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Grains and Gas in the Ejecta of Classical Novae

Grains and Gas in the Ejecta of Classical Novae. R. D. Gehrz Department of Astronomy, University of Minnesota. Outline. Novae and Galactic chemical evolution Outburst parameters from radio/IR data Physical properties of nova grains Comparisons with ISM and the Solar System Grains

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Grains and Gas in the Ejecta of Classical Novae

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  1. Grains and Gas in the Ejecta of Classical Novae R. D. Gehrz Department of Astronomy, University of Minnesota R. D. Gehrz

  2. Outline • Novae and Galactic chemical evolution • Outburst parameters from radio/IR data • Physical properties of nova grains • Comparisons with ISM and the Solar System Grains • Gas Phase abundances • Summary R. D. Gehrz

  3. IR/Radio Observations of Classical Novae: Collaborators University of Minnesota: R. D. Gehrz, T. J. Jones, T. Harrison, J. Lyke, C. G. Mason, E. P. Ney, M. Schuster, C. E.Woodward Cornell University: T. Hayward, J. R. Houck, J. Miles Caltech: K. Matthews, G. Neugebauer, K. Sellgren University of Wyoming: G. Grasdalen, J. Hackwell UK and Europe: M. Barlow, A. Evans, J. Krautter, A. Salama Additional Collaborators: M. Greenhouse (GSFC), R. M. Hjellming (NRAO), S. G. Starrfield (AZ State), J. Truran (Chicago), R. E. Williams (STScI), A. F. Bentley (Eastern Montana), D. H. Wooden (NASA ARC), F. C. Witteborn (NASA ARC), S. A. Sandford (NASA ARC), L. J. Allamandola (NASA ARC), J. D. Bregman (NASA ARC), M. Klapisch (NRL) R. D. Gehrz

  4. A Classical Nova Explosion: Accretion followed by a TNR R. D. Gehrz

  5. The Role of Classical Novae in Galactic Chemical Evolution R. D. Gehrz

  6. IR/Radio Development Phases • The luminosity of the outburst fireball is Lo LEdd • c measures nH and the ejected ionized gas mass Mgas during the free-free expansion phase • Lo LEdd = LIR for optically thick dust shells  Lo = constant for a long time Fireball Expansion Phase Free-Free Expansion Phase Coronal Phase in ONeMg Novae Dust Cocoon Phase in CO Novae  in m R. D. Gehrz (1988, 1990) R. D. Gehrz

  7. Physical Parameters Derivable from IR SED’s and Spectra TBB in K and time of the outburst to in JD for expanding photospheres and dust shells The apparent luminosity; for blackbodies, f = 1.36 ( f )max in W cm-2 The free-free self-absorption wavelength c in m The outflow velocity Vo in Km s-1 from emission lines R. D. Gehrz

  8. Mass of the Ejecta from IR SED’s in M From Thomson scattering, which dominates the shell opacity during the fireball/free-free transition: From c during the optically thin free-free phase: Mgas  1-3x10-4 M for ONeMg WD’s Mgas  1-5x10-5 M for CO WD’s in M These methods are independent of D as long as Vo is known from IR spectra R. D. Gehrz

  9. Radio Free-Free Emission: Light Curves R. D. Gehrz

  10. Ejected Mass from Modeling Radio Data The data are best fit by a “Hubble flow” (V deceases linearly as a function of depth in the ejecta) in an optically thin free-free shell This leads to a   r-3 density distribution from which a shell mass can be determined given D and V(r) R. D. Gehrz

  11. Ejected Gas Mass Determination from IR/Radio Observations: Conclusions Radio and IR observations give ejected masses of ionized gasthat are consistent with one another These masses are lower limits to the true ejected mass These lower limits are substantially larger than the ejected masses predicted by existing theoretical TNR models The potential of Classical Novae for making significant contributions to ISM/Solar System abundances is therefore substantial and may have been underestimated R. D. Gehrz

  12. Physical Parameters from IR/Radio SED’s, Light Curves, and Direct Imaging in arcseconds Angular radii of blackbody photospheres and shells: Distance by blackbody and direct expansion parallaxes: The luminosity of the WD central engine given D: in kpc in L (Note that Lo LEdd ) R. D. Gehrz

  13. SOFIA and Classical Nova Explosions What can SOFIA tell us about the mineralogy of dust produced in Classical Nova Explosions? • Stardust formation, mineralogy, and abundances • SOFIA’s spectral resolution and wavelength coverage is required to study amorphous, crystalline, and hydrocarbon components • Contributions to ISM clouds and the Primitive Solar System QV Vul QV Vul R. D. Gehrz

  14. Dust Condensation in CO Novae Dust Formation in NQ Vul • Tc 1000 K • , where Vo is the • outflow velocity Visual Transition  Lo LEdd = LIR Tc = 1000K R. D. Gehrz (1988, 1990) R. D. Gehrz

  15. Nova Grain Properties Novae produce carbon, SiC, silicates, and hydrocarbons Abundances can be derived from visual opacity, IR opacity, and IR emission feature strength The grains grow to radii of 0.2-0.7m R. D. Gehrz

