Transcript PPT - Harvard-Smithsonian Center for Astrophysics

The COMPLETE Survey of
Star-Forming Regions:
Nature vs. Nurture
Alyssa A. Goodman
Harvard-Smithsonian Center for Astrophysics
cfa-www.harvard.edu/~agoodman
The
COordinated
Molecular
Probe
Line
Extinction
Thermal
Emission
Survey
COMPLETE
Alyssa A. Goodman, Principal Investigator (CfA)
João Alves (ESA, Germany)
Héctor Arce (Caltech)
Paola Caselli (Arcetri, Italy)
James DiFrancesco (HIA, Canada)
Mark Heyer (UMASS/FCRAO)
Di Li (CfA)
Doug Johnstone (HIA, Canada)
Naomi Ridge (UMASS/FCRAOCfA)
Scott Schnee (CfA, PhD student)
Mario Tafalla (OAS, Spain)
Tom Wilson (MPIfR)
Nature
Shu, Adams & Lizano 1987
Nurture
Corporations
Shu, Adams & Lizano 1987
Environmentalists
Theory
Shu, Adams & Lizano 1987
Observation
Star Formation 101: A “Natural” Framework
"Cores" and
Outflows
1 pc
Molecular or
Dark Clouds
Jets and
Disks
Extrasolar System
On the way to Star Formation
201
Ten Years Ago, this picture was OK…but
now I know that:
Structures in a turbulent, self-gravitating, flow
are highly transient
Outflows are episodic
Young stars can move rapidly
Energetically significant spherical outflows
(e.g. SNe, winds) are common in starforming regions
How do I know “that”?
Optical imaging
Near-infrared imaging
Thermal dust imaging
Molecular spectral-line mapping
MHD Simulations
Spectral Line MappingVelocity
Spectral Line Observations
Loss of
1 dimension
Mountain Range
No loss of
information
Star Forming Regions as Turbulent Flows:
MHD Simulations
b=0.01
Stone, Gammie & Ostriker 1999
[T / 10 K]
b=[
2
-3
nH / 100 cm ][ B / 1.4 mG]
2
b=1
•Driven Turbulence; M K; no gravity
•Colors: log density
•Computational volume: 2563
•Dark blue lines: B-field
•Red : isosurface of passive contaminant after saturation
Characterizing
Spectral Line Maps of
Observed & Simulated
“Turbulent “Flows
The Spectral
Correlation Function
(SCF)
See also PCA analysis (Heyer et al.)
& many other methods
Simulated map, based on work of Padoan, Nordlund, Juvela, et al.
Excerpt from realization used in Padoan, Goodman &Juvela 20023
Falloff of Correlation with Scale
Summary Results from SCF Analysis
“Equipartition”
Models
“Reality”
“Stochastic”
Models
Scaled
“Superalfvenic”
Models
Magnitude of Spectral Correlation at 1 pc
Padoan,
Goodman
& Juvela 2003
Falloff of Spectral Correlation with Scale
Do existing turbulence simulations
“match” molecular clouds?
13CO
maps
Super-Alfvénic MHD Simulations
Magnitude of Spectral Correlation at 1 pc
Padoan, Goodman & Juvela 2003
Structures
are Highly
Transient
•MHD turbulence gives “t=0”
conditions; Jeans mass=1
Msun
•50 Msun, 0.38 pc, navg=3 x
105 ptcls/cc
•forms ~50 objects
•T=10 K
•SPH, no B or L, G
•movie=1.4 free-fall times
Bate, Bonnell & Bromm
2002
QuickTime™ and a Cinepak decompressor are needed to see this picture.
