1. X-rays from star-forming regions : Stellar and Interstellar Studies with XMM (and Chandra)
Thierry Montmerle (Grenoble)
with : Nicolas Grosso & Hideki Ozawa (Grenoble)
Myha Vuong (Saclay), Eric Feigelson (Penn State)

2. Outline 1. Nearby star formation in clusters :
Introduction : case of the r Oph cloud
2. EPIC results : Stellar studies
data analysis
comparison with Chandra
3. Interstellar studies : Metallicity of nearby star-forming clouds using X-ray absorption

3. Looking towards and through molecular clouds
1. Introduction
Looking towards and through
molecular clouds

4. ISOCAM
Chandra ACIS
XMM EPIC
The r Oph cloud core in X-rays : Chandra (5+100 ksec) + XMM (25 ksec) fields

5. AV(tX=1) UV EUV optical C N O IR X 1 surface 10 medium 100 core dust
Lyman disc.
dust
gas+dust
Röntgen, 1895
AV(tX=1) UV
EUV
x 107
Cloud
optical
~ EX–2.5 C
1 surface N O IR X
10 medium
XMM/Chandra
100 core
10 mm mm
0.1 keV keV keV
2 mm
2 keV ™

6. 2. XMM/EPIC observations of the r Oph cloud
Comparison with Chandra

7. The XMM view of the r Oph cloud core
(Grosso, Ozawa, Montmerle et al. 2003)

8. Cross-Identification of MOS1, MOS2, and PN sources
3 s + 1” ⇒　same source
Several “binary” sources → caused by alignment ?
MOS1
MOS2 PN A ○ ×
out B C D E F G H

9. Identification between MOS1 and 2MASS
3 s + 1” ⇒　same source
DETX (“)
DETY(“)
rotation N 1
-0.6
-0.4
-1.5e-3 25 2
-0.8
-1.2e-3 3
-2.2
0.6
7.4e-3 4
-1.2
-0.7
-3.6e-3 5
2.8e-3 6
-2.4
-3.1
1.2e-3 8 7
-3.2
1.0
-9.4e-3

10. Identification between MOS2 and 2MASS
3 s + 1” ⇒　same source
DETX (“)
DETY(“)
rotation N 1
0.3
-1.4
-0.6e-3 21 2
-1.2
-1.0
-3.8e-3 12 3
0.7
-1.9
0.4e-3 4
-0.8
0.1
3.7e-3 5
2.0
-2.7
-1.1e-3 6
-0.2
-2.5
4.5e-3 7
-1.3
1.9e-3

11. Identification between PN and 2MASS
3 s + 1” ⇒　same source
DETX (“)
DETY(“)
rotation N
all
-0.2
-0.1
-0.2e-3 57

12. Position correction of the EPIC images
Before correction
After correction

13. Position correction of the EPIC images
Before correction
After correction

14. Source detection and Identification with Chandra X-ray sources
XMM-Newton
Chandra
Number of sources 87
Number of sources in both F.O.V 47 81
Detection by both 43
F.O.V
~30` diameter
17`x17`
Time
30 ks
100 ks
(Chandra data from Imanishi et al. 2001)

15. Identification with Infrared YSOs
X-ray detection rate
Class I : 7/11
(protostars : envelopes)
Class II : 28/61
(T Tauri stars with disks)
Class III : 14/15
(diskless T Tauri stars)
Classification by Bontemps et al. 2001

16. Lx vs. Lbol LX/Lbol is not constant with Lbol
Weak correlation between Lbol and LX　　index : 0.11
LX/Lbol　 is not constant with Lbol

17. 3. Looking through the r Oph cloud
First measurement of the metallicity
of a molecular cloud
(Vuong et al. 2003)

18. IR sources

19. X-rays (> 100 cts) => NH,X
NIR to MIR => AJ

20. NH,X : Cross-check between Chandra and XMM (3 sources)

21. ?
Galactic relation
µ X-ray counts

22. <=> grain properties
NH,X <=>
Metallicity
from X-ray
absorption
AJ => AV via RV
<=> grain properties

23. Conclusions (among others)
The wide FOV of XMM/EPIC allows to capture the essence of high-energy star formation in one single exposure; links with IR however necessary to understand the nature of the sources
=> X-ray properties evolve significantly from protostars (envelopes) to “old” T Tauri stars (without disk)
Spectral properties (absorption up to very high values) may be used to probe the metallicity of molecular clouds -a specific property of X-rays