Title: ALOHA: High-sensitivity JCMT/SCUBA-2 850 micron observation of Infrared Dark Clouds
Speaker: Zhiyuan Ren 任致远
Institute: National Astronomical Observatories of China
Host: Siyi Feng
Time: 14:30-16:30, Thursday, September, 22
Location: Physics Building 552 (online)
The JCMT SCUBA-2 legacy survey ALOHA is aimed to provide high-sensitivity 850 micron continuum images of the nearby infrared dark clouds (IRDCs) with relatively dense and compact gas distributions and high masses. The image data reaches a sensitivity of 2 to 6 mJy/beam, corresponding to a column density coverage down to 1.5x10^21 cm-2, which exceeds most of the previous studies, and would be sufficient to recover the major fraction of the extended turbulent gas. It enables a more detailed comparative study of the interplay between the turbulent gas and the dense, self-gravitating gas in the IRDC main structures. The preliminary findings include: (1) the low column density gas can always be well fitted by a single or multiple log-normal (LN) profiles; (2) the spatial distribution of power-law component is usually surrounded by the LN component, suggesting that gravitating gas is generated from turbulent gas, hence the turbulence decay should be an indispensable step for the dense gas assembly in IRDCs. The scientific analysis of the data products is still ongoing. We welcome colleagues to join the collaboration and inspect the data for any related studies.
papers are being written;
Zhiyuan Ren is a research fellow in the National Astronomical Observatories, Chinese Academy of Sciences (NAOC). He received his PhD in 2012 from the Peking University. From 2013 to 2015, he was a FAST Postdoctoral Fellow in NAOC working in Prof. Di Li’s group. During his Postdoc study, he visited the University de Chile and JCMT in Hawaii. His research interests are early stages in high-mass star formations through observational astronomy from submillimeter to radio wavelengths.