On the way to Star Formation
201
Structures in a turbulent, self-gravitating, flows are highly
transient
Outflows are episodic
Young stars can move rapidly
Energetically significant spherical outflows (e.g. SNe,
winds) are common in star-forming regions
Episodic Outflows, from Moving Sources
0
10
Power-law Slope of Sum = -2.7
(arbitrarily >2)
10
Slope of Each Outburst = -2
-1
Mass [Msun]
as in Matzner & McKee 2000
10
10
10
10
-2
-3
-4
-5
2
0.1
3
4 5 6 78
2
3
1
4
2
5 6 78
10
Velocity [km s-1]
Episodicity changes Energy/Momentum
Deposition (time)
(Some) Young stars may
zoom through ISM
L1448
Bachiller, Tafalla & Cernicharo 1994
YSO Outflows
are Highly Episodic
B5
Yu Billawala & Bally 1999
Bachiller et al. 1990
Lada & Fich 1996
Position-Velocity Diagrams show
Outflow Episodes:Position-Velocity Diagrams
NGC2264
Figure from Arce & Goodman 200az1a
HH300
Episodic Outflows:
Steep Mass-Velocity Slopes Result from Summed Bursts
10
0
Power-law Slope of Sum = -2.7
(arbitrarily >2)
Mass [Msun]
10
10
10
10
10
Slope of Each Outburst = -2
-1
as in Matzner & McKee 2000
-2
-3
-4
-5
2
0.1
3
4 5 6 78
2
3
1
4
5 6 78
2
10
Velocity [km s-1]
Arce & Goodman 2001b
Powering source of (some) outflows may zoom
through ISM
“Giant”
HerbigHaro Flow
from
PV Ceph
1 pc
Image from Reipurth, Bally & Devine 1997
PV Ceph
Episodic ejections
from a precessing or
wobbling moving
source
Goodman & Arce 2003
PV Ceph is
moving at
~10 km s-1
Goodman & Arce 2003
4x 10
“Plasmon” Model of PV Ceph
18
500x10
70
15
60
Star
Distance along x-direction (cm)
y k not positions (cm)
400
2
Star-Knot
Difference
(%)
50
300
Star-Knot
Difference
40
30
200
1
Star-Knot Difference/Star Offset (Percent)
3
20
Knot
100
Initial jet 250 km s1; star motion 10
km s-1
0
-4x 10
17
-2
10
0
0
5
10
15x10
3
0
0
x k not posns. w.r.t. star "now" (c m)
Elapsed Time since Burst (Years)
Goodman & Arce 2003
4x 10
“Plasmon” Model of PV Ceph
18
10
9
8
3
"Dynamical Time"/Elapsed Time
y k not positions (cm)
7
2
6
For an HH object at 1 pc from
source,
dynamical time calculation
overestimates age by factor of ten.
5
4
3
2
1
1
0.0
0.5
1.0
1.5
2.0
2.5
3.0x10
18
Distance of Knot from Source (cm)
0
-4x 10
17
-2
0
x k not posns. w.r.t. star "now" (c m)
Goodman & Arce 2002
“Giant” Outflows, c. 2002
See references in H. Arce’s Thesis 2001
The action of
multiple
outflows in
NGC 1333?
SCUBA 850 mm Image shows
Ndust (Sandell & Knee 2001)
Dotted lines show CO outflow
orientations (Knee & Sandell
2000)
On the way to Star Formation
201
Structures in a turbulent, self-gravitating, flows are highly
transient
Outflows are episodic
Young stars can move rapidly
Energetically significant spherical outflows (e.g. SNe,
winds) are common in star-forming regions
Preview Now, More Later!
COMPLETE Preview:
Discovery of a Heated Dust Ring in Ophiuchus
2 pc
Goodman, Li & Schnee 200
COMPLETE
Preview:
Great Bubble
in Perseus
Does fecundity = demise?
Bipolar outflows from young stars
+
Stellar Winds (& photons) from older stars
+
Large Explosions (SNe, GRBs)
All have the power both to create & destroy
Nature
Shu, Adams & Lizano 1987
Nurture
Star Formation 201
“Nurture”
Star Formation 201
“Nurture”
Corporations
Shu, Adams & Lizano 1987
Environmentalists
Environmental Impact Statement
•
How do processes in each stage impact upon each
other? (Sequential star formation, outflows
reshaping clouds…)
•
How long do “stages” last and how are they mixed?
