of ~50 Class I YSO’s

-- Low resolution (R~600) L-band

- Medium resolution (R~10000) M-band

- Other programs

Spectra embedded sources

Gibb et al. 2000

SIRTF R~600 only at >10 m => ground-basedhigh resolution in 3-5 m range

Ophiuchus sources

- Strong solid CO

- Gas-phase CO inabsorption or

emission

- narrow and

broad lines

Pontoppidan et al. 2002

Ophiuchus (cont’d)

Note fit of all spectra with just 3 components

Serpens sources

Orion sources

Note shallow absorption at 2175 cm-1: not OCN-

R CrA sources

Chamaeleon sources

Vela sources/L1489 in Taurus

CO gas / solid low-mass YSOsCO gas / solid low-mass YSOs

RE50

TPSC78

• CO co-exists in gas phase and solid state

• Different objects show different ratios of gas:ice, related to their evolution

• Observed line profiles provide clues to structure ices by comparison with lab data

Pontopidan, et. al., A&A, (2002), in prep VLT-ISAAC large program

Detection of abundant solid CO in an edge-on circumstellar disk

VLT-ISAAC K’

VLT-ISAAC

Thi, Pontoppidan, vD et al. 2002

Solid CO

Additional data

• ESO-TIMMI2 8-13 m R~200 (with Waters + MPIA-Heidelberg); brightest sources only to check variability

• OVRO imaging embedded sources (with Geoff)• VLT-VISIR 8-13 m, 17-22 m, R~104;

commissioning summer 2003, follow-up bright sources for gas species

• JCMT-SCUBA maps of cores (see Neal’s talk)