Title: SUNRISE: The rich molecular inventory of high-redshift dusty galaxies revealed by broadband spectral line surveys

Speaker：Chentao Yang(Chalmers University of Technology)

Location：Small conference room, 3rd floor

Time：2:00pm, Oct. 09th, Monday

Tencent Meeting：576-157-8290 Password: 6360

Abstract：

Understanding the nature of high-redshift dusty galaxies, the ancestors of most galaxies today, requires a comprehensive view of their interstellar medium (ISM) and molecular complexity. However, the molecular ISM at high redshifts is commonly studied using only a few species beyond CO, limiting our understanding. In this talk, I will present the results of deep 3 mm spectral line surveys using the NOrthern Extended Millimeter Array (NOEMA) targeting two lensed dusty galaxies observed when the Universe was less than 1.8 Gyr old: APM 08279+5255, a quasar at redshift z = 3.911, and NCv1.143, a z = 3.565 starburst galaxy. The spectral line surveys cover both galaxies' rest-frame frequencies from about 330 to 550 GHz. We report the detection of 38 and 25 emission lines in APM 08279+5255 and NCv1.143, respectively. The transitions originate from 17 species, namely CO, 13CO, C18O, CN, CCH, HCN, HCO+, HNC, CS, C34S, H2O, H3O+, NO, N2H+, CH, cC3H2, as well as the vibrationally excited HCN (HCN-VIB lines) and neutral carbon (fine-structure [CI] line). The spectra reveal the chemical richness and the complexity of the physical properties of the ISM. From these rich toolsets of molecular lines, we begin now to have a clearer picture of star formation, AGN, fueling and feedback, and structural formation of these galaxies, of which I will show some during this talk. Such deep spectral line surveys open a new window to study the physical and chemical properties of the ISM and the radiation field of galaxies in the early Universe.

Bio:

Chentao Yang is currently a postdoctoral researcher at Chalmers University of Technology, and he was an ESO Fellow in Chile with ALMA duties before joining Chalmers. He has been working on the observational studies of the molecular ISM in galaxies near and far, trying to understand the origin and evolution of the dusty galaxies by studying their star formation, AGN activity, and the baryonic cycle of these galaxies.