•
What is the time-history of star production in a
“cloud”? Are all the stars formed still “there”?
(Big cloud--“Starless” Core--Outflow--Planet
Formation--Clearing)
What’s the right
“environmentalist” approach?
Gather a sample where you can statistically understand:
Observing Biases
Temporal Behavior
Regional Variations
The Environmentalist’s Toolkit
Optical imaging
Extinction, reddening dust grain sizes, dust column density distribution
Shocked gas (e.g. HH jets)
Near-infrared imaging
Same as optical, plus reveals deeply “embedded” young sources (+ disks)
X-ray Imaging and Spectroscopy
Reveals “embedded” sources & identifies sources of bipolar & spherical
outflows
Thermal dust imaging
Cold dust “glows” at far-IR and sub-mm wavelengthsdust grain sizes,
dust temperature, plus disk characteristics
Molecular and atomic spectral-line mapping
Gives gas density, temperature & velocity distribution
MHD Simulations
Nagahama et al. 1998 13CO (1-0) Survey
Un(coordinated) MolecularProbe Line, Extinction and
Thermal Emission
Observations
Molecular Line
Map
2MASS/NICER Extinction Map of Orion
1:50
50
1 pc
55
2:00
2:00
05
10
10
20
15
1 pc
20
30
25
SCUBA
30
40
5:41:00
20
40
R.A. (2000)
40
42:00
SCUBA
42:00
Johnstone et al. 2001
Lombardi & Alves 2001
30
41:00
R.A. (2000)
30
Johnstone et al. 2001
5:40:00
The
COMPLETE
COordinate
d
Molecular
Probe
Line
Extinction
Thermal
Emission
Survey
The Value of Coordination: B68
Optical
Image
Dust Emission
C18O
Coordinated Molecular-Probe Line, Extinction &
Thermal Emission Observations of Barnard 68
This figure highlights the work of Senior Collaborator
João Alves and his collaborators. The top left panel
shows a deep VLT image (Alves, Lada & Lada 2001).
The middle top panel shows the 850 mm continuum
emission (Visser, Richer & Chandler 2001) from the dust
causing the extinction seen optically. The top right panel
highlights the extreme depletion seen at high extinctions
in C18O emission (Lada et al. 2001). The inset on the
bottom right panel shows the extinction map derived from
applying the NICER method applied to NTT near-infrared
observations of the most extinguished portion of B68.
The graph in the bottom right panel shows the incredible
radial-density profile derived from the NICER extinction
map (Alves, Lada & Lada 2001). Notice that the fit to
this profile shows the inner portion of B68 to be
essentially a perfect critical Bonner-Ebert sphere
NICER
Extinction
Map
Radial Density
Profile, with Critical
Bonnor-Ebert
Sphere Fit
5 degrees (~tens of
pc)
COMPLETE,
Part 1
SIRTF Legacy
Coverage of
Perseus
Observations:
2003-- Mid- and Far-IR SIRTF Legacy Observations: dust temperature and
>10-degree scale NearIR Extinction, Molecular
Line and Dust Emission
Science:
Surveys of Perseus,
Ophiuchus & Serpens
column density maps ~5 degrees mapped with ~15" resolution (at 70 mm)
2002-- NICER/2MASS Extinction Mapping: dust column density maps ~5
degrees mapped with ~5' resolution
2003-- SCUBA Observations: dust column density maps, finds all "cold" source
~20" resolution on all AV>2”
2002-- FCRAO/SEQUOIA
13CO
and
13CO
Observations: gas temperature,
density and velocity information ~40" resolution on all AV>1
–Combined Thermal Emission data: dust spectral-energy distributions, giving
emissivity, Tdust and Ndust
–Extinction/Thermal Emission inter-comparison: unprecedented constraints
on dust properties and cloud distances, in addition to high-dynamic range Ndust
map
–Spectral-line/Ndust Comparisons Systematic censes of inflow, outflow &
turbulent motions enabled
Is this Really Possible Now?
