planets & brown dwarf...
TRANSCRIPT
1
Gaël Chauvin, David Mouillet & Jean-Luc Beuzit
(LAOG Grenoble Observatory)
High contrast and High Angular Resolution Imaging
Planets & Brown Dwarf Companions
Spirit of Lyot Conference, Berkeley, June 2007
Gaël Chauvin
LAOG-CNRS, Grenoble Observatory, France
Outline
I- Brief introductionFirst discoveries (Gl299B, 51 Peg b).Development of new observing techniques.Advantage of direct imaging to explore the 5-500 AU missing link.
II- Observing challenge & technical needsFaint companion close to bright stars. Observing Limitations.Technical needs: AO, Coronography, Differential Imaging...
III- Target selection & main surveysTargets identification and selection: distance and age.Young, nearby stars. Intermediate-old stars, Very, nearby stars and Exoplanet hostsSummary of the main surveys: observing technique, sample size and performances
IV- Observing strategy & main results1) Deep imaging, 2) Astrometry and 3) Photometry + SpectroscopyAccess to planetary masses. Physical and chemical properties. Origin of formationTypical detection limits and statistical analysis
VI- Conclusion & perspectives
Spirit of Lyot Conference, Berkeley, June 2007
2
Gl 229 Ad = 5.7 pcAge ~0.5 GyrMA = 0.5 MSun
Gl 229 BTeff = 900 KMB=25 MJup
Sep = 45 UA
1995 : First brown dwarf, companion to Gliese 229 (Nakajima et al. 1995)Adaptive optics + coronography, Palomar Observatory
Brie
f Int
rodu
ctio
nFirst Brown Dwarf Discovery
Brown Dwarf: “predicted to be not massive enough to start Hydrogen-burning” (Kumar 1962)
Mass < 75 MJup
Brie
f Int
rodu
ctio
n
Detection of the companion Epsilon Indi B (brown dwarf binary Ba & Bb)
Epsilon Indi A & Bab d = 3.6 pcAge = 0.8 - 2 GyrMBa = 50 MJup
MBb = 40 MJup
Sep = 1460 UA
1996-1997: Beginning of large surveys in optical (SDSS) and nIR (2MASS, DENIS) Hundreds of isolated brown dwarfs in the field (+600) ~10 Brown dwarf companions detected at large separations > 1000 AU
(Scholz et al. 2003)
Important Population of Brown Dwarfs
Brie
f Int
rodu
ctio
nB
rief I
ntro
duct
ion
3
1997-2002 : New spectral classification beyond late-M dwarfs
- L Dwarfs (1300-2200K): atmosphere saturated with dust, extremely red colors. (optical) absence of TiO and VO - absorption of H2O
- T Dwarfs (500-1300K): dust condensation or rain-out in the atmosphere, bluer, near-IR spectra: absorption of H2O and CH4
L D w a r f s
T D w a r f s
M D w a r f s
E G P s M < 1 3 M J u p
B D s 1 3 < M < 7 5 M J u p
S t a r s M > 7 5 M J u p
New Spectral Classification
(Burrows et al. 2001)
Brie
f Int
rodu
ctio
nB
rief I
ntro
duct
ion
Discovery of the First Exo-planet
•1995 : Radial velocity measurements, 1st Exo-planet orbiting 51 Peg (Mayor & Queloz 1995)
Minimum mass of M2sini > 0.45 MJup and a period P = 4.23 days
Brie
f Int
rodu
ctio
nB
rief I
ntro
duct
ion
4
Nowadays,
•- The most successful technique!•- More than 200 Exo-planets discovered (www.exoplanets.org) •- Brown dwarf desert at short separations < 4 AU•- High diversity of masses, orbital parameters (P, a, e, M2sini)
•Period – Mass – Eccentricity Distributions- RV precision allows access to telluric masses
- Host Stars Studies: Impact of MetallicityMultiplicityAge
Large Diversity of Planetary Systems
•1995 : Radial velocity measurements, 1st Exo-planet orbiting 51 Peg (Mayor & Queloz 1995)
> G . M a r c y ' s R e v i e w
> X . B o n fi l s ' s T a l k
> M . M u g r a u e r ' s T a l k a n d T . S c h m i d t ' s P o s t e r
> X . B o n fi l s ' s T a l k
Minimum mass of M2sini > 0.45 MJup and a period P = 4.23 days
Brie
f Int
rodu
ctio
nB
rief I
ntro
duct
ion
Ind
ire
ct
dir
ec
t
+ Astrometric Wobbling (VLTI/PRIMA, GAIA), Interferometry (SIM, TPF/Darwin)
> Spectroscopic Characterization of Planet and BD atmopsheres
Radial Velocity
Pulsar Timing
Gravitational Micro-lensing
Photometric Transit(Secondary Eclipse)
Classical, HC & HAR Imaging
m2 sini (hyp. m1) P, e, a, ω, T0
m2 sini (hyp. m1) P, e, a, ω, T0
m2, m1, d P, a (single event)
R2, R1, m1 (e=0; R*-M*) P, a, i, T0
m1, m2P, a, e, i, ω, T0
Planets (& BDs) hunting techniques
Brie
f Int
rodu
ctio
nB
rief I
ntro
duct
ion
5
RV, Transit,Micro-lensing (< 5 AU)
> 200 exo-planetsBrown dwarf desert
Large surveys(> 500 AU)
~10 brown dwarf companions2MASS and DENIS
Missing Link between 5 and 500 AU
- S o l a r S y s t e m
