J/ApJ/785/63 Rotation curve of the Milky Way (Bhattacharjee+, 2014)
Rotation curve of the Milky Way out to ∼200 kpc.
Bhattacharjee P., Chaudhury S., Kundu S.
<Astrophys. J., 785, 63 (2014)>
=2014ApJ...785...63B 2014ApJ...785...63B (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Galaxies, rotation ; Stars, distances ;
Rotational velocities
Keywords: dark matter - Galaxy: general - Galaxy: kinematics and dynamics
Abstract:
The rotation curve (RC) of our Galaxy, the Milky Way, is constructed
starting from its very inner regions (few hundred parsecs) out to a
large galactocentric distance of ∼200 kpc using kinematical data on a
variety of tracer objects moving in the gravitational potential of the
Galaxy, without assuming any theoretical models of the visible and
dark matter (DM) components of the Galaxy. We study the effect on the
RC due to the uncertainties in the values of the Galactic constants
(GCs) R0 and V0 (these being the Sun's distance from and circular
rotation speed around the Galactic center, respectively) and the
velocity anisotropy parameter β of the halo tracer objects used
for deriving the RC at large galactocentric distances. The resulting
RC in the disk region is found to depend significantly on the choice
of the GCs, while the dominant uncertainty in the RC at large
distances beyond the stellar disk comes from the uncertainty in the
value of β. In general we find that the mean RC steadily declines
at distances beyond ∼60 kpc, independently of the value of β.
Also, at a given radius, the circular speed is lower for larger values
of β (i.e., for more radially biased velocity anisotropy).
Considering that the largest possible value of β is unity, which
corresponds to stellar orbits being purely radial, our results for the
case of β=1 give a lower limit to the total mass of the Galaxy
within ∼200 kpc, M(200 kpc)≳(6.8±4.1)x1011 M☉,
independently of any model of the DM halo of the Galaxy.
Description:
In this paper, we consider a combination of currently available large
samples of a variety of both disk and non-disk tracers to construct
the rotation curve (RC) of the Galaxy from ∼0.2 kpc to ∼200 kpc.
We perform a detailed analysis of the dependence of the RC on the
choice of the Galactic constants (GCs) and also the dependence on the
anisotropy parameter β of the non-disk tracers.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 28 151 Rotation Curve of the Milky Way
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See also:
VII/70 : Galaxies Rotation Curves (Baiesi-Pillastrini+ 1983)
J/A+A/275/67 : Velocity Field of the outer Galaxy (Brand+ 1993)
J/AJ/139/59 : Milky Way halo velocity dispersion profile (Brown+, 2010)
J/ApJ/714/1170 : Faraday rotation at high Galactic latitude (Mao+, 2010)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 F3.1 kpc R0 Sun's distance from Galactic center
5- 7 I3 km/s V0 Sun's circular rotation velocity around Galactic
center
9- 14 F6.2 kpc r Distance from Galactic center
16- 21 F6.2 km/s Vc Circular velocity
23- 28 F6.2 km/s e_Vc The 1-σ error in Vc
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 28-Jun-2017