Ronaldo Laishram: Mapping the large scale structure and environmental dependence of star forming galaxies

Thursday, 09 November 2023 2 p.m. — 3 p.m. MST

Gemini North Hilo Base Facility | 670 N A’ohoku Place Hilo, Hawaii, 96720, USA

Gemini North Talks
Ronaldo Laishram (Tohoku University, Sendai, Japan)

Ronaldo Laishram

Galaxies are distributed inhomogeneously on small scales in the Universe, forming large-scale structures (LSS). To understand the evolution of cluster galaxies, we must determine how galaxies change their properties due to the hierarchical growth of the LSS. This work studies the environmental dependence of narrow-band selected star-forming galaxies. We demonstrate a method to estimate accurate redshifts for star-forming galaxies by measuring the flux ratio of the same emission line observed through two adjacent narrow-band filters using the Hyper Suprime-Cam on the Subaru Telescope. We also study the environmental dependence of star-forming activity, measure Hα and stellar continuum sizes, and explore the 3-D structure of the cosmic web at z=0.4 with HSC triple NB imaging. Additionally, we investigate the relationship between the [OII]λ3727/Hα flux ratios of emission line galaxies and their physical parameters, and measure dust extinction and metallicity using this flux ratio. We also probe a prominent filamentary overdensity of [OII]-selected galaxies at z~1.5. This study aims to unveil the morphological intricacies of these galaxies and examine the interplay between their star formation activities and their environments. We investigate the morphological distinctions of galaxies in these environments and relate them to their star formation activities, stellar masses, and other vital physical parameters.

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