Oral Presentation

SMA and ALMA Study of the Protostellar Binaries in the L1551 Region with Paul

Author(s): Shigehisa Takakuwa, Miyu Kido, Kazuya Saigo (Kagoshima), Hsi-Wei Yen, Jeremy Smallwood, Pingao Gu, Nagayoshi Ohashi, & Paul T. P. Ho (ASIAA)

Presenter: Shigehisa Takakuwa (Kagoshima University)

I will talk about our series of SMA and ALMA studies of the protostellar binaries in the L1551 region with Paul, and report our ongoing efforts. The L1551 region contains three binaries, L1551 IRS 5, L1551 NE, and XZ Tau. L1551 IRS 5 is my first object for the SMA observations with Paul, and then we expanded our projects to the other binaries. ALMA observations of L1551 IRS 5 and NE in the 0.9-mm dust-continuum emission reveal spiral arm features in the circumbinary disks. While the spiral arms in L1551 NE show an m=1 mode, those in L1551 IRS 5 show two, point symmetric spirals. We have also detected channel flows connecting between the two circumstellar disks in L1551 IRS 5 in the C18O (3-2) observations. With the analyses of the multi-epoch ALMA archival data of XZ Tau, we identified proper motion of the two binaries. The kinetic energy of the stellar motion is likely higher than the gravitational energy, suggesting that XZ Tau is a fly-by system. I will summarize these findings and future plans.