2 Observations

CRBR 2422.8-3423 was observed with the ESO VLT-ANTU mounted with the Infrared Spectrometer And Array Camera (ISAAC) on May 6, 2002. A spectrum at $R\approx 10^4$ was obtained in the M band using a slit-width of 0 $.\!\!^{\prime\prime}$3, which matched the excellent seeing ($\simeq$0 $.\!\!^{\prime\prime}$3 at 4 $\mu$m). The integration time was 36 min, resulting in a continuum S/N of $\simeq$20. The spectra of BS 6084 (B1III) and BS 6378 (A2.5Va), observed immediately before and after CRBR 2422.8-3423, were used to remove the atmospheric features and to calibrate the spectrum in flux and wavelength. All the reduction steps were carried out using an in-house data reduction package written in IDL.

Observations of gaseous CO (sub)millimeter lines on source and at an offset position 30 $^{\prime\prime}$ south were obtained at the James Clerk Maxwell Telescope (JCMT) in June 2002. The dual-polarization receiver B3 was tuned to observe the ¹²CO  $J=3\rightarrow 2$ (345.796 GHz, beam 13 $.\!\!^{\prime\prime}$8) and ¹³CO  $J=3\rightarrow 2$ (330.587 GHz, beam 14 $.\!\!^{\prime\prime}$4) lines, and receiver A3 to obtain C¹⁸O $J=2\rightarrow 1$ (219.560 GHz, beam 22 $.\!\!^{\prime\prime}$2). The backend was the Digital Autocorrelator Spectrometer, set at a resolution of $\sim$0.15 km s^-1. The beam efficiencies are $\eta_{\rm mb}=0.63$ (345 GHz) and $\eta_{\rm mb}=0.69$ (230 GHz). The fluxes were calibrated against the bright nearby source IRAS 16293-2422. The observations were acquired in position switching with a throw of 1800 $^{\prime\prime}$ south and reduced using the SPECX software.