COSMIC WEB AND STAR FORMATION ACTIVITY IN GALAXIES AT z ∼ 1

• Published in: The Astrophysical journal 2014-11, Vol.796 (1), p.1-13
• Main Authors: Darvish, B, Sobral, D, Mobasher, B, Scoville, N Z, Best, P, Sales, L V, Smail, I
• Format: Article
• Language: English
• Subjects: ALGORITHMS; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Clusters; COLOR; DENSITY; Elevation; Emitters; Filaments; GALAXIES; GALAXY CLUSTERS; Galaxy formation; INTERACTIONS; MASS; STAR EVOLUTION; Star formation; STARS; UNIVERSE
• ISSN: 1538-4357; 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/796/1/51

We investigate the role of the delineated cosmic web/filaments on star formation activity by exploring a sample of 425 narrow-band selected H[alpha] emitters, as well as 2846 color-color selected underlying star-forming galaxies for a large-scale structure at z = 0.84 in the COSMOS field from the HiZELS survey. Using the scale-independent Multi-scale Morphology Filter algorithm, we are able to quantitatively describe the density field and disentangle it into its major components: fields, filaments, and clusters. We show that the observed median star formation rate (SFR), stellar mass, specific SFR, the mean SFR-mass relation, and its scatter for both H[alpha] emitters and underlying star-forming galaxies do not strongly depend on different classes of environment, in agreement with previous studies. However, the fraction of H[alpha] emitters varies with environment and is enhanced in filamentary structures at z ~ 1 - We propose mild galaxy-galaxy interactions as the possible physical agent for the elevation of the fraction of H[alpha] star-forming galaxies in filaments. Our results show that filaments are the likely physical environments that are often classed as the "intermediate" densities and that the cosmic web likely plays a major role in galaxy formation and evolution which has so far been poorly investigated.