21 Mars 2006Visions for infrared astronomy1 Protoplanetary worlds at the AU scale Jean Philippe Berger J. Monnier, R. Millan-Gabet, W. Traub, M. Benisty,

21 Mars 2006 Visions for infrared astronomy 1

Protoplanetary worlds at the AU scale

Jean Philippe BergerJ. Monnier, R. Millan-Gabet, W. Traub, M. Benisty, F.

Malbet, E. Pedretti


Outline

A young star’s environment The contribution of two telescope

broadband infrared interferometry to the knowledge of disk structure

First steps towards imaging Conclusion


A young star’s environment

Presence of a flared disk of gas and dust associated with bipolarmass loss: winds and/or highly collimated jets, Typical disk sizes: 50-1000AU.

Infrared excess

Optical(HubbleAO)/mm imaging


The standard disk model

• Optically thick disk both for inner gas and outer dust

• Simple power-law temperature distribution (T r-0.75, T r-0.5)

• Oblique disk heating

-> fits rather well spectral energy distributions (SEDs)

e.g. Malbet & Bertout (1995, A&AS 113, 369)


Tuthill, Monnier & Danchi 2001

Optically Thin Cavity

Optically Thick, Geometrically Thin Disk

2001: important revision of the model

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

Dullemond et al. 2001Natta, 2001


2T interferometry: the near-IR view

PTI, IOTA and Keck have played a major role in near infrared YSO observing during (Malbet& Berger 98, Millan-Gabet 2001,Akeson2000,02 Eisner2002,2004, Monnier)

Authors concluded Herbig AeBe and T Tauri estimated sizes often bigger than predicted with standard disk model.

Signs for disk flattening at the astronomical unit scale.



Eisner, 2004









TTauris



1. Evidence for inner rim (Muzerolle 2004)

2. Flared disk can account for some estimated sizes (Lachaume 2003)

3. Fu Orionis stars observations compatible with standard models provided renmant envelopes or putative companions are taken into account (Malbet 2005, Millan-Gabet 20050





Herbig Be Stars

1. Some visibilities observations are compatible with standard disk (Malbet, 2005)

2. Evolutionary status of these stars should be debated (Monnier 2006)

Wind

Disk Disk





Presence of resolvedFlux (halo, envelop renmant)

IntrinsicVariability

Visibility modelling is highly sensitiveTo the knowledge of short baseline incohernetFlux and stellar vs. disk emission ratio


2T interferometry: the midIR view

Sizes consistent with flat self-shadowed / flaring disk model SED classification

Flaring

Self-shadowed

Leinert et al. (2004, A&A, 423, 537)

Sizes consistent with flat self-shadowed / flaring disk model SED classification


First steps towards imaging This IONIC3/IOTA campaign

was aimed at surveying the brightest HerbigAeBe and Ttauri stars in search for any asymetry (departure from zero closure phase) at the astronomical unit scale in order to select candidates for imaging.

Both a flared disk and disk with inner rim generate asymetries.



Isella et al 2005


First steps towards imaging

Malbet 2001

This IONIC3/IOTA campaign was aimed at surveying the brightest HerbigAeBe and Ttauri stars in search for any asymetry (departure from zero closure phase) at the astronomical unit scale in order to select candidates for imaging.

Both a flared disk and disk with inner rim generate asymetries.



Results

Essentially zero closure phases

Evidence for resolved flux (incoherent)?


Interpretation in the inner rim context


Interpretation in the inner rim context


Parametric imaging


Direct imaging





Berger et al, 2006Image reconstruction:Meimon, Mugnier, ONERA




Imaging protoplanetary disks

Imaging the inner AU requires a lot of telescopes and (preferably than) or a lot of array configurations

Model ambiguities often vanish at longer baselines

YSO short baselines images (i.e AO), are essential.

Simultaneous photometry is very important

Understanding the disk structure would ideally require joint near and mid-infrared observations

Second generation VLTI instrumentation is more than welcome.

IOTA3 @ H

CHARA @ K260 m baseline!

Keck-I @ KKlahr & Kley (2005, A&A in press)

Hot accreting planets in disks?

Micro-jets

Documents

21 Mars 2006Visions for infrared astronomy1 Protoplanetary worlds at the AU scale Jean Philippe Berger J. Monnier, R. Millan-Gabet, W. Traub, M. Benisty,