J/A+A/679/A154 Spiral shocks induced in galactic gaseous disk (Aktar+, 2023)
Spiral shocks induced in a galactic gaseous disk:
Hydrodynamic understanding of observational properties of spiral galaxies.
Aktar R., Xue L., Zhang L.-X., Luo J.-Y.
<Astron. Astrophys., 679, A154 (2023)>
=2023A&A...679A.154A 2023A&A...679A.154A (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Models
Keywords: Galaxy: disk - galaxies: spiral - galaxies: star formation -
shock waves
Abstract:
We investigate the properties of spiral shocks in a steady, adiabatic,
non-axisymmetric, self-gravitating, mass-outflowing accretion disk
around a compact object.
We obtained the accretion-ejection solutions in a galactic disk and
applied them to spiral galaxies in order to investigate the possible
physical connections between some observational quantities of
galaxies.
We considered the self-gravitating disk potential to examine the
properties of the galactic gaseous disk. We obtained spiral
shock-induced accretion-ejection solutions following the point-wise
self-similar approach.
We observed that the self-gravitating disk profoundly affects the
dynamics of the spiral structure of the disk and the properties of the
spiral shocks. We find that the observational dispersion between the
pitch angle and shear rate and between the pitch angle and star
formation rate in spiral galaxies contains some important physical
information.
There are large differences among the star formation rates of galaxies
with similar pitch angles. These differences may be explained by the
different star formation efficiencies caused by distinct galactic
ambient conditions.
Description:
We considered a steady, adiabatic, non-axisymmetric accretion flow
around a compact star. We assumed that the effect of gravity on the
accretion disk is significant enough compared to the central object.
Therefore, we consider a self-gravitating disk in this paper. We also
adopted the spiral shock model proposed by Chakrabarti
(1990ApJ...361..406C 1990ApJ...361..406C). In this work, we simultaneously solve the
radial and the azimuthal components of momentum equations, and we
assume that the accretion flow is in vertical hydrostatic equilibrium
throughout the disk.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 131 79 Parameters for spiral galaxy
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Galaxy name
15- 18 F4.1 deg theta Observational pitch angle
20- 23 F4.2 --- GAMMA Observational shear rate
25 I1 --- ns Observational number of spiral shocks
27- 32 F6.2 km/s VK(rmid) Observational local Keplerian velocity
at mid radial distance
34- 38 F5.2 kpc rmid Observational mid radial distance of the disk
40- 45 F6.4 --- k Theoretical value of k
47- 52 F6.4 --- q2cm Theoretical rotational velocity at the
sonic point for minimal values
54- 59 F6.4 --- qrhocm Theoretical density at the sonic point
for minimal values
61- 66 F6.4 --- q2-m Theoretical pre-shock rotational velocity
for minimal values
68- 73 F6.4 --- q2+m Theoretical post-shock rotational velocity
for minimal values
75- 80 F6.4 Msun/yr SFRmin Theoretically estimated minimum
star formation rate
82- 88 F7.5 --- q2cM Theoretical rotational velocity at the sonic
point for maximal value
90- 96 F7.5 --- qrhocM Theoretical density at the sonic point
for maximal value
98-104 F7.5 --- q2-M Theoretical pre-shock rotational velocity
for maximal value
106-111 F6.4 --- q2+M Theoretical post-shock rotational velocity
for maximal value
113-120 F8.5 Msun/yr SFRmax Theoretically estimated maximum
star formation rate
122-126 F5.2 Msun/yr SFRObs ?=- Observed star formation rate
128-131 F4.2 Msun/yr e_SFRObs ? Observed star formation rate error
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 08-Apr-2024