We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.

Durham Research Online
You are in:

Identifying true satellites of the Magellanic Clouds.

Sales, L.V. and Navarro, J.F. and Kallivayalil, N. and Frenk, C.S. (2017) 'Identifying true satellites of the Magellanic Clouds.', Monthly notices of the Royal Astronomical Society., 465 (2). pp. 1879-188.


The hierarchical nature of ΛCDM suggests that the Magellanic Clouds must have been surrounded by a number of satellites before their infall into the Milky Way halo. Many of those satellites should still be in close proximity to the Clouds, but some could have dispersed ahead/behind the Clouds along their Galactic orbit. Either way, prior association with the Clouds constrains the present-day positions and velocities of candidate Magellanic satellites: they must lie close to the nearly polar orbital plane of the Magellanic Stream, and their distances and radial velocities must follow the latitude dependence expected for a tidal stream with the Clouds near pericentre. We use a cosmological numerical simulation of the disruption of a massive sub-halo in a Milky Way-sized ΛCDM halo to test whether any of the 20 dwarfs recently discovered in the Dark Energy Survey, the Survey of the MAgellanic Stellar History, Pan-STARRS, and ATLAS surveys are truly associated with the Clouds. Of the six systems with kinematic data, only Hor 1 has distance and radial velocities consistent with a Magellanic origin. Of the remaining dwarfs, six (Hor 2, Eri 3, Ret 3, Tuc 4, Tuc 5, and Phx 2) have positions and distances consistent with a Magellanic origin, but kinematic data are needed to substantiate that possibility. Conclusive evidence for association would require proper motions to constrain the orbital angular momentum direction, which, for true Magellanic satellites, must be similar to that of the Clouds. We use this result to predict radial velocities and proper motions for all new dwarfs, assuming that they were Magellanic satellites. Our results are relatively insensitive to the assumption of first or second pericentre for the Clouds

Item Type:Article
Full text:(VoR) Version of Record
Download PDF
Publisher Web site:
Publisher statement:This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Date accepted:31 October 2016
Date deposited:02 March 2017
Date of first online publication:02 November 2016
Date first made open access:02 March 2017

Save or Share this output

Look up in GoogleScholar