Is the Milky Way still breathing? RAVE-Gaia streaming motions

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

We use data from the Radial Velocity Experiment (RAVE) and the Tycho-Gaia astrometric solution (TGAS) catalogue to compute the velocity fields yielded by the radial (VR), azimuthal (Vϕ),and vertical (Vz) components of associated Galactocentric velocity. We search in particular for variation in all three velocity components with distance above and below the disc midplane, as well as how each component of Vz (line-of-sight and tangential velocity projections) modifies the obtained vertical structure. To study the dependence of velocity on proper motion and distance, we use two main samples: a RAVE sample including proper motions from the Tycho-2, PPMXL, and UCAC4 catalogues, and a RAVE-TGAS sample with inferred distances and proper motions from the TGAS and UCAC5 catalogues. In both samples, we identify asymmetries in VR and Vz. Below the plane, we find the largest radial gradient to be ∂VR/∂R = -7.01 ± 0.61 km s-1 kpc-1, in agreement with recent studies. Above the plane, we find a similar gradient with ∂VR/∂R = -9.42 ± 1.77 km s-1 kpc-1. By comparing our results with previous studies, we find that the structure in Vz is strongly dependent on the adopted proper motions. Using the Galaxia Milky Way model, we demonstrate that distance uncertainties can create artificial wave-like patterns. In contrast to previous suggestions of a breathing mode seen in RAVE data, our results support a combination of bending and breathing modes, likely generated by a combination of external or internal and external mechanisms.

Detaljer

Författare
  • I. Carrillo
  • I. Minchev
  • G. Kordopatis
  • M. Steinmetz
  • J. Binney
  • F. Anders
  • O. Bienaymé
  • J. Bland-Hawthorn
  • B. Famaey
  • K. C. Freeman
  • G. Gilmore
  • B. K. Gibson
  • E. K. Grebel
  • A. Helmi
  • A. Just
  • A. Kunder
  • G. Monari
  • U. Munari
  • J. Navarro
  • Q. A. Parker
  • W. Reid
  • G. Seabroke
  • S. Sharma
  • A. Siebert
  • F. Watson
  • J. Wojno
  • R. F.G. Wyse
  • T. Zwitter
Enheter & grupper
Externa organisationer
  • Leibniz Institute for Astrophysics Potsdam (AIP)
  • Côte d'Azur Observatory
  • University of Oxford
  • University of Strasbourg
  • University of Sydney
  • Australian National University
  • University of Cambridge
  • Heidelberg University
  • Stockholms universitet
  • INAF - Osservatorio Astronomico di Padova
  • University of Victoria
  • University of Hong Kong
  • Macquarie University, Sydney
  • Western Sydney University
  • University College London
  • Johns Hopkins University
  • University of Ljubljana
  • University of Hull
  • University of Groningen
  • Saint Martin's University
  • Australian Astronomical Observatory
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Astronomi, astrofysik och kosmologi

Nyckelord

Originalspråkengelska
Sidor (från-till)2679-2696
Antal sidor18
TidskriftMonthly Notices of the Royal Astronomical Society
Volym475
Utgivningsnummer2
StatusPublished - 2018 apr 1
PublikationskategoriForskning
Peer review utfördJa