Lunch talk on Sep. 11, 2023

The Evolution of Blue Compact Dwarf Galaxies Studied with the Integral Field Spectroscopic Survey — MaNGA

Speaker: Mengting Ju (UCAS)

Venue: SWIFAR Building 2111

Time: 12:30 PM, Monday, Sep. 11, 2023

Abstract: 

Blue Compact Dwarf galaxies (BCDs) are a type of star-forming galaxies with extremely low metallicities. These galaxies are considered as local counterparts of bright and compact star forming galaxies detected at higher redshifts. Using data from the Integral Field Spectroscopic Surveys, such as MaNGA, we found 8313-1901, an interesting BCD galaxy, which has a clear blue clump in the northeast of the galaxy direction in its optical image (the NE clump). The NE clump may be a result of gas accretion. Exploring the properties of the BCDs and their connection with other types of dwarf galaxies is point of the issue, which can help us understand the mechanisms of star formation and the evolution of BCDs. We further selected five galaxies with off-centered clumps from the BCD galaxy candidates in the MaNGA survey, including 8313-1901. Using the stellar population synthesis software FADO, we obtained the spectra of these galaxies in different ages and the corresponding synthesized g-band images to explore the evolution of these galaxies and the clumpy structures. We found that most of the clumps in these five galaxies were formed within hundreds million years.  8257-3704 seems to be an exception, exhibiting two starburst activities that appeared at 500Myr-1Gyr and ≤100Myr, in different locations. The spatially resolved stellar population analysis of five BCD galaxies can be applied to larger galaxy samples to help us understand the evolution history of the host galaxies and the clumps in more starbursting galaxies.