A ride in the Green Valley: towards a better understanding of galaxy evolution with J-PAS

• Grant number: 13/25629-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: March 01, 2014
• End date: July 31, 2015
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Laerte Sodré Junior
• Grantee: Loic Jean Francois Le Tiran
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 12/00800-4 - The 3-D universe: astrophysics with large galaxy surveys, AP.TEM

Abstract

The J-PAS instrument, built by Brazil and Spain, will provide integral-field low-resolution spectroscopy of a large region of the sky. It will provide spatially-resolved spectroscopy of an unprecedented number of galaxies. We propose to use this instrument to improve our understanding of galaxy evolution, by focusing on the "green valley'', a phase galaxies shortly undergo while transitioning from a state where their physics is dominated by star-formation processes to their quiescent mode. Many processes have been suggested to explain this transition, but the question remains open and the "green valley'' is one of the most fundamental investigations in the field of galaxy evolution. We propose to use the data obtained by J-PAS, and by its precursor, J-PLUS, to obtain spatially-resolved informations about the types of stellar populations present in these galaxies and insights about their history. We will make comparisons depending on the position of the galaxy in the color-magnitude diagram. We will determine their morphology. We will check for the presence of AGNs and check the correlation with the stage of evolution of the galaxies. We will use stacking analysis to extract the information from the low signal-to-noise regions. We will use the 3D maps produced by J-PAS to investigate environmental effects such as galaxies undergoing a major merger phase, multiple minor mergers, or effect of the hot gas halo. (AU)