Cosmic Web and Star Formation Activity in Galaxies at z~1
  We investigate the role of the delineated cosmic web/filaments on the 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 (LSS) at z=0.84 in the COSMOS field from the HiZELS
survey. Using the scale-independent Multi-scale Morphology Filter (MMF)
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
star formation rate (sSFR), 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 which 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.
