High-contrast Polarimetry Observation of T Tau Circumstellar Environment

TL;DR

This study used high-contrast polarimetry to reveal detailed circumstellar structures around the T Tau system, constraining disk sizes, orientations, and outflow features in a young stellar environment.

Contribution

First detailed polarimetric imaging of T Tau system revealing circumstellar disks, outflows, and their orientations, providing new constraints on the system's structure.

Findings

Discovered a nearly face-on disk around T Tau N no larger than 117 AU.

Identified a highly inclined circumbinary disk around T Tau S, about 44 AU in radius.

Detected multiple outflow-related structures and their likely origins.

Abstract

We conducted high-contrast polarimetry observations of T Tau in the H-band, using the HiCIAO instrument mounted on the Subaru Telescope, revealing structures as near as 0.$\arcsec$1 from the stars T Tau N and T Tau S. The whole T Tau system is found to be surrounded by nebula-like envelopes, and several outflow-related structures are detected in these envelopes. We analyzed the detailed polarization patterns of the circumstellar structures near each component of this triple young star system and determined constraints on the circumstellar disks and outflow structures. We suggest that the nearly face-on circumstellar disk of T Tau N is no larger than 0.$\arcsec$8, or 117 AU, in the northwest, based on the existence of a hole in this direction, and no larger than 0.$\arcsec$27, or 40 AU, in the south. A new structure "N5" extends to about 0.$\arcsec$42, or 59 AU, on the southwest of the star, believed to be part of the disk. We suggest that T Tau S is surrounded by a highly inclined circumbinary disk with a radius of about 0.$\arcsec$3, or 44 AU, with a position angle of about 30$^\circ$, that is misaligned with the orbit of the T Tau S binary. After analyzing the positions and polarization vector patterns of the outflow-related structures, we suggest that T Tau S should trigger the well-known E-W outflow, and is also likely to be responsible for a southwest precessing outflow "coil" and a possible south outflow.