Sptzer Keck Spectroscopy

1
Sp?tzerKeck Spectroscopy the Building Blocks
of Planetary Systems
VV Ser
Geoffrey A. Blake GPS Division
Astronomy Colloqium, 26October2005, Caltech
2
Talk Outline

• Why do we care about chemistry star/
• planet formation?
• What has Spitzer imaging told us?
• - Low mass end, timescales.
• III. What about the dustice and gas?
• - Keck Spitzer IRS.
• What might the future hold in store?

26Oct2005
3
People Really Doing the Work!
Caltech -Adwin Boogert, Joanna Brown,
Colette Salyk Leiden w/Ewine van Dishoeck
Michiel Hogerheijde -Klaus Pontoppidan (now
at Caltech), Jes Jørgensen, Fred Lahuis
(SRON), Kees Dullemond (MPI) c2d -UT
Austin (N.J. Evans, P.I.), Caltech/JPL, Harvard
Smithsonian, Leiden, UMaryland, Northern
Arizona

26Oct2005
4
We have dreamed of extrasolar planets for a long
time,
Why chemistry developing systems? I
English engraving 1798 (and Physics Today
4/2004).
5
with spectroscopy, we can now detect them!
Radial velocity surveys are sensitive to
Jupiter/Saturn mass planets out to gt5
AU, Neptune masses further in.
http//exoplanets.org/exoplanets_pub.html
6
Why do we care about gas ice in disks?
Disk-star- and protoplanet interactions lead to
migration while the gas is present. Core-
accretion ice?
Theory
1 AU at 140 pc subtends 0."007. Jupiter (5
AU) Vdoppler 13 m/s Vorbit 13 km/s
Simulation G. Bryden (JPL)
Observation?
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From whence volatiles?
Why chemistry developing systems? II
Late planetesimal accretion from the outer solar
nebula?
8
How are isolated Sun-like stars formed?
outflow
x1000 in scale
infall
Cloud collapse
Rotating disk
Planet formation
Mature solar system
Picture largely derived from indirect tracers,
especially SEDs.
Adapted from McCaughrean
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How do we probe gas/dust of solar composition?
Use dust, chemistry.
H
O
C
All Else
N
He
Si

Fe
26Oct2005
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What is Spitzer?

• Infrared Great Observatory
• Background Limited Performance 3 - 180 mm
• 85 cm f/12 Beryllium Telescope, T lt 5.5K
• 6.5 mm Diffraction Limit
• New Generation Detector Arrays
• Instrumental Capabilities
• Imaging/Photometry, 3-180 mm
• Spectroscopy, 5-40 mm
• Spectrophotometry, 50-100 mm
• Planetary Tracking, 1 arcsec/sec
• gt75 of observing time for the
• General Scientific Community
• 2.5 yr Lifetime/5 yr Goal
• Launched in August 2003 (Delta 7920H)
• Solar Orbit
• 450 M Development Phase Cost Cap
• Cornerstone of NASAs Origins Program

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Extra-galactic Legacy Programs

• Great Observatories Origins Deep Survey (GOODS)
• M. Dickinson (STScI) and 40 co-Is at 14
  institutions
• Deep 300 square arcmin IRAC and MIPS (24 microns)
  survey overlapping HST and CXO deep fields
• Galaxy formation and Evolution, z 1 6
• The SIRTF Wide-area Infrared Extragalactic Survey
  (SWIRE)
• C. Lonsdale (IPAC/CIT ) and 19 co-Is at 9
  institutions
• 100 sq. deg., high latitudes, reaching z 2.5
• Evolution of dusty, star-forming galaxies, AGN
• The SIRTF Nearby Galaxies Survey (SINGS) Physics
  of the star-forming ISM and Galaxy Evolution
• R. Kennicutt (Arizona) and 14 co-Is at 7
  institutions
• Imaging and spectroscopy of 75 nearby galaxies
• Connections between ISM and star formation,
  templates for high z

