Multi-Epoch Submillimeter Array Observations Of The L1448c(N) Protostellar Sio Jet

L1448C(N) is a young protostar in Perseus, driving an outflow and an extremely high-velocity molecular jet. We present multi-epoch observations of SiO J = 8 - 7 and CO J = 3 - 2 lines, and the 345 GHz dust continuum toward L1448C(N) in 2006, 2010, and 2017 with the Submillimeter Array. The knots traced by the SiO line show the averaged proper motion of similar to 006 yr(-1) and similar to 004 yr(-1) for the blue- and redshifted jet, respectively. The corresponding transverse velocities are similar to 78 km s(-1) (blueshifted) and similar to 52 km s(-1) (redshifted). Together with the radial velocity, we found the inclination angles of the jets from the plane of the sky to be similar to 34 degrees for the blueshifted jet and similar to 46 degrees for the redshifted jet. Given the new inclination angles, the mass-loss rate and mechanical power were refined to be similar to 1.8 x 10(-6) M and similar to 1.3 L, respectively. In the epoch of 2017, a new knot was detected at the base of the redshifted jet. We found that the mass-loss rate of the new knot is three times higher than the averaged mass-loss rate of the redshifted jet. Besides, the continuum flux has been enhanced by similar to 37% between 2010 and 2017. These imply that a variation of the mass-accretion rate by a factor of similar to 3 has occurred in a short timescale of similar to 10-20 yr. In addition, a knot in the downstream of the redshifted jet is found to be dimming over the three epochs.