1. A Dyson’s Dream - Dusty Early-Type Galaxies Nicky Agius * A.E. Sansom, C.C. Popescu, G. Natale + GAMA + H-ATLAS *NKAgius@uclan.ac.uk http://www.star.uclan.ac.uk/~nka/index.html

2. Breakdown 1. Intro: Early-Type Galaxies (ETGs) 2. Intro: Early-Types with dust 3. GAMA and Herschel-ATLAS 4. Properties of ETG samples 5. Modified BB and SED fitting 6. Case Studies Nicky Agius Jeremiah Horrocks Institute, UCLan

3. Old vs. New Tuning Forks Cappellari et al (2011) Credit: http://www.sdss.org How can we differentiate between galaxy types?

4. EllipticalLenticularSpiral Red bulge Smooth ProfileBlue/Red extended diskBluish arms/extended disk High surface brightnessModerate surface brightness Circular/elongatedElongatedSpiral arms Little or no dust laneDusty?Dusty Absorption lines onlyEmission + abs. lines?Emission + absorption lines No rotationRotating disk Found in clustersFound in all environments Classification and Morphology of External Galaxies – G. de Vaucouleurs Early-Type GalaxiesLate-Type Galaxies CenA – Marina Rejkuba (ESO-Garching) M87 – David Malin (AAO) M86 –NOAO/SCIENCE PHOTO LIBRARY M74 - NASA - Hubble

5. Peng, 2010: Sérsic Profiles Conselice, 2006: Red Sequence + Blue Cloud Dressler, 1980: Morphology-Density Relation Nicky Agius Jeremiah Horrocks Institute, UCLan

6. APOD – dust lane Knapp (1999) – connects cold gas and dust Ellipticals: originally no observed cold gas – hot (10 6 - 10 7 K) ionised gas – dust destroyed in situ (sputtering) (EINSTEIN, ROSAT, ASCA observations) Adding some stardust Nicky Agius Jeremiah Horrocks Institute, UCLan

7. Planck Function: ISM Emission Radio = cold neutral gas FIR/sub-mm = cold dust MIR = warm dust Optical/UV = stellar light = HII emission X-ray = hot ionised gas Hartigan, Palmer & Cleeves (2012)

8. Nicky Agius Jeremiah Horrocks Institute, UCLan Hierarchical Formation? Georgakakis et al (2001) – dust masses don’t come from old stars Scenario: Elliptical with no interactions within sputtering timescale ≈ 10 7 – 10 8 years = no dust!! Questions: E’s with significant dust masses not yet achieved massive end-stage Elliptical status? Can dust be used as a smoking gun? Shabala et al (2012) – dusty ETGs have higher SFRs

9. Galaxy and Mass Assembly Nicky Agius Jeremiah Horrocks Institute, UCLan Driver et al (2009)

10. Nicky Agius Jeremiah Horrocks Institute, UCLan Herschel-ATLAS Credit: esa.org  Largest Open-Time Key Project with Herschel  PACS – 100μm & 160μm  SPIRE – 250μm, 350μm & 500μm  Full survey: 550 deg 2, ~200,000 detections, z med ~1  Source extraction described in Rigby et al, 2011  ~66,500 Phase 1 detections: =10,000 GAMA matches over 160 deg 2 Parallel Mode Eales et al (2010), Poglitsch et al (2010), Griffin et al (2010) PACS 100μmPACS 160μmSPIRE 250μmSPIRE 350μmSPIRE 500μm FWHM8”12”18”25”36” 5σ Noise132mJy126mJy32mJy36mJy45mJy

11. Our Sample Aims  High fidelity sample of dusty ETGS  PACS + SPIRE data (H-ATLAS)  UV/Optical/NIR data (GAMA)  MIR data (WISE)  Control sample of non-dusty ETGs  Undetected in FIR/sub-mm  UV/Optical/NIR data (GAMA)  Kelvin et al (in prep) Parent Sample for optical classifications Nicky Agius Jeremiah Horrocks Institute, UCLan

