I study intergalactic medium to understand gas flows in a galaxy cluster for my Ph.D. thesis. Multiple QSO sightlines behind the Virgo Cluster were selected to find Lyα absorption lines. Overall distribution of Lyα absorbing warm gas in a cluster and its relation to cluster galaxies are investigated.

Also, the gas kinematics of HI-rich galaxies is being studied with EVLA data to find the origin of the HI-extended disks.

Warm Gas in the Virgo Cluster: I. Distribution of Lyα Absorbers (ADS, arXiv)

The Influence of Environment on the Circumgalactic Medium (ADS, arXiv)

Many stellar streams are found in the Galactic halo with the achievements of large area sky surveys. Dynamically cold stellar streams are fragile to massive encounters such as dark matter subhalos. I ran dynamical simulations of Pal 5 with an impact of dark matter subhalo encounters to probe the possibilities of detecting them from the remaining signatures on the stream. Please see my paper for details.

Clumpy Streams from Clumpy Halos: Detecting Missing Satellites with Cold Stellar Structures (ADS, arXiv)

Galaxies in various environments show different observable properties. I developed a new method to measure the local density of galaxies that overcome the current limitation, fiber collision in a dense environment, in SDSS. With the method, I constructed a galaxy catalog and examined the different properties of galaxies in a cluster (see my master’s thesis).

Spectro-photometric Search for Galaxy Clusters in SDSS (ADS, arXiv)

A Demography of Galaxies in Galaxy Clusters with Spectro-photometric Density Measurement. (Master’s thesis, PDF)

3D Movie showing SDSS galaxy distribution in a 100*100*100 Mpc^3 box. (Download)

- Blue and red dots show blue and red galaxies (based on g-r color). The space is colored by local galaxy density (see Yoon et al. 2008), i.e., yellow space presents dense regions such as galaxy clusters.