- C i r c u m s t e l l a r D i s k s
- M u l t i p l i c i t y
0 50 100 1000 (AU)1000
........... O o r t C l o u dK u i p e r
Brie
f Int
rodu
ctio
nB
rief I
ntro
duct
ion
High Contrast/High Angular Resolution Direct Imaging
(Lowrance et al. 1999)TWA5 B (HST/NICMOS)
R a p i d c o n fi r m a t i o n ( 1 - 2 y r s )
S p e c t r a l c h a r a c t e r i z a t i o n
S t u d y o f o r b i t a l p a r a m e t e r s
P h y s i c o - c h e m i s t r y ( S t r u c t u r e & a t m o s p h e r e )
O r i g i n o f f o r m a t i o n
Missing Link between 5 and 500 AU
- S o l a r S y s t e m
- C i r c u m s t e l l a r D i s k s
- M u l t i p l i c i t y
0 50 100 1000 (AU)1000
........... O o r t C l o u dK u i p e r
Brie
f Int
rodu
ctio
nB
rief I
ntro
duct
ion
6
Outline
Spirit of Lyot Conference, Berkeley, June 2007
I- Brief introductionFirst discoveries (Gl299B, 51 Peg b).Development of new observing techniques.Advantage of direct imaging to explore the 5-500 AU missing link.
II- Observing challenge & technical needsFaint companion close to bright stars. Observing Limitations.Technical needs: AO, Coronography, Differential Imaging...
III- Target selection & main surveysTargets identification and selection: distance and age.Young, nearby stars. Intermediate-old stars, Very, nearby stars and Exoplanet hostsSummary of the main surveys: observing technique, sample size and performances
IV- Observing strategy & main results1) Deep imaging, 2) Astrometry and 3) Photometry + SpectroscopyAccess to planetary masses. Physical and chemical properties. Origin of formationTypical detection limits and statistical analysis
VI- Conclusion & perspectives
Observing Challenge
D e t e c t / c h a r a c t e r i z e s o m e t h i n g f a i n t , s p a t i a l l y c l o s e t o s o m e t h i n g b r i g h t
- Relative flux (photometry)
Emitted light of the companionLuminosity vs model predictions(Mass, luminosity, Teff...)
- Relative position (astrometry)
proper motion (comoving?) orbital motion (Bound companion?)
- Spectral information (spectroscopy)
Atmosphere characterizationMolecules, Dust propertiesGravity, Effective Temperature
Obs
ervi
ng C
halle
nge
and
Tech
nica
l Nee
ds
7
Technical Needs
- High image quality
High angular resolution PSF Stability
Calibration of statical aberrations
- PSF Halo Brightness
Halo attenuation? Inner working angle? Speckle-noise Photon-noise
- Intrinsic companion faintness
Long overall observationsBackground/Readout-noise limits
Obs
ervi
ng C
halle
nge
and
Tech
nica
l Nee
ds
C . M a r o i s , R . S o u m m e r ' s T a l k s
D e t e c t / c h a r a c t e r i z e s o m e t h i n g f a i n t , s p a t i a l l y c l o s e t o s o m e t h i n g b r i g h t
ESO3.6m/Come-On+ 1994
(Neuhäuser et al 05) (Janson et al. 2007)
Technical Needs
I m p r e s s i v e E v o l u t i o n
G Q l u p
VLT/NACO 2005
Obs
ervi
ng C
halle
nge
and
Tech
nica
l Nee
ds
•L a r g e t e l e s c o p e s , w i t h A O s y s t e m f r o m t h e g r o u n d ( > L i s a P o y n e e r )
•Handling instrumental artefacts: design, active correction, calibration
8
Technical Needs
•L a r g e t e l e s c o p e s , w i t h A O s y s t e m f r o m t h e g r o u n d
•Handling instrumental artefacts: design, active correction, calibration
•Coronography
Obs
ervi
ng C
halle
nge
and
Tech
nica
l Nee
ds
- Occulting Mask Saturated Imaging
- Lyot Coronography
Technical Needs
D e t e c t i o n L i m i t s :D e t e c t i o n L i m i t s :
H - b a n dH - b a n d
O b s . T i m e ~ 1 0 m i nO b s . T i m e ~ 1 0 m i n
S t a r , H = 5 - 6S t a r , H = 5 - 6
( d = 5 0 p c )( d = 5 0 p c )
Obs
ervi
ng C
halle
nge
and
Tech
nica
l Nee
ds
•L a r g e t e l e s c o p e s , w i t h A O s y s t e m f r o m t h e g r o u n d
•Handling instrumental artefacts: design, active correction, calibration
•Coronography
9
Technical Needs
•L a r g e t e l e s c o p e s , w i t h A O s y s t e m f r o m t h e g r o u n d
•Handling instrumental artefacts: design, active correction, calibration
•Coronography
•Differential techniques: ADI, SDI, Polarimetry
H S T r o l l a n g l e H S T r o l l a n g l e ( L o w r a n c e e t a l . 9 9 ; 0 0 ; 0 5 )( L o w r a n c e e t a l . 9 9 ; 0 0 ; 0 5 )
B e i n g r e v i s i t e d / o p t i m i z e d , f o r o b s .B e i n g r e v i s i t e d / o p t i m i z e d , f o r o b s .
