2025 Project Description

Invisible siblings : uncovering the hidden gas-rich companions around massive dusty galaxies at high redshifts with ALMA

Supervisors

Chian-Chou Chen (TC), Wei-Hao Wang
Find out more about supervisors on ASIAA website

Task Description and Goals

The environment of galaxies plays a key role in galaxy formation and evolution. Dusty star-forming galaxies (DSFGs) in the early Universe are hypothesized to be embedded within dense structures, such as nodes or thick filaments of the cosmic web. However, recent studies have shown a mixture of results. One possibility is that some of these companions are gas-rich sources that are missed in previous searches and are best uncovered with blind spectroscopic surveys of gas emission lines. Recently our team has acquired a uniform ALMA data cubes centered at a flux-limited sample of DSFGs, and the decent size field of view of ALMA represents an excellent opportunity to search for these gas-rich siblings of these DSFGs.

The student is expected to first become familiar with interferometry data, run line searching codes on the ALMA data cubes, cataloging these line emitters, and characterizing their properties. We will quantify the fraction of DSFGs that have gas-rich companions and compare the results to model predictions. We will also estimate the halo masses of the central DSFGs using a dynamical approach, which can be compared to other independent measurements.

Required Background

Basic knowledge of physics and mathematics.
Additional knowledge of cosmology and galaxies would be an asset.
Basic knowledge and skills of computer programing would be desirable.