Decoupling star-gas rotation - I: the fundamental links to morphology and halo spin

Decoupling star-gas rotation - I: the fundamental links to morphology and halo spin


Chris Duckworth

October 07, 2019


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    Decoupling star-gas rotation - I: the fundamental links to morphology

    and halo spin Chris Duckworth, Rita Tojeiro 7th October 2019 SDSS-IV Project 0535: SDSS-IV Paper 0391:
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    This project in a nutshell… • First in a series

    which uses a combination of MaNGA and IllustrisTNG (TNG) to comprehensively understand why galaxies have decoupled rotation between stars and gas (kinematic misalignment) • Here we focus on: • Morphological dependence of kinematic misalignment (MaNGA & TNG) • Relationship with angular momentum and gas content at z = 0 (MaNGA & TNG) • Identifying galaxies with stellar rotation but ‘messed up’ gas rotation as potential progenitors of misaligned galaxies (MaNGA) • Relationship with the halo spin back to z = 1 (TNG)
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    Stars Ionized gas 1) Looking at 3 different types of

    galaxies. 1) Galaxies with aligned rotation between stars and gas (usual expectation from basic TTT) i.e. ΔPA = |PAstars – PAgas | < 30° # = 3378 galaxies
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    Stars Ionized gas 2) Looking at 3 different types of

    galaxies. 2) Kinematically misaligned galaxies with a difference between rotational axes of stars and gas i.e. ΔPA = |PAstars – PAgas | > 30° # = 420 galaxies
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    Stars Ionized gas 3) Looking at 3 different types of

    galaxies. 3) Coherent stellar rotation but dispersion dominated or depleted gas Will refer to them as NGRs (no gas rotation) # = 742 galaxies
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    I have classified the velocity fields for every MaNGA MPL-8

    galaxy. The plan is to share the catalogue with the collaboration early next year. Email me if you are interested in using this catalogue before then.
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    ΔPA > 30°: 28±3% of 301 ETGs 10±1% of 677

    S0-Sas 5.4±0.6% of 1634 Sb-Sds ETG centrals are more likely to be misaligned than ETG satellites! Morphologies from GalaxyZoo;
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    General properties of decoupled galaxies (MaNGA) Little difference in stellar

    mass when considering population as a whole but individual trends when broken down by morphology Morphologies from GalaxyZoo;
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    General properties of decoupled galaxies (MaNGA) This holds regardless of

    morphology and cut in ΔPA (i.e. those with ΔPA > 150° have the same angular momentum as those with >30°)
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    General properties of decoupled galaxies (MaNGA) Gas mass based on

    dust attention from Pipe3D; Since angular momentum loss and gas loss seem crucial in misalignment are NGRs progenitors of misaligned (i.e before gas is re-accreted)?
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    1) For every MPL-8 object, found unique subhalo with most

    similar combination of stellar mass, size and g-r colour 2) Made MaNGA like observation (particle based with co-added noise and PSF of typical MaNGA observations for each subhalo up- to same number of Re as matched MaNGA galaxy 3 Same eyeballing of velocity fields and kinematic classifications IllustrisTNG-100 mock MaNGA sample Example output from a TNG subhalo
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    Specific angular momentum of all DM particles in subhalo Galaxies

    with decoupled star-gas rotation at z=0 are in haloes of lower spin going back past z=1!
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    Paper submitted to collaboration, to be submitted to MNRAS ~

    22nd October Paper in late stage however feedback/comments greatly appreciated and co-authorship (as appropriate) welcomed.
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    Ongoing work in this series • Relationship with black hole

    feedback in TNG • (Preliminary) Correlates with black hole mass • (Preliminary) Correlates with black hole luminosity (with time lag!) • Currently looking at relationship with energy injection and misalignment • Relationship with mergers for ETGs in TNG / MaNGA • Currently looking at relaxation timescales • Currently looking at merger relationship on individual galaxy basis These projects are not SDSS-IV (currently) but if you are interested feel free to get in touch!