23 research outputs found
Star-gas misalignment in galaxies: I. The properties of galaxies from the Horizon-AGN simulation and comparisons to SAMI
Full text linkRecent integral field spectroscopy observations have found that about 11% of
galaxies show star-gas misalignment. The misalignment possibly results from
external effects such as gas accretion, interaction with other objects, and
other environmental effects, hence providing clues to these effects. We explore
the properties of misaligned galaxies using Horizon-AGN, a large-volume
cosmological simulation, and compare the result with the result of the
Sydney-AAO Multi-object integral field spectrograph (SAMI) Galaxy Survey.
Horizon-AGN can match the overall misalignment fraction and reproduces the
distribution of misalignment angles found by observations surprisingly closely.
The misalignment fraction is found to be highly correlated with galaxy
morphology both in observations and in the simulation: early-type galaxies are
substantially more frequently misaligned than late-type galaxies. The gas
fraction is another important factor associated with misalignment in the sense
that misalignment increases with decreasing gas fraction. However, there is a
significant discrepancy between the SAMI and Horizon-AGN data in the
misalignment fraction for the galaxies in dense (cluster) environments. We
discuss possible origins of misalignment and disagreement.Comment: 23 pages with 15 figures. Accepted for publication in Ap
Star-Gas Misalignment in Galaxies. I. The Properties of Galaxies from the Horizon-AGN Simulation and Comparisons to SAMI
Get PDFRecent integral field spectroscopy observations have found that about 11% of galaxies show star-gas misalignment. The misalignment possibly results from external effects such as gas accretion, interaction with other objects, and other environmental effects, hence providing clues to these effects. We explore the properties of misaligned galaxies using Horizon-AGN, a large-volume cosmological simulation, and compare the results with those of the Sydney-AAO Multi-object integral field spectrograph (SAMI) Galaxy Survey. Horizon-AGN can match the overall misalignment fraction and reproduces the distribution of misalignment angles found by observations surprisingly closely. The misalignment fraction is found to be highly correlated with galaxy morphology both in observations and in the simulation: early-type galaxies are substantially more frequently misaligned than late-type galaxies. The gas fraction is another important factor associated with misalignment in the sense that misalignment increases with decreasing gas fraction. However, there is a significant discrepancy between the SAMI and Horizon-AGN data in the misalignment fraction for the galaxies in dense (cluster) environments. We discuss possible origins of misalignment and disagreement.S.K.Y.
acted as the corresponding author and acknowledges support
from the Korean National Research Foundation (NRF2017R1A2A05001116). D.J.K. acknowledges support from
Yonsei University through Yonsei Honors Scholarship. J.J.B.
acknowledges support from an Australian Research Council
Future Fellowship (FT180100231). J.B.H. is supported by an
ARC Laureate Fellowship that funds Jesse van de Sande
and an ARC Federation Fellowship that funded the SAMI
prototype. M.S.O. acknowledges funding support from the
Australian Research Council through a Future Fellowship
(FT140100255). J.v.d.S. is funded under Bland-Hawthornâs
ARC Laureate Fellowship (FL140100278). Parts of this
research were conducted by the Australian Research Council
Centre of Excellence for All Sky Astrophysics in 3 Dimensions
(ASTRO 3D), through project No. CE170100013. This work
relied on the HPC resources of the Horizon Cluster hosted by
Institut dâAstrophysique de Paris. We warmly thank S.
Rouberol for running the cluster on which the simulation was
post-processed. This work is partially supported by the Spin(e)
grant ANR-13-BS05-0005 of the French Agence Nationale de
la Recherche. The SAMI Galaxy Survey is based on
observations made at the Anglo-Australian Telescope. The
Sydney-AAO Multi-object Integral field spectrograph (SAMI)
was developed jointly by the University of Sydney and the
Australian Astronomical Observatory. The SAMI input catalog
is based on data taken from the Sloan Digital Sky Survey, the
GAMA Survey and the VST ATLAS Survey. The SAMI
Galaxy Survey is supported by the Australian Research
Council Centre of Excellence for All Sky Astrophysics in 3
Dimensions (ASTRO 3D), through project No. CE170100013,
the Australian Research Council Centre of Excellence for Allsky Astrophysics (CAASTRO), through project No.
CE110001020, and other participating institutions. The SAMI
Galaxy Survey website is http://sami-survey.org/
