Interferometric observations for oxygen-containing organic molecules toward Orion-KL

Area of Science:

• Astrochemistry
• Star Formation Regions
• Molecular Clouds

Background:

• Orion-KL is a well-studied region of active star formation, crucial for understanding chemical complexity in protostellar environments.
• Previous studies have identified various molecules, but high spatial resolution mapping of specific species like methanol and its related organic molecules is limited.

Purpose of the Study:

• To investigate the spatial distribution and column densities of methanol (CH3OH), methyl formate (HCOOCH3), and dimethyl ether [(CH3)2O] in Orion-KL.
• To explore potential chemical links between these molecules and outflowing material from the protostar IRc2.

Main Methods:

• Utilized the Nobeyama Millimeter Array for high spatial resolution (approx. 5 arcseconds) observations.
• Focused on specific 3 mm transitions of CH3OH, HCOOCH3, and (CH3)2O.
• Analyzed emission patterns and derived column densities for identified molecular condensations.

Main Results:

• Methanol emission shows an elongated distribution between IRc2 and the Southern Condensation (SC), suggesting a connection to IRc2's outflow.
• Methyl formate and dimethyl ether emissions are concentrated toward the SC (approx. 6.5" size).
• An additional oxygen-rich condensation west of IRc2 (approx. 4.5" size) exhibits comparable column densities for HCOOCH3 and (CH3)2O.

Conclusions:

• The spatial distribution of methanol supports its association with the outflow from IRc2.
• The concentration of methyl formate and dimethyl ether toward the SC indicates distinct chemical environments or formation pathways.
• The presence of multiple condensations with significant column densities highlights the chemical richness and complexity of the Orion-KL core.