Mopra line survey mapping of NGC6334I and I(N) at 3mm

TL;DR

This study maps a 5'x5' region around NGC6334I and I(N) at 3mm using the Mopra telescope, revealing molecular distributions and star formation activity with high spatial resolution.

Contribution

It provides the first comprehensive 3mm molecular line survey of NGC6334I and I(N), utilizing broadband capabilities for detailed spatial mapping.

Findings

Most molecules trace star formation sites.

CH3CN closely associated with NGC6334I and I(N).

N2H+ and HC3N are reliable dense gas tracers.

Abstract

A 5'x5' region encompassing NGC6334I and I(N) has been mapped at a wavelength of 3mm (from 83.5 to 115.5GHz) with the Mopra telescope at an angular resolution between 33 arcsec and 36 arcsec. This investigation has made use of the recently installed 3mm MMIC receiver and the Mopra Spectrometer (MOPS) with broadband capabilities permitting total coverage of the entire frequency range with just five different observations. In total, the spatial distribution of nineteen different molecules, ions and radicals, along with additional selected isotopologues have been studied. Whilst most species trace the sites of star formation, CH_3CN appears to be most closely associated with NGC6334I and I(N). Both CN and C_2H appear to be widespread, tracing gas that is not associated with active star formation. Both N_2H^+ and HC_3N closely resemble dust continuum emission, showing they are reliable tracers of dense material, as well as the youngest stages of high mass star formation. Hot (E_u/k>100K) thermal CH_3OH emission is preferentially found towards NGC6334I, contrasting with I(N), where only cold (E_u/k<22K) thermal CH_3OH emission is found.