Second Core Formation and High Speed Jets: Resistive MHD Nested Grid Simulations

Details Second Core Formation and High Speed Jets: Resistive MHD Nested Grid Simulations Second Core Formation and High Speed Jets: Resistive MHD Nested Grid Simulations

2006-03-17

arxiv.org/abs/astro-ph/0603456v1

Astrophys.J.647:L151-L154,2006

Astronomy and Astrophysics

Astrophysics

12 pages, 3 figures, Submitted to ApJL, For high resolution figures see http://www2.scphys.kyoto-u.ac.jp/~machidam/diffusion

Scientific paper

10.1086/507179

The stellar core formation and high speed jets driven by the formed core are studied by using three-dimensional resistive MHD nested grid simulations. Starting with a Bonnor-Ebert isothermal cloud rotating in a uniform magnetic field, we calculate the cloud evolution from the molecular cloud core (n = 10^6 cm^-3, r_c = 4.6 times 10^4 AU) to the stellar core (n \simeq 10^23 cm^-3, r_c \simeq 1 solar radius). We resolve cloud structure over 7 orders of magnitude in spatial extent and over 17 orders of magnitude in density contrast. For comparison, we calculate two models: resistive and ideal MHD models. Both models have the same initial condition, but the former includes dissipation process of magnetic field while the latter does not. The magnetic fluxes in resistive MHD model are extracted from the first core during 10^12 cm^-3 < n < 10^16 cm^-3 by Ohmic dissipation. Magnetic flux density of the formed stellar core (n \simeq 10^20 cm^-3) in resistive MHD model is two orders of magnitude smaller than that in ideal MHD model. Since magnetic braking is less effective in resistive MHD model, rapidly rotating stellar core (the second core) is formed. After stellar core formation, the magnetic field of the core is largely amplified both by magneto-rotational instability and the shearing motion between the stellar core and ambient medium. As a consequence, high speed (simeq 45 km,s^-1) jets are driven by the second core, which results in strong mass ejection. A cocoon-like structure around the second core also forms with clear bow shocks.

Affiliated with

Also associated with

No associations

Rating

Second Core Formation and High Speed Jets: Resistive MHD Nested Grid Simulations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Second Core Formation and High Speed Jets: Resistive MHD Nested Grid Simulations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Second Core Formation and High Speed Jets: Resistive MHD Nested Grid Simulations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-79869