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Galactic Legacy Programs

• The SIRTF Galactic Plane Survey (GLIMPSE)
• E. Churchwell (Wisconsin) and 13 co-Is at 6
  institutions
• 240 square deg. IRAC survey of inner Galactic
  plane
• Galaxy structure and star formation
• From Molecular Cores to Planet-forming Disks
  (c2d)
• N. Evans (Texas) and 10 co-Is at 8 institutions
• Imaging (IRAC and MIPS) and spectroscopy of star
  forming regions
• Evolution of molecular cores to stars, disks,
  sub-stellar objects
• The Formation and Evolution of Planetary Systems
  Placing our Solar System in Context (FEPS)
• M. Meyer (Arizona) and 18 co-Is at 12
  institutions
• Imaging and spectroscopy of 300 young stars with
  disks
• Evolution from accretion disks to planet formation

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From Cores to Disks (c2d) N.J. Evans, P.I.
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c2d Observations
Spitzer image of VV Ser region BIRAC 2 GIRAC
4 RMIPS 1

• (275 hr) IRAC and MIPS Mapping
• Map 5 large clouds (20 sq. deg.) Obs. done,
  being analyzed
• 88 smaller cores obs. Just completed, being
  analyzed
• (50 hr) IRAC and MIPS Photometry
• 190 stars obs. nearly finished, being
  analyzed
• (75 hr) Spectroscopy of disk material (IRS)
• about 200 targets about 2/3 obs., being
  analyzed
• Ancillary/complementary data from optical to mm
• Collecting a very large data base
• Will be publicly available eventually

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What can we learn?

• The initial conditions for collapse
• Study starless cores (extinction mapping, )
• The full population of young stellar objects
  (YSOs)
• Sensitive surveys, can find rare objects
• Timescales for various stages
• More complete, less biased surveys
• How low in mass do YSOs extend?
• Use Spitzer MIR sensitivity to detect low-mass
  disks
• Timescales for disk evolution
• Study large sample of stars (excess vs. age)
• How do the building blocks of planets evolve?
• Evolution of dust, ice, gas

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Perseus as seen by IRAC
IC 348
NGC1333
3.6, 4.5, 8.0
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The Well Known Cluster Regions (courtesy L. Allen)
Perseus / NGC1333
Perseus / IC348
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Very Low-mass Objects
Fits model atmosphere of brown dwarf (purple
line) (40 Mjup) Has MIR excess Fits model of
disk (green line). c2d mapping sensitive down
to 1-2 Mjup in Oph, Cha. Need deep
optical data!
Allers et al. 2006, in prep. (Ophiuchus)
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Spitzer/IRSs Forte High Sensitivity Spectra
IRS (5-40 mm long slit, R150, 10-38 mm
echelle, R600)
HH 46
L1014
L1014 (substellar)
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Young, deeply embedded protostars in Perseus
H2O CH4 Silicates
Extraordinary extinctions/ice bands!
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What ices are present?
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Ices Can Be Complex Early!
Knez et al. 2005
Minor species Blue with silicate removed Black
with H2O ice also removed Red fit with HCOOH and
6.8 mm carrier
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Protostars Comets?
HH46 W33A Hale-Bopp Water
100 100 100 CO 20
1 23 CO2 30 3
6 CH4 4 0.7
0.6 H2CO 2 1 CH3OH
7 10 2 HCOOH 2
0.5 0.1 NH3 9
4 0.7 OCS 0.05
0.4
SpitzerKeck studies are mapping out both gas
phase grain mantle composition, comparable to
that found in massive YSOs, comets. Clouds are
primed with ices that can form complex
organics, even before star formation.
26Oct2005
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What about older, visible stars disks?
outflow
x1000 in scale
infall
Cloud collapse
Rotating disk
Planet formation
Mature solar system
Picture largely derived from indirect tracers,
especially SEDs.
Adapted from McCaughrean
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Classical T Tauri Stars
Strong evidence for intense near- through mid-IR
excess, bigger than expected. Requires extra
flux likely due to accretion shock. Corroborated
by PTI KI K-band sizes.
Cieza et al. 2005 in press
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Spectroscopy of Disk Atmospheres
HD 141569

IR disk surface within several 0.1
several tens of AU (sub)mm disk surface
at large radii, disk interior
26Oct2005
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The Radial Vertical Chemical Structure of Disks
X-rays
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Grain Growth in Disks
10 mm band
20 mm band
Data
Models
Kessler-Silacci et al. 2006, in press
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Grain Growth in Disks II Edge on Disks
Flying Saucer
Grains gt10 mm at disk the photosphere must be
lofted. Goldreich-Ward instability for
planetesimal formation inhibited?
Shape and depth of mid-IR valley very sensitive
to grain size. For this source, grains at
least ten mm in size are inferred.
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Can ices be seen in edge-on disks?

