Download Galactic Star Formation Science with Integral Field

Galactic Star
Formation Science
with Integral Field
Spectroscopy
Tracy Beck, STScI
Galactic Star Formation
Science
with Integral Field Spectroscopy
• Introduction to the formation of sun-like stars in the
Milky Way
• Studies of star formation (SF) with IFUs
– First uses of IFUs for SF science
– Herbig Haro Objects
– Young Star Binaries
• Star Formation at high contrast with IFUs: A Search for
IR H2 Emission from the Disks of Young Stars
• Cutting Edge Science: Laser-Fed AO IFU spectroscopy
of young stars
• Prospects for JWST and the ELTs
Formation of Sun-like Stars
in the Milky Way
Sub-mm continuum of
protostellar cores
Shirley et al. (2000)
Formation of Sun-like stars
in the Milky Way
Young stars with Circumstellar disks +
extended Envelopes (“Class I” Protostars)
HST NICMOS Imaging of Protostars (Padgett et al. 1999)
Formation of Sun-like stars
in the Milky Way
Young stars with Circumstellar disks, no
envelope material left (“Class II” Protostars,
“Classical” T Tauri Stars)
Orion Proplyds
O’Dell & Wen (1994)
Formation of Sun-like stars
in the Milky Way
Beta Pic Debris
Disk
Dust disk dissipates in
<1Gyr timescale
Meyer et al. (2008)
Formation of Sun-like stars
in the Milky Way
“Class II” Protostars with Disks +
Outflows – “Classical T Tauri Stars”
IFUs in Star Formation Science
MPE 3D w/ Calar Alto (3.5m)
H and K-band
Observations of T Tau
8”
Herbst et al. “A Near-Infrared Spectral Imaging
Study of T Tau” 1996 AJ v.111, 2403
IFUs in Star Formation Science
IFUs are very powerful tools for spatially
resolving emission line structures in the
environments of bright T Tauri Stars
Lavalley et al. “Sub-arcsecond morphology and kinematics of the DG Tauri jet in
the [O I]λ6300 line” 1997 A&A v.327, 671
Herbig Haro
Objects
HH 111
• HH Objects:
– optical/infrared tracers of YSO jets, seen where
jets from young stars plow into ambient cloud
material and shock the gas into emission
– Pure emission line objects
– viewed in optical/infrared permitted and
forbidden transitions – Ha, [O I], [N II], [S II],
[FeII], trace atomic gas excited by shocks
– Shock-excited H2 emission in the IR
 Natural IFU Sources
Beck et al. 2004, 2007, Lopez et al. 2008, 2010
Giannini et al. 2008
HH 46/47
Wings of
the Bow
Shock
Herbig Haro
Objects
• HH 99B:
H2 1-0 S(1) 2.12mm H2 2-1S(17) 1.758mm
Head of the
Bow Shock
[Fe II] 1.644 mm
HI Pab 1.28 mm
[Fe II] 1.749 mm
[P II] 1.188 mm
– Very sensitive VLT + SINFONI
observations
– 170+ Emission lines detected
– Many very high excitation lines
of H2 and [Fe II]
– Bow-shock apex shows
extremely high temperature T~6000K - revealing that the
H2 molecule persists in these
very high temperature regions
Giannini et al. “Near-infrared,
IFU spectroscopy unravels the
bow-shock HH99B“ 2008, A&A
v.481, 123
Young Star Binaries
• Most stars (50-60%) form as binary or higher
order multiple systems
• Understand young star binary characteristics,
particularly disk and mass accretion evolution
• The more massive primary star often has more
active mass accretion, indicating a larger
circumstellar disk reservoir of mass. I.e.,
preferential accretion from circumsystem
material onto the more massive star in a binary
• Spatially Resolved Observations of Young Star
binaries 0.”1 to ~1” separations, Programs
ongoing using NIFS, SINFONI & OSIRIS
Young Star Binaries – Z CMa
• Protostellar B star (Herbig Be star)
primary, FU Ori eruptive variable
companion
• System has become a prototype
for understanding eruptive mass
accretion in young star binaries
0.”1 binary observed
with OASIS – 0.”11
microlenses!
• OASIS observations in [OI] 6300A
Garcia et al. “Spatially resolved spectroscopy of Z Canis Majoris
components” 1999, A&A v.346, 892
Young Star Binaries – Z CMa
• The Massive Herbig
Be star does drive the
parsec scale outflow!
•The companion is
discovered for the
first time to drive its
own small scale jet
•First detection of a
collimated jet from a
FU Ori outbursting
variable star!