10
A V~5 mag, Resolution~1'
3
1 day for a
map then
A V~30 mag, Resolution~10"
13CO
10
Time (hours)
10
10
13
CO Spectra for 32 Positions
in a Dark Cloud (S/N~3)
Sub-mm Map of a Dense Core
at 450 and 850 mm
2
1 Day
1
0
1 Hour
NICER/8-m
10
1 Week
-1
1 Minute
SEQUOIA+
10
10
-2
1 minute for a
13CO map now
SCUBA-2
-3
1 Second
10
NICER/2MASS
-4
1980
1985
1990
1995
NICER/SIRTF
2000
Year
2005
2010
2015
Re-calibrated IRAS Dust Column Density
Re-Calibrated IRAS Dust Temperature
Heated
Dust
Ring
Smoke
Signals:
COMPLET
E’s Ophiuchus
ROSAT PSPC
0.5 x 1051 erg SN
into 105 cm-3
2 pc in 200,000 yr
T=38K
vexp=1.7 km s-1
Goodman, Gaensler,
Wolk & Schnee 2003
ROSAT Pointed Observation
The star r-Oph
and
RXJ1625.52326
Region
known
as
“r-Oph
Cluster”
Real r-Oph
Cluster
inside newly
discovered
heated ring
1RXS J162554.5-233037
In each panel where it is sho n, the white ring shows a 2 pc circle,
corresponding to the size and shape of the heated ring apparent in the IRAS
Perseus in
(Coldish)
Molecular
Gas
QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.
Map of 1200 13CO Spectra from Bachiller & Cernicharo 1986
(made with Bordeaux 2.5-m, Beam Area = 31 x FCRAO)
COMPLETE/FCRAO noise is twice as low, and velocity resolution is 6 x higher
Perseus in
(Warmish)
Dust
2 x 1051 erg SN
into 104 cm-3
5 pc in 1 Myr
T=30K
vexp=1.5 km s-1
COMPLET
E
Perseus
IRAS +
FCRAO
(73,000 13CO Spectra,
see Scott Schnee!)
Perseus
Total Dust Column (0 to 15 mag AV)
(Based on 60/100 microns)
Dust Temperature (25 to 45 K)
(Based on 60/100 microns)
QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture.
QuickTime™ and a TIFF (LZW) decompressor are needed to see this picture.
Hot Source in a Warm Shell
Column
Density
Temperature
+
QuickTime™
and
TIFF
(LZW)
decompressor are needed to see this picture.
QuickTime™ and a TIFF (LZW) decompressor
are needed
toasee
this
picture.
=
(Lee, Myers & Tafalla 2001).
COMPLE
TE, Part 2
(2003-5)
FCRAO N2H+ map with CS spectra superimposed.
Observations, using target list generated from Part 1:
<arcminute-scale core
maps to get density &
Science:
velocity structure all the
way from >10 pc to 0.01
pc
NICER/8-m/IR camera Observations: best density profiles for
dust associated with "cores". ~10" resolution
FCRAO + IRAM N2H+ Observations: gas temperature, density
and velocity information for "cores” ~15" resolution
Multiplicity/fragmentation studies
Detailed modeling of pressure structure on <0.3 pc scales
Searches for the "loss" of turbulent energy (coherence)
On the way to Star Formation
201
Structures in a turbulent, self-gravitating, flows are highly
transient
Outflows are episodic
Young stars can move rapidly
Energetically significant spherical outflows (e.g. SNe,
winds) are common in star-forming regions
“COMPLETE” Star Formation c.
