Structure Analysis of OMC1 at 1.1 mm

TL;DR

This study presents a detailed 1.1 mm emission map of the OMC1 region, revealing cloud cores and filaments, and analyzes the structure's size distribution through power spectrum analysis, finding a power-law behavior with a spectral break at 0.3 pc.

Contribution

First high-resolution 1.1 mm emission map of OMC1 using AzTEC, with analysis of the structure's power spectrum and identification of a spectral break at 0.3 pc.

Findings

Power-law fit to the power spectrum with slope ~ -2.6.

Detection of a spectral break at ~0.3 pc.

Power spectrum consistent with numerical simulations.

Abstract

We present a 1.1 mm emission map of the OMC1 region observed with AzTEC, a new large-format array composed of 144 silicon-nitride micromesh bolometers that was in use at the James Clerk Maxwell Telescope (JCMT). The AzTEC observations of the OMC1 region at 1.1 mm reveal dozens of cloud cores and a tail of filaments in a manner that is almost identical to the submillimeter continuum emission of the entire OMC1 region at 450 and 850 micronm. The density power spectrum provides the size distribution of the structures. We find that a single power law might be fitted to the calculated power spectrum of the 1.1 mm emission between 0.3 pc and 0.03 pc. The slope of the best fit power law is \gamma \sim -2.6 and is similar to the spectral index of the power spectrum of \gamma \sim -2.7 found in numerical simulations. However, there is a distinct spectral break in the power spectrum at a characteristic scale of ~0.3 pc in OMC1. The effects of beam size and noise spectrum on the shape and slope of the power spectrum are also included in the present analysis. The slope of the power law and a range of different scales change at scales below ~0.3 pc as the beam size increases.