• Keck OSIRIS [Fe II] 1.644mm observations of Z Cma
Whelan et al. “The 2008 Outburst of Z CMa: The First Detection of Twin
Jets” 2010, ApJL v.720,L119
High Contrast IFU
Spectroscopy in Star
Formation – Gas in
Circumstellar Disks
HH 30
Dust in Circumstellar Disks – Traced by infrared excess
Emission, seen in scattered light images of T Tauri stars
Gas in Circumstellar Disks – As much as 99% of the mass in
circumstellar disks is in GAS not DUST
Disk Gas is traced by:
• mm molecular observations of cold outer disk gas
• IR emission species trace warm gas from ~terrestrial
regions of disks
Most studies cannot spatially resolve the gas in the inner disk regions and
measure trace components of the disks, ~70% of the disk by mass is in H2
The Search for IR Molecular
Hydrogen Gas in Young Star Disks
FWHM ~0.”1
Gemini + NIFS
IFU
observations
of six T Tauri
Stars – all
known to drive
YSO outflows
K-band
Continuum
Images
Beck et al. “Spatially Resolved Molecular Hydrogen in the Inner 200 AU
Environments of T Tauri Stars” 2008 ApJ, v.676, 472
The Search for IR Molecular
Hydrogen Gas in Young Star Disks
Herbig Haro
Flows
From Classical
T Tauri stars w/
outflows, H2
arises from
shocked
emission
surrounding
the HH flows
Beck et al. “Spatially Resolved Molecular Hydrogen in the Inner 200 AU Environments
of T Tauri Stars” 2008 ApJ, v.676, 472
IFU Observations of T Tau
Across a Decade…
Herbst et al. 1996
MPE 3D Data from Calar Alto 3.5m
Jan. 1995
Beck et al. 2008
NIFS Data from Gemini-N 8m
Oct. 2005
The Search for Molecular
Hydrogen Gas in Young
T Tau in [Fe II]
Star Disks
H2 Emission
Flux
H2 Velocity
H2 Velocity
Dispersion
• VLT + SINFONI Observations
of T Tau, detection of H2
from the face-on disk around
T Tau N?
Gustofsson et al. “Spatially resolved H2
emission from the disk around T Tau N”
2008
Where is the IR Molecular
Hydrogen Gas in Young Star
Disks?
3”
• Doing a Gemini + NIFS IFU survey of additional young
stars, more than doubling the past sample – this
includes stars that have evidence for dust disk gaps
(from IR SED shapes), and/or “disk-like” H2 from past
long-slit observations
*
Highlight = GG Tau A, 0.”3 binary young
star, with the prototypical
“Circumbinary Ring” of dust (Roddier
et al. 1996)
Circumbinary Ring seen in scattered light
Subaru CIAO Observations of GG Tau A
T. Beck, J. Bary et al. “The Search for Spatially
Resolved IR H2 from the Disks of Classical T
Tauri Stars” (in prep.)
The Search for IR H2 from a Disk
High Contrast for Star Formation
IR Spectrum of GG Tau A –
typical of young stars
Brg
NIFS 2.12mm continuum image
of the 0.”3 GG Tau A binary
H2??
H2!!
Fe I
Looking for a signal of ~few 100 cts, on a continuum of
30K+ cts, with a photospheric Fe I feature in the way!
The Search for IR Molecular
Hydrogen Gas in Young Star Disks
T. Beck, J. Bary et al. “The Search for Spatially Resolved IR H2 from the Disks of Classical T
Tauri Stars” (in prep.)
The Search for IR Molecular
Hydrogen Gas in Young Star Disks
H2 Emission in the Environment of GG Tau
A
• H2 2-1 S(1) / 1-0 S(1) line ratio not
indicative of fluorescent pumping by UV
photons, is consistent with X-ray heating of
the gas
• Gas/Dust in Protostellar binaries should
NOT exist (Artymowicz & Lubow 1994):
• Circumstellar: at spatial locations
beyond ~1/3 of the semi-major axis of
the binary (disk truncation)
• Circumbinary: at spatial locations
within ~3x the semi-major axis of the
H2 1-0 S(1) @ 2.12mm
binary (gap clearing)
• Clearing
ofClassical
years! T
T. Beck, J. Bary et al. “The Search for Spatially Resolved
IR Htimescale
from the~100’s
Disks of
2
Tauri Stars” (in prep.)
The Search for IR Molecular
Hydrogen Gas in Young Star Disks
40AU – Pluto’s
semi-major axis
H2 1-0 S(1) @ 2.12mm
H2 1-0 Q(1) @ 2.40mm
T. Beck, J. Bary et al. “The Search for Spatially Resolved IR H2 from the Disks of Classical T
Tauri Stars” (in prep.)
Cutting Edge SF Science: Laser-Fed
AO Observations of Young Stars
Pushing to Higher Mass:
• Comparably few detailed spatially
resolved observations of collimated
outflows toward protostars with higher
mass than the sun-like T Tauris.
• Keck Observatory LGS AO + OSIRIS IFU
Observations of the very young Herbig Ae
star LkHa 233
• Investigate whether the similarity on
large spatial scales between outflows
from T Tauri and Herbig Ae stars still holds
true on finer spatial scales.
