The Merian Survey: Characterizing dark matter and feedback in star-forming dwarf galaxies with medium-band filters on DECam


The Merian survey is an ongoing medium-band imaging survey on the CTIO 4-meter Blanco telescope. With two new medium-band filters on DECam, we expect to detect ~100,000 star-forming dwarf galaxies at z~0.1 in the HSC-SSP wide field (~800 deg^2), aiming to characterize dark matter halo and stellar feedback in dwarf galaxies. The Merian survey will allow us to measure the full dark matter profile of dwarf galaxies via weak gravitational lensing, for the first time. In this talk, I will present how we designed the Merian survey, and discuss the performance by comparing the mock and actual Merian data. I will show the early science results with the Merian Year 1 data release. I will also show that the Merian medium-band filter set is able to select objects at higher redshifts out to z~4.8. In the end, I will discuss dwarf lensing with future surveys such as the DESI-2 medium-band imaging survey.

Yifei Luo (罗逸飞), University of California Santa Cruz
KIAA Shu Qi meeting room
Tuesday, March 12, 2024 - 1:30PM to Tuesday, March 12, 2024 - 2:30PM