p r o c e d u r e s a n d d a t a a n a l y s i sp r o c e d u r e s a n d d a t a a n a l y s i s
( M a r o i s e t a l . 2 0 0 6 ) ( M a r o i s e t a l . 2 0 0 6 )
D e t a i l s d e p e n d e n t o n t e l e s c o p e ,D e t a i l s d e p e n d e n t o n t e l e s c o p e ,
F o c u s , d e f e c t s o r i g i n a n d s t r u c t u r eF o c u s , d e f e c t s o r i g i n a n d s t r u c t u r e ……
> C . M a r o i s ' s T a l k
> J . F a r i h i a n d D . L a f r e n i è r e T a l k s
Obs
ervi
ng C
halle
nge
and
Tech
nica
l Nee
ds
Technical Needs
M e t h a n e - r i c h c o m p a n i o n , T 2 - T 8 B D s M e t h a n e - r i c h c o m p a n i o n , T 2 - T 8 B D s
S D I C o n c e p t :S D I C o n c e p t :
C F H T / T R I D E N T C F H T / T R I D E N T
( R a c i n e e t a l . 1 9 9 9 ; M a r o i s e t a l . 2 0 0 0 )( R a c i n e e t a l . 1 9 9 9 ; M a r o i s e t a l . 2 0 0 0 )
R e s u l t s :R e s u l t s : ( M c C a u g h r e a n e t a l . 1 9 9 4 ; ( M c C a u g h r e a n e t a l . 1 9 9 4 ;
C l o s e e t a l . 2 0 0 5 ; B i l l e r e t a l . 2 0 0 6 )C l o s e e t a l . 2 0 0 5 ; B i l l e r e t a l . 2 0 0 6 )
> B . B i l l e r ' s T a l k
> G . M o n t a g n i e r ' s T a l k
Obs
ervi
ng C
halle
nge
and
Tech
nica
l Nee
ds
•L a r g e t e l e s c o p e s , w i t h A O s y s t e m f r o m t h e g r o u n d
•Handling instrumental artefacts: design, active correction, calibration
•Coronography
•Differential techniques: ADI, SDI, Polarimetry
10
Outline
Spirit of Lyot Conference, Berkeley, June 2007
I- Brief introductionFirst discoveries (Gl299B, 51 Peg b).Development of new observing techniques.Advantage of direct imaging to explore the 5-500 AU missing link.
II- Observing challenge & technical needsFaint companion close to bright stars. Observing Limitations.Technical needs: AO, Coronography, Differential Imaging...
III- Target selection & main surveysTargets identification and selection: distance and age.Young, nearby stars. Intermediate-old stars, Very, nearby stars and Exoplanet hostsSummary of the main surveys: observing technique, sample size and performances
IV- Observing strategy & main results1) Deep imaging, 2) Astrometry and 3) Photometry + SpectroscopyAccess to planetary masses. Physical and chemical properties. Origin of formationTypical detection limits and statistical analysis
VI- Conclusion & perspectives
Targ
et S
elec
tion
& M
ain
HA
R a
nd H
C im
agin
g S
urve
ys
D i s t a n c e < 1 0 0 – 2 0 0 p c
Target Selection: Stars near the Sun
11
E G P s M < 1 3 M J u p
B D s 1 3 < M < 7 5 M J u p
S t a r s M > 7 5 M J u p
Target Selection: AgeTa
rget
Sel
ectio
n &
Mai
n H
AR
and
HC
imag
ing
Sur
veys
(Burrows et al. 2001)
- 1983. TW Hya, an isolated T Tauri star (Rucinski & Krautter 1983)
- 1997. Identification of 5 first members of the TWA Association (Kastner et al. 1997)
- Now. 5 associations: TWA, β Pictoris, AB Dor,Tucana/Horologium & η Chameleontis
+ New stars from the SACY survey
> Total of 200 - 300 young, nearby (AFGKM) stars
Identification Groups: Zuckerman, Song et al.; Torres, de la Reza et al. Mamajek et al.; Ortega et al.; ByN et al.
