what is the true distribution of star-forming material in molecular clouds? alyssa a. goodman (with...

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

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Barnard’s Perseus

QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.

COMPLETE/IRAS Ndust

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

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

QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.QuickTime™ and aTIFF (LZW) decompressorare needed to see this picture.

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