slide1 n.
Download
Skip this Video
Download Presentation
Outline

Loading in 2 Seconds...

play fullscreen
1 / 32

Outline - PowerPoint PPT Presentation


  • 66 Views
  • Uploaded on

Outline. Introducing thermonuclear supernovae. Scales: time, space & physics . Many sins of turbulent deflagrations. Foreplay counts: forgotten tale of the ICs. Detonating Failed Deflagrations. Confronting DFD with observations. Summary. What Are Supernovae?. Massive and Even More Massive.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Outline' - vaschel


Download Now 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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide2

Outline

Introducing thermonuclear supernovae

Scales: time, space & physics

Many sins of turbulent deflagrations

Foreplay counts: forgotten tale of the ICs

Detonating Failed Deflagrations

Confronting DFD with observations

Summary

slide4

Massive and Even More Massive

Type II

Massive

Single

H-rich

Type Ia

Medium mass

Binary

H/He-free

slide5

Type Ia SN Appearance

P. Nugent (LBNL)

slide6

Why Do We Care?

  • SN Ia are crucial for galactic chemical evolution.
  • SN Ia are also crucial for cosmology: probes allowing study of expansion and geometry (M, ) of the Universe, nature of dark energy
  • Provide astrophysical setting for basic combustion problems.

COBE

High-Z Supernova Search Team, HST

slide7

40 Years of Theory

1960s

  • WD explosion proposed for Type Ia (Hoyle & Fowler)
  • 1D detonation model (Arnett)

1970s

  • detonation models (several groups)
  • deflagration models (Nomoto)

1980s

  • improved 1-D deflagration models (Nomoto)
  • first 2-D deflagration model (Mueller & Arnett)

1990s

  • 2-D and 3-D deflagration models, DDT (Khokhlov)
  • non-standard models 2-D He detonations (Livne & Arnett)
  • small scale flame turbulence (Niemeyer & Hillebrandt)

2000s

  • 3-D deflagration models (NRL, MPA, Barcelona, Chicago)
  • 3-D DDT models (NRL)
slide8

Problem Parameters

Channels for progenitors

  • Binary evolution
  • Population synthesis

Initial conditions

  • State of the stellar core
  • Metallicity
  • Rotation profile
  • Magnetic fields

Basic physics

  • Flame on intermediate scales
  • Unsteadiness
  • DDT

Numerics

  • Multiphysics coupling
  • Nucleosynthesis postprocessing

R. Hynes

INCITE 2004

F. Timmes

Zhang et al. (2006)

Khokhlov (2003)

slide9

Explosive Stage of SN Ia

102/4-7 cm

mild

ignition

1010 seconds

deeply subsonic,

Ma ~ 10-4

10-3/5-8 cm

few seconds

deflagration

subsonic: Ma ~ 0.3

101/5-8 cm

detonation

0.5 second

compressible: Ma ~ 2

slide11

RT-driven Turbulence

Zhang et al. (2006)

slide12

Major Sins of Classic Central Deflagrations

1. Uniformly mixed ejecta, unburned low-velocity carbon

2. Explosion energies too low, need ~50% more burning

3. Initial conditions either too idealized or defined ad hoc

4. Large Ni-rich structures visible at maximum light

5. Insufficient production of intermediate mass elements

slide13

Central Ignition Whole Star Model

INCITE 2004

  • Two models, 255,000 SUs and 5TB of data per model, 8 km resolution
slide14

Ejecta Composition: Pure Deflagrations

  • Ni

C/O

  • Si
  • Mg

Gamezo et al. (2003)

Reinecke et al. (2002)

Roepke et al. (2005)

Garcia-Senz & Bravo (2004)

slide15

Stratification, Energy: Speculative DDT

  • 3-D pure deflagration
  • 3-D speculative DDT

Gamezo et al. (2003)

slide16

Initial Conditions

Garcia-Senz & Woosley (1995)

Hoeflich & Stein (2002)

Kuhlen, Woosley, & Glatzmeier (2005)

slide17

Single Bubble, Three Different Methods…

2-D

2-D

Livne, Asida, & Hoeflich (2005)

3-D

Niemeyer, Hillebrandt, & Woosley (1996)

…and virtually the same result!

Calder et al. (2004)

slide18

Initial Conditions: Location, Velocity Field

r1y100v100a3030in (inflowing, 100 km/s)

INCITE 2004

slide19

Initial Conditions: Conclusion

Garcia-Senz & Woosley (1995)

Hoeflich & Stein (2002)

Woosley, Wunsch, & Kuhlen (2004)

Calder et al. (2004)

Livne, Asida, & Hoeflich (2005)

Kuehlen, Woosley, & Glatzmeier (2005)

Based on analytic, semi-analytic, and numerical models, the most likely outcome of a mild ignition is

the off-center deflagration.

slide24

Model Validation – Radiative Transfer

Kasen, Thomas, & Nugent (2006): Multi-dimensional time-dependent Monte Carlo radiative transfer

slide25

Model Validation – Radiative Transfer

Kasen, Thomas, & Nugent (2006): Multi-dimensional time-dependent Monte Carlo radiative transfer

slide26

Overall Spectrum Shape

DFD at 18 days vs. SN1981B at maximum light.

slide28

Velocity Evolution

Orientation effects

controlled by the deflagration

phase in the DFD model

Benetti et al. (2005)

slide30

GCD Spectral Signatures

Kasen & Plewa (2005)

slide31

Tycho SNR Iron Distribution

FS

RS

???

Warren et al. (2005)

slide32

Summary

  • Detonating Failed Deflagration
    • displays several main characteristics of observed objects
    • energetics, light curves, spectra/spectral features
    • emphasized importance of the initial conditions
    • detonation in unconfined environment
    • natural chain of events, not by-hand, but from first principles
    • Extremely rare case in theoretical astrophysics!

To be continued!