The Pisces Plume and the Magellanic wake-Reference-Cited by-同舟云学术

The Pisces Plume and the Magellanic wake

Published:2019-06-27 Issue:1 Volume:488 Page:L47-L52
ISSN:1745-3925
Container-title:Monthly Notices of the Royal Astronomical Society: Letters
language:en
Short-container-title:

Author:

Belokurov Vasily¹²^ORCID,Deason Alis J³^ORCID,Erkal Denis⁴^ORCID,Koposov Sergey E¹⁵^ORCID,Carballo-Bello Julio A⁶⁷,Smith Martin C⁸,Jethwa Prashin⁹^ORCID,Navarrete Camila⁶¹⁰¹¹^ORCID

Affiliation:

1. Institute of Astronomy, Madingley Rd, Cambridge CB3 0HA, UK

2. Center for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, USA

3. Institute for Computational Cosmology, Department of Physics, University of Durham, South Road, Durham DH1 3LE, UK

4. Department of Physics, University of Surrey, Guildford GU2 7XH, UK

5. Department of Physics, McWilliams Center for Cosmology, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA

6. Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago, Chile

7. Chinese Academy of Sciences South America Center for Astronomy, National Astronomical Observatories, CAS, Beijing 10010, People’s Republic of China

8. Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, People’s Republic of China

9. European Southern Observatory, Karl-Schwarzschild-Str 2, D-85748 Garching, Germany

10. Millennium Institute of Astrophysics, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago, Chile

11. European Southern Observatory, Alonso de Córdova 3107, 7630000 Vitacura, Santiago, Chile

Abstract

ABSTRACT Using RR Lyrae stars in the Gaia Data Release 2 and Pan-STARRS1 we study the properties of the Pisces overdensity, a diffuse substructure in the outer halo of the Milky Way. We show that along the line of sight, Pisces appears as a broad and long plume of stars stretching from 40 to 110 kpc with a steep distance gradient. On the sky Pisces’s elongated shape is aligned with the Magellanic Stream. Using follow-up VLT FORS2 spectroscopy, we have measured the velocity distribution of the Pisces candidate member stars and have shown it to be as broad as that of the Galactic halo but offset to negative velocities. Using a suite of numerical simulations, we demonstrate that the structure has many properties in common with the predicted behaviour of the Magellanic wake, i.e. the Galactic halo overdensity induced by the infall of the Magellanic Clouds.

Funder

European Research Council

Seventh Framework Programme

Royal Society

Science and Technology Facilities Council

National Sleep Foundation

National Key Basic Research and Development Program of China

National Natural Science Foundation of China

Publisher

Oxford University Press (OUP)

Subject

Space and Planetary Science,Astronomy and Astrophysics