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arXiv · 1809.06283

ALMA Observation of NGC5135: The Circumnuclear CO(6-5) and Dust Continuum Emission at 45 Parsec Resolution[$\star$]

Tianwen Cao·Nanyao Lu·C. Kevin Xu·Yinghe Zhao·Venu Madhav Kalari·Yu Gao·Vassilis Charmandaris·Tanio Diaz Santos·Paul van der Werf·Chen Cao·Hong Wu·Hanae Inami·Aaron Evans
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Abstract

We present high-resolution (0.17\arcsec $\times$ 0.14\arcsec) Atacama Large Millimeter/submillimeter Array (ALMA) observations of the CO\,(6-5) line, and 435\um\ dust continuum emission within a $\sim$9\arcsec $\times$ 9\arcsec\ area centered on the nucleus of the galaxy NGC\,5135. NGC\,5135 is a well-studied luminous infrared galaxy that also harbors a Compton-thick active galactic nucleus (AGN). At the achieved resolution of 48 $\times$ 40\,pc, the CO\,(6-5) and dust emissions are resolved into gas "clumps" along the symmetrical dust lanes associated with the inner stellar bar. The clumps have radii between $\sim$45-180\,pc and CO\,(6-5) line widths of $\sim$60-88\,\kms. The CO\,(6-5) to dust continuum flux ratios vary among the clumps and show an increasing trend with the \FeII/Br-$\gamma$ ratios, which we interpret as evidence for supernova-driven shocked gas providing a significant contribution to the \co65\ emission. The central AGN is undetected in continuum, nor in CO\,(6-5) if its line velocity width is no less than $\sim$\,40\,\kms. We estimate that the AGN contributes at most 1\% of the integrated CO\,(6-5) flux of 512 $\pm$ 24$\,$Jy\kms\ within the ALMA field of view, which in turn accounts for $\sim$32\% of the CO\,(6-5) flux of the whole galaxy.

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Tianwen Cao, Nanyao Lu, C. Kevin Xu, Yinghe Zhao, Venu Madhav Kalari, Yu Gao, Vassilis Charmandaris, Tanio Diaz Santos, Paul van der Werf, Chen Cao, Hong Wu, Hanae Inami, Aaron Evans. 2018-09-17. ALMA Observation of NGC5135: The Circumnuclear CO(6-5) and Dust Continuum Emission at 45 Parsec Resolution[$\star$]. https://doi.org/10.3847/1538-4357/aae1f4

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