resolving the gap and au-‐scale asymmetries in pre ... · ori is filled with substan al amounts...
TRANSCRIPT
Resolving the gap and AU-‐scale asymmetries in pre-‐transi�onal disks with mul�-‐wavelength interferometry
Stefan Kraus1,2,3, Michael Ireland4, Michael Sitko5,6,10, John Monnier3, Nuria Calvet3, Catherine Espaillat2, Carol Grady7, Tim Harries1, Sebas�an Hönig8, Ray Russell9,10, Daryl Kim9,10, Jeremy Swearingen5, Chelsea Werren5, David Wilner2
(1) University of Exeter, (2) Harvard-‐Smithsonian Center for Astrophysics, (3) University of Michigan, (4) Macquarie University,
(5) University of Cincinna�, (6) Space Science Ins�tute, (7) Eureka Scien�fic Inc. and Goddard Space Flight Center, (8) University of California Santa Barbara, (9) The Aerospace Corpora�on, (10) Visi�ng Scien�st NASA IRTF
H band
K band
L band
Op�cally thick inner disk (R=0.18-‐0.27 AU),
resolved by VLTI/AMBER + KI/ASTRA
near-‐infrared interferometry
Op�cally thin material located in the gap (R=0.27-‐46 AU),
resolved by VLTI/MIDI + Gemini/TReCS mid-‐infrared speckle interferometry
Pre-‐transi�onal disks exhibit a significantly reduced mid-‐infrared excess compared to classical (T Tauri-‐type) protoplanetary disks, possibly indica�ng a gapped disk structure. We emp l o y n e a r -‐ a n d m i d -‐ i n f r a r e d interferometry in order to study the structure of these objects and to solve ambigui�es that result from fi�ng the SED alone.
Density inhomogenei�es in the gap region,
detected with Keck/NIRC2 aperture masking interferometry
Spa�al Frequency [106 λ]
Visib
ility
Spa�al Frequency [106 λ] Spa�al Frequency [106 λ]
è The detected asymmetries trace complex density structures on AU-‐scales.
è We cau�on that these signatures can be easily misinter-‐preted as companion signatures.
è The gap in V1247 Ori is filled with substan�al amounts of op�cally thin material (Σgap≈ 9×10-‐6 g/cm2) with a carbon-‐dominated dust mineralogy. The presence of this op�cally thin material cannot be deduced from the SED alone.
è Our IRTF/SpeX+BASS spectra show strong hydrocarbon-‐related (“PAH”) line-‐emission, whose spa�al origin we constrain with MIDI interferometry to within the gap region.
è We detect a narrow ring of op�cally thick hot dust at the dust sublima�on radius, followed by an extended disk gap.
V1247 Ori, Ar�st Im
pressio
n, NASA/JPL-‐Calte
ch
Reference: Kraus et al. 2013, ApJ 768, 80; Contact: [email protected] This work is supported at The Aerospace Corpora�on by the Independent Research and Development program.
RESULTS: V1247 Ori Spa�ally resolved observa�ons provide unambiguous evidence for a gapped disk structure.
The gap is filled with substan�al amoun t s o f o p� c a l l y t h i n carbonaceous dust, possibly indica�ng a par�cularly early stage of disk clearing.
Complex density inhomogenei�es might reflect the dynamical interac�on of disk material with the gap-‐opening bodies.
Future direc�ons of work:
Observa�ons on a larger sample of transi�onal & pre-‐transi�onal disks are needed to establish the evolu�onary sequence of disk clearing.
Mul�-‐epoch interferometric imaging could unravel the origin, structure and �me-‐evolu�on of the detected asymmetries.