VLT
Yes, the small molecules in ices are similar
in protostellar envelopes and disks.
Flux (Jy)
ISAAC
26Oct2005
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Crystalline Silicates in Disks
ISO SWS HAe Stars
Spitzer Brown Dwarf!
Age
An intense central source of wind/ radiation is
not required to anneal silicates. Products of
planetesimal collisions? Companions?
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How can we probe gas in the planet-forming region?
(pre-ALMA) The size scales are too small even for
the largest current near-term arrays. IR
spectroscopy to the rescue!
Theory
Jupiter (5 AU) Vdoppler 13 m/s Vorbit 13
km/s
Observation?
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High Resolution IR Spectroscopy Disks
R10,000-100,000 (30-3 km/s) echelles
(ISAAC,NIRSPEC, PHOENIX,TEXES) on 8-10 m
telescopes can now probe typical T Tauri/Herbig
Ae stars
Keck

CO M-band
TW Hya
NIRSPEC R25,000
L1489 IRS
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In older/inclined systems, CO disk emission
Herbig Ae stars, from face-on (AB Aur) to
highly inclined (HD 163296). CO lines correlated
with inclination and much narrower than those of
H I Disk!
CO lines give distances slightly larger than
K-band interferometry, broad H I traces gas much
closer to star (see also Brittain Rettig 2002,
ApJ, 588, 535 Najita et al. 2003, ApJ, 589,
931). Can do 20-30 objects/night.
Pf b
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Where does the CO emission come from?
Flared disk models often possess 2-5 micron
deficiency in model SEDs, where a bump is
often observed for Herbig Ae stars.
Dullemond et al. 2002/ Muzerolle et al. 2004
Explanation Dust sublimation near the star
exposes the inner disk to direct stellar
radiation, heating the dust and puffing up
the disk.
26Oct2005
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SED Fits versus IR Interferometry
Fits to AB Aur SED yield an inner radius of 0.5
AU (and 0.06 AU for T Tau).
(Monnier Millan-Gabet 2002, ApJ)
Dullemond et al. 2002
This model can now be directly tested via YSO
size determinations with K-band
interferometry. Intense dust emission pumps
CO, rim shadowing can produce moderate Trot.
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Testing the Model Line Width Trends
AB Aur

• Objects thought to be face on have the narrowest
  line widths, highly inclined systems the largest.
• As the excitation energy increases, so does the
  line width (small effect).
• Consistent with disk emission, radii range from
  0.5-5 AU at high J.
• Low J lines also resonantly scatter 5 mm photons
  to much larger distances.
• Asymmetries (VV Ser)?

inclination
VV Ser
Blake Boogert 2004, ApJL 606, L73.
26Oct2005
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Do T Tauri stars behave similarly?
CO gas radii versus stellar luminosity.
Dullemond et al. 2002/ Muzerolle et al. 2004
Gas and dust radii are comparable, to first
order. How is the CO protected if the dust
sublimates at smaller radii?
26Oct2005
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Do ices evaporate in disks, to what effect?
IRS 46
CRBR 2422.8
Hot cores massive YSOs.
26Oct2005
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Can verify evaporation in hot cores w/echelles
NGC 7538 IRS9
Disks?

Boogert et al. 2004, ApJ 615, 344
26Oct2005
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A pleasant surprise IRS 46
Spitzer IRS R600 Short Hi Data
IRS 46
C2H2 HCN CO2
CRBR 2422.8
T300-700 K. Is this grain mantle evaporation
only, or does gas phase chemistry play a
role? Need high resolution spectra!
26Oct2005
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IRS 46 complementary data
Keck HCN 3 mm and CO 4.7 mm
JCMT HCN J4-3

• Spitzer-IRS data indicate huge column density
  (gt1016 cm-2) of hot HCN
• Keck data show hot HCN and CO blue-shifted by 25
  km/s
• Submm lines optically thick expect 400 K
  line if emission fills beam
• JCMT 4-3 spectrum indicates at most 0.02 K
  emitting size lt11 AU

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Hot chemistry in inner 10 AU of disks

• Model of flared disk with puffed up inner rim ,
  seen at inclination 70o
• Line of sight through puffed-up inner rim. Need
  to measure vstar
• Produces large enough column and T
• HCN and C2H2 abundances 10-5 w.r.t. H2
• Probe of chemistry in planet-forming zones?

