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)

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

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

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

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 1 mm 0.1 keV 1 keV 10 keV 2 mm 2 keV ™

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

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

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

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

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

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

Position correction of the EPIC images Before correction After correction

Position correction of the EPIC images Before correction After correction

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)

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

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

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

IR sources

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

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

? Galactic relation µ X-ray counts

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

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