SHAO Astrophysics Colloquium
Title: Understanding connections between star formation and dust obscuration in galaxies over time
Speaker: Prof. Xianzhong Zheng (PMO)
Time: 3:00 pm, October 31st (Thursday)
Location: Lecture Hall, 3rd floor
Abstract: About half energy of the radiation from cosmic star formation is absorbed and re-emitted by dust into the far-infrared. How dust obscures star formation in galaxies across cosmic time remains to be explored. In this talk, I will present recent progresses in exploring the relationships between star formation, dust obscuration (IRX=L_IR/L_UV) and other galaxy parameters. Recently, we found that dust obscuration of star-forming galaxies obeys an empirical relation, jointly determined by IR luminosity, galaxy size, metallicity and axial ratio. This empirical relation also holds for distant SFGs out to z = 3 in a population-averaged sense, suggesting it to be universal across cosmic age. This universal relation reveals that star formation, structure buildup and chemical enrichment are closely linked with each other in the mass assembly of galaxies. The implications to galaxy evolution will be discussed.
Bio: XianZhong Zheng is a professor in Purple Mountain observatory, CAS, and leading a research group on galaxy formation and wide-field survey. He obtained his PhD in astrophysics in 2002 from the National Astronomical Observatories, CAS, and worked as a postdoctoral fellow in Observatoire de Paris-Meudon and the Max-Planck Institute in Astronomy (MPIA) in Heidelberg from 2003 to 2007. He joined Purple Mountain Observatory in 2007 with support by the CAS hundred Talents Program. His research works were mostly on observational studies of galaxy formation and evolution, producing 80 publications. He was also leading the 2.5meter wide-field survey telescope (WFST) project, recently funded by university of Science and telescope of China.
Title: The Javalambre-Physics of the Accelerating Universe Astrophysical Survey
Speaker: Renato Dupke (National Observatory Brazil)
Time: 10:30 am, October 30th (Wednesday)
Location: Lecture Hall, 3rd floor
Abstract: The Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Astrophysical Observatory in Spain with a purpose-built, dedicated 2.5m telescope and a 4.7 sq.deg. camera with 1.2Gpix. Starting full operation in the end of 2019, J-PAS plans to observe >8000sq.deg. of Northern Sky and measure sigma_z~0.003(1+z) photo-z for up to 9E7 LRG and ELG galaxies plus several million QSOs, sampling an effective volume of ~ 14 Gpc^3 up to z~1.3 reaching Stage IV radial BAO experiment. J-PAS is expected to detect ~7E5 galaxy clusters and groups, setting constraints on Dark Energy which rival those obtained from its BAO measurements. Thanks to the superb characteristics of the site (seeing ~0.7 arcsec), J-PAS is expected to obtain a deep, sub-arcsec multi-band image of the Northern sky, which combined with its unique photo-z precision will have an immense legacy value for almost all astrophysical areas. J-PAS unprecedented spectral time domain information will enable a self-contained SN survey that, without the need for external spectroscopic follow-up, will detect, classify and measure sigma_z~ 0.5% redshifts for ~ 4000 SNe Ia and ~ 1000 SNecc. The key to the J-PAS potential is its innovative approach: a contiguous system of 54 filters with 145A width, placed 100A apart over a multi-degree FoV is a powerful "redshift machine", with the survey speed of a 4000 multiplexing low resolution spectrograph. Its commissioning camera, PathFinder, has been running and collecting data since the beginning of 2018 with all J-PAS filters of a variety of targets and fields, in particular of the AEGIS field (mini-JPAS) as a proof of concept for photo-z depth. Here I will present the status of J-PAS and some preliminary results from mini-JPAS.
CV: Dr. Renato Dupke is a research scientist at National Observatory, Brazil. He is the J-PAS Science Director. Please find below the attached file for more details.
