PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING
This article reports a measurement of the proper motion of Leo II, a dwarf galaxy that is a likely satellite of the Milky Way, based on imaging with the Hubble Space Telescope and Wide Field Camera. 3. The measurement uses compact background galaxies as standards of rest in both channels of the came...
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ndltd-arizona.edu-oai-arizona.openrepository.com-10150-6247412017-07-19T03:00:30Z PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING Piatek, Slawomir Pryor, Carlton Olszewski, Edward W. Univ Arizona, Steward Observ galaxies: dwarf galaxies: individual (Leo II) proper motions This article reports a measurement of the proper motion of Leo II, a dwarf galaxy that is a likely satellite of the Milky Way, based on imaging with the Hubble Space Telescope and Wide Field Camera. 3. The measurement uses compact background galaxies as standards of rest in both channels of the camera for two distinct pointings of the telescope, as well as a QSO in one channel for each pointing, resulting in the weighted average of six measurements. The measured proper motion in the the equatorial coordinate system is (mu(alpha), mu(delta))= (-6.9 +/- 3.7, -8.7 +/- 3.9) mas century(-1) and in the Galactic coordinate system it is (mu(l), mu(b)) = (6.2 +/- 3.9, -9.2 +/- 3.7) mas. century(-1). The implied space velocity with respect to the Galactic center is (Pi, Theta, Z) =(-37 +/- 38, 117 +/- 43, 40 +/- 16) km s(-1) or, expressed in Galactocentric radial and tangential components, (V-r, V-tan) = (21.9 +/- 1.5, 127 +/- 42) km s(-1). The space velocity implies that the instantaneous orbital inclination is 68 degrees, with a 95% confidence interval of (66 degrees, 80 degrees). The measured motion supports the hypothesis that Leo. II, Leo. IV, Leo. V, Crater. 2, and the globular cluster Crater fell into the Milky Way as a group. 2016-11-17 Article PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING 2016, 152 (6):166 The Astronomical Journal 1538-3881 10.3847/0004-6256/152/6/166 http://hdl.handle.net/10150/624741 http://arizona.openrepository.com/arizona/handle/10150/624741 The Astronomical Journal en http://stacks.iop.org/1538-3881/152/i=6/a=166?key=crossref.de796a032ef4a3b636b93032111cb02c © 2016. The American Astronomical Society. All rights reserved. IOP PUBLISHING LTD |
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en |
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galaxies: dwarf galaxies: individual (Leo II) proper motions |
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galaxies: dwarf galaxies: individual (Leo II) proper motions Piatek, Slawomir Pryor, Carlton Olszewski, Edward W. PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING |
description |
This article reports a measurement of the proper motion of Leo II, a dwarf galaxy that is a likely satellite of the Milky Way, based on imaging with the Hubble Space Telescope and Wide Field Camera. 3. The measurement uses compact background galaxies as standards of rest in both channels of the camera for two distinct pointings of the telescope, as well as a QSO in one channel for each pointing, resulting in the weighted average of six measurements. The measured proper motion in the the equatorial coordinate system is (mu(alpha), mu(delta))= (-6.9 +/- 3.7, -8.7 +/- 3.9) mas century(-1) and in the Galactic coordinate system it is (mu(l), mu(b)) = (6.2 +/- 3.9, -9.2 +/- 3.7) mas. century(-1). The implied space velocity with respect to the Galactic center is (Pi, Theta, Z) =(-37 +/- 38, 117 +/- 43, 40 +/- 16) km s(-1) or, expressed in Galactocentric radial and tangential components, (V-r, V-tan) = (21.9 +/- 1.5, 127 +/- 42) km s(-1). The space velocity implies that the instantaneous orbital inclination is 68 degrees, with a 95% confidence interval of (66 degrees, 80 degrees). The measured motion supports the hypothesis that Leo. II, Leo. IV, Leo. V, Crater. 2, and the globular cluster Crater fell into the Milky Way as a group. |
author2 |
Univ Arizona, Steward Observ |
author_facet |
Univ Arizona, Steward Observ Piatek, Slawomir Pryor, Carlton Olszewski, Edward W. |
author |
Piatek, Slawomir Pryor, Carlton Olszewski, Edward W. |
author_sort |
Piatek, Slawomir |
title |
PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING |
title_short |
PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING |
title_full |
PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING |
title_fullStr |
PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING |
title_full_unstemmed |
PROPER MOTION OF THE LEO II DWARF GALAXY BASED ON HUBBLE SPACE TELESCOPE IMAGING |
title_sort |
proper motion of the leo ii dwarf galaxy based on hubble space telescope imaging |
publisher |
IOP PUBLISHING LTD |
publishDate |
2016 |
url |
http://hdl.handle.net/10150/624741 http://arizona.openrepository.com/arizona/handle/10150/624741 |
work_keys_str_mv |
AT piatekslawomir propermotionoftheleoiidwarfgalaxybasedonhubblespacetelescopeimaging AT pryorcarlton propermotionoftheleoiidwarfgalaxybasedonhubblespacetelescopeimaging AT olszewskiedwardw propermotionoftheleoiidwarfgalaxybasedonhubblespacetelescopeimaging |
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1718497049829179392 |