Perrin et al. “Laser Guide Star Adaptive Optics Integral Field Spectroscopy of a
Tightly Collimated Bipolar Jet from the Herbig Ae star LkHa 233” 2007 ApJ, v.670,
499
Cutting Edge SF Science: Laser-Fed
AO Observations of Young Stars
Perrin et al. “Laser Guide Star Adaptive Optics Integral Field Spectroscopy of a
Tightly Collimated Bipolar Jet from the Herbig Ae star LkHa 233” 2007 ApJ, v.670,
499
Cutting Edge SF Science: Laser-Fed AO
IFU Observations of Young Stars
Pushing to Lower Mass:
HST Image From Glauser et al. 2008
Beck et al. “Laser Fed Adaptive Optics
Imaging Spectroscopy of the Candidate
Proto-Brown Dwarf IRAS 04158+2805”
in Prep.
• IRAS 04158+2805 = young proto-object in the
Taurus SFR (d~140pc)
• Seen in the optical largely in scattered light,
with a ‘bipolar’ nebula structure typical of
opaque disk material along the mid-plane
(Glauser et al. ’08), interpreted as a source
with a disk inclined by ~63o
• YOUNG! (<~1Myo!) w./ M6 type, commonly
adopted SpT for young BD limit
• HR Diagram fitting = substellar ~0.05Msolar
(large uncertainty in models)
• Andrews et al ‘08 detected the disk in submm, high spatial resolution dust continuum
and CO gas! extends out to >~500AU from
the central source - MASSIVE disk with
~1000+ AU total extent!
• Stellar mass estimate + extended massive
disk! – Mdisk / Mstar ~15-20%!
100 AU
Laser-fed AO Spectral Imaging,
IRAS 04158+2805
1.644mm [Fe II]
(Jet!)
2mm K-band
(Scattered Light!)
2.12mm H2
(Wide-Angle Outflow!)
– Gemini LGS AO w/ NIFS = Goal - Determine if H2 gas traces disk material in
the BD candidate environment - it doesn’t!
– Data reveals fspatially resolved 2-D spectral images of a well collimated jet
from a very young BD candidate
– BLUE-shifted, collimated [Fe II] jet associated with the brighter lobe of the
scattered light nebulosity - no redshifted jet detected
– Jet Orientation consistent w/ 63o viewing disk inclination
Beck et al. “Laser Fed Adaptive Optics Imaging Spectroscopy of the Candidate
Proto-Brown Dwarf IRAS 04158+2805” in Prep.
Laser-Fed Spectral Imaging of BD
Environments
TTGS
r~17.6mag
Gemini Observing
Tool View
IRAS 04158+2805
K~11.6 mag, R~21
AO TTGS
Area
• Laser-Fed AO on large groundbased telescopes is a powerful
means to reveal the inner
environments of BDs at high
spatial resolution using IR
emission lines…
• Complication = BDs are optically
very faint, but you need an
optical tip-tilt guide star! (TTGS)
• Observations of IRAS 04158+2805
were only possible with Gemini
+LGS AO because of the nearby
r~17.6 magnitude guide star
The Future: SF Science with
the JWST and ELT IFUs
Younger – Sun-Like
stars at earlier
epochs of
formation – the
“Class I” phase w/
envelope material
remaining, or even
younger!
Lower Mass – BDs
and Free-Floating
Planets in nearby
star forming
regions like Taurus
and Orion!
FAINTER!
More Distant–
Probe the Star
formation process
to low mass M
stars, approaching
the BD limit in the
LMC and SMC!
Higher Mass –
Massive O&B stars
form in very dense
cocoons of
gas+dust, pierce
through the
extinction to see
the forming stars!
Spectral Imaging of young
Star Environments with
JWST
The James Webb Space Telescope
• The James Webb Space
Telescope - operating at L2
in ~2014
• 6.5m Segmented Primary
• 4 Science Instruments:
– NIRCam - Near-InfraRed
Camera
– NIRSpec - Near-InfraRed
Spectrograph w/ IFU!
– TFI - Tunable Filter Imager
– MIRI - Mid-InfraRed
Instrument w/ IFU
A schematic view of the JWST focal plane,
including the placement of the science
entrance apertures for each instrument.
NIRSpec and MIRI have Integral Field Units for very sensitive high-contrast
spectral imaging of young star environments.
The Future: SF Science with IFUs
on the ELTs
Nearby T Tauri stars are bright for large aperture
telescopes – but we really need the ELT spatial resolution
to push our observations to the ~Jupiter environs!
GMT
For Kinematics and spectral line
detection/characterization, star formation science
greatly benefits from HIGH spectral resolution!
(R~20,000 or greater)
Mandell et al. (2009)
R~27,000
When considering properties for IFUs for large telescopes,
please don’t forget about star formation science! & Consider
a high spectral resolution IFU mode for the IR…!!
TMT
The Future: Next Generation
Observations of T Tau?
Herbst et al. 1996
Data from Jan.
1995
?
Beck et al. 2008
Data from Oct. 2005
Next Generation
IFU View of T Tau
THANKS!! For Your Attention!