  16. Amorphous Carbon Grains in the Ejecta of NQ Vul, LW Ser, and V1668 Cyg Gehrz 1988, ARA&A, 26, 377 Iron seems not to be an option based on abundance arguments Gehrz et al. 1984, ApJ, 281, 303 R. D. Gehrz

  17. Carbon and SiC Grains in Nova 1370 Aql (1982) Data from Gehrz et al. 1984, ApJ, 281, 303 R. D. Gehrz

  18. Grain Condensation in V842 Cen (1986) • Amorphous Carbon • Hydrocarbons • Silicates From R. D. Gehrz, 1990, in Physics of Classical Novae, eds. A. Cassatella and R. Viotti, Springer-Verlag: Berlin, p. 138. R. D. Gehrz

  19. Grain Condensation in Nova QV Vul 1987 (1) Carbon, SiC, silicates, and hydro-carbons were produced at different epochs • The fireball and dust shell expansion • rates show velocity gradients as large • as a factor of three R. D. Gehrz

  20. Grain Condensation in Nova QV Vul 1987 (2) • Carbon, Silicates, SiC, and PAH grains formed at different epochs • suggesting abundance gradients in the ejecta. • A. D. Scott (MNRAS, 313, 775-782 (2000)) has shown that this could • be explained by an asymmetric ejection due to a TNR on a rotating WD R. D. Gehrz

  21. Grain Condensation in V705 Cas (1993) • s Free-free, amorphous carbon, silicates, and hydrocarbon UIR emission are required to fit the IR spectrum in detail. There are many variables – constraining data are needed R. D. Gehrz

  22. Modeling the IR SED of V705 Cas (1993) There are many variables – constraining data are needed See C. Mason et al. 1998, ApJ, 494, 783 R. D. Gehrz

  23. Grain Mass, Abundance, and Size in M Mdust from the infrared luminosity of the dust shell: Abundance of the grain condensables is given by: Grain radius from the optical depth of the visual transition and LIR: compared to solar abundance in m (agr 0.2-0.7m) R. D. Gehrz

  24. Comets as the “Rosetta Stone” of the Solar System • They are the remaining “planetesimals” from the epoch of planet formation in the primitive Solar nebula • The material released from comet nuclei during perihelion passage is therefore a sample of the content of this primordial environment • IR imaging photometry and spectroscopy can be used to deduce the composition and physical properties of the gas, dust, and ices present when the planets were forming R. D. Gehrz

  25. Dust and Gas in Regions of Star Formation • The IR spectrum of W33A, a region of star formation, shows an abundance of features from grains, molecular gases, and ices in the 2-40 m spectral region • These materials are the building blocks of comet nuclei and can be identified in the IR emission spectra of comets R. D. Gehrz

  26. Hydrocarbon Dust and Regions of Star Formation R. D. Gehrz

  27. Mineral Dust and Regions of Star Formation "8-13 Micron Maps of the Trapezium Region of the Orion Nebula," R.D. Gehrz, J.A. Hackwell and J.R. Smith, 1975, Ap.J. (Letters), 202, L33. R. D. Gehrz

  28. SOFIA and Comets: Mineral Grains What can SOFIA observations of comets tell us about the origin of the Solar System? ISO Data • Comet dust mineralogy: amorphous, crystalline, and organic constituents • Comparisons with IDPs and meteorites • Comparisons with Stardust • Only SOFIA can make these observations near perihelion Spitzer Data The vertical lines mark features of crystalline Mg-rich crystalline olivine (forsterite) R. D. Gehrz

  29. Comet Grain Properties R. D. Gehrz

  30. Comet Dust and Nova Dust Compared agr  0.7m agr  0.2m Comet Hale-Bopp r = 1.21 AU  TBB = 253K • Both Comet dust and nova dust contain silicates and carbon • Comets have coma emission dominated by grains the size of those produced in nova outflows R. D. Gehrz

  31. Novae and the Primitive Solar System: Interplanetary Dust Particles (IDPs) • IDP’s are composed of sub micron grains within a “Cluster of Grapes” fractal structure tens to hundreds of microns across • IDP sub- grains are similar in structure, size, and composition to nova “stardust” • IDP’s have Carbon, Silicate, and hydrocarbon components seen in nova grains R. D. Gehrz

  32. SOFIA and Comets: Protoplanetary Disks What can SOFIA observations of comets tell us about the origins of our Solar System and other solar systems? ISO Observations — Adapted from Crovisier et al. 1996, Science 275, 1904 and Malfait et al. 1998, A&A 332, 25 Image of Solar System IDP (Interplanetary Dust Particle) Disk System 50 microns ISO Data Solar System Comet • The silicate features in HD 100546 and C/1995 O1Hale-Bopp are well-matched, suggesting that the grains in the stellar disk system and the small grains released from the comet nucleus are similar R. D. Gehrz

  33. SOFIA and Extra-Solar Circumstellar Disks What can SOFIA tell us about circumstellar disks? 850 µm JCMT beam • SOFIA imaging and spectroscopy can resolve disks to trace the evolution of the spatial distribution of the gaseous, solid, and icy gas and grain constituents • SOFIA can shed light on the process of planet formation by studying the temporal evolution of debris disks 53 µm 88µm Debris disk around e Eridanae SOFIA beam sizes R. D. Gehrz

