The Evolution of Galaxy Angular Momentum

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1 icc.dur.ac.uk/eagle KMOS redshift one spectroscopic survey The Evolution of Galaxy Angular Momentum The KROSS team: Harrison, Johnson, Tiley, Stott, Swinbank, Bower, Bureau, Smail, Bunker, Cirasuolo, Sobral, Sharples, Best, Jarvis, Magdis The EAGLE project: Durham: Michelle Furlong, RGB, Carlos Frenk, Matthieu Schaller, James Trayford, Yelti Rosas- Guevara, Tom Theuns, Yan Qu, John Helly, Adrian Jenkins,Stu McAlpine, Jaime Salcido. Leiden: Joop Schaye. LJMU : Rob Crain, Ian McCarthyROW: Claudio Dalla Vecchia, Craig Booth + Virgo Consortium

2 A transition mass in galaxy properties Galaxy properties exhibit a sharp transition. This is reproduced in Eagle transition mass In independent Eagle we of zcan see that at a fixed halo mass galaxies with large BH have a long SF growth timescale This transition occurs at a similar halo mass at all redshifts Passive galaxies pile up at the transition mass Kauffmann et al 2003 : a transition mass scale in the properties of galaxies more SF galaxies at low z, but same mass distribution Muzzin et al 2013, Peng et al 2010; reproduced in Eagle Furlong et al 2015

3 A (new) Galaxy Formation Cartoon Star Formation Feedback Feedback stalls BANG!! Black Hole Feedback Cold diffuse gas Cool filaments flow into centre effective feedback ejects low ang. mom.gas feedback weakens as the corona becomes established failing feedback triggers rapid black hole growth What s changed? cold accretion (in low mass haloes) AGN feedback sets an upper limit to galaxy growth through star formation mergers only important for the most massive galaxies stellar feedback is critical 2 M * ~ M h : stronger in low mass galaxies the main sequence of galaxy formation balancing inflow and outflow evolution of the star formation rate driven by the evolution of halo accretion White & Rees 1978; White & Frenk 1991; Keres et al 2006; Dekel & Birnboim 2006; Croton 2006; Bower et al 2006; 2016

4 What can we learn from galaxy dynamics?

5 the TF relation - a test of galaxy formation? So many different galaxy model can generate the same TF relation better to look at the Angular momentum? Ferrero et al 2016

6 How do galaxies get their angular momentum? Fall & Efstathiou 1980; Mo, Mao & White 1998 a basic theory for the origin of galaxy spin this is really Mhalo! but why does it work? gas gain/looses angular momentum as it spirals in low angular momentum gas may be preferentially ejected stellar mass is a complex function of halo mass this is really jhalo! collapsing baryons can alter halo shape Fall & Efstathiou 1980, Mo et al 1998, Romanowsky & Fall 2012; Danovich et al 2015; Burket et al 2016

7 How do galaxies get their angular momentum? Fall & Efstathiou 1980; Mo, Mao & White 1998 a basic theory for the origin of galaxy spin fractions of halo am conserved but why does it work? gas gain/looses angular momentum as it spirals in low angular momentum gas may be preferentially ejected stellar mass is a complex function of halo mass theory prediction fraction of mass in stars collapsing baryons can alter halo shape Fall & Efstathiou 1980, Mo et al 1998, Romanowsky & Fall 2012; Danovich et al 2015; Burket et al 2016; Harrison et al 2016

8 KROSS KMOS redshift one spectroscopic survey The KROSS team Harrison, Johnson, Tiley, Stott, Swinbank, Bower, Bureau, Smail, Bunker, Cirasuolo, Sobral, Sharples, Best, Jarvis, Magdis Harrison et al., 2016 (see also Tiley et 2016, Stott et al 2016)

9 The KMOS + MUSE integral field spectrographs on ESO VLT provides ~24x speed improvement over previous instruments. 24 pickoff arms KROSS and KMOS-3D (Forster-Schreiber et al) : similar aims, different strategies

10 Parent Sample IFS survey of 795 galaxies redshift 0.6-1; median redshift 0.85 typical star forming galaxies that dominate the SFRD at this redshift. fields are E-CDFS, COSMOS, UDS, SA22 redshifts from spectroscopic surveys

11 552 galaxies with spatially resolved Halpha

12 line fitting by max likelihood use IFU continuum peak to identify rotation centre optical image to determine PA (where possible) compare PA from dynamics Data products measure rotation at 2 R 1/2 correct rotation for seeing, and dispersion (Johnson et al 2016) we are releasing this data!

