Simulating cosmological substructure in the solar neighbourhood

We explore the predictive power of cosmological, hydrodynamical simulations for stellar phase-space substructure and velocity correlations with the auriga simulations and aurigaia mock Gaia catalogues. We show that at the solar circle the auriga simulations commonly host phase-space structures in the stellar component that have constant orbital energies and arise from accreted subhaloes. These structures can persist for a few Gyr, even after coherent streams in position space have been erased. We also explore velocity two-point correlation functions and find this diagnostic is not deterministic for particular clustering patterns in phase space. Finally, we explore these structure diagnostics with the aurigaia catalogues and show that current catalogues have the ability to recover some structures in phase space but careful consideration is required to separate physical structures from numerical structures arising from catalogue generation methods.

[1]  Sarah Loebman,et al.  Synthetic Gaia DR3 surveys from the FIRE cosmological simulations of Milky-Way-mass galaxies , 2023, 2306.16475.

[2]  S. White,et al.  The effects of dynamical substructure on Milky Way mass estimates from the high-velocity tail of the local stellar halo , 2019, Monthly Notices of the Royal Astronomical Society: Letters.

[3]  S. White,et al.  On the ridges, undulations & streams in Gaia DR2: Linking the topography of phase-space to the orbital structure of an N-body bar , 2019, Monthly Notices of the Royal Astronomical Society.

[4]  V. Belokurov,et al.  The local high-velocity tail and the Galactic escape speed , 2019, Monthly Notices of the Royal Astronomical Society.

[5]  F. Combes,et al.  Disk origin of the Milky Way bulge: the necessity of the thick disk , 2019, Astronomy & Astrophysics.

[6]  Anthony G. A. Brown,et al.  The merger that led to the formation of the Milky Way’s inner stellar halo and thick disk , 2018, Nature.

[7]  N. Martin,et al.  Ghostly tributaries to the Milky Way: charting the halo’s stellar streams with the Gaia DR2 catalogue , 2018, Monthly Notices of the Royal Astronomical Society.

[8]  A. Helmi,et al.  A dynamically young and perturbed Milky Way disk , 2018, Nature.

[9]  T. A. Lister,et al.  Gaia Data Release 2. Summary of the contents and survey properties , 2018, 1804.09365.

[10]  V. Springel,et al.  Aurigaia: mock Gaia DR2 stellar catalogues from the auriga cosmological simulations , 2018, Monthly Notices of the Royal Astronomical Society.

[11]  Sergey E. Koposov,et al.  The Milky Way Halo in Action Space , 2018, 1802.03351.

[12]  Paul Torrey,et al.  FIRE-2 simulations: physics versus numerics in galaxy formation , 2017, Monthly Notices of the Royal Astronomical Society.

[13]  H. Rix,et al.  Origin of chemically distinct discs in the Auriga cosmological simulations , 2017, 1708.07834.

[14]  V. Springel,et al.  Quenching and ram pressure stripping of simulated Milky Way satellite galaxies , 2017, 1705.03018.

[15]  S. White,et al.  Lessons from the Auriga discs : the hunt for the Milky Way's ex situ disc is not yet over. , 2017, 1704.08261.

[16]  Federico Marinacci,et al.  The Auriga Project: the properties and formation mechanisms of disc galaxies across cosmic time , 2016, 1610.01159.

[17]  A. Helmi,et al.  A box full of chocolates: The rich structure of the nearby stellar halo revealed by Gaia and RAVE , 2016, 1611.00222.

[18]  V. Springel,et al.  On the relevance of chaos for halo stars in the solar neighbourhood , 2015, 1508.00579.

[19]  A. Helmi,et al.  The evolution of streams in a time-dependent potential , 2015, 1504.00008.

[20]  U. Maryland,et al.  Formation of in situ stellar haloes in Milky Way-mass galaxies , 2015, 1501.04630.

[21]  Chinese Academy of Sciences,et al.  Creating mock catalogues of stellar haloes from cosmological simulations , 2014, 1406.2320.

[22]  University of Surrey,et al.  The hunt for the Milky Way's accreted disc , 2014, 1407.4464.

[23]  A. Helmi,et al.  Streams in the Aquarius stellar haloes , 2013, 1307.0008.

[24]  B. O’Shea,et al.  Signatures of minor mergers in Milky Way-like disc kinematics: Ringing revisited , 2011, 1105.4231.

[25]  Amina Helmi,et al.  On the identification of merger debris in the Gaia era , 2010, 1004.4974.

[26]  Taylor S. Chonis,et al.  STELLAR TIDAL STREAMS IN SPIRAL GALAXIES OF THE LOCAL VOLUME: A PILOT SURVEY WITH MODEST APERTURE TELESCOPES , 2010, 1003.4860.

[27]  A. Helmi,et al.  On the identification of substructure in phase space using orbital frequencies , 2009, 0904.1377.

[28]  A. Helmi,et al.  Galactic stellar haloes in the CDM model , 2009, 0910.3211.

[29]  Durham,et al.  Phase-space structure in the local dark matter distribution and its signature in direct detection experiments , 2008, 0812.0362.

[30]  Princeton,et al.  The Field of Streams: Sagittarius and Its Siblings , 2006, astro-ph/0605025.

[31]  J. Bullock,et al.  Tracing Galaxy Formation with Stellar Halos. I. Methods , 2005, astro-ph/0506467.

[32]  A. Helmi,et al.  The phase-space structure of cold dark matter haloes : insights into the Galactic halo , 2002, astro-ph/0208041.

[33]  Amina Helmi,et al.  Mapping the substructure in the Galactic halo with the next generation of astrometric satellites , 2000, astro-ph/0007166.

[34]  P. T. de Zeeuw,et al.  Debris streams in the solar neighbourhood as relicts from the formation of the Milky Way , 1999, Nature.

[35]  A. Helmi,et al.  Building up the stellar halo of the Galaxy , 1999, astro-ph/9901102.

[36]  B. Tinsley.  Stellar lifetimes and abundance ratios in chemical evolution , 1979 .