Age & membership diagonostic- Abnormal colors, luminosity Optical/nIR photometry- Rotation & Stellar Activity Optical Spectroscopy: SpT, Hα, Li- Li Abundance X-ray Activity- Stellar Kinematics RV and proper motions
A g e ( < 1 0 0 M y r )
D i s t a n c e ( < 1 0 0 p c )
1) Young, nearby Associations
Targ
et S
elec
tion
& M
ain
HA
R a
nd H
C im
agin
g S
urve
ys
12
- HST/NICMOS Corono 45 Lowrance et al. (1999, 2000, 2005) - Keck/NIRC AO-Corono - MacIntosh et al. (01); Kaisler et al. (01) - ESO3.6m/ADONIS AO-Corono 29 Chauvin et al. (2002, 2003) - NTT3.5m/Sharp Saturated 32 Neuhäuser et al. (2003, 2005) - VLT/NACO AO-Saturated 28 Masciadri et al. (2005)- VLT/NACO AO-Lp 22 Kasper et al. (2007)- VLT & MMT AO-SDI 45 Biller et al. (2007), Close et al. (2005)
> Beth Biller's Talk
G S C 8 0 5 7 B
( C h a u v i n e t a l 2 0 0 3 )
T W A 5 B
( L o w r a n c e e t a l 1 9 9 9 )
H R 7 3 2 9 B
( L o w r a n c e e t a l 2 0 0 0 )
A B P i c B
( C h a u v i n e t a l 2 0 0 5 )
1) Young, nearby Associations
A g e ( < 1 0 0 M y r )
D i s t a n c e ( < 1 0 0 p c )
T y p i c a l d e t e c t i o n l i m i t s : MB
> 1 Mj u p
a t p h y s i c a l s e p a r a t i o n s > 1 0 - 4 0 A U
T o s e a r c h f o r a n d t o c h a r a c t e r i z e p l a n e t a r y m a s s c o m p a n i o n s
Targ
et S
elec
tion
& M
ain
HA
R a
nd H
C im
agin
g S
urve
ys
- HST/NICMOS Corono 45 Lowrance et al. (1999, 2000, 2005) - Keck/NIRC AO-Corono - MacIntosh et al. (01); Kaisler et al. (01) - ESO3.6m/ADONIS AO-Corono 29 Chauvin et al. (2002, 2003) - NTT3.5m/Sharp Saturated 32 Neuhäuser et al. (2003, 2005) - VLT/NACO AO-Saturated 28 Masciadri et al. (2005)- VLT/NACO AO-Lp 22 Kasper et al. (2007)- VLT & MMT AO-SDI 45 Biller et al. (2007), Close et al. (2005)
> Beth Biller's Talkand more results to come- HST/NICMOS Corono 109 > Jay Farihi's Talk- Gemini/GPDS AO-ADI 85 > David Lafreniere's Talk- VLT/NACO AO-Corono - Melo et al.; Chauvin et al.- Gemini/NICI AO-Corono - Liu et al.
1) Young, nearby Associations
Targ
et S
elec
tion
& M
ain
HA
R a
nd H
C im
agin
g S
urve
ys A g e ( < 1 0 0 M y r )
D i s t a n c e ( < 1 0 0 p c )
T y p i c a l d e t e c t i o n l i m i t s : MB
> 1 Mj u p
a t p h y s i c a l s e p a r a t i o n s > 1 0 - 4 0 A U
T o s e a r c h f o r a n d t o c h a r a c t e r i z e p l a n e t a r y m a s s c o m p a n i o n s
13
- Gemini/Hokupa'a Classical 31 Potter et al. (2002) - Keck/NIRC AO-Corono 102 McCarthy & Zuckerman (2004) Lick/GEMINI AO-Corono 178- Palomar PALAO AO-Corono 101 Metchev et al. (2005, 2006) KeckII/NIRC2- Spitzer Classical-midIR 73 Luhman et al. (2006)
H D 4 9 7 9 7 B
( M e t c h e v e t a l 2 0 0 4 )
H D 1 3 0 9 4 8 B C
( P o t t e r e t a l 2 0 0 2 )
H D 2 0 3 0 3 0 B
( M e t c h e v e t a l 2 0 0 6 )
2) Intermediate-old Stars
H N P e g B
( L u h m a n e t a l 2 0 0 6 ) Targ
et S
elec
tion
& M
ain
HA
R a
nd H
C im
agin
g S
urve
ys A g e ( 0 . 1 - 1 . 0 G y r )
D i s t a n c e ( < 2 0 - 5 0 p c )
T y p i c a l d e t e c t i o n l i m i t s : MB
> 1 0 Mj u p
( > 1 0 - 2 0 A U )
B D c o m p a n i o n s t u d y : E x t e n s i o n o f t h e B D d e s e r t a t i n t e r m e d i a t e s e p a r a t i o n s ?
