J/A+A/621/A48 Gaia-DR2 extended kinematical maps. I. (Lopez-Corredoira+, 2019)
Gaia-DR2 extended kinematical maps.
I. Method and application.
Lopez-Corredoira M., Sylos Labini F.
<Astron. Astrophys. 621, A48 (2019)>
=2019A&A...621A..48L 2019A&A...621A..48L (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Radial velocities ; Velocity dispersion
Keywords: Galaxy: kinematics and dynamics - Galaxy: disk
Abstract:
The Gaia Collaboration has used Gaia-DR2 sources with six-dimensional
(6D) phase space information to derive kinematical maps within 5kpc
of the Sun, which is a reachable range for stars with relative error
in distance lower than 20%.
Here we aim to extend the range of distances by a factor of two to
three, thus adding the range of Galactocentric distances between 13kpc
and 20kpc to the previous maps, with their corresponding error and
root mean square values.
We make use of the whole sample of stars of Gaia-DR2 including radial
velocity measurements, which consists in more than seven million
sources, and we apply a statistical deconvolution of the parallax
errors based on the Lucy's inversion method of the Fredholm integral
equations of the first kind, without assuming any prior.
The new extended maps provide lots of new and corroborated information
about the disk kinematics: significant departures of circularity in
the mean orbits with radial Galactocentric velocities between -20 and
+20km/s and vertical velocities between -10 and +10km/s; variations of
the azimuthal velocity with position; asymmetries between the northern
and the southern Galactic hemispheres, especially towards the
anticenter that includes a larger azimuthal velocity in the south; and
others.
These extended kinematical maps can be used to investigate the
different dynamical models of our Galaxy, and we will present our own
analyses in the forthcoming second part of this paper. At present, it
is evident that the Milky Way is far from a simple stationary
configuration in rotational equilibrium, but is characterized by
streaming motions in all velocity components with conspicuous velocity
gradients.
Description:
We use here the data of the second Gaia data release (Gaia DR2; Gaia
Collaboration 2018, Cat. I/345) for the stars with available radial
heliocentric velocities: 7224631 sources, from which we take only
those with parallax error less than 100% (7103123 sources), observed
with a Radial Velocity Spectrometer (RVS) that collects
medium-resolution spectra (spectral resolution
λ{DELTA}λ~=11700) over the wavelength range 845-872nm
centered on the calcium triplet region. This radial velocity data set
contains the median radial velocities, averaged over the 22-month
time span of the observations. The sources are nominally brighter
than twelfth magnitude in the GRVS photometric band, most having
magnitudes brighter than 13 in the G filter. Radial velocities are
only reported for stars with effective temperatures in the range
3550-6900 K.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig8vr.dat 64 16786 Radial component of the Galactocentric velocity
Median (V) for |b|<10°, Plx/e_Plx>1
fig8vp.dat 64 16786 Azimuthal component of the Galactocentric velocity
Median (V) for |b|<10°, Plx/e_Plx>1
fig8vz.dat 64 16786 Vertical component of the Galactocentric velocity
Median (V) for |b|<10°, Plx/e_Plx>1
fig9vr.dat 64 14380 Radial component of the Galactocentric velocity
Median (V) for 160°<l<200°, Plx/e_Plx>1
fig9vp.dat 64 14380 Azimuthal component of the Galactocentric velocity
Median (V) for 160°<l<200°, Plx/e_Plx>1
fig9vz.dat 64 14380 Vertical component of the Galactocentric velocity
Median (V) for 160°<l<200°, Plx/e_Plx>1
fig10vr.dat 64 13391 Radial component of the Galactocentric velocity
Median (V) for 120°<l<160°, Plx/e_Plx>1
fig10vp.dat 64 13391 Azimuthal component of the Galactocentric velocity
Median (V) for 120°<l<160°, Plx/e_Plx>1
fig10vz.dat 64 13391 Vertical component of the Galactocentric velocity
Median (V) for 120°<l<160°, Plx/e_Plx>1
fig11vr.dat 64 16150 Radial component of the Galactocentric velocity
Median (V) for 200°<l<240°, Plx/e_Plx>1
fig11vp.dat 64 16150 Azimuthal component of the Galactocentric velocity
Median (V) for 200°<l<240°, Plx/e_Plx>1
fig11vz.dat 64 16150 Vertical component of the Galactocentric velocity
Median (V) for 200°<l<240°, Plx/e_Plx>1
fig12vr.dat 64 17746 Radial component of the Galactocentric velocity
Median (V) for -20°<l<+20°, Plx/e_Plx>1
fig12vp.dat 64 17704 Azimuthal component of the Galactocentric velocity
Median (V) for -20°<l<+20°, Plx/e_Plx>1
fig12vz.dat 64 17704 Vertical component of the Galactocentric velocity
Median (V) for -20°<l<+20°, Plx/e_Plx>1
fig16vr.dat 64 12560 *Radial component of the Galactocentric velocity
Median (V) for |b|<10°, Plx/e_Plx>1
fig16vp.dat 64 12560 Azimuthal component of the Galactocentric velocity
Median (V) for |b|<10°, Plx/e_Plx>1
fig16vz.dat 64 12560 Vertical component of the Galactocentric velocity
Median (V) for |b|<10°, Plx/e_Plx>1
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Note on fig16vr.dat, fig16vp.dat, fig16vz.dat: introducing a correction to the
zero-point bias of parallaxes Pkxc=Plx+0.03mas.
