Detection of a radial velocity gradient in the extended local disc with RAVE
Using a sample of 213,713 stars from the Radial Velocity Experiment (RAVE) survey, limited to a distance of 2 kpc from the Sun and to |z|<1 kpc, we report the detection of a velocity gradient of disc stars in the fourth quadrant, directed radially from the Galactic centre. In the direction of...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal article |
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2010
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| _version_ | 1826274992507060224 |
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| author | Siebert, A Famaey, B Minchev, I Seabroke, G Binney, J Burnett, B Freeman, K Williams, M Bienayme, O Bland-Hawthorn, J Campbell, R Fulbright, J Gibson, B Gilmore, G Grebel, E Helmi, A Munari, U Navarro, J Parker, Q Reid, W Siviero, A Steinmetz, M Watson, F Wyse, R Zwitter, T |
| author_facet | Siebert, A Famaey, B Minchev, I Seabroke, G Binney, J Burnett, B Freeman, K Williams, M Bienayme, O Bland-Hawthorn, J Campbell, R Fulbright, J Gibson, B Gilmore, G Grebel, E Helmi, A Munari, U Navarro, J Parker, Q Reid, W Siviero, A Steinmetz, M Watson, F Wyse, R Zwitter, T |
| author_sort | Siebert, A |
| collection | OXFORD |
| description | Using a sample of 213,713 stars from the Radial Velocity Experiment (RAVE) survey, limited to a distance of 2 kpc from the Sun and to |z|<1 kpc, we report the detection of a velocity gradient of disc stars in the fourth quadrant, directed radially from the Galactic centre. In the direction of the Galactic centre, we apply a simple method independent of stellar proper motions and of Galactic parameters to assess the existence of this gradient in the RAVE data. This velocity gradient corresponds to |K+C| < 3 km/s/kpc, where K and C are the Oort constants measuring the local divergence and radial shear of the velocity field, respectively. In order to illustrate the effect, assuming a zero radial velocity of the Local Standard of Rest we then reconstruct the two-dimensional Galactocentric velocity maps using two different sets of proper motions and photometric distances based either on isochrone fitting or on K-band magnitudes, and considering two sets of values for the Galactocentric radius of the Sun and local circular speed. Further observational confirmation of our finding with line-of-sight velocities of stars at low latitudes, together with further modelling, should help constrain the non-axisymmetric components of the Galactic potential, including the bar, the spiral arms and possibly the ellipticity of the dark halo. |
| first_indexed | 2024-03-06T22:51:54Z |
| format | Journal article |
| id | oxford-uuid:5f12a730-814b-4eaf-95ad-e6f84257242d |
| institution | University of Oxford |
| last_indexed | 2024-03-06T22:51:54Z |
| publishDate | 2010 |
| record_format | dspace |
| spelling | oxford-uuid:5f12a730-814b-4eaf-95ad-e6f84257242d2022-03-26T17:44:38ZDetection of a radial velocity gradient in the extended local disc with RAVEJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5f12a730-814b-4eaf-95ad-e6f84257242dSymplectic Elements at Oxford2010Siebert, AFamaey, BMinchev, ISeabroke, GBinney, JBurnett, BFreeman, KWilliams, MBienayme, OBland-Hawthorn, JCampbell, RFulbright, JGibson, BGilmore, GGrebel, EHelmi, AMunari, UNavarro, JParker, QReid, WSiviero, ASteinmetz, MWatson, FWyse, RZwitter, TUsing a sample of 213,713 stars from the Radial Velocity Experiment (RAVE) survey, limited to a distance of 2 kpc from the Sun and to |z|<1 kpc, we report the detection of a velocity gradient of disc stars in the fourth quadrant, directed radially from the Galactic centre. In the direction of the Galactic centre, we apply a simple method independent of stellar proper motions and of Galactic parameters to assess the existence of this gradient in the RAVE data. This velocity gradient corresponds to |K+C| < 3 km/s/kpc, where K and C are the Oort constants measuring the local divergence and radial shear of the velocity field, respectively. In order to illustrate the effect, assuming a zero radial velocity of the Local Standard of Rest we then reconstruct the two-dimensional Galactocentric velocity maps using two different sets of proper motions and photometric distances based either on isochrone fitting or on K-band magnitudes, and considering two sets of values for the Galactocentric radius of the Sun and local circular speed. Further observational confirmation of our finding with line-of-sight velocities of stars at low latitudes, together with further modelling, should help constrain the non-axisymmetric components of the Galactic potential, including the bar, the spiral arms and possibly the ellipticity of the dark halo. |
| spellingShingle | Siebert, A Famaey, B Minchev, I Seabroke, G Binney, J Burnett, B Freeman, K Williams, M Bienayme, O Bland-Hawthorn, J Campbell, R Fulbright, J Gibson, B Gilmore, G Grebel, E Helmi, A Munari, U Navarro, J Parker, Q Reid, W Siviero, A Steinmetz, M Watson, F Wyse, R Zwitter, T Detection of a radial velocity gradient in the extended local disc with RAVE |
| title | Detection of a radial velocity gradient in the extended local disc with
RAVE |
| title_full | Detection of a radial velocity gradient in the extended local disc with
RAVE |
| title_fullStr | Detection of a radial velocity gradient in the extended local disc with
RAVE |
| title_full_unstemmed | Detection of a radial velocity gradient in the extended local disc with
RAVE |
| title_short | Detection of a radial velocity gradient in the extended local disc with
RAVE |
| title_sort | detection of a radial velocity gradient in the extended local disc with rave |
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