2005
Statistical Evaluation of Outflows’ Role
Evaluation of Constructive/Destructive Role of
Explosions/Winds
Tracking down progeny (includes USNO-B work)
The
COordinated
Molecular
Probe
Line
Extinction
Thermal
Emission
Survey
COMPLETE
Alyssa A. Goodman, Principal Investigator (CfA)
João Alves (ESA, Germany)
Héctor Arce (Caltech)
Paola Caselli (Arcetri, Italy)
James DiFrancesco (HIA, Canada)
Mark Heyer (UMASS/FCRAO)
Di Li (CfA)
Doug Johnstone (HIA, Canada)
Naomi Ridge (UMASS/FCRAOCfA)
Scott Schnee (CfA, PhD student)
Mario Tafalla (OAS, Spain)
Tom Wilson (MPIfR)
Extra Slides
COMPLETE:
JCMT/SCUBA
>10 mag A
V
8
6
4
2
~100 hours at
SCUBA
10 pc
10 pc
Ophiuchus
Perseus
Johnstone, Goodman & the
COMPLETE team, SCUBA
2003(?!)
• Slope steepens when t
corrections made
– Previously unaccounted-for
mass at low velocities
• Slope often (much) steeper
than “canonical” -2
• Seems burstier sources have
steeper slopes?
Mass/Velocity
“Steep” Mass-Velocity
Relations
-3
-8
Velocity
-4
-8
HH300 (Arce & Goodman 2001a)
How much gas will be pulled along for the ride?
Goodman & Arce 2002
Just how fast
is PV Ceph
going?
Velocity from
Spectroscopy
Observed Spectrum
Telescope 
Spectrometer
1.5
Intensity
1.0
0.5
0.0
All thanks to Doppler
-0.5
100
150
200
250
"Velocity"
300
350
400
Radio Spectral-line Observations of Interstellar Clouds
Spectral Line Observations
Radio Spectral-line Observations of Interstellar Clouds
Radio Spectral-Line Survey
Alves, Lada & Lada 199
Star Formation 101
"Cores" and
Outflows
1 pc
Molecular or
Dark Clouds
Jets and
Disks
Extrasolar System
Star Formation 101
"Cores" and
Outflows
1 pc
Molecular or
Dark Clouds
Jets and
Disks
Extrasolar System
Cores: Islands of Calm in a Turbulent Sea?
"Rolling Waves" by KanO
Tsunenobu © The Idemitsu
Museum of Arts.
Islands of Calm in a Turbulent Sea
Goodman, Barranco, Wilner & Heyer 1998
Islands (a.k.a. Dense Cores)
AMR Simulation
Simulated NH3 Map
Berkeley Astrophysical Fluid Dynamics Group
http://astron.berkeley.edu/~cmckee/bafd/results.html
Barranco & Goodman 1998
Observed ‘Starting’ Cores: 0.1 pc Islands of (Relative) Calm
“Dark Cloud”
“Coherent Core”
TMC-1C, OH 1667 MHz
TMC-1C, NH 3 (1, 1)
-0.10±0.05
D v intrinsic =(0.25±0.02)T
1
9
8
8
7
7
-1
]
9
D v intrinsic [km s
-1
D v [km s ]
Velocity Dispersion
1
A
6
5
4
5
4
3
3
Dv=(0.67±0.02)T
2
6
-0.6±0.1
A
2
3
4
5
6
7
8
9
2
6
7
1
TA [K]
Goodman, Barranco, Wilner & Heyer 1998
8
9
2
3
0.1
Size Scale
4
5
6
7
8
9
1
TA [K]
Cores = Order from Chaos
~0.1 pc
(in Taurus)
Order; N~R0.9
Chaos; N~R0.1
Star Formation 101
"Cores" and
Outflows
1 pc
Molecular or
Dark Clouds
Jets and
Disks
Extrasolar System
…and the famous “1RXS
J162554.5-233037” is
right in the Middle !?
2 pc