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
Byte-by-byte Description of file: fig8vr.dat fig16vr.dat
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Bytes Format Units Label Explanations
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7- 12 F6.3 kpc Xgal Galactocentric X coordinate
19- 25 F7.3 kpc Ygal Galactocentric Y coordinate
31- 38 F8.3 km/s Vr Radial component of the Galactocentric velocity
45- 51 F7.3 km/s e_Vr Error of Vr
58- 64 F7.3 km/s s_Vr r.m.s. of Vr
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Byte-by-byte Description of file: fig9vr.dat fig1[012]vr.dat
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Bytes Format Units Label Explanations
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7- 12 F6.3 kpc Xgal Galactocentric X coordinate
19- 25 F7.3 kpc Zgal Galactocentric Z coordinate
31- 38 F8.3 km/s Vr Radial component of the Galactocentric velocity
45- 51 F7.3 km/s e_Vr Error of Vr
58- 64 F7.3 km/s s_Vr r.m.s. of Vr
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Byte-by-byte Description of file: fig8vp.dat fig16vp.dat
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Bytes Format Units Label Explanations
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7- 12 F6.3 kpc Xgal Galactocentric X coordinate
19- 25 F7.3 kpc Ygal Galactocentric Y coordinate
31- 38 F8.3 km/s Vphi Azimuthal component of the Galactocentric velocity
45- 51 F7.3 km/s e_Vphi Error of Vphi
58- 64 F7.3 km/s s_Vphi r.m.s. of Vphi
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Byte-by-byte Description of file: fig9vp.dat fig1[012]vp.dat
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Bytes Format Units Label Explanations
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7- 12 F6.3 kpc Xgal Galactocentric X coordinate
19- 25 F7.3 kpc Zgal Galactocentric Z coordinate
31- 38 F8.3 km/s Vphi Azimuthal component of the Galactocentric velocity
45- 51 F7.3 km/s e_Vphi Error of Vphi
58- 64 F7.3 km/s s_Vphi r.m.s. of Vphi
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Byte-by-byte Description of file: fig8vz.dat fig16vz.dat
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Bytes Format Units Label Explanations
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7- 12 F6.3 kpc Xgal Galactocentric X coordinate
19- 25 F7.3 kpc Ygal Galactocentric Y coordinate
31- 38 F8.3 km/s Vz Vertical component of the Galactocentric velocity
45- 51 F7.3 km/s e_Vz Error of Vz
58- 64 F7.3 km/s s_Vz r.m.s. of Vz
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Byte-by-byte Description of file: fig9vz.dat fig1[012]vz.dat
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Bytes Format Units Label Explanations
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7- 12 F6.3 kpc Xgal Galactocentric X coordinate
19- 25 F7.3 kpc Zgal Galactocentric Z coordinate
31- 38 F8.3 km/s Vz Vertical component of the Galactocentric velocity
45- 51 F7.3 km/s e_Vz Error of Vz
58- 64 F7.3 km/s s_Vz r.m.s. of Vz
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Acknowledgements:
Martin Lopez-Corredoira, fuego.templado(at)gmail.com
(End) Patricia Vannier [CDS] 13-Nov-2018