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MATISSE
Multi AperTure Mid-Infrared SpectroScopic Experiment
Sebastian Wolf
MATISSE Project Scientist
Emmy Noether Research Group “Evolution of Circumstellar Dust Disks to Planetary Systems”
Max Planck Institute for Astronomy, Heidelberg
Bruno Lopez
PI
Observatoire de la Cote d’Azur, Nice
+ Science Team
The Progenitor: MIDI
Mid-Infrared Interferometric Instrument
Perfect combination of observing wavelength (~10mm)
and spatial resolution (VLTI baselines => 10-20mas)
=> regions with hot dust can be spatially resolved
since 2002
observations of the hot dust in circumstellar disks, AGB stars,
winds of hot stars, massive star forming regions, tori of AGNs, …
Results:
Very successful in interferometric spectroscopy
(chemical composition of dust on different spatial scales)
Concept of mid-infrared long-baseline interferometry proven to work
but …
MIDI’s limitations
a) Small number of visibility points
b) Lack of Phase Information
Investigation of small-scale structures (= main goal of MIDI)
and quantitative analysis of spectroscopic observation strongly limited
c) Interpretation of MIDI data:
Comparison between modelled and observed visibility points,
using 2D models with point-symmetry
(usually even rotation symmetry)
Approach justified only by large-scale (if at all existing) symmetries,
but expected to be strongly misleading or simply wrong
on size scales investigated with MIDI
MATISSE
Multi AperTure Mid-Infrared SpectroScopic Experiment
High-Resolution Multi-Band Image Reconstruction
+ Spectroscopy in the Mid-IR
Proposed 2nd Generation VLTI Instrument
Specifications:
• L, M, N, Q band: ~2.7 – 25 mm
• Spectral resolutions: 30 / 100-300 / 500-1000
• Simultaneous observations in 2 spectral bands
What’s new?
• Image reconstruction
on size scales of 3 / 6 mas (L band) 10 / 20mas (N band) using ATs / UTs
• Multi-wavelength approach in the mid-infrared
3 new mid-IR observing windows for interferometry (L,M,Q)
• Improved Spectroscopic Capabilities
MATISSE
Multi AperTure Mid-Infrared SpectroScopic Experiment
MATISSE
AMBER
MATISSE
Multi AperTure Mid-Infrared SpectroScopic Experiment
High-Resolution Multi-Band Image Reconstruction
+ Spectroscopy in the Mid-IR
Successor of MIDI:
Imaging Capability in the entire mid-IR
accessible from the ground
Successor of AMBER:
Extension down to 2.7mm
+ General use of closure phases
Ground Precursor of DARWIN
Wavelength range 6-18mm
The MATISSE Team
The MATISSE Team
Individual Contributions
Obs. de Lyon, Obs. de Grenoble, Universite de Lille,
TLS Tautenburg
Letters of Intent
Meudon, Torino-INAF
Science Team
Studies:
a) Science Cases:
Complex Structures
• Star and Planet Formation
• Circumstellar Environment:
• Protostellar Disks:
• Extrasolar Planets
• AGBs / Evolved Stars / Hot Stars
• Active Galactic Nuclei
b) Image Reconstruction Studies
Low / Intermediate mass stars
Massive Stars
Multiple Stars
Planet Formation
Disk evolution: Young => Debris Disks
The circumstellar environment of young
low and intermediate mass stars
• Planet forming region
d=140pc
Earth
- 14 mas
Jupiter - 74 mas
Neptune - 429 mas
• Emission from hot dust from the inner region
Complex outer disk structures observed
=> Complex inner disk structure expected
FU Orionis outbursts -- Variability in general (flux, polarization)
-- Expected influence from the formation of Jets/Outflows
AB Aurigae (Fukagawa, 2004)
The circumstellar environment of young
low and intermediate mass stars
Is there indirect or direct evidence for the presence of planets?
Protoplanets:
Significant influence on the surface density / brightness profile: Hot spot / Gaps
Hot Accretion Region
around the Planet
10mm surface brightness
profile of a T Tauri disk with an
embedded planet ( inner
40AUx40AU, distance: 140pc)
[Wolf & Klahr 2005]
i=0deg
i=60deg
The circumstellar environment of young
low and intermediate mass stars
Is there indirect or direct evidence for the presence of planets?
