Master's Thesis Defense by Utkarsh Detha
Supervisor: Lise Christensen
External examiner: Steen Hannestad
Title: Exploring large-scale filaments in the COSMOS field using NB118-excess objects
Abstract: I study the large-scale structure inside the COSMOS field by tracing the projected cosmic web for redshifts upto z=2.2. I selected an NB118 excess sample from Ultra-VISTA DR3 data in combination with the results of GTO data from VISTA telescope. LePhare is used for photometric redshift estimation and identifying the dominant emission line objects, namely Halpha, [OIII]/Hbeta and [OII] emitters. Power-law and broken power law fits were used to scrutinize the low-mass end of the galaxy main-sequence. I then used DisPerSE to trace projected cosmic filaments in the emission line bins. By considering a mass-limited sub-sample, I obtain robust and uniform projected skeletons for the Halpha and the [OII] objects, and identified potential clusters in all emission line bins.