Acetone in Orion BN/KL - High-resolution maps of a special oxygen-bearing molecule - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Astronomy and Astrophysics - A&A Année : 2013

Acetone in Orion BN/KL - High-resolution maps of a special oxygen-bearing molecule

Résumé

As one of the prime targets of interstellar chemistry study, Orion BN/KL clearly shows different molecular distributions between large nitrogen- (e.g., C2H5CN) and oxygen-bearing (e.g., HCOOCH3) molecules. However, acetone (CH3)2CO, a special complex O-bearing molecule, has been shown to have a very different distribution from other typical O-bearing molecules in the BN/KL region. We searched for acetone within our IRAM Plateau de Bure Interferometer 3 mm and 1.3 mm data sets. Twenty-two acetone lines were searched within these data sets. The angular resolution ranged from 1.8 X 0.8 to 6.0 X 2.3 arcsec^2, and the spectral resolution ranged from 0.4 to 1.9 km s-1. Nine of the acetone lines appear free of contamination. Three main acetone peaks (Ace-1, 2, and 3) are identified in Orion BN/KL. The new acetone source Ace-3 and the extended emission in the north of the hot core region have been found for the first time. An excitation temperature of about 150 K is determined toward Ace-1 and Ace-2, and the acetone column density is estimated to be 2-4 X 10^16 cm-2 with a relative abundance of 1-6 X 10^-8 toward these two peaks. Acetone is a few times less abundant toward the hot core and Ace-3 compared with Ace-1 and Ace-2. We find that the overall distribution of acetone in BN/KL is similar to that of N-bearing molecules, e.g., NH3 and C2H5CN, and very different from those of large O-bearing molecules, e.g., HCOOCH3 and (CH3)2O. Our findings show the acetone distribution is more extended than in previous studies and does not originate only in those areas where both N-bearing and O-bearing species are present. Moreover, because the N-bearing molecules may be associated with shocked gas in Orion BN/KL, this suggests that the formation and/or destruction of acetone may involve ammonia or large N-bearing molecules in a shocked-gas environment.

Dates et versions

hal-00822073 , version 1 (14-05-2013)

Identifiants

Citer

T.-C. Peng, D. Despois, N. Brouillet, Alain Baudry, C. Favre, et al.. Acetone in Orion BN/KL - High-resolution maps of a special oxygen-bearing molecule. Astronomy and Astrophysics - A&A, 2013, 554, pp.id.A78. ⟨10.1051/0004-6361/201220891⟩. ⟨hal-00822073⟩
380 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More