Filamentary Flows and Clump-fed High-mass Star Formation in G22

G22 is a hub-filament system composed of four supercritical filaments. Velocity gradients are detected along three filaments. A total mass infall rate of 700 M_⊙ Myr^-1 would double the hub mass in about three free-fall times. The most massive clump C1 would be in global collapse with an infall velocity of 0.26 km s^-1 and a mass infall rate of 5 × 10^-4 M_⊙ yr^-1, which is supported by the prevalent HCO⁺ (3-2) and ¹³CO (3-2) blue profiles. A hot molecular core (SMA1) was revealed in C1. At the SMA1 center, there is a massive protostar (MIR1) driving multipolar outflows which are associated with clusters of class I methanol masers. MIR1 may be still growing with an accretion rate of 7 × 10^-5 M_⊙ yr^-1. Filamentary flows, clump-scale collapse, core-scale accretion coexist in G22, suggesting that high-mass starless cores may not be prerequisite to form high-mass stars. In the high-mass star formation process, the central protostar, the core, and the clump can grow in mass simultaneously.