Lunch talk on Jun. 26, 2023

Estimating the Molecular Gas mass of and within Low-redshift Galaxies from the Mid-infrared emission

Speaker: Yang Gao (Dezhou University)

Venue: SWIFAR Building 2111

Time: 12:30 PM, Monday, Jun. 26, 2023

Abstract: 

With the development of radio astronomy, it has been realized that stars are formed by the collapse of molecular clouds. Therefore, measuring the molecular gas content within individual galaxies and among galaxy populations is essential for understanding many key processes in galaxy formation and evolution. However, due to the limited number of galaxies with observed CO (molecular gas) up to now, we build a useful estimator of molecular gas content based on the mid-infrared data from WISE all sky survey with an accuracy of 0.2 dex. Subsequent studies were carried out in three directions: different scales, different molecular gas tracers, and different types of galaxies. It has been found that the correlation between CO and 12μm emission still continues (over 5 orders of magnitude in luminosity) on sub-kpc scales; compared with various (dense) molecular gas tracers and SFR, 12 μm emission is more tightly correlated with 12CO emission, likely because of polycyclic aromatic hydrocarbons (PAH). In addition, we also verified that the correlation between 12μm and CO still exists in early-type gas-poor galaxies. So this estimator is potentially applicable to both the large galaxy populations and small regions within individual galaxies, as a compensation.

Report PPT:  SWIFAR_Yang Gao.pdf