Location of the Planet formation region =>
Gaps are expected to occur in the midinfrared bright region of disks
Density profile of a 0.05 Msun disk with a Jupiter-mass planet
orbiting a solar-mass star [Wolf, Gueth, Henning, Kley 2002]
10mm image of
a) an undisturbed disk and
b) a disk with a gap at 4AU
Massive Star Formation
M*>10Msun
Butterfly Star
(low mass young stellar object)
In a typical distance
of nearby massive star forming regions.
Massive Star Formation
M*>10Msun
High-mass star forming regions are much more distant (in average)
than those of low-mass stars (high-mass: 3-7kpc vs. low-mass: 0.1-0.3 kpc)
OB stars
- form preferentially in the centre of dense star clusters
- seem to live pref. in (tight) binary and higher order systems
High number density of objects
Enhanced outflow activity
Strong stellar winds from
the massive stars after ignition
JHK composite of NGC 3603
from ISAAC data, dimension 25'' x 25''
The Orion BN/KL region at 12.5mm,
dimension 10'' x 10'' (distance 450 pc)
[Shuping et al. 2004]
Massive Star Formation
M*>10Msun
What we can do with MIDI …
MATISSE
will for the first time allow
a comprehensive comparison between
low and high mass star formation
[Disks, Jets, Multiplicity,…]
Objects of this class are often faint in the near-IR,
but bright in the mid-IR!
Linz et al. 2004
W3: UCHII region
Image Reconstruction Studies
Goal:
Justification that MATISSE
will indeed be able to answer
the questions addressed
in the individual
Science Case Studies
Strategy:
Simulation of a realistic
observation procedure
Image Reconstruction Studies
Problem:
There are no observed 10mm images
of the targets on the size scale
to be investigated
Solution:
Radiative Transfer Simulations (MC3D)
10mm image of a circumstellar disk with an
inner hole, radius 4AU (inclination: 60deg;
distance 140pc, inner 60AU x 60AU)
Image Reconstruction Studies
SimVLTI3 :
-
Based on SimVLTI
Simulation of 3/4 beam combination
+ closure phases
Location of all AT stations added
Output: OI-FITS format
Definition of the Observing Procedure
+ location of ATs, number of nights, noise, etc, …
Image Reconstruction Studies
Tracks in the uv plane
Image Reconstruction Studies
Building Block Method
(K.-H. Hofmann)
Hybrid Mapping & Self-Calibration
(S. Kraus)
Difference Mapping
(L. Mosoni)
Image Reconstruction Studies
Reconstruction with Building Block Method
Conclusions: Image Reconstruction Studies
All 3 applied image reconstruction
techniques allow to reconstruct
main features in the considered
disk model
Best results: Building Block Method
(Hofmann & Weigelt)
Sufficient uv coverage:
3-5 nights of observations with ATs
(at varying locations)
Improvement of reconstructed
images:
4 telescopes (instead of 3)
UT Single-dish data + VLTI (UTs/ATs)
interferometric data
Multiwavelength Imaging
(L - M - N - Q)
Observations in different bands
• … trace regions with different characteristic temperatures
• …provide image with different spatial resolution
• … allow a comparison with lower-resolution images
obtained at large telescopes with adaptive optics
– tracing the large scale structure if the targets –
in different wavelength regions (L/M: NACO, N/Q: VISIR)
L
M
N
Q
Multiwavelength Imaging
(L - M - N - Q)
Depending on the individual band
• …unique spectral features (dust/gas) are accessible
• …spectral features can be investigated that correspond
to dust species which can also be observed in N band
L
M
N
Q
L band
• H2O ice broad band feature
(2.7-4.0mm)
• PAHs: 3.3mm, 3.4mm
• Nanodiamonds: 3.52mm
• Highest Sensitivity in the MIR
(reduced background emission)
M band
• CO fundamental transition
series (4.6-4.78mm)
• CO ice features (4.6-4.7mm)
• Recombination lines,
(e.g., Pfb at 4.65mm)
Spectroscopy
The 3-25mm spectral region is extremly rich in spectral diagnostics of gas
and dust – covering a huge range of physical and chemical conditions
Gas
strong vibrational lines of abundant molecules (CO, OH, H2O, SiO, C2H2)
Dust
oxygen-rich dust
amorphous silicates, crystalline silicates (e.g. forsterite)
simple oxides (SiO2, amourphous Al2O3, Spinel – MgAl2O2)
carbon-rich dust
volatile dust or ice species
TiC, PAHs, Nano-Diamonds
H2O ice (3.1 / 12mm), CO (4.7mm)
other dust species
FeS (most abundant sulfur bearing solid), …
Example Application
Planet Formation - Protoplanetary Disks
Critical tests of models for the radial distribution of different dust species
Dust evolution in disks?
