Kinematic properties of double-barred galaxies: Simulations versus integral-field observations

Using high-resolution N-body simulations, we recently reported that a dynamically cool inner disk embedded in a hotter outer disk can naturally generate a steady double-barred (S2B) structure. Here we study the kinematics of these S2B simulations, and compare them to integral-field observations from...

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Main Authors: Du, M, Debattista, V, Shen, J, Cappellari, M
Format: Journal article
Published: Institute of Physics 2016
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author Du, M
Debattista, V
Shen, J
Cappellari, M
author_facet Du, M
Debattista, V
Shen, J
Cappellari, M
author_sort Du, M
collection OXFORD
description Using high-resolution N-body simulations, we recently reported that a dynamically cool inner disk embedded in a hotter outer disk can naturally generate a steady double-barred (S2B) structure. Here we study the kinematics of these S2B simulations, and compare them to integral-field observations from ATLAS3D and SAURON. We show that S2B galaxies exhibit several distinct kinematic features, namely: (1) significantly distorted isovelocity contours at the transition region between the two bars, (2) peaks in σLOS along the minor axis of inner bars, which we term "σ-humps," that are often accompanied by ring/spiral-like features of increased σLOS, (3)h3-V anti-correlations in the region of the inner bar for certain orientations, and (4) rings of positive h4 when viewed at low inclinations. The most impressive of these features are the σ-humps; these evolve with the inner bar, oscillating in strength just as the inner bar does as it rotates relative to the outer bar. We show that, in cylindrical coordinates, the inner bar has similar streaming motions and velocity dispersion properties as normal large-scale bars, except for σz, which exhibits peaks on the minor axis, i.e., humps. These σz humps are responsible for producing the σ-humps. For three well-resolved early-type S2Bs (NGC 2859, NGC 2950, and NGC 3941) and a potential S2B candidate (NGC 3384), the S2B model qualitatively matches the integral-field data well, including the "σ-hollows" previously identified. We also discuss the kinematic effect of a nuclear disk in S2Bs.
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spelling oxford-uuid:c456774e-a223-4902-b5e9-e9c2546ba7e12022-03-27T06:22:41ZKinematic properties of double-barred galaxies: Simulations versus integral-field observationsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:c456774e-a223-4902-b5e9-e9c2546ba7e1Symplectic Elements at OxfordInstitute of Physics2016Du, MDebattista, VShen, JCappellari, MUsing high-resolution N-body simulations, we recently reported that a dynamically cool inner disk embedded in a hotter outer disk can naturally generate a steady double-barred (S2B) structure. Here we study the kinematics of these S2B simulations, and compare them to integral-field observations from ATLAS3D and SAURON. We show that S2B galaxies exhibit several distinct kinematic features, namely: (1) significantly distorted isovelocity contours at the transition region between the two bars, (2) peaks in σLOS along the minor axis of inner bars, which we term "σ-humps," that are often accompanied by ring/spiral-like features of increased σLOS, (3)h3-V anti-correlations in the region of the inner bar for certain orientations, and (4) rings of positive h4 when viewed at low inclinations. The most impressive of these features are the σ-humps; these evolve with the inner bar, oscillating in strength just as the inner bar does as it rotates relative to the outer bar. We show that, in cylindrical coordinates, the inner bar has similar streaming motions and velocity dispersion properties as normal large-scale bars, except for σz, which exhibits peaks on the minor axis, i.e., humps. These σz humps are responsible for producing the σ-humps. For three well-resolved early-type S2Bs (NGC 2859, NGC 2950, and NGC 3941) and a potential S2B candidate (NGC 3384), the S2B model qualitatively matches the integral-field data well, including the "σ-hollows" previously identified. We also discuss the kinematic effect of a nuclear disk in S2Bs.
spellingShingle Du, M
Debattista, V
Shen, J
Cappellari, M
Kinematic properties of double-barred galaxies: Simulations versus integral-field observations
title Kinematic properties of double-barred galaxies: Simulations versus integral-field observations
title_full Kinematic properties of double-barred galaxies: Simulations versus integral-field observations
title_fullStr Kinematic properties of double-barred galaxies: Simulations versus integral-field observations
title_full_unstemmed Kinematic properties of double-barred galaxies: Simulations versus integral-field observations
title_short Kinematic properties of double-barred galaxies: Simulations versus integral-field observations
title_sort kinematic properties of double barred galaxies simulations versus integral field observations
work_keys_str_mv AT dum kinematicpropertiesofdoublebarredgalaxiessimulationsversusintegralfieldobservations
AT debattistav kinematicpropertiesofdoublebarredgalaxiessimulationsversusintegralfieldobservations
AT shenj kinematicpropertiesofdoublebarredgalaxiessimulationsversusintegralfieldobservations
AT cappellarim kinematicpropertiesofdoublebarredgalaxiessimulationsversusintegralfieldobservations