  34. How does the chemistry of disks vary with radius? • High spectral resolution can determine where species reside in the disk; • small radii produce double-peaked, wider lines. • Observing many sources at different ages in this way will trace the disk • chemical evolution R. D. Gehrz

  35. SOFIA and Comets: Gas Phase Constituents What can SOFIA observations of comets tell us about the origin of the Solar System? C. E. Woodward et al. 2007, ApJ, 671, 1065 B. P. Bonev et al. 2007, ApJ, 661, L97 Theory C/2003 K4 Spitzer • Production rates of water and other volatiles • Water H2 ortho/para (parallel/antiparallel) hydrogen spin isomer ratio gives the water formation temperature; a similar analysis can done on spin isomers of CH4 • Only SOFIA can make these observations near perihelion R. D. Gehrz

  36. On the Nature of the Dust in the Debris Disk around HD 69830C. M. Lisse, C. A. Beichman, G. Bryden, and M. C. Wyatt The Astrophysical Journal, 658:584–592, 2007 March 20 Using a robust approach to determine the bulk average mineralogical composition of the dust, we show it to be substantially different from that found for comets 9P/Tempel 1 and C/ Hale-Bopp 1995 O1 or for the comet-dominated YSO HD 100546.Lacking in carbonaceous and ferrous materials but including small icy grains, the composition of the HD 69830 dust most closely resembles that of a disrupted P- or D-type asteroid. R. D. Gehrz

  37. Comet and Debris Disk Grains Compared R. D. Gehrz

  38. Dust and Gas in Regions of Star Formation R. D. Gehrz

  39. SOFIA and Classical Nova Explosions What can SOFIA tell us about gas phase abundances in Classical Nova Explosions? • Gas phase abundances of CNOMgNeAl • Contributions to ISM clouds and the primitive Solar System • Kinematics of the Ejection R. D. Gehrz

  40. Abundances from IR Forbidden Emission Lines Greenhouse et al. 1988, AJ, 95, 172 Gehrz et al. 1985, ApJ, 298, L47 Hayward et al. 1996, ApJ, 469, 854 R. D. Gehrz

  41. Abundance Anomalies in “Neon” Novae ONeMg TNR’s can produce and excavate isotopes of CNO, Ne, Na, Mg, Al, Si, Ca, Ar, and S, etc. that are expelled in their ejecta ONeMg TNR’s are predicted to have highly enhanced 22Na and 26Al abundances in their outflows. These isotopes are implicated in the production of the 22Ne (Ne-E) and 26Mg abundance anomalies in Solar System meteoritic inclusions : 22Ne via: 22Na  22Ne + e + +  (1/2 = 2.7 yr) 26Mg via: 26Al  26Mg + e + +  (1/2 = 7105 yr) R. D. Gehrz

  42. Classical Novae and Abundance Anomalies • Novae process  0.3% of the ISM • (dM/dt)novae 7x10-3 M yr-1 • (dM/dt)supernovae 6x10-2 M yr-1 Gehrz, Truran, and Williams 1993 (PPIII, p. 75) and Gehrz, Truran, Williams, and Starrfield 1997 (PASP, 110, 3) have concluded that novae may affect ISM abundances: Novae may be important on a global Galactic scale if they produce isotopic abundances that are  10 times SN and  100 times Solar; Ejected Masses calculated from IR/Radio methods give a lower limit R. D. Gehrz

  43. Chemical Abundances in Classical Novae from IR Data (1) R. D. Gehrz

  44. Chemical Abundances in Classical Novae from IR Data (2) R. D. Gehrz

  45. Chemical Abundances in Classical Novae from IR Data (3) R. D. Gehrz

  46. Summary and Conclusions IR/Radio data yield quantitative estimates for physical parameters characterizing the nova outburst: D , Lo , Mgas , Tdust , adust , Mdust , Vo , Lo , grain composition, and elemental abundances Nova ejecta produce all known types of astrophysical grains: amorphous carbon, SiC, hydrocarbons, and silicates Classical Nova ejecta have large overabundances (factors of 10 to 100) of CNO, Ne, Mg, Al, S, Si R. D. Gehrz

  47. Summary and Conclusions: Pre-Solar Clouds IR/Radio data show that the mineral composition and size distribution of the “stardust” made by novae are similar to those of the small grains released by comets in the Solar System IR/Radio data confirms theoretical predictions suggesting that nova TNRs can produce ejecta that lead to 22Ne (Ne-E) and 26Mg enhancements such as are seen in meteorites Novae are therefore a potential source for at least some of the solids that were present in the primitive Solar Nebula R. D. Gehrz

  48. Future Research Physical parameters and abundances must be obtained for a larger sample of novae to improve statistics Observations of stellar populations in M33 will be conducted using SIRTF to understand the global galactic contributions of classical novae Further examination of IDPs and meteoritic inclusions should be made to identify pre-solar grains from novae R. D. Gehrz

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