"Distance mapping" and the 3-D structure of BB +30 3639

Дата и время публикации : 2012-03-15T21:38:17Z

Авторы публикации и институты :
S. Akras
W. Steffen

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 11 pages, 12 figures, 1 table, Accepted to MNRAS
Первичная категория: astro-ph.SR

Все категории : astro-ph.SR, astro-ph.GA

Краткий обзор статьи: BD +30 3639 is a member of a group of uncommon planetary nebula with Wolf-Rayet central star and higher expansion velocities in [O III] than in [N II] lines. Images and high-resolution spectra from the literature are used in order to construct a 3-D model of the nebula using the morpho-kinematic code SHAPE. We find that two homologous expansion laws are needed for the [N II] and [O III] shell. We conclude that the internal velocity field of BD +30 3639 decreases with the distance from the central star at least between the [O III] and [N II] shells. A cylindrical velocity component is used to replicate the high-speed bipolar collimated outflows. We also present a new kinematic analysis technique called "distance mapping". It uses the observed proper motion vectors and the 3-D velocity field to generate maps that can be used as a constraint to the morpho-kinematic modeling with SHAPE as well as improve the accuracy for distance determination. It is applied to BD+30 3639 using 178 internal proper motion vectors from Li et al. (2002) and our 3-D velocity field to determine a distance of 1.52 pm 0.21 kpc. Finally, we find evidence for an interaction between the eastern part of nebula and the ambient H2 molecular gas.

Category: Physics