Dynamical Mass Estimates of Large‐Scale Filaments in Redshift Surveys

We propose a new method to measure the mass of large-scale filaments ingalaxy redshift surveys. The method is based on the fact that the mass per unitlength of isothermal filaments depends only on their transverse velocitydispersion. Filaments that lie perpendicular to the line of sight may thereforehave their mass per unit length measured from their thickness in redshiftspace. We present preliminary tests of the method and find that it predicts themass per unit length of filaments in an N-body simulation to an accuracy of~35%. Applying the method to a select region of the Perseus-Pisces superclusteryields a mass-to-light ratio M/L_B around 460h in solar units to within afactor of two. The method measures the mass-to-light ratio on length scales ofup to 50h^(-1) Mpc and could thereby yield new information on the behavior ofthe dark matter on mass scales well beyond that of clusters of galaxies.Comment: 21 pages, LaTeX with 6 figures included. Submitted to Ap