- Palomar/AOC AO-Corono 24 (<10 pc) Nakajima et al. (1994) - HST/WFPC Classical 13 (<13 pc) Schroeder et al. (2000) - Palomar (60i, 200i) AO-Corono 107 (<8 pc) Oppenheimer et al. (2001)- Palomar PALAO AO-Corono 80 (<22 pc) Carson et al. (2005, 2006) - Palomar PALAO AO-Corono EPIcS sample > A. Tanner's Talk
3) Very Nearby Stars
H R 7 6 7 2 B
( L i u e t a l 2 0 0 2 )
G l 2 2 9 B
( N a k a j i m a e t a l 1 9 9 5 )
Targ
et S
elec
tion
& M
ain
HA
R a
nd H
C im
agin
g S
urve
ys A g e ( 0 . 1 - 1 0 . 0 G y r )
D i s t a n c e ( < 1 0 - 3 0 p c )
T y p i c a l d e t e c t i o n l i m i t s : MB
> 2 0 Mj u p
( 1 G y r ) a n d MB
> 6 0 Mj u p
( 1 0 G y r ) a t ( > 1 - 1 0 A U )
B D c o m p a n i o n s t u d y : E x t e n s i o n o f t h e B D d e s e r t a t i n t e r m e d i a t e s e p a r a t i o n s ?
> V o l u m e - l i m i t e d s a m p l e o f A F G K M s t a r s
14
- Gemini/Hokupa'a AO-Classical 39 Close et al. (2002, 2003) - VLT/Gemini/Subaru AO-Classical 36 (<30 pc) Siegler et al., (2003, 2005) - CFHT/PUE'O AO-Classical (<12 pc) Beuzit et al. (2004) - Gemini/Altair-NIRI AO-Saturated 41 (<20pc) Daemgen et al. (2007) - VLT/NACO AO-Classical Biller et al. (2006); Montagnier et al. (2006)
S C R 1 8 4 5 B
( B i l l e r e t a l 2 0 0 6 )
3) Very Nearby StarsTa
rget
Sel
ectio
n &
Mai
n H
AR
and
HC
imag
ing
Sur
veys A g e ( 0 . 1 - 1 0 . 0 G y r )
D i s t a n c e ( < 1 0 - 3 0 p c )
T y p i c a l d e t e c t i o n l i m i t s : MB
> 2 0 Mj u p
( 1 G y r ) a n d MB
> 6 0 Mj u p
( 1 0 G y r ) a t ( > 1 - 1 0 A U )
B D c o m p a n i o n s t u d y : E x t e n s i o n o f t h e B D d e s e r t a t i n t e r m e d i a t e s e p a r a t i o n s ?
> V o l u m e - l i m i t e d s a m p l e o f A F G K M s t a r s
> F o c u s e d o n M s t a r s
- Gemini/Hokupa'a AO-Classical 39 Close et al. (2002, 2003) - VLT/Gemini/Subaru AO-Classical 36 (<30 pc) Siegler et al., (2003, 2005) - CFHT/PUE'O AO-Classical (<12 pc) Beuzit et al. (2004) - Gemini/Altair-NIRI AO-Saturated 41 (<20pc) Daemgen et al. (2007) - VLT/NACO AO-Classical Biller et al. (2006); Montagnier et al. (2006)
3) Very Nearby Stars
Targ
et S
elec
tion
& M
ain
HA
R a
nd H
C im
agin
g S
urve
ys A g e ( 0 . 1 - 1 0 . 0 G y r )
D i s t a n c e ( < 1 0 - 3 0 p c )
T y p i c a l d e t e c t i o n l i m i t s : MB
> 2 0 Mj u p
( 1 G y r ) a n d MB
> 6 0 Mj u p
( 1 0 G y r ) a t ( > 5 - 1 0 A U )
B D c o m p a n i o n s t u d y : E x t e n s i o n o f t h e B D d e s e r t a t i n t e r m e d i a t e s e p a r a t i o n s ?
