In the first project of this thesis, we studied galaxies with faster inside-out assembly at lower redshifts using data from SDSS, WISE, GALEX, and Galaxy Zoo. We analyzed 48,127 IOAG candidate galaxies with stellar mass log M∗ = 10.73 − 11.03 L⊙ and redshift z < 0.1. Our classification found 20% were star-forming, 40% AGN, and 40% composite galaxies. Morphologically, 37% were spirals, 12% elliptical, and many had uncertain classifications. Most star-forming IOAG candidates were spirals with main sequence alignment, while Seyfert 2 and composite galaxies had quiescent SFRs and spiral morphologies. IOAG galaxies often fell below the main sequence, indicating potential quenching from blue cloud to red sequence, particularly in AGN-classified galaxies.
The other two studies focused on the overdensity of LBGs around three luminous Hot DOGs. Using deep GMOS-S and Magellan/IMACS imaging, we estimated the surface density of LBGs around W2246-0526, W0410–0913, and W0813+0140, finding significant overdensities. The optimized photometric selection criteria revealed steep declines in overdensity beyond physical scales of ~1.5 Mpc for W0410–0913 and W0813+0140, and ~0.5 Mpc for W2246–0526. This suggests Hot DOGs live in dense environments, making them excellent tracers of protoclusters.
(Text above is a summary of PhD thesis abstract)
Type of project: PhD thesis
Status: Finished. Graduated 2024
Researchers: Dejene Zewdie, Roberto Assef, Manuel Aravena
Funding source: Becas ANID/ Basal CATA2