Letter to the Editor

Spitzer's large CO₂ ice detection toward the L723 class 0 object

¹ Institut d'Astrophysique Spatiale, UMR 8617, Université Paris-Sud, bâtiment 121, 91405 Orsay, France e-mail: emmanuel.dartois@ias.u-psud.fr
² Leiden Observatory, PO Box 9513, 2300 RA Leiden, The Netherlands
³ ESTEC, ESA, Research Support Science Department, PO Box 2200AZ, Noordwijk, The Netherlands
⁴ Centro de Astrobiologia, Spain

Received: 15 August 2005
Accepted: 3 November 2005

Abstract

The L723 low mass class 0 protostellar object has been observed with the IRS low resolution spectrometer onboard Spitzer Space Telescope. A huge CO₂ ice column density of 6.3 ± 1  10¹⁸ cm^-2 is detected toward this extremely red object. We constructed the spectral energy distribution (SED) of L723 by combining the Spitzer spectral data with Infrared Space Observatory (ISO) camera extracted fluxes, IRAS points, ISO long wavelength spectrometer (LWS) observations and millimeter ground based observations. A self consistent 1D model was developed to fit the SED. We show that, besides the high CO₂ column density, the abundance ratio of CO₂ ice to silicates grain cores is similar to other lines-of-sight.