Title: Extreme properties in distant dusty galaxies and the molecular gas reservoirs in high-z protocluster

Speaker: Shuowen Jin

Institute: Instituto de Astrofísica de Canarias (IAC), Spain

Host: Yu Gao

Time: 14:30-16:00, Thursday, April 1

Location: Physics Building 552

Abstract:

Dusty star-forming galaxies at z>5 are very rare and their existence challenges current galaxy models. Recently, using our "Super-deblending" technique we selected a sample of z>6 candidates in the COSMOS field and followed up them with ALMA and NOEMA observations. All these galaxies have been spectroscopically confirmed at z=3.6--6 via detection of multiple CO and/or CI emission lines. Remarkably, these galaxies show extreme properties, e.g., optically-dark at Ks/H band, extremely cold dust temperatures, steep RJ slopes impacted by CMB, and compact dust content that is likely even optically thick in FIR. I will present the latest findings of this project.

Meanwhile, I will report the first results of the COALAS large program: a CO(1-0) survey of the Spiderweb protocluster at z=2.16 with the Australia Telescope Compact Array (ATCA) 475 hours observations. We obtained a robust sample of several dozen CO(1-0) detections, constituting the largest sample of molecular gas measurements in high-z clusters to date. We use the CO emitters to place the first constraint on the CO luminosity function and molecular gas density in a high-z cluster environment, which are significantly higher than observed in random fields.

Bio: 靳硕文，2018年于南京大学获得天文学博士学位，2015--2017年期间在法国原子能所联合培养。2019年1月--2021年1月在西班牙加纳利天体物理研究所Instituto de Astrofísica de Canarias从事博士后研究，近期将去哥本哈根DAWN研究所从事博士后研究。研究兴趣：高红移星系的演化，星系团，早期宇宙的尘埃和星际介质，红外和亚毫米波观测。

Ref:

https://astro.xmu.edu.cn/info/1231/2929.htm

https://ui.adsabs.harvard.edu/abs/2019ApJ...887..144J/abstract