English

Molecular Hydrogen Kinematics in Cepheus A

Astrophysics 2009-11-10 v1

Abstract

We present the radial velocity structure of the molecular hydrogen outflows associated to the star forming region Cepheus A. This structure is derived from doppler shift of the H_2 v=1-0 S(1) emission line obtained by Fabry-Perot spectroscopy. The East and West regions of emission, called Cep A(E) and Cep A(W), show radial velocities in the range -20 to 0 km/s with respect to the molecular cloud. Cep A(W) shows an increasing velocity with position offset from the core indicating the existence of a possible accelarating machanism. Cep A(E) has an almost constant mean radial velocity of -18 km/s along the region although with a large dispersion in velocity, indicating the possibility of a turbulent outflow. A detailed analysis of the Cep A(E) region shows evidence for the presence of a Mach disk on that outflow. Also, we argue that the presence of a velocity gradient in Cep A(W) is indicative of a C-shock in this region. Following Riera et al. (2003), we analyzed the data using wavelet analysis to study the line width and the central radial velocity distributions. We found that both outflows have complex spatial and velocity structures characteristic of a turbulent flow.

Cite

@article{arxiv.astro-ph/0408395,
  title  = {Molecular Hydrogen Kinematics in Cepheus A},
  author = {David Hiriart and Luis Salas and Irene Cruz-Gonzalez},
  journal= {arXiv preprint arXiv:astro-ph/0408395},
  year   = {2009}
}

Comments

24 pages, 15 figures

R2 v1 2026-07-22T08:41:39.533Z