Magnetohydrodynamic Simulations of a Plunging Black Hole into a Molecular Cloud

Mariko Nomura, Tomoharu Oka, Masaya Yamada, Shunya Takekawa, Ken Ohsuga, Hiroyuki R. Takahashi, Yuta Asahina

Research output: Contribution to journalArticle

3 Citations (Scopus)


Using two-dimensional magnetohydrodynamic simulations, we investigated the gas dynamics around a black hole (BH) plunging into a molecular cloud. In these calculations, we assumed a parallel-magnetic-field layer in the cloud. The size of the accelerated region is far larger than the Bondi-Hoyle-Lyttleton radius, being approximately inversely proportional to the Alfvén Mach number for the plunging BH. Our results successfully reproduce the "Y" shape in position-velocity maps of the "Bullet" in the W44 molecular cloud. The size of the Bullet is also reproduced within an order of magnitude using a reasonable parameter set. This consistency supports the shooting model of the Bullet, according to which an isolated BH plunged into a molecular cloud to form a compact broad-velocity-width feature.

Original languageEnglish
Article number29
JournalAstrophysical Journal
Issue number1
Publication statusPublished - 2018 May 20



  • ISM: clouds
  • ISM: kinematics and dynamics
  • magnetohydrodynamics (MHD)
  • methods: numerical

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Nomura, M., Oka, T., Yamada, M., Takekawa, S., Ohsuga, K., Takahashi, H. R., & Asahina, Y. (2018). Magnetohydrodynamic Simulations of a Plunging Black Hole into a Molecular Cloud. Astrophysical Journal, 859(1), [29].