We performed a molecular line survey of 82 high-mass protostellar objects in a search for inflow signatures associated with high-mass star formation. Using the (HCO+)-C-13 (1-0) line as an optically thin tracer, we detected a statistically significant excess of blue asymmetric line profiles in the HCO+ (1-0) transition, but nonsignificant excesses in the HCO+ (3-2) and H2CO (2(12)-1(11)) transitions. The negative blue excess for the HCN (3-2) transition suggests that the line profiles are affected by dynamics other than inflow motion. The HCO+ (1-0) transition thus seems to be the suitable tracer of inflow motions in high-mass star-forming regions, as previously suggested. We found 27 inflow candidates that have at least 1 blue asymmetric profile and no red asymmetric profile, and derived the inflow velocities to be 0.23-2.00 km s(-1) for 20 of them using a simple two-layer radiative transfer model. Our sample is divided into two groups in different evolutionary stages. The blue excess of the group in relatively earlier evolutionary stages was estimated to be slightly higher than that of the other in the HCO+ (1-0) transition.

Recent developments in compact object astrophysics, especially the discovery of merging neutron stars by LIGO, the imaging of the black hole in M87 by the Event Horizon Telescope, and high- precision astrometry of the Galactic Center at close to the event horizon scale by the GRAVITY experiment motivate the development of numerical source models that solve the equations of general relativistic magnetohydrodynamics (GRMHD). Here we compare GRMHD solutions for the evolution of a magnetized accretion flow where turbulence is promoted by the magnetorotational instability from a set of nine GRMHD codes: Athena++, BHAC, Cosmos++, ECHO, H-AMR, iharm3D, HARM-Noble, IllinoisGRMHD, and KORAL. Agreement among the codes improves as resolution increases, as measured by a consistently applied, specially developed set of code performance metrics. We conclude that the community of GRMHD codes is mature, capable, and consistent on these test problems.