> V o l u m e - l i m i t e d s a m p l e o f A F G K M s t a r s
> F o c u s e d o n M s t a r s
> L and T dwarfs multiplicity studies Bouy et al. (2003); Gizis et al. (2003) Reid et al. (03): Burgasser et al. (2003)
15
4) Stars with RV planets & RV driftsTa
rget
Sel
ectio
n &
Mai
n H
AR
and
HC
imag
ing
Sur
veys A g e ( 0 . 1 - 1 0 . 0 G y r )
D i s t a n c e ( < 5 0 p c )
T y p i c a l d e t e c t i o n l i m i t s : MB
> 2 0 Mj u p
( 1 G y r ) a n d MB
> 6 0 Mj u p
( 1 0 G y r ) a t ( > 1 0 - 2 0
A U )
> Stars with RV planets
M a s s i v e c o m p a n i o n s a t l o n g - p e r i o d s ?
D y n a m i c a l i m p a c t o n i n n e r p l a n e t a r y s y s t e m s ?
- KeckII/kCam AO-Saturated 25 Luhman & Jayawardhana (2002) - NTT/Sofi Classical-Saturated - Mugrauer et al. (2004, 2006, 2007) - VLT/NACO AO-Corono 26 Chauvin et al. (2006, 2007)- VLT/NACO AO-Classical 103 Eggenberger et al. (2007) - Spitzer Classical-midIR 48 Luhman et al. (2006)
> Stars with long RV trends
- VLT/NACO AO-SDI > G . M o n t a g n i e r ' s T a l k
• Young Brown dwarfs
Favorable Contrast IR-AO, LGS-AO
> L. Close's Talk
• Star Forming Regions (1-120 Myr and >100 pc)
Chameleon, Pleiades, Taurussubstellar IMF StudiesVLM multiplicity
> A. Tanner's Talk
• White dwarfs
GD 165 B (Becklin & Zuckerman 1988) Fossil of planetary system?
and more.....
D H T a u B
( I t o h e t a l 2 0 0 5 )
C H X R 7 3 B
( L u h m a n e t a l 2 0 0 6 )
G Q L u p B
( N e u h ä u s e r e t a l 2 0 0 5 )
2 M 1 2 0 7 B
( C h a u v i n e t a l 2 0 0 4 )
Targ
et S
elec
tion
& M
ain
HA
R a
nd H
C im
agin
g S
urve
ys
16
Outline
Spirit of Lyot Conference, Berkeley, June 2007
I- Brief introductionFirst discoveries (Gl299B, 51 Peg b).Development of new observing techniques.Advantage of direct imaging to explore the 5-500 AU missing link.
II- Observing challenge & technical needsFaint companion close to bright stars. Observing Limitations.Technical needs: AO, Coronography, Differential Imaging...
III- Target selection & main surveysTargets identification and selection: distance and age.Young, nearby stars. Intermediate-old stars, Very, nearby stars and Exoplanet hostsSummary of the main surveys: observing technique, sample size and performances
IV- Observing strategy & main results1) Deep imaging, 2) Astrometry and 3) Photometry + SpectroscopyAccess to planetary masses. Physical and chemical properties. Origin of formationTypical detection limits and statistical analysis
VI- Conclusion & perspectives
AB Pic
NACO/VLT, Ks + S27 (27 mas/pix), FoV 28'' × 28''Classical and coronographic (Ø = 0.7” et Ø = 1.4”) imagingObserving Time / source ~ 1 hr
I/3- Systematic Search for Faint Objects
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
17
Proper motion study of AB Pic b
AB Pic A:- Proper motion - Parallactic Motion
Follow-up at several epochs
2/3- Astrometric Follow-up Observations Background object or physical companion ?
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
AB Pic B2M0345 (L1)
H2OH2O
NaI 12CO 2-0
3-1
4-2
5-3
AB Pic BM ~ 10-20 Mjup et Sep = 260 AUSpectral Type ~L1
!! Gliese 86 B case !!same nIR L/colors for BD or WD
•Photometry versus predictions evolutionary modelsa •Identification of atomic and molecular lines: H20, CO, CH4, FeH, NaI, CaI, KI…•Confirmation of a cool atmosphere
3/3- Photometric & Spectroscopic Characterization
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
18
Results: Substellar companions of nearby stars
1 9 9 5 2 0 0 0 2 0 0 2 2 0 0 4 2 0 0 61 9 9 8
- G J 5 8 4 C
- G J 3 3 7 C D
- G l 5 7 0 D - ε I n d i B a b
- G l 4 1 7 B C- Gl1048 B
- GJ1001 BC
- Gl569 Bab
Gl229 B
TWA5 B HR7329 B
HD130948 BC
HR7672 B
GSC8048 B
HD49197 B Gl577 BC
DHTau B
HD203030 B
SCR1845 B
CHXR73 B
HD3651 B
HNPeg B
GQ Lup B
AB Pic B
G 1 9 6 - 3 B
AO, HST
Large Surveys, Classical Imaging
Spitzer
- GGTau B
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
2M1207 B
Results: Physical and Chemical Properties
Thermal Emission:
L (Teff & R) Mass, Age, composition (& Formation)
Companions, thanks to the primary:
> known distance Hipparcos ParallaxMoving Cluster Method
> known metallicity Primary optical spectroscopy
