from brown dwarfs to giant planets stan metchev (stony brook astronomy group) stan metchev (stony...

From Brown Dwarfs to Giant Planets

From Brown Dwarfs to Giant Planets

Stan Metchev(Stony Brook Astronomy Group)

Stan Metchev(Stony Brook Astronomy Group)

Artist’s rendition of a brown dwarf: R. Hurt (NASA)Artist’s rendition of a brown dwarf: R. Hurt (NASA)PHY 688 seminar in Spring 2009PHY 688 seminar in Spring 2009

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Areas of InterestAreas of Interest

Imaging of brown dwarf companions to stars

Properties of nearby brown dwarfs

Modeling of circumstellar disks

Imaging of brown dwarf companions to stars


Modeling of circumstellar disks

3/353/35

Brown Dwarfs: Link between Stars and Giant Planets

Brown Dwarfs: Link between Stars and Giant Planets

Burrows et al. (2001)Burrows et al. (2001)

starsbrown dwarfs“planets”

giant planet formationgiant planet formation

13 MJup10 M

Jup

5 MJup

1 MJupstars

brown dwarfs“planets”

no H fusion substellar objects

<0.08 M ~ 80 MJup

star-like formation planet-like

properties?

no H fusion substellar objects

<0.08 M ~ 80 MJup

star-like formation planet-like

properties?

M

73 MJup

80 MJup

211 MJup = 0.2 M

4/354/35

The Stellar/Substellar ContinuumThe Stellar/Substellar Continuum

Sun

M dwarf T dwarfL dwarf Jupiter

brown dwarfs planetsstars

5700 K ~3500 K ~2000 K ~1000 K 160 K

(G dwarf)

R. Hurt (Caltech/IPAC)R. Hurt (Caltech/IPAC)visible light

5/355/35

Brown Dwarfs: Population is UncertainBrown Dwarfs: Population is Uncertain detection is challenging more numerous than stars? relevance:

bottom of star-like formation galaxy mass-to-light ratios dark matter

detection is challenging more numerous than stars? relevance:

bottom of star-like formation galaxy mass-to-light ratios dark matter

Reid et al. (1999); Allen et al. (2005)Reid et al. (1999); Allen et al. (2005)WMAP€

N(M)∝M−α

6/356/35

Some Outstanding Questions


????????????

What are the properties of substellar companions? can we image extrasolar planets?

What are the properties of isolated brown dwarfs? do cooler, planetary-mass objects exist in isolation?

How do planetary systems evolve? is the Solar System typical?




7/357/35



????????????







8/358/35

First L and T Dwarfs Discovered as Companions to Stars

First L and T Dwarfs Discovered as Companions to Stars

GD 165 B: first L dwarfGD 165 B: first L dwarf

U Hawai’i 2.2 m telescopeU Hawai’i 2.2 m telescope

Gl 229 B: first T dwarfGl 229 B: first T dwarf

Palomar 1.5 m

discovery

Palomar 1.5 m

discovery

Becklin & Zuckerman (1988); Nakajima et al. (1995)Becklin & Zuckerman (1988); Nakajima et al. (1995)

Hubble Telescope

confirmation

Hubble Telescope

confirmation

J H K

9/359/35

Brown Dwarfs Companions to Stars

Brown Dwarfs Companions to Stars

independent constraints on substellar properties: age distance (luminosity) internal chemistry

lowest mass substellar companions: planets

young stars are optimal targets

independent constraints on substellar properties: age distance (luminosity) internal chemistry

lowest mass substellar companions: planets

young stars are optimal targets

Nakajima et al. (1995)Nakajima et al. (1995)

(AO)

Gl 229 B

1″

HD 18940 A/B

Palomar AO

AO off

AO on

10/3510/35

QuickTime™ and aCinepak decompressor

are needed to see this picture.

11/3511/35

What Planets May Look LikeWhat Planets May Look Like

Ks = 11.3 mag (104.5) at 2.6”

Ks = 13.6 mag (105.4) at 3.3”

Palomar 5m telescope + AO

Ks band (2.16µm);

Neptune’s orbit(a = 30 AU)

12/3512/35Mazeh et al. (2003)Mazeh et al. (2003)

planetsplanets

10–15%10–15%

brownbrowndwarfsdwarfs<0.5%<0.5%

starsstars

~22%~22%

Planet Detection:Precision Radial Velocity Context

Planet Detection:Precision Radial Velocity Context

13/3513/35

Planet Detection:Direct Imaging Has Lagged

Planet Detection:Direct Imaging Has Lagged

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

plan

ets

brow

ndw

arfs

star

s

Chauvin (2007)

HST, Gemini, Keck, VLT: now

J

S

M2

(MJu

p)

Physical Separation (AU)

1

10

100

conventional AO

brown dwarf desert

<0.5% companion frequency

brown dwarf desert

<0.5% companion frequency

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Metchev & Metchev & Hillenbrand (2008)Hillenbrand (2008)

Companion Imaging Survey Success Rates

(r.v.)

Survey sensitivity:

<13 MJup

13–30 MJup

>30 MJup

15/3515/35

Project 1Project 1

Search for faint substellar companions to stars

Characterize their atmospheres

Search for faint substellar companions to stars

Characterize their atmospheres

Lick 3mCalifornia

Keck 3mHawaii

Spitzer 0.9mSpace Telescope

16/3516/35









????????????

