One-armed Spiral Instability in a Low- T /| W | Postbounce Supernova Core

2005 ◽  
Vol 625 (2) ◽  
pp. L119-L122 ◽  
Author(s):  
Christian D. Ott ◽  
Shangli Ou ◽  
Joel E. Tohline ◽  
Adam Burrows
Keyword(s):  
Spiral Instability ◽  
Armed Spiral

scholarly journals One‐armed Spiral Instability in Differentially Rotating Stars

2003 ◽  
Vol 595 (1) ◽  
pp. 352-364 ◽  
Author(s):  
Motoyuki Saijo ◽  
Thomas W. Baumgarte ◽  
Stuart L. Shapiro
Keyword(s):  
Rotating Stars ◽  
Spiral Instability ◽  
Armed Spiral

scholarly journals One-armed Spiral Instability in Double-degenerate Post-merger Accretion Disks

2017 ◽  
Vol 840 (1) ◽  
pp. 16 ◽  
Author(s):  
Rahul Kashyap ◽  
Robert Fisher ◽  
Enrique García-Berro ◽  
Gabriela Aznar-Siguán ◽  
Suoqing Ji ◽  
...  
Keyword(s):  
Accretion Disks ◽  
Spiral Instability ◽  
Armed Spiral

scholarly journals The Ballistic Particle Model

1983 ◽  
Vol 100 ◽  
pp. 133-134
Author(s):  
Frank N. Bash
Keyword(s):  
Radial Velocity ◽  
Gravitational Potential ◽  
Molecular Clouds ◽  
Milky Way ◽  
Terminal Velocity ◽  
Particle Model ◽  
The Sun ◽  
Giant Molecular Clouds ◽  
Spiral Pattern ◽  
Armed Spiral

Bash and Peters (1976) suggested that giant molecular clouds (GMC's) can be viewed as ballistic particles launched from the two-armed spiral-shock (TASS) wave with orbits influenced only by the overall galactic gravitational potential perturbed by the spiral gravitational potential in the arms. For GMC's in the Milky Way, the model predicts that the radial velocity observed from the Sun increases with age (time since launch). We showed that the terminal velocity of CO observed from l ≃ 30° to l ≃ 60° can be understood if all GMC's are born in the spiral pattern given by Yuan (1969) and live 30 × 106 yrs. Older GMC's were predicted to have radial velocities which exceed observed terminal velocities.

THE EFFECTS OF DIFFERENT PERTURBATIONS ON THE DYNAMICS OF THE ACCRETION DISK AROUND THE BLACK HOLE

2007 ◽  
Vol 22 (10) ◽  
pp. 1875-1898 ◽  
Author(s):  
ORHAN DÖNMEZ
Keyword(s):  
Shock Wave ◽  
Black Hole ◽  
Shock Waves ◽  
Accretion Disk ◽  
Periodic Oscillation ◽  
Single Star ◽  
Special Cases ◽  
Galactic Black Hole ◽  
General Relativistic ◽  
Armed Spiral

We investigate the special cases of the formation of shocks in the accretion disks around the nonrotating (Schwarzschild) black holes in cases where one or few stars perturb the disk. We model the structure of disk with a 2D fully general relativistic hydrodynamic code and investigate a variety of cases in which the stars interacting with the disk are captured at various locations. We have found the following results: (1) if the stars perturb the disk at nonsymmetric locations, a moving one-armed spiral shock wave is produced and it destroys the disk eventually; (2) if the disk is perturbed by a single star located close to the black hole, a standing shock wave is produced while the disk becomes an accretion tori; (3) if the disk is perturbed by stars at symmetric locations, moving two-armed spiral shock waves are produced while the disk reaches a steady state; (4) continuous injection of matter into the stable disk produces a standing shock wave behind the black hole. Our outcomes reinforce the view that different perturbations on the stable accretion disk carry out different types of shock waves which produce Quasi-Periodic Oscillation (QPO) phenomena in galactic black hole candidates and it is observed as a X-ray.

scholarly journals How Massive is the Black Hole in M87?

1995 ◽  
Vol 10 ◽  
pp. 535-538
Author(s):  
S.K. Chakrabarti
Keyword(s):  
Black Hole ◽  
Dwarf Galaxy ◽  
Hubble Space Telescope ◽  
Elliptical Galaxy ◽  
Wide Field ◽  
Line Profiles ◽  
Present Contribution ◽  
Doppler Shifts ◽  
Spiral Structures ◽  
Armed Spiral

Using the Faint Object Spectrograph (FOS) on Hubble Space Telescope (HST), Harms et al. (1994, H94) have recently reported the spectroscopy of central region of the elliptical galaxy M87. Ford et al. 1994 (hereafter F94), using Wide Field Planetary Camera-2 have imaged the region around the nucleus in Hα+[NII] and find an ionized disk with spiral structures of mainly two arms. From the kinematical argument, based on the Doppler shifts of several lines emitted from the disk, and assuming a Keplerian motion of the emitting gas, they conclude that the mass of the disk plus the nucleus: Mc(R < 18pc) = (2.4± 0.7)× 109M⊙ and the inclination angle of the disk with the line of sight is i = (42±5)°. However, if the bright spiral structures are real, and represent shocked region in the disk, we expect that the disk is strongly non-Keplerian and therefore the mass of the black hole must be higher than above estimation.In the present contribution, we provide a complete description of the velocity field of the ionized disk and compute the shape of typical line profiles expected from various parts of the disk. Our analysis is based on the solution of a non-axisymmetric disk which includes two armed spiral density waves. We find a very good agreement between the theoretical and observed line profiles as regards to the Doppler shifts, line widths and the intensity ratios and estimate the mass of the black hole to be (4 ± 0.2) × 109M⊙. Details of this work will be published elsewhere (Chakrabarti, 1995).In a binary system with a thin accretion disk, the binary companion can induce two armed spiral shocks in the disk (e.g., Matsuda et al. 1987, Spruit 1987, Chakrabarti & Matsuda, 1992). In the case of active galaxies, a passing companion (or a globular cluster or a dwarf galaxy) which is more massive than the disk can induce the same effect.

NGC 4378's one-armed spiral pattern: Leading or trailing?

1994 ◽  
Vol 108 ◽  
pp. 2078 ◽  
Author(s):  
Gene Byrd ◽  
Tarsh Freeman ◽  
Sethanne Howard
Keyword(s):  
Spiral Pattern ◽  
Armed Spiral

NGC 4027 - an interacting one-armed spiral galaxy with a warped ring

1992 ◽  
Vol 400 ◽  
pp. 516 ◽  
Author(s):  
Bikram Phookun ◽  
Lee G. Mundy ◽  
Peter J. Teuben ◽  
Richard J. Wainscoat
Keyword(s):  
Spiral Galaxy ◽  
Armed Spiral
Sign in / Sign up

Export Citation Format

Share Document