1 / 35

Departures from Axisymmetry in PNe and SN1987A

Departures from Axisymmetry in PNe and SN1987A. M. Bobrowsky. Axisymmetry is well known. (It forms in the last part of the superwind phase -- e.g., see poster by Speck & Dijkstra) Classifications and correlations done by: Balick 1987, 2007 (APN4) Corradi & Schwarz 1995

bluma
Download Presentation

Departures from Axisymmetry in PNe and SN1987A

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Departures from Axisymmetry in PNe and SN1987A M. Bobrowsky

  2. Axisymmetry is well known. (It forms in the last part of the superwind phase -- e.g., see poster by Speck & Dijkstra) Classifications and correlations done by: Balick 1987, 2007 (APN4) Corradi & Schwarz 1995 Manchado et al. 1996, 2000 Sahai et al. 2007 Schwarz, Corradi, & Stanghellini 1992 Shaw et al. 2001 Stanghellini et al. 1999, 2000, 2002

  3. Classification of deviations from axisymmetry • Soker & Hadar (2002) considered several types of departure from axisymmetry • Limited mainly to departures in the equatorial plane

  4. Cause of departure — external or internal External (e.g., interaction with the ISM) Observations: Jacoby 1981; Tweedy & Kwitter 1994, 1996;Xilouris et al. 1996; Kerber et al. 2000, 2001; Muthu, Anandarao & Pottasch 2000, Rauch et al. 2000; Martin, Xilouris & Soker 2002 Theory: Borkowski, Sarazin, & Soker 1990; Soker, Borkowski, & Sarazin 1991; Villaver, Manchado, & Garcia-Segura 2000;Villaver, Garcia-Segura, & Manchado 2003; Villaver, Garcia-Segura, & Manchado 2003; Dgani & Soker 1998; see Dgani 2000 for a review

  5. InternalDeparture (e.g., binary companion) Observations Soker, Rappaport, & Harpaz 1998; Soker 1994, 1999 Theory: Sahai 2000; Miranda et al. 2001; Miranda, Guerrero, & Torrelles 2001

  6. About 50% of all PNe in Soker and Hadar’s sample havelarge-scale departure (compared to a 25-30% incidence of binaries). In the present work, 58% were found to have a departure from axisymmetry.

  7. Questions to Answer • What can we learn from the departures from axisymmetry? • Can departures be generalized to other objects?

  8. Types of Departure

  9. Types of Departure • Displacement of the Central Star

  10. IC 418 (Also see poster by Morisset & Georgiev)

  11. MyCn 18

  12. MyCn 18

  13. Hen 3-1357 (The Stingray Nebula)

  14. Central Star Displacement in the Stingray Nebula R/R~10% Assume: age = 104 yr, mass of companion = 1 Msun, and mass of central star = 1 Msun before losing mass. --> orbital period = 7.3  104 yr Distance of central star from CM of system = 1100 AU Orbital velocity = 0.5 km s-1 --> During nebular formation, star moved 1/8 of a circle in its orbit -- approximately 45˚.

  15. SN 1987A

  16. Types of Departure • Displacement of the central star

  17. Types of Departure • Displacement of the central star • Unequal size and shape of two sides

  18. IRAS 16268-4556 = Hen 2-166

  19. IRAS 20119+2924 = Hen 2-459

  20. Types of Departure • Displacement of the central star • Unequal size and shape of two sides

  21. Types of Departure • Displacement of the central star • Unequal size and shape of two sides • Bent planetary nebulae

  22. IRAS 16409-1851 = Hen 2-180

  23. IRAS 16409-1851 = Hen 2-180

  24. NGC 6886

  25. Types of Departure • Displacement of the central star • Unequal size and shape of two sides • Bent planetary nebulae

  26. Types of Departure • Displacement of the central star • Unequal size and shape of two sides • Bent planetary nebulae • Different lobe structures

  27. IRAS 21282+5050 =J900

  28. PK 130-11˚1

  29. Why different structures? • Instabilities in outer lobes when a fast wind interacts with jets? (See poster by Akashi, Soker, & Blondin.) • Fragmentation of explosively launched clumps? (See poster by Dennis, Cunningham, Frank, Balick, & Mitran.) • Other possibilities?

  30. Podsiadlowski & Cumming 1994

  31. SN 1987A Model Morris & Podsiadlowski 2007, Science, 315, 1103 Podsiadlowski 2007, APN4

  32. How to explain the additional 2 km sec-1 velocity? Possibilities include: • a non-radial pulsational mode excited during the early spiral-in phase • orbital motion caused by a more distant low-mass third star in the system

  33. Conclusions • Departures from axisymmetry are significant and measurable. • Orbital motion can give expelled mass additional velocity in the direction of orbital motion. • Prospects for the Future: Generalize to other types of objects? Possibly, but use caution!

More Related