Determination of crystallization region / processes? - Radial Mixing Efficiency?
Origin of nano-diamonds in meteorites + IPD?
Distribution of Volatiles
Key importance for understanding the complex disk chemistry:
Many (organic) molecules are formed in ice mantles – Transport to inner disk
region – Sublimation / Release to the gas phase
Spatial distribution of water / CO ice? - Where is the snowline?
Summary
Poster by B. Lopez et al.
Multi AperTure Mid-Infrared SpectroScopic Experiment
High-Resolution Multi-Band Image Reconstruction
+ Spectroscopy in the Mid-IR
Specifications:
• L, M, N, Q band: ~2.7 – 25 mm
• Spectral resolutions: 30 / 100-300 / 500-1000
• Simultaneous observations in 2 spectral bands
• Image reconstruction
on size scales of 3 / 6 mas (L band) 10 / 20mas (N band) using ATs / UTs
• Multi-wavelength approach in the mid-infrared
3 new mid-IR observing windows for interferometry (L,M,Q)
• Improved Spectroscopic Capabilities
• Key Science Programs can be performed in 3-5 AT nights
• Perfect complement to high-resolution facilities in the near-IR and mm
extra slides
Active Galactic Nuclei
~1% of all Galaxies hosts an AGN
Dust Torus => Obscuration in the optical (=> Seyfert I/II)
Structure of the Torus?
Preparatory Studies: MIDI
What is the size of the torus? How does it depend on luminosity?
What is the overall shape of the torus?
Emission of the Tori of Seyfert I/II galaxies compatible with the unified scheme?
MATISSE
In how far is the torus structure regulated by outflow phenomena (supersonic winds, jets)?
What fraction of the dust emission from the inner few parsecs of an AGN is emitted by the torus?
Is the torus just the inner, AGN heated part of the central molecular disk in the host galaxy?
Can we find direct evidence for the clumpiness of torii?
The circumstellar environment of young
low and intermediate mass multiple stars
•
•
•
Degree of Multiplicity ~ 40% - 60% (depending on SpT)
Multiplicity observed in all stages of stellar evolution
Multiplicity plays explicit role in the evolution of the companions
Case Study: Close young binary/multiple systems:
1.
2.
3.
Do we find binary/multiple stars with individual / circumbinary disks?
What is the spatial distribution of the circumstellar material within the system?
How do Binary/Multiple Systems evolve during the formation process?
Binary
evolution,
low angular
momentum
[Bate et al. 1997]
MIDI measures the auto-correlation function only!
Dust and Winds from AGB / Evolved Stars
Low/Intermediate Mass Stars => Cool Late Type Stars
=> Develop dense dusty stellar wind (10-8-10-4 Msun)
=> Loose up to 80% of their initial mass
=> Contribute significantly to the replenishment of the ISM
Mechanism (stellar pulsation + radiation pressure) poorly understood
•
Red Super Giants:
Bipolar Outflows? Asymmetric Envelopes?
Asymptotic Giant Branch Stars:
Clumpy Environment?
R Coronae Borealis:
Localization of the Dust Cloud Formation?
Post-AGB, RV Tau:
Geometry of the disk torus?
Symbiotic Stars / Novae:
Role of Binarity?
Planetary Nebulae:
Disk Geometry?
Hot Stars
•
•
Stellar Winds from Hot Stars strongly affect the ISM by many aspects
but:
Nature of these Winds still poorly understood.
How can dust be formed in this hostile environment?
Goals:
1.
2.
3.
Dust geometry in Carbon Wolf-Rayet Binaries
Conditions of dust formation in B[e] stars
Dust core of Eta Car
Two epochs of near-infrared images of WR 104,
tracing the rotation of the spiral nebula [Monnier at el. 1999]
Deconvolved MIDI acquisition image at 8.7mm
[Chesneau et al. 2005]