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From whence the complex nebular organics?
An amazing variety of organics are found in
chondrites, including a wide variety of aliphatic
and aromatic hydrocarbons, carboxylic acids,
amino acids, purines, pyrimidines, and sugars.
Synthesis?
dD values are large, structural diversity
complete. Supposedly formed by aqueous
alteration of ISM precursors on parent bodies,
but organic and silicate aqueous signatures are
contradictory. Can the organics be made in the
disk? The oxygen fugacity is critical.
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Is there steam? If so, how might we find it?
Herschel
Tera incognita!

THz Uniquely sensitive to first row
atoms, hydrides, torsions.
Cannot resolve spatially, need sub-km/s spectra.
26Oct2005
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More evolved sources Do SED dips demand gaps?
For a few T Tauri stars, the relative lack of
mid-IR flux is often attributed to gaps induced
by planet formation. Rare, so must be a short-
lived phase. How to test?
(Rlt24 AU)
Calvet et al. 2002
(Rlt4 AU)
The TW Hya lines are extremely narrow, with i7
R0.4 AU. Similar for SR 9 and DoAr
44, but gas radius ltlt dust radius
(SED)? Recall hnCO 11.09 eV to dissociate.

Calvet et al. 2005
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CO Emission from Transitional Disks?
For dust sublimation alone, the lines from T
Tauri disks should be broader than those from
Herbig Ae starsdisks. Often observed, but
The TW Hya lines are extremely narrow, with i7
R0.4 AU. Similar for SR 9, DoAr 44,
GM Aur but gas radius ltlt dust radius
(SED)? Recall hnCO 11.09 eV to dissociate. Gas
rich, but extensive grain growth.

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Other gap/grain tracers? What can mm-waves tell
us?
HH 30
Chiang Goldreich 1997

(sub)mm disk surface at large radii,
disk interior IR disk surface within
several several tens of AU
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Current mm-arrays disk structure
Disk properties vary widely with radius, height
and depend on accretion rate, etc. (Aikawa et al.
2002, w/ DAlessio et al. disk models).
Currently sensitive only to Rgt50 AU in gas
tracers, Rlt50 AU dust. CO clearly optically
thick, isotopes reveal extensive depletion,
poor mass tracer. The fractional ionization is
10-9, easily sufficient for MRI transport.
Qi et al. 2003
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Future of U.S. University Arrays CARMA
CARMA OVRO (6 10.4m) BIMA (9 6.1m) SZA (8
3.5m) arrays
Cedar Flat 7300 ft.


March 29th, 2004
2004 SUP approved! 2004 SZA at OVRO 2004 move
6.1m 2005 move 10.4m 2006 full operations 2008
merge w/SZA
Spectral line fringes, October 17th, 2005
August 12th, 2005
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CARMA 2008 BIMAOVROSZA
dramatically improved (uv) coverage,
OVRO
SZA
CARMA SZA
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and fidelity!
Mel Wright, http//www.mmarray.org/memos/carma
_memo27.pdf
230 GHz
10"
Fidelity200
CARMA-23 CDSZA w/3.5-6.1m spacings
CARMA-15 AB
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Spectroscopy Developing Planetary Systems
- Conclusions
HH46

• Spectra of embedded/edge-on Sun-like protostars
• can be studied in the IR for the first time
  with
• Spitzer8-10m telescopes.
• The ice composition is remarkably similar in all
  
• stages, and can drive a rich organic chemistry
  if
• the oxygen fugacity is low. Water? (Herschel)
• Grain growth is ubiquitous, silicate annealing
• can be seen even in brown dwarf disks. Due to
• planetesimal collisions? Planetary
  companions?
• Expanded mm-arrays (CARMA, eSMA, PdBI,
• ALMA) will provide access to much smaller
• scales, and should be able to image the larger
• gaps proposed for some transitional disks.

VV Ser
AU Mic