TY - JOUR
T1 - Drivers of disc tilting I
T2 - Correlations and possible drivers for Milky Way analogues
AU - Earp, Samuel W.F.
AU - Debattista, Victor P.
AU - Macciò, Andrea V.
AU - Wang, Liang
AU - Buck, Tobias
AU - Khachaturyants, Tigran
N1 - Funding Information:
SWFE would like to thank the Max-Planck-Institut für Astronomie, Heidelberg for their hospitality, as well as Aaron Dutton, Benjamin MacFarlane and Min Du for useful conversations. VPD is supported by STFC Consolidated grant number ST/R000786/1. TB acknowledges support from the Sonderforschungsbereich SFB 881 ‘The Milky Way System’ (subproject A2) of the German Research Foundation (DFG). Simulations were carried out on the High Performance Computing resources at New York University Abu Dhabi. This work made use of the PYNBODY package (Pontzen et al. 2013) to analyse simulations and the PYTHON package MATPLOTLIB (Hunter 2007) to generate all the figures for this work. The data analysis for this work was carried out using the PYTHON packages SCIPY, NUMPY, IPYTHON, and JUPYTER (Jones et al. 2001; Van Der Walt, Colbert & Varoquaux 2011; Pérez & Granger 2007; Kluyver et al. 2016).
Funding Information:
SWFE would like to thank the Max-Planck-Institut f?r Astronomie, Heidelberg for their hospitality, as well as Aaron Dutton, Benjamin MacFarlane and Min Du for useful conversations. VPD is supported by STFC Consolidated grant number ST/R000786/1. TB acknowledges support from the Sonderforschungsbereich SFB 881 'The Milky Way System' (subproject A2) of the German Research Foundation (DFG). Simulations were carried out on the High Performance Computing resources at New York University Abu Dhabi. This work made use of the PYNBODY package (Pontzen et al. 2013) to analyse simulations and the PYTHON package MATPLOTLIB (Hunter 2007) to generate all the figures for this work. The data analysis for this work was carried out using the PYTHON packages SCIPY, NUMPY, IPYTHON, and JUPYTER (Jones et al. 2001; Van Der Walt, Colbert & Varoquaux 2011; P?rez & Granger 2007; Kluyver et al. 2016).
Publisher Copyright:
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
PY - 2019/10/1
Y1 - 2019/10/1
N2 - The direction of the spin vectors of disc galaxies change over time. We present the tilting rate of a sample of galaxies in the NIHAO suite of cosmological hydrodynamical simulations. Galaxies in our sample have been selected to be isolated and to have well-determined spins. We compare the tilting rates to the predicted observing limit of Gaia, finding that our entire sample lies above the limit, in agreement with previous work. To test the role of dark matter and of gas, we compare the weighted Pearson's correlation coefficients between the tilting rates and various properties. We find no correlation between the dark halo's tilting rate, shape, or misalignment with respect to the disc, and the tilting rate of the stellar disc. Therefore, we argue that, in the presence of gas, the dark halo plays a negligible role in the tilting of the stellar disc. On the other hand, we find a strong correlation between the tilting rate of the stellar disc and the misalignment of the cold gas warp. Adding the stellar mass fraction improves the correlation, while none of the dark matter's properties together with the cold gas misalignment improves the correlation to any significant extent. This implies that the gas cooling on to the disc is the principal driver of disc tilting.
AB - The direction of the spin vectors of disc galaxies change over time. We present the tilting rate of a sample of galaxies in the NIHAO suite of cosmological hydrodynamical simulations. Galaxies in our sample have been selected to be isolated and to have well-determined spins. We compare the tilting rates to the predicted observing limit of Gaia, finding that our entire sample lies above the limit, in agreement with previous work. To test the role of dark matter and of gas, we compare the weighted Pearson's correlation coefficients between the tilting rates and various properties. We find no correlation between the dark halo's tilting rate, shape, or misalignment with respect to the disc, and the tilting rate of the stellar disc. Therefore, we argue that, in the presence of gas, the dark halo plays a negligible role in the tilting of the stellar disc. On the other hand, we find a strong correlation between the tilting rate of the stellar disc and the misalignment of the cold gas warp. Adding the stellar mass fraction improves the correlation, while none of the dark matter's properties together with the cold gas misalignment improves the correlation to any significant extent. This implies that the gas cooling on to the disc is the principal driver of disc tilting.
KW - Dynamics
KW - Galaxy: disc
KW - Galaxy: evolution
KW - Galaxy: kinematics
KW - Reference systems
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U2 - 10.1093/mnras/stz2109
DO - 10.1093/mnras/stz2109
M3 - Article
AN - SCOPUS:85083240333
SN - 0035-8711
VL - 488
SP - 5728
EP - 5738
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -