K. Perraut, J. Bouvier, J.B. Le Bouquin, M. Benisty · K. Perraut, J. Bouvier, J.B. Le Bouquin, M. Benisty 15/02/2013 Atelier VEGAS – NICE – Karine Perraut 1

K.Perraut,J.Bouvier,J.B.LeBouquin,M.Benisty

15/02/2013 Atelier VEGAS – NICE – Karine Perraut 1

4

Nuage moléculaire

10 pc ― 4°

Effondrement Fragmentation

1 pc ― 20’ 0.1 pc ― 2’ (Taurus)

1000 AU ― 7’’ 300 AU ― 2’’ 30 AU ― 0.2’’

Accretion disk and bipolar ejection

Molecular clouds Collapse Fragmentation

Debris disk and protoplanets Planetary system

105 / 106 yrs old

[Bou

vier

& M

albe

t 200

1]

TTauristars(TTS): ‐Solarmassobjects(~M☉) ‐SpectraltypesG‐M

HH30 - HST

Jet

Disk

•  OpEcallythickdisks•  ObscuraEonthecentralstaraccordingtogeometry•  DetailedverEcalstructureofthedisk,physicsofgrainformaEon•  Jetsandnebularstructure(accreEon,shocks)

HH30 seen almost edge-on by the HST (optical + NIR)

  HAEBE=PMSstarsofintermediatemass(1.5–10M)  Spectraltypes:BtoF8

  Surroundedbyaprotoplanetarydiskofgasanddust(complexenvironment)

  LikeTTauristars,alargefracEonofHAEBEliesinmulEplesystems(68±11%–Bainesetal.2006).

  BUTcontrarytothelessmassiveTTauristars,formaEonscenarioisveryuncertain.

⇒HAEBEareataninterfacebetweentworegimesofstarforma6on

5

[Dul

lem

ond

& M

onni

er 2

010]

  Accre6onviatheaccreEoncolumns(TTau)ortheinnerdisk⇒Veiling,IRexcess

  ConnecEonsstar/innerdisk,innerdisk/dustdisk?  Morphologyoftheinnerrimofthedustdisk?

  ProcessusofdissipaEonandevoluEonofthedisk?  Lawoftemperature,velocity,densityinthedisk?

  Ejec6onviaawind(star,disk,…)andjets  Launchingpointandmorphologyofjets?

  MechanismsthatfavorjetcollimaEon?

  Mass‐lossratewrtmass‐accreEonrate?

  Forma6onoftheHydrogenemissionlines⇒ConnecEonbetweenaccreEonandejecEon

  Lineformingregions?

  Mechanismsthatcouldexplainthetemporalvariability?

6

  Near‐infrared(spectro‐)interferometrydirectlyprobestheemissionwithintheinnermost astronomical unit (AU), where key quanEEes for the star‐disk‐protoplanet(s) interacEons are set. The regions probed by this technique aremuchmorecomplexthanexpected.

  3DMHDsimula6onsofaccreEon(drivenbymagneto‐rota3onalinstability)ontoarotaEngmagneEzedstarwithaElteddipolemagneEcfieldproducecomplexmaps.

  Allthesecomplicatedinner

diskstructuresarestrongly

6mevariableonaEmescale

ofweekstoyears…

[Romanova et al. 2012]

8

Simultaneousspectroscopyandphotometrystudies[Bouvier et al. 1999, 2003, 2007]

[Ménard et al. 2003]

Light curve shows periodical (~ 8.2 days) eclipses of the photosphere that occur without much color variation.

The linear polarization increases as the system fades.

Periodical occultation of the photosphere by an optically thick, magnetically-warped inner disk region

Periodicaleclipses

(innerdiskwarp)

P=8.22d

Balmerlines

(accre6onfunnel)

Veiling

(accre6onshock)

Diskwarp,accre6oncolumn,accre6onshock:allspa6allyassociated

Inclinedmagnetosphere

[Bouvier et al. 2007]

[Donati et al. 2010]

Spectro‐polarimetricstudies:

2‐3kGdipolarmagneEcfield,Eltedat~20degontotherotaEonaxis

HeI

Themagne6cpoleislocatedataboutthesameazimuthasthediskwarpthatproducestheeclipse Bothacold(magneEc)spotandahot(accreEon)

spotarefoundclosetothemagneEcpole

Shortterm(weeks)variabilitysupportstheideaof“magnetosphericaccre6oncycles”onaEmescaleofafewrotaEonperiodsinaccreEngTTauristars.

MagneEcconfiguraEonsofthestar‐diskinteracEoncanalsovaryonamuchlongerEmescale(~afewyears).

AATau’seclipses

0.6mas

•  StarsorbitinagapopenedbyEdalinteracEonsinsideacircumbinarydisk.

•  Youngshortperiodbinaries(P<afew10days,sep~afew0.1AU)cannotsupportlargecircumstellardisks.⇒Theyaresurroundedbyacircumbinarydisk.

•  EvidenceofenhancedemissionlineacEvityclosetoperiastronpassages(DQTau(Basrietal.1997),UZTauE(Martynetal.2005)⇒ non‐axisymmetricaccre6onperturbedbytheorbitalinteracEonwiththeinnerdisk

Howdoesaccre6onproceedfromthecircumbinarydiskontothe

componentsofthesystem?

Howdothecomponentsevolveifpreferen6alaccre6on? 12

[de Val-Borro et al. 2011]

V4046Sgr

13

[de Val-Borro et al. 2011]

0.2mas

Magnitude en R = 9.5

Stronginteresttoaccesstoimagingcapabili6esoftheseobjects

inthevisible(+IR)ranges

09/11/2012 Conférence XX - Mon Nom et mon prénom - lieu YY 14

15

1 mas 10 mas

16

0

10

20

30

40

50

60

70

4,5 5,5 6,5 7,5 8,5 9,5 10,5 11,5 12,5 13,5 14,5 15,5 16,5 17,5 18,5 19,5 20,5

Obj

ect n

umbe

rs

Magnitude

Pre-Main sequence stars in Taurus-Auriga

K

R

From Kenyon et al. 2008

KinemaEcsstudiesareofstrongimportancefor:

  Windandjets:◦  SeveralspectralchannelsinHα

  AccreEonflows:◦  Smallradialvelocityofthefunnelflowclosetotheinnerrimofthedisk

◦  Freefallvelocity(~300km/s)closetothestar

Spectralresolu6onofseveralthousandsandupto20000

09/11/2012 Conférence XX - Mon Nom et mon prénom - lieu YY 17

[Whe

lan

& Ga

rcia

20

08]

AllphenomenaareEmelyvariable

onEmescalesofdaysorevenhours.

18

[Catala et al 1999]

Snapshotimaging

  Interesttohavealimi6ngmagnitudehighenoughtoallowtostudyafewnumbersoftypicalobjects.

◦  TODO:idenEfythesetypicalobjects

  SpectralResolu6on:structureandmorphologycanbestudiedwithHαconsideredasawhole

◦  SeePionierYSOsurvey

  Interestofdifferentspectrallines

(HαbutalsoOIforinstance)

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