Contributions if Interferometry for Orion

M. Robberto

(ESA/STScI)

The

Gre

at O

rion

Neb

ula

The Orion Cluster

2mass near-IR image

The Orion Cluster

Why Orion is important?

• Is the nearest GMC and the most recent episode of massive star formation

• Distance is fairly well known (~450pc)

• Background contamination is low

• Is the paradigm for typical star formation

• Is the paradigm for typical planet formation?

The HST mosaic

HST; Ha+[OIII]+[SII](courtesy Bob O’Dell)

HST; F547M (courtesy Bob O’Dell)

VLT JHK composite

3.5 micron image

Lada et al., 2000

10 micron image

10 micron image

BN-KL

Ney-Allen

OMC1-S

174 point N-micron point sources

Understanding the IR emission of Understanding the IR emission of

photoevaporated disksphotoevaporated disks• Disks in HII regions are under the Disks in HII regions are under the influence of a complex radiation fieldinfluence of a complex radiation field• HST dataHST data constrain the model constrain the model parameters (tilt angle with respect to the parameters (tilt angle with respect to the ionizing star and to the Earth, distance ionizing star and to the Earth, distance from the ionizing star, disk size…)from the ionizing star, disk size…)

Robberto, Beckwith and Panagia, Ap.J, 2002 (in press)

S 2.2m 3.5m 10m

182-336

1.0

10.0

100.0

0.1 1.0 10.0 100.0l (m)

Fn(J

y) x

10

11

dereddened

M0V star

observed

face-on passive disk

170-337

0

0

1

10

100

0.1 1.0 10.0 100.0l (m)

Fn(J

y) x

10

11

observedM0.5 stardereddenedface-on passive disk

Robberto, Beckwith and Herbst, 2000

MID-IR imaging > photometry > SEDs vs. disk models

BN/KL

IRC2

MAX N-band

Dougados et al. 1993 ApJ 406,111

OMC1-South

Search for the OMC1-South exciting source

Ney-Allen nebula

MAX 10/20mHST/WFPC2 F547M

MAX 10m

1Ori-C and SC3

F336W – PC 1s

1Ori-C and SC3

F336W – PC 30s

1Ori-C and SC3

F439W – PC 1s

1Ori-C and SC3

F439W – PC 30s

1Ori-B is extended/binary

F457M – PC 30s

Modeling the arcs

1Ori-D anomaly

Is Ney Allen Nebula associatedto 1Ori-D?