> relatively well known age: age of the young, nearby associationPhotometry vs evol. modelsStellar kinematics, Dust lumikosityLi abundance, Stellar rotationStellar activity: X-ray, Hα, emission lines
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
19
nIR photometry L, Teff, R, M
Evolutionary Interior Models> Internal structure (Teff, L, mass, radius)Tucson: (Burrows et al. 1997; 1999)NASA-Ames: Marley et al. (2007) Lyon: (Chabrier et al. 2000, Baraffe et al. 1998, 2003)
Synthetic spectra of Atmospheric Models> Molecular, dust opacities. Dust formation/condensation> Boundary conditions on interior calculationsTucson: Burrow et al. (2001; 2002; 2006) NASA-Ames: Marley et al. (1999; 2002) Lyon: Allard et al. (2001; 2003)
d , a g e
Results: Physical and Chemical PropertiesO
bser
ving
Stra
tegy
& M
ain
Res
ults
Results: Physical and Chemical Properties
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
nIR photometry L
nIR spectroscopy
d a g e
Teff, R, M
Spectral Type (Old field BDs)Spectral indexes (H2O, CO, CH4) Bolometric corrections
Evol. Interior Models
Young / Old M, L dwarfs:
AB Pic B (10-20 Mjup; 260 AU)Spectral Type ~L1(Song et al. 2006)
2MASS 0141; L0-L2(Kirkpatrick et al. 06)
20
R, M, L, age log(g), Teff
Results: Physical and Chemical Properties
Synthetic spectra of substellar atmospheres> Molecular, dust opacities. Dust Formation/condensation> Boundary conditions on interior calculationsTucson: Burrow et al. (2001; 2002; 2006) NASA-Ames: Marley et al. (1999; 2002) Lyon: Allard et al. (2001; 2003)
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
> K . L u h m a n ' s T a l k
d
nIR photometry L
nIR spectroscopy
d a g e
Teff, R, M
Spectral Type (Old field BDs)Spectral indexes (H2O, CO, CH4) Bolometric corrections
Evol. Interior Models
M o d e l s : n e e d t o b e c a l i b r a t e d f o r y o u n g ( < 1 0 0 M y r ) a g e s a n d v e r y l o w m a s s e s
> D y n a m i c a l m a s s e s : E c l i p s i n g B i n a r y , D i s k K i n e m a t i c s , A s t r o m e t r y & S p e c t r o s c o p y
D M T a u , C Y T a u ( S i m o n e t a l . 2 0 0 0 ) H D 9 8 8 0 0 A B ( B o d e n e t a l . 2 0 0 5 ) T W A 5 A a b ( K o n o p a c k i e t a l . 2 0 0 7 )
2 M A S S 0 5 3 5 A B ( S t a s s u n e t a l . 2 0 0 6 )
A B D o r ( C l o s e e t a l . 0 5 , 0 7 ; L u h m a n e t a l . 2 0 0 6 )
Results: Physical and Chemical Properties
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
> A . B o c c a l e t t i ' s T a l k
M . M a r l e y ' s T a l k : > U n c e r t a i n t i e s w i t h E v o l u t i o n a n d A t m o s p h e r i c M o d e l s
i n i t i a l C o n d i t i o n s
C o n v e c t i o n
F o r m a t i o n m e c h a n i s m s
C l o u d M o d e l l i n g
R e m a i n i n g l i n e s
C o m p o s i t i o n
21
M o d e l s : n e e d t o b e c a l i b r a t e d f o r y o u n g ( < 1 0 0 M y r ) a g e s a n d v e r y l o w m a s s e s
> D y n a m i c a l m a s s e s : E c l i p s i n g B i n a r y , D i s k K i n e m a t i c s , A s t r o m e t r y & S p e c t r o s c o p y
> H R - r e s o l u t i o n s p e c t r o s c o p y i n o p t i c a l + A t m o s p h e r i c M o d e l s
( M o h a n t y e t a l . 2 0 0 4 a , 2 0 0 4 b )
Results: Physical and Chemical PropertiesO
bser
ving
Stra
tegy
& M
ain
Res
ults
M . M a r l e y ' s T a l k : > U n c e r t a i n t i e s w i t h E v o l u t i o n a n d A t m o s p h e r i c M o d e l s
i n i t i a l C o n d i t i o n s
C o n v e c t i o n
F o r m a t i o n m e c h a n i s m s
C l o u d M o d e l l i n g
R e m a i n i n g l i n e s
C o m p o s i t i o n
Large Surveys
Transits
Radial Velocity
µ Lensing
H C & H A R I m a g i n g
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
Results: Substellar companions of nearby stars
22
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts MB ~ 8 MJup
MA ~ 24 MJup
2M1207B, (Chauvin et al. 2005; Lodato et al. 2005)
•> Opacity limit for fragmentation reached (Larson 1969)
•> Overlap between formation mechanisms
•Other substellar companions (HC & HAR imaging):
•> Mass ratio, wide separation star/BD formation mechanism
•Soon, some ambiguous cases?
