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Supernova Remnants and Molecular Clouds

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Supernova Remnants and Molecular Clouds Gloria Dubner IAFE, Buenos Aires, Argentina The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 A Supernova Remnant (SNR) is the structure and products created during and after the explosion and through the interaction with the surrounding matter. The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 A Supernova Remnant (SNR) is the structure and products created during and after the explosion and through the interaction with the surrounding matter. The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 Thermonuclear SNe (SN Ia): originate from stars ending their lives on timescales from 0.03 Gyr up to the Hubble time. Represent about 29% of all SNe Core-collapse SNe (SN II, Ib/c): resulting from young, massive stars that explode on short timescales (few millions to several tenths of a million year) close to their birth-places. Represent about 71% of all SNe The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 Why study SNR-MC Association ? (Dame et al. 2001) Molecular gas takes up half of the mass of the ISM in our Galaxy Most core-collapse SNe are located close to GMCs , their birth places How many SNR/MC? A large percentage of the ~ 270 Galactic What are the SNRs are expected to be interacting with consequences of such MCs (Reynoso & Mangum 2000); interaction? The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 Unique Physical and Chemical effects take place when SNR shocks impact molecular clouds Shocks can compress, heat, and produce turbulent mixing in the molecular gas Condensed clumps created by this mechanism may eventually end as new stars. Shocks can excite, ionize, dissociate and even create molecules They influence chemical evolution & Expanding supernova remnant produce otherwise impossible interacting with a molecular cloud, molecular emission（e.g. 1720MHz resulting in OH maser emission from + ） the shocked cloud material (Wardle & OH maser, HCO , etc. Yusef-Zadeh 2002). The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 SNRs as the factory of Galactic cosmic rays The interaction of SNR shocks with dense molecular gas can give origin to inelastic proton-proton scattering with production and decay of neutral pions resulting in high- energy g-ray emission. The combined study of the radio-continuum emission of SNRs complemented with an analysis of the surrounding molecular gas, is the key to advance in the comprehension of the physics underlying the g-ray emission and the origin of CRs. The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 How can be proved that a MC is being shocked by a SNR? • Presence of OH (1720 MHz) masers • Wings, asymmetries and broadenings in the molecular lines • High line ratios (for ex. elevated 12CO:2-1/ 12CO:1-0 ratio) • NIR H2 lines • IR colors • Morphological and kinematical agreement of molecular features The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 Jiang et al. (2010 ApJ 712, 1147) presented a list of SNR/MC interactions compiled in our Galaxy based on the former criteria, finding 34 confirmed 64 cases 11 probable (morph. association) 19 possible (IR colors) The way to prove a hadronic origin for the g-emission connection SNR/CR The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 Other way to prove that a SNR /MC interaction can accelerate CRs is measuring ionization (molecular ions) in dense MCs shocked by a SNR: Ceccarelli et al. (2011, CRISM Proc.) From Ceccarelli (2011) Measurements of Ionization degree through molecular ions observations, H13 CO+ J:1-0 and DCO+ J:1-0 at 87 GHz SNR W44 evolving in a molecular environment 13CO emission The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 Radio spectrum of Radio and IR emission the SNR W44 of the SNR W44 Castelletti et al. 2007, A&A 471, 537 The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 Star formation in the periphery of W44 ASTE observations of 12CO J = 3−2, 13CO J = 3−2, HCO+ J = 4−3 and CS J = 7−6 lines . IRAS 18542+0114 Paron et al. 2009, A&A 498, 445 12CO HCO+ Radio + 8 and 24 microns The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 SNR Puppis A – interacting with molecular clouds Paron et al. 2008, A&A480, 439 (Paron et al.The 2009)LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 SNR IC443: Radio and optical emissions Castelletti, Dubner, Clarke & Kassim 2011, astro-ph 1104.0205 (Paron et al.The 2009)LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 Radio spectral index and CO emission in IC443 Flat spectrum of thermal origin OH masers Flat spectrum of non- thermal origin The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 VLA radio at 330 MHz TeV VERITAS (Acciari et 12 CO (Zhang et al. 2010)T (Castelletti et al. 2011) al. 2009) source VERJ0616.9+2230 The LLAMA Project Evaluation Workshop Currently 129FAPESP, detected Sao interstellar Paulo, Augustmolecules8 (from– 9, 2011 November 2005) Fermi-LAT detection of GeV Gamma Rays emission from Supernova Remnants Interacting with Molecular Clouds Uchiyama et al. 2011, astro-ph 1104.1197 The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 Reynoso & Mangum 2001 Dubner et al. 2004 The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 In summary: The study of SNRs/ MC interactions at intermediate angular resolution is an invaluable tool to understand several issues of great interest at present: • Shock astrochemistry • Star birth induced by dying stars • Origin of galactic cosmic rays • Nature of gamma-ray sources • Properties of the cold ISM Great synergy with CTA project The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011 List of SNR-MC Association (I) Jiang et al. 2010, ApJ 712, 1147 64 in total 34 confirmed Evidence: 1. OH maser 2. Molecular LB 3. High line ratio 4. NIR H2 lines 5. IR colors 6. MA of molecular features Bing Jiang SNR-MC Association 11 probable … … 6. MA of molecular features 19 possible … … 5. Rough IR colors … 7.Rough correspondence (RC) of molecular features 64 in total >21 γ-ray detections As the most significant source of chemical enrichment and energy input in the interstellar medium, SNRs offer us a most valuable laboratory to study: • heavy element nucleosynthesis, • the physics of the extreme associated with neutron stars and associated pulsar wind nebulae and • the acceleration of cosmic rays in the Galaxy The LLAMA Project Evaluation Workshop FAPESP, Sao Paulo, August 8 – 9, 2011.
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