TY - JOUR
T1 - The influence of Sagittarius and the Large Magellanic Cloud on the stellar disc of the Milky Way Galaxy
AU - Laporte, Chervin F.P.
AU - Johnston, Kathryn V.
AU - Gómez, Facundo A.
AU - Garavito-Camargo, Nicolas
AU - Besla, Gurtina
N1 - Funding Information: We thank Volker Springel for giving us access to the GADGET-3 code. We are thankful for valuable discussions with Benoit Famaey, Rodrigo Ibata, Keith Hawkins, Vasily Belokurov, Jorge Peñarrubia, and Raphaël Errani. CL is supported by a Junior Fellow of the Si-mons Society of Fellows award from the Simons Foundation. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number OCI-1053575. We also acknowledge the use of computing facilities at the Rechenzentrum Garching (RZG) and the Max Planck Institute for Astrophysics (MPA). KVJ’s contributions were supported by NSF grants AST-1312196 and AST-1614743. N.G-C is supported by the McCarthy-Stoeger scholarship from the Vatican Observatory. CL dedicates this work to all the New York jazz cats and in particular his mentors Aaron Parks and Donald Vega for their continued support and Dr. Barry Harris for his teachings. Funding Information: We thank Volker Springel for giving us access to the GADGET-3 code.We are thankful for valuable discussions with Benoit Famaey, Rodrigo Ibata, Keith Hawkins, Vasily Belokurov, Jorge Peñarrubia, and Raphael Errani. CL is supported by a Junior Fellow of the Simons Society of Fellows award from the Simons Foundation. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number OCI-1053575.We also acknowledge the use of computing facilities at the Rechenzentrum Garching (RZG) and the Max Planck Institute for Astrophysics (MPA). KVJ's contributions were supported by NSF grants AST-1312196 and AST-1614743. N.G-C is supported by the McCarthy-Stoeger scholarship from the Vatican Observatory. CL dedicates this work to all the New York jazz cats and in particular hismentors Aaron Parks and Donald Vega for their continued support and Dr. Barry Harris for his teachings. Publisher Copyright: © 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2018/11/21
Y1 - 2018/11/21
N2 - We present N-body simulations of a Sagittarius (Sgr)-like dwarf spheroidal galaxy that follows its orbit about the Milky Way (MW) since its first crossing of the Galaxy's virial radius to the present day. As Sgr orbits around the MW, it excites vertical oscillations, corrugating and flaring the Galactic stellar disc. These responses can be understood by a two-phase picture in which the interaction is first dominated by torques from the wake excited by Sgr in the MW dark halo before transitioning to tides from Sgr's direct impact on the disc at late times. We show for the first time that a massive Sgr model simultaneously reproduces the locations and motions of arclike overdensities, such as theMonoceros Ring and the Triangulum Andromeda stellar clouds, that have been observed at the extremities of the disc, while also satisfying the solar-neighbourhood constraints on the vertical structure and streaming motions of the disc. In additional simulations, we include the Large Magellanic Cloud (LMC) self-consistently with Sgr. The LMC introduces coupling through constructive and destructive interference, but no new corrugations. In our models, the excitation of the current structure of the outer disc can be traced to interactions as far back as 6-7Gyr ago (corresponding to z ≤ 1). Given the apparently quiescent accretion history of the MW over this time-scale, this places Sgr as the main culprit behind the vertical oscillations of the disc and the last major.
AB - We present N-body simulations of a Sagittarius (Sgr)-like dwarf spheroidal galaxy that follows its orbit about the Milky Way (MW) since its first crossing of the Galaxy's virial radius to the present day. As Sgr orbits around the MW, it excites vertical oscillations, corrugating and flaring the Galactic stellar disc. These responses can be understood by a two-phase picture in which the interaction is first dominated by torques from the wake excited by Sgr in the MW dark halo before transitioning to tides from Sgr's direct impact on the disc at late times. We show for the first time that a massive Sgr model simultaneously reproduces the locations and motions of arclike overdensities, such as theMonoceros Ring and the Triangulum Andromeda stellar clouds, that have been observed at the extremities of the disc, while also satisfying the solar-neighbourhood constraints on the vertical structure and streaming motions of the disc. In additional simulations, we include the Large Magellanic Cloud (LMC) self-consistently with Sgr. The LMC introduces coupling through constructive and destructive interference, but no new corrugations. In our models, the excitation of the current structure of the outer disc can be traced to interactions as far back as 6-7Gyr ago (corresponding to z ≤ 1). Given the apparently quiescent accretion history of the MW over this time-scale, this places Sgr as the main culprit behind the vertical oscillations of the disc and the last major.
KW - Galaxy: disc -Galaxy: evolution
KW - Galaxy: formation
KW - Galaxy: halo
KW - Galaxy: kinematics and dynamics
KW - Galaxy: structure
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U2 - 10.1093/mnras/sty1574
DO - 10.1093/mnras/sty1574
M3 - Article
SN - 0035-8711
VL - 481
SP - 286
EP - 306
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -