1) A region within a system where mass or energy is given up, in contrast to a
→ source, where mass or energy is released.
M.E. sinken, O.E. sincan, from verb; cf. O.S. sinkan, O.N. sökkva, M.Du. sinken, Du. zinken, O.H.G. sinkan, Ger. sinken, Goth. sigqan "to sink."
Câhak, from câh "a well" (Mid.Pers. câh "a well;" Av. cāt- "a well," from kan- "to dig," uskən- "to dig out;" O.Pers. kan- "to dig;" Mod.Pers. kandan "to dig;" cf. Skt. khan- "to dig," khanati "he digs," kha- "cavity, hollow, cave, aperture") + -ak diminutive suffix.
Fr.: particule puits
In hydrodynamics codes, a way of treating a collapsing or accreting region, such as a star, as a simple → point mass. Indeed, in many situations, the scale of interest is much larger than the scale of the → accreting object itself and it would be impossible to perform the calculation otherwise. → Sinks are generally modeled as → Lagrangian particles (see, e.g., Bates et al. 1995, MNRAS 277, 362; Krumholz et al. 2004, ApJ 611, 399; Federrath et al. 2010, ApJ 713, 269).