12. Parent Sample Nicky AgiusLunchtime Talk – St-AndrewsJeremiah Horrocks Institute GAMA CAT 0.013<z<0.06 r pet ≤ 19.8 mag M r ≤ -17.4 mag

13. Nicky AgiusLunchtime Talk – St-AndrewsJeremiah Horrocks Institute Kelvin et al (in prep)

14. Nicky Agius Jeremiah Horrocks Institute, UCLan Active Galactic Nuclei BPT Diagram – Baldwin et al (1981); Kauffmann et al (2003a) Foster et al, in prep - Use GANDALF software to measure emission lines to get ratios shown here. Submm detections: 8 AGN of 17 Non-detections: 93 AGN of 175

15. E + S0a + Ellipticity (1-(b/a) ≤ 0.7) + Redshift (0.013≤z ≤ 0.06) + Remove AGN + Remove spiral arms + Sub-mm detections = 220 ETGs (5.4% of eyeballed sample) E + S0a + Ellipticity (1-(b/a) ≤ 0.7) + Redshift (0.013≤z ≤ 0.06) + Remove AGN + Remove spiral arms + Sub-mm undetected = 551 ETGs (13.4% of eyeballed sample) Nicky Agius Jeremiah Horrocks Institute, UCLan

16. Sample Properties

17. Agius et al (submitted) Nicky Agius Jeremiah Horrocks Institute, UCLan

18. Nicky AgiusLunchtime Talk – St-AndrewsJeremiah Horrocks Institute

19. Nicky Agius Jeremiah Horrocks Institute, UCLan Basic FIR/Sub-mm Properties

20. Dust in Galaxies Nicky Agius Jeremiah Horrocks Institute, UCLan  Single component – isothermal fitting o Modified BB equation with β=2.0 (Draine & Li, 2007) o Fit galaxies with SPIRE emission ≥ 3σ o Dust mass and temperature – K = k-correction – D L = luminosity distance – κ 250 = absorption coefficient = 0.89m 2 kg -1 (Dunne et al, 2011) Dust Mass:

21. Modified Blackbody Fits

22. Isothermal Fitting Results Nicky Agius Jeremiah Horrocks Institute, UCLan 3σ sample T d,mean 22.1K T d,range 9-30K M d,mean 1.8×10 7 M  M d,range (0.08-35) ×10 7 M 

23. Problems with isothermal fitting  1 component  Try two/multi-component fitting  Only outputs dust mass & temperature  Fit other wavebands  What if collisional heating contributes?  Use dust templates Nicky Agius Jeremiah Horrocks Institute, UCLan

24. SED Template Fits Nicky Agius Jeremiah Horrocks Institute, UCLan  Multiple components – Radiative Heating  Diffuse radiation field template  PDR/HII radiation template  Additional component – Collisional Heating Fischera et al (2011), Natale et al (2010)

25. SED Template Fits Nicky Agius Jeremiah Horrocks Institute, UCLan  Multiple components – Radiative Heating  Diffuse radiation field template  Dust heated by the diffuse ISRF in galaxy  Dust comp: graphite, silicates & PAHs  Fits vary intensity & colour of radiation field  Quantifies emission heated by old/young stellar populations  Dust emission calculated taking into account the stochastic fluctuations of dust grains Fischera et al (2011), Natale et al (2010)

26. SED Template Fits Nicky Agius Jeremiah Horrocks Institute, UCLan PAH line emissionFIR cold dust emission

27. SED Template Fits Nicky Agius Jeremiah Horrocks Institute, UCLan  Multiple components – Radiative Heating  Diffuse radiation field template  PDR/HII radiation template  Quantifies obscured ongoing SF  Popescu et al (2011) for more details  Template: MW SF region fit + Groves et al (2008) model

28. SED Template Fits Nicky Agius Jeremiah Horