(1: Kobe University, 2: Nagoya University, 3: NAOJ)

1
T??????XZ Tauri????????????
Tomonori Hioki1 (otopen_at_kobe-u.ac.jp), Yoichi
Itoh1, Yumiko Oasa1, Misato Fukagawa2, SDPS Team3
(1 Kobe University, 2 Nagoya University, 3
NAOJ)
?Abstract? We obtained a high spatial resolution
(FWHM 0.1) near-infrared image of XZ Tau, a
0.3 separated binary system, using Subaru/CIAO.
A jet-like structure (Jet1 of Fig 5) was detected
at northeast side of the binary. It is possibly
driven from the secondary. Previous HST
observations of the binary showed a shock (bubble
structure of Fig 3) created by another jet (Jet2
of Fig 5) from the primary.
4. Result 4.1 Jet from the secondary Fig5
presents that the jet (Jet1) drive from the
secondary in the direction of P.A.54 deg.
4.2 H-band Magnitude,
Separation, Position Angle

• Introduction
• 1.1 Motivation
• Many T Tauri stars (1 Myr) have protoplanetary
  disks and bipolar jets.
• The observations have focused mainly on single T
  Tauri stars.
• More than half of T Tauri stars are binaries.
  (Ghez et al)
• A limited number of studies have so far examined
  the disks and the jets around binary systems.
  (e.g., UY Aur Hioki et al. 2007)
• 1.2 CIAO-Coronagraphic Imager with Adaptive
  Optics
• Mask has 2 transmission for the central star.
• A pupil Lyot stop reduce the diffracted light.
• ?CIAO is effective for the detection of
  protoplanetary disks and jets around the stellar
  vicinity.
• 1.3 XZ Tau (Classical T Tauri Binary)
• Location Taurus star forming region (L1551
  d140 pc, Elias 1978)
• Separation 0.3 (40 AU Haas et al. 1990)
• Mass 0.4 Msun (Primary), 0.3 Msun (Secondary)
  (Hartigan Kenyon 2003)

Brightness ? r -4
Fig1 Circumstellar disk and jet of HH30
(HST/WFPC2 Burrows et al. 1996)
?Northeast ?Southwest
Limiting magnitude
Fig5 Coronagraphic image of XZ Tau
Fig6 Brightness of the northeast (?) and
southwest (?) jets from the secondary
ltNortheast sidegt?Extending to 300 AU from the
secondary?Surface brightness ? r -4 (r
distance from the secondary)If the structure is
scattering from the central binary, its
brightness ? r-3. Therefore, 1 the more it
is distant from the stars, the optically thinner
or 2 it emits not only by scattering but also
by emission lines (such as Fe II). ltSouthwest
sidegtOutstanding structure is not seen. ?The
jet is probably obscured by a circumbinary disk
(if any) in the plane perpendicular to the jet.
Fig2 Coronagraph structure
Fig3 XZ Tau image taken by HST/WFPC2 (R-band
Krist et al. 1999)
BlueSeparation 0.3 (42 AU)Red Angular
velocity 1.2 deg/yr ?Orbital period 300 yrs
Total mass 0.8 M sun (assuming its orbit is
circular)
Blue Secondary (0.6 mag up)Red Primary (1.3
mag down) These variations may originate from
variable accretion rate to the stars rotation
of the secondary with hot spots on its surface.
The variation of the primary possibly
contributes to its outburst.
On the other hand, it is thought that the
secondary is equable compared with the primary.
?Does the secondary drive the jet? or not??
5. Discussion 5.1 Jet? or Reflection Nebulae? It
is possibility that the jet-like structure is
scattering from the central binary. ?We also
carried out the Fe II observations in 2007
Dec. 5.2 Result of Fe II image
2.Observations Date 2005 Nov 9, 2007 Dec
16 Instrument Subaru/ CIAO FOV 22 by
22 Wavelength H-band (1.6 um), Fe
II PSF-reference stars were obtained before and
after XZ Tau observations.
Mask size arcsec Ex time sec FWHMarcsec
XZ Tau 0.6 720 0.1
PSF-ref 0.6 228 0.1
Was a weak Fe II emission detected?? If it is
real, the jet-like structure corresponds to the
jet from the secondary. Because forbidden lines
are indicative of the jet from young stellar
objects. But This image is the result of
simplified reduction. More detailed reduction is
needed!!
3.Reduction (IRAF) ?Dark subtraction
?Flat-fielding by twilight flat ?Hot and bad
pixel removal ?Sky subtraction ?Shift
each frame to adjust the position of the stars
?Rotation of PSF-reference stars to adjust the
position angle of the spider ?Combining XZ
Tau frames subtracted their PSFs
Fig7 Fe II coronagraphic image of the XZ Tau
binary (ex time 1280 s)