Lien 
vers le site de l'ENS
ÉCOLE NORMALE SUPÉRIEUREPARIS
Lien vers l'accueil
lancer la recherche

» Conférences d’après mars 2011 : nouveau site

2771

Séminaire MHD (SEMHD)

< précédent | suivant >

Reduced Models of Accretion Disks
Pierre Lesaffre (ENS/LERMA)

8 février 2010

Dwarf novae are white-dwarf stars whose luminosity is highly variable over time scales ranging from days to weeks. This bursting behavior is thought to arise from an instability of the accretion disk surrounding the white dwarf. I present the assumptions which lie under the classical "Disk Instability Model" (DIM), which remains the standard model used to interpret the observations of such stars. I stress how features of the bursts can help us put constraint on the transport mechanisms in the disk. I then detail two of my attempts to validate / improve the assumptions of the DIM. To that purpose, I present shearing box simulations of magnetised disks with simplified thermal properties. I then derive reduced models of these simulations and show how they can relate to the DIM.
Bibliography:
Lesaffre P., Balbus S.A., Latter H.N. "A comparison of local simulations and reduced models of MRI-induced turbulence", MNRAS 396 (2009), 779.

Écouter
pictogrammeformat audio mp3 - 24.14 Mo

- Visualiser
- Télécharger
pictogrammeformat quicktime mov, vidéo à la demande / streaming

Télécharger
pictogrammeFormat pdf - 2.07 Mo

Pierre Lesaffre Pierre Lesaffre (ENS/LERMA)

En savoir plus

Site officiel du sminaire SEMHD

Autres conférences

en physique