Formation scenario?
- Mdisk > 0.3 MA- Tcore Accr. > 10 Myr
Core-accretion (Pollack et al. 1996) Disk Instability (Boss 1997) Collapse/Fragmentation (stars & BDs)
Results: 2M1207B, First Planetary Mass Companion?O
bser
ving
Stra
tegy
& M
ain
Res
ults
Y o u n g , N e a r b y S t a r
G K s t a r
K ~ 7
A g e ~ 1 0 M y r
d ~ 3 0 p c
E v o l . M o d e l
( B a r a f f e e t a l . 0 3 )
Results: Detection Limit Interpretation
23
Physical properties (mass, a, e) of EGP and BD companion population
Monte Carlo Simulations
Detection Limits(minimum mass, projected physical separation)
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
tsResults: Statistical Analysis
Formation mechanisms of BDs & EGPs
Young (10-30 Myr), nearby stars: Population of EGPs at wide orbits?
- Probability Distributions: Semi-major axis P(a) ~ aα [0.3 – amax] AUEccentricity e = 0; RV distribution a
EGP Mass P(m) ~ m-1.5 [1 - 50] Mjup
- adjustement with RV surveys (3%, 1-3 AU, > 1 Mjup, Marcy et al. 2005)
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts
> Observational constraints on the outer part of the planetray systems
Inp
ut
s
Results: Statistical Analysis
MC Drawing: Comparison with detection limits & null-detection
Probability for an EGP population to be consistent with the survey
Results: VLT/NACO-Lp (Kasper et al. 2007) Small outer radii (amax < 15 AU) and Decreasing radial distrib. (α<0)
MMT-VLT/SDI (Biller et al. 2007) > Poster by E. NielsenRule out combination of M, e, constant-a distributions, amax
24
Very nearby MS stars: BD desert at intermediate separations?
- Set of simulated orbits: a, e, i, ω
- BD Mass function similar to SFRs
Obs
ervi
ng S
trate
gy &
Mai
n R
esul
ts (Carson et al. 2006; 2007)
Inp
ut
s
Results: Statistical Analysis
MC Drawing: Comparison with detection limits & null-detection
Fraction of BD companion
Results: BD desert studies revisited for intermediate separations
fBD of 0.0 – 9.3% for a =[25 – 100] AU
RV: fBD < 1% for a < 3 AU (Marcy & Butler 2000)
> no significant conclusion about the BD desert extension
- Difference in the companion fraction between stellar/BD companions?
- Efficiency of the Acretion/ejection BD mechanism (Reipurth & Clarke 2001)?
Outline
Spirit of Lyot Conference, Berkeley, June 2007
I- Brief introductionFirst discoveries (Gl299B, 51 Peg b).Development of new observing techniques.Advantage of direct imaging to explore the 5-500 AU missing link.
II- Observing challenge & technical needsFaint companion close to bright stars. Observing Limitations.Technical needs: AO, Coronography, Differential Imaging...
III- Target selection & main surveysTargets identification and selection: distance and age.Young, nearby stars. Intermediate-old stars, Very, nearby stars and Exoplanet hostsSummary of the main surveys: observing technique, sample size and performances
IV- Observing strategy & main results1) Deep imaging, 2) Astrometry and 3) Photometry + SpectroscopyAccess to planetary masses. Physical and chemical properties. Origin of formationTypical detection limits and statistical analysis
VI- Conclusion & perspectives
25
Con
clus
ions
& P
ersp
ectiv
esConclusions
- HC and HAR Direct Imaging: - complementary to other techniques (RV, transit...)
- Spectral characterization, orbit monitoring
- Missing link between 5 – 500 AU
- Impressive evolution: - Technique: telescope, AO, observing modes
- Target selection (Young, nearby associations)
- Key results: - increasing number of substellar companions since 1995
- Importance of atmosphere and evolution models
- access to planetary mass companions
> raising questions related to fomation mechanisms
- Interpration of survey detection limits
> outer part of planetary systems
> constraints for planetary and BD formation scenarii
Con
clus
ions
& P
ersp
ectiv
es
Perspectives
- Upcoming:
NTT/Sofi, HST/NICMOS, GDPS-ADIGemini/NICI, VLT/NACO SACY surveyAEOS/Lyot project
- Horizon 2010
Subaru/HiCIAOGemini Planet ImagerVLT/SPHERE
> Session (tomorrow): Futur Instruments & Telescopes