J/ApJ/885/87 Milky Way mass model and rotation curve (McGaugh, 2019)
The Imprint of Spiral Arms on the Galactic Rotation Curve.
McGaugh S.S.
<Astrophys. J., 885, 87 (2019)>
=2019ApJ...885...87M 2019ApJ...885...87M
ADC_Keywords: Models; Milky Way; Galaxies, rotation
Keywords: Galaxy kinematics ; Milky Way dynamics ; Gravitation ;
Milky Way dark matter halo ; the Milky Way ; Milky Way disk ;
Milky Way mass ; Milky Way rotation
Abstract:
We discuss a model for the Milky Way obtained by fitting the observed
terminal velocities with the radial acceleration relation. The
resulting stellar surface density profile departs from a smooth
exponential disk, having bumps and wiggles that correspond to massive
spiral arms. These features are used to estimate the term for the
logarithmic density gradient in the Jeans equation, which turn out to
have exactly the right location and amplitude to reconcile the
apparent discrepancy between the stellar rotation curve and that of
the interstellar gas. This model also predicts a gradually declining
rotation curve outside the solar circle with slope -1.7km/s/kpc, as
subsequently observed.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 65 78 Milky Way mass model
table3.dat 38 38 Jeans term and rotation curve
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/ApJ/827/L19 : Central surface densities in SPARC disk galaxies (Lelli+, 2016)
J/ApJ/831/124 : Milky Way kinematics. II. (McClure-Griffiths+, 2016)
J/ApJ/816/42 : Mass models for the Milky Way (McGaugh, 2016)
J/MNRAS/486/2995 : GD-1 stellar stream (Malhan+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 F8.4 kpc Rad Galaxy model radius
10- 17 F8.4 km/s Vbulge Circular speed of bulge gravitational potential
19- 26 F8.4 km/s Vgas Circular speed of gas gravitational potential
28- 34 F7.3 km/s Vdisk Circular speed of disk gravitational potential
36- 42 F7.3 km/s Vc Circular speed of model gravitational potential
(1)
44- 51 F8.2 Msun/pc2 Sbulge Surface Density of the bulge
53- 58 F6.2 Msun/pc2 Sdisk Surface Density of the disk
60- 65 F6.3 Msun/pc2 Sgas Surface Density of gas
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Note (1): All mass components.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 F5.2 kpc Rad Galaxy Radius
7- 11 F5.2 [-] dSdR logarithmic density gradient
13- 15 F3.1 [-] E_dSdR Upper error in dSdR
17- 19 F3.1 [-] e_dSdR Lower error in dSdR
21- 26 F6.2 km/s Vcc Circular speed
28- 32 F5.2 km/s E_Vcc Upper error in Vcc
34- 38 F5.2 km/s e_Vcc Lower error in Vcc
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 13-Sep-2021