CARMA $\lambda$ = 1 cm Spectral Line Survey of Orion-KL

TL;DR

This paper presents the first 1 cm spectral line survey of Orion-KL, detecting 89 transitions from 14 molecules, providing new insights into molecular distributions and formation mechanisms in this star-forming region.

Contribution

It introduces the first spectral survey at 1 cm wavelength of Orion-KL, expanding the molecular inventory and spatial understanding of the region.

Findings

Detected 89 transitions from 14 molecular species and isotopologues.

Provided spatial distribution data for complex molecules.

Reduced line confusion by observing at longer wavelengths.

Abstract

Orion-KL is a well known high mass star forming region that has long been the target of spectral line surveys and searches for complex molecules. One spectral window where the region had never been surveyed is around wavelengths of $\lambda$=1 cm. This is an important window to observe due to the fundamental and low energy transitions of numerous complex molecules that indicate the maximum spatial extent of the molecular species; knowing the spatial distribution of a molecule aids in determining the formation mechanism(s) of that molecule. Additionally, there are fewer transitions in this window, reducing confusion caused by blended lines that can be very problematic at shorter wavelengths ($\lambda<$3 mm). In this work, we present the first spectral line survey at $\lambda$=1 cm of the Orion-KL region. A total of 89 transitions were detected from 14 molecular species and isotopologues and two atomic species. The observations were conducted with the Combined Array for Research in Millimeter-wave Astronomy in both interferometric and single dish modes.