Detecting Effects of Filaments on Galaxy Properties in the Sloan Digital
  Sky Survey III
  We study the effects of filaments on galaxy properties in the Sloan Digital
Sky Survey (SDSS) Data Release 12 using filaments from the `Cosmic Web
Reconstruction' catalogue (Chen et al. 2016), a publicly available filament
catalogue for SDSS. Since filaments are tracers of medium-to-high density
regions, we expect that galaxy properties associated with the environment are
dependent on the distance to the nearest filament. Our analysis demonstrates
that a red galaxy or a high-mass galaxy tend to reside closer to filaments than
a blue or low-mass galaxy. After adjusting the effect from stellar mass, on
average, early-forming galaxies or large galaxies have a shorter distance to
filaments than late-forming galaxies or small galaxies. For the Main galaxy
sample (MGS), all signals are very significant ($>6\sigma$). For the LOWZ and
CMASS sample, the stellar mass and size are significant ($>2 \sigma$). The
filament effects we observe persist until $z = 0.7$ (the edge of the CMASS
sample). Comparing our results to those using the galaxy distances from
redMaPPer galaxy clusters as a reference, we find a similar result between
filaments and clusters. Moreover, we find that the effect of clusters on the
stellar mass of nearby galaxies depends on the galaxy's filamentary
environment. Our findings illustrate the strong correlation of galaxy
properties with proximity to density ridges, strongly supporting the claim that
density ridges are good tracers of filaments.