17/3517/35

Brown Dwarf PropertiesBrown Dwarf Properties

CIA H2

L dwarfs (stars+brown dwarfs) metallic hydrides, H2, H2O

T dwarfs (brown dwarfs) CH4, H2, H2O

L dwarfs (stars+brown dwarfs) metallic hydrides, H2, H2O

T dwarfs (brown dwarfs) CH4, H2, H2O

IRTF Spectral Library, Cushing et al. (2005)IRTF Spectral Library, Cushing et al. (2005)

J H K

18/3518/35


Sun



5700 K ~3500 K ~2000 K ~1000 K 160 K

(G dwarf)

R. Hurt (Caltech/IPAC)R. Hurt (Caltech/IPAC)visible light

19/3519/35


Sun



5700 K ~3500 K ~2000 K ~1000 K 160 K

(G dwarf)

R. Hurt (Caltech/IPAC)R. Hurt (Caltech/IPAC)near-infrared light

20/3520/35

Brown Dwarf PropertiesBrown Dwarf Properties

L dwarfs (stars+brown dwarfs) metallic hydrides, H2, H2O red in visible and in near-IR Teff < 2300 K

T dwarfs (brown dwarfs) CH4, H2, H2O red in visible, vast color

range in near-IR Teff < 1400 K

L dwarfs (stars+brown dwarfs) metallic hydrides, H2, H2O red in visible and in near-IR Teff < 2300 K

T dwarfs (brown dwarfs) CH4, H2, H2O red in visible, vast color

range in near-IR Teff < 1400 K

L

T0–T4

T5–T8

visible

L T

near-IR

L TF2.1µm / F1.6µm

F1.

6µm /

F1.

2µm

21/3521/35

Finding Nearby Brown DwarfsFinding Nearby Brown Dwarfs

near-IRnear-IR2MASS J04454316+2540233

2MASS J (1.2µm) 2MASS H (1.6µm) 2MASS KS (2.1µm)

POSS–I R (0.6µm) POSS–II R (0.6µm)Kirkpatrick et al. (1997)Kirkpatrick et al. (1997) Strauss et al. (1999)Strauss et al. (1999)

SDSS i (0.8µm)

SDSS z (0.9µm)

22/3522/35

Most L’s and T’s Now Found from Large-Area Imaging Surveys

Most L’s and T’s Now Found from Large-Area Imaging Surveys

0

50

100

150

200

250

300

2MASS SDSS DENIS Companions Others

L

T

>500>500

~100~100

>500>500

~100~100

DwarfArchives.orgDwarfArchives.org

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L

T0–T4

T5–T810–5

10–4

10–3

10–2

(S

pT)

[pc

–3 S

pT–1

]

L0 L5 T0 T5 T8

Cool Brown Dwarfs: Numerous but Difficult to Find

Cool Brown Dwarfs: Numerous but Difficult to Find

Burgasser (2006)Burgasser (2006) ; Cruz et al. (2007); Cruz et al. (2007)

2MASS

24/3524/35

10–5

10–4

10–3

10–2

(S

pT)

[pc

–3 S

pT–1

]

L0 L5 T0 T5 T8

Burgasser (2006)Burgasser (2006) ; Cruz et al. (2007); Cruz et al. (2007)

2MASS

; Metchev et al. (2008); Metchev et al. (2008)

SDSS i SDSS z

2MASS KS2MASS J

z = 19.1

J = 15.9

Cool Brown Dwarfs: Use Database Cross-Correlation

Cool Brown Dwarfs: Use Database Cross-Correlation

25/3525/35

Project 2Project 2

complete nearby T dwarf census in SDSS + 2MASS

search for the coolest brown dwarfs

complete nearby T dwarf census in SDSS + 2MASS

search for the coolest brown dwarfs

NASA IRTF 3mHawaii

Palomar 5mCalifornia

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????????????

27/3527/35

From Stars to Disks to PlanetsFrom Stars to Disks to Planets

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture. Bok globules in IC 2944HST/WFPC2

1´ = 0.5 pc

Reipurth et al. (1997)

Orion protoplanetary disksHST/WFPC2

O’Dell & Wien (1994)

1" = 400 AU

Pictoris debris disk

500 AU

25"

(Kalas & Jewitt 1996)

Beckwith (1996)

28/3528/35

Disk evolution movieDisk evolution movie

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Debris Disks:Context for the Solar System


zodiacal light, asteroid belt, Kuiper belt analogs


Solar System debris disk

(P. Kalas, UC Berkeley)

Pictoris debris disk

500 AU

25"

(Kalas & Jewitt 1996)

LIR / Lstar = 10–3

10 Myr

LIR / Lstar = 10–7

4.5 Gyr

30/3530/35




comets


comets

Beichman et al. (2005)

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comets

embedded planets


comets

embedded planets

(Liou & Zook 1999)60 AU

Solar System model23 µm grains

HD 107146 disk HST/ACS

(Ardila et al. 2004)

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Evidence for Embedded Planets is Strong: Fomalhaut

Evidence for Embedded Planets is Strong: Fomalhaut

Kalas et al. (2005)HST/ACS

a = 119 AU planet (Quillen 2006)

13"100 AU

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HD 107146: A Face-on RingHD 107146: A Face-on Ring

Metchev et al., in preparation

Solar System modelLiou & Zook (1999)

50–200 AU

(HST)

HST survey of 40 more debris disks

34/3534/35

Project 3Project 3

Analyze the properties of circumstellar debris disks

Search for dynamical evidence of embedded planets

Analyze the properties of circumstellar debris disks

Search for dynamical evidence of embedded planets

Spitzer 0.9mSpace Telescope

Hubble 2.4mSpace Telescope

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Imaging of substellar companions


Modeling of debris disks

Imaging of substellar companions


Modeling of debris disks

Areas of InterestAreas of Interest

from brown dwarfs to giant planets stan metchev (stony brook astronomy group) stan metchev (stony...

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