TY - JOUR
T1 - Spiral shocks and accretion in discs
AU - Spruit, H. C.
AU - Matsuda, T.
AU - Inoue, M.
AU - Sawada, K.
N1 - Funding Information:
A part of this work was supported by grant-in-aid for scientific research No. 61540183 of the Ministry of Education and Culture in Japan. The numerical simulations were performed on the VP200 at the data processing centre of Kyoto university and on the VP50 at the Nobeyama radio observatory. TM would like to thank them. HS thanks Dr F. Meyer for comments on the manuscript.
Publisher Copyright:
© Royal Astronomical Society • Provided by the NASA Astrophysics Data System
PY - 1987/12
Y1 - 1987/12
N2 - Recent numerical and analytical results on disc-like accretion with shock waves as the only dissipation mechanism are compared. The global properties of the process are similar to those of the viscous (α) disc model, but precise values of the effective α value as a function of the accretion rate can be calculated. At low values of the ratio of specific heats (γ<1.45) accretion is possible without radiative losses. Such adiabatic accretion can occur in practice at high accretion rates on to low mass objects and may be important in the formation of planets. Following Donner, and Lynden-Bell, it is pointed out that non-axisymmetric perturbations in the outer parts of a disc increase in amplitude as they propagate in and cause spiral shocks more easily in a disc than perturbations originating in the inner parts. It is suggested for this reason that the cause of spiral structure in normal spiral galaxies lies in moderate non-axisymmetries in their gaseous outer discs.
AB - Recent numerical and analytical results on disc-like accretion with shock waves as the only dissipation mechanism are compared. The global properties of the process are similar to those of the viscous (α) disc model, but precise values of the effective α value as a function of the accretion rate can be calculated. At low values of the ratio of specific heats (γ<1.45) accretion is possible without radiative losses. Such adiabatic accretion can occur in practice at high accretion rates on to low mass objects and may be important in the formation of planets. Following Donner, and Lynden-Bell, it is pointed out that non-axisymmetric perturbations in the outer parts of a disc increase in amplitude as they propagate in and cause spiral shocks more easily in a disc than perturbations originating in the inner parts. It is suggested for this reason that the cause of spiral structure in normal spiral galaxies lies in moderate non-axisymmetries in their gaseous outer discs.
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U2 - 10.1093/mnras/229.4.517
DO - 10.1093/mnras/229.4.517
M3 - Article
AN - SCOPUS:84941459627
SN - 0035-8711
VL - 229
SP - 517
EP - 527
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -