what is the true distribution of star-forming material in molecular clouds? alyssa a. goodman (with...
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What is the True Distribution of Star-Forming Material in Molecular Clouds?
Alyssa A. Goodman
(with N. Ridge & S. Schnee)
140
120
100
80
60
40
20
01.00.50.0-0.5-1.0
Log (Equivalent AV [mag])
IRASlog normal fit to
IRAS column density
140
120
100
80
60
40
20
02MASS/NICER
log normal fit to 2MASS column density
(all panels)
140
120
100
80
60
40
20
0
13CO
Implied Column Density Distributions and lognormal Fits(Perseus COMPLETE data)
What is the True Distribution of Star-Forming Material in Molecular Clouds?
MHD Turbulence Theory: lognormal
(very robust result)
E. Ostriker, J. Stone & C. Gammie 2001
Alyssa A. Goodman, Principal Investigator (CfA)João Alves (ESO, Germany)
Héctor Arce (Caltech)Paola Caselli (Arcetri, Italy)
James DiFrancesco (HIA, Canada)Jonathan Foster (CfA, PhD Student)
Mark Heyer (UMASS/FCRAO)Helen Kirk (HIA, Canada)
Di Li (CfA)Doug Johnstone (HIA, Canada)
Naomi Ridge (CfA)Scott Schnee (CfA, PhD student)
Mario Tafalla (OAN, Spain)Tom Wilson (ESO, Germany)
COMPLETE
The COordinated Molecular Probe Line Extinction Thermal Emission Survey
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are needed to see this picture.
Barnard’s Perseus
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COMPLETE/IRAS Ndust
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COMPLETE/FCRAO W(13CO)
Embracing the Confusion is
Key to Understanding
conspiracies of chemical excitation & depletion, optical depth,
Tdust, Tgas, “,” can be critically misleading
(especially for gullible theorists)
Dust Density & Dust Temperature in Perseus
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Total Dust Column (0 to 15 mag AV) (Based on 60/100 microns)
Dust Temperature (25 to 45 K)(Based on 60/100 microns)
IRAS Ndust
H-
em
issi
on,W
HA
M/S
HA
SS
A S
urve
ys (
see
Fin
kbei
ner
2003
)
H
IRAS Ndust
H-
em
issi
on,W
HA
M/S
HA
SS
A S
urve
ys (
see
Fin
kbei
ner
2003
)
H
2MASS/NICER Extinction
Why “COMPLETE”?
QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.+ =
IRAS Column Density
IRASTemperature
NICER Extinction Map
Alves, Lombardi & Foster+ 2004
Schnee et al. 2004Ridge et al. 2004
Why “COMPLETE”?
QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.+ =
IRAS Column Density
IRASTemperature
NICER Extinction Map
Alves, Lombardi & Foster+ 2004
Schnee et al. 2004Ridge et al. 2004
What is the True Distribution of Star-Forming Material in Molecular Clouds?
Alyssa A. Goodman
(with N. Ridge & S. Schnee)
140
120
100
80
60
40
20
01.00.50.0-0.5-1.0
Log (Equivalent AV [mag])
IRASlog normal fit to
IRAS column density
140
120
100
80
60
40
20
02MASS/NICER
log normal fit to 2MASS column density
(all panels)
140
120
100
80
60
40
20
0
13CO
Implied Column Density Distributions and lognormal Fits(Perseus COMPLETE data)
12
10
8
6
4
2
0
W(13
CO) K km s
-1
121086420
N2MASS [mag]
Cold Dense Clouds Ring
Integrated 13
CO vs. 2MASS "Extinction"
12
10
8
6
4
2
0
NIRAS
[mag]
121086420
N2MASS [mag]
Cold Dense Clouds Ring
IRAS vs. 2MASS "Extinction"
Not all Measures of Column Density are Created Equal