13 Data products rotation velocities by fitting the major axis rotation curve - for most sources, this is simply a means of interpolating the data. Dispersion determined from outer profile > 2 R 1/2 corrected for beam smearing (Johnson et al 2016)

14 Results Velocity - Mass (the inverse Tully-Fisher relation) local comparison sample currently working on SAMI comparison Tiley et al. 2016

15 (Specific) Angular Momentum Factor ~2 growth in angular momentum between z~1 and today Angular momentum is fundamental way of looking at galaxy formation. together with SFR, Angular momentum distinguishes galaxies morphology Angular momentum of accreting gas grows as the Universe expands Harrison et al 2016, Burket et al ; Obreschkow& Glazebrrok 2015

16 Relation to halo angular key question in galaxy formation physics - how is disk AM related to the halo AM momentum hint of ~ 30% drop in retention factor between z=0 and z=1 * Romanowsky et al 2012 f* Dutton et al 2010 f* is fraction of gas that forms stars; fj is fraction of angular momentum retained Why are jhalo and jstar related? Harison et al 2016; Burket et al 2016

17 Does angular momentum determine everything? log(m s /M o )= log(m s /M o )= log(m s /M o )= highest j for fixed mass km/s 0.2 Does angular momentum drive morphology? lowest j for fixed mass 164km/s km/s and star formation -1.2 history? 59km/s 123km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s km/s

18 the end of star formation (and the start of the Hubble sequence) Bower et al 2016

19 Angular momentum of star-forming galaxies in our MUSE & KMOS surveys Total angular momentum, J, scales as J ~ M 5/3, better to plot J / M 5/3 vs redshift to remove observational biases (selection + surface brightness limits). Data suggest factor 1.6x increase in J / M 5/3 between z = 1.5 and z = 0. Consistent with models which expel low angular momentum material from outflows, and accrete high-j gas from ISM. What are relative contributions? Need to tie in metallicity-gradients and outflows. Swinbank et al MN; Harrison et al. 2015

20 Black Holes : the nemesis of galaxy formation What is the impact of black holes? do black holes grow in lockstep with their haloes? A new paradigm for the interaction between black holes and galaxies BH mass relative to halo mass Add plot to show the dependence of black hole mass on halo mass and impact on galaxy sequence Contours: observational data, Ilbert et al 2015 Transition mass scale

21 Simple model - Comparison to EAGLE EAGLE with ONLY AGN feedback observational data (savorgnan 2016) Blue: late type Red: early type simple model Bower et al

22 Where next?

23 Where next? A reasonable fraction of the galaxy rotation curves flatten, and even turn over. These have diagnostic power to test the disk dark matter connection (since they require a halo and a disk). However, these tend to be the most massive/extended objects (M*~ Mo c.f. M*~ Mo for full sample). Why is this important? Limiting factor is spatial resolution - DM core radius is ~1 2kpc (c.f. 4kpc seeing) - so degeneracies in dynamical modelling substantial. - understand Baryon contribution to SINFONI/AO can resolve dynamics of few acceleration 10 s galaxies, but evolution in DM/disk properties with redshift in statistical sample will require combination of increased spatial resolution and collecting area (to resolve turn over in rotation curves at high-z). - does radial distribution of gas drive star formation rate?

24 Degeneracies in Models are extreme this diagram compares baryonic contribution to centripetal acceleration with total evidence for MOND? Ludlow et al 2016; McGough et al 2016

25 Are high-z disks more turbulent? What s the idea? high-z infall rate much faster = 1 matterial has low ang. mom. What sets the dispersion of a disk? Toomre stability of disks? the clump mass function impact of clumps on morphology Obreschkow et al 2015 Elmegreen & Elmegreen 2005, Bournaud et al 2007, Genzel et al 2008, Forster-Schreiber 2006, Wisnioski et al 2015

26 Summary A picture for how disk galaxies form and evolve is emerging Looking at rotation speed is complicated by degeneracies; Angular momentum is simpler! provides a simple way to understand the Universe Angular momentum of the gas follows that of the halo despite the complexity of gas accretion low am systems need star formation to become stable Black holes are a critical part of this picture bringing star formation to an end - morphology follows from lack of star formation Next steps: angular momentum within galaxies : testing the stability picture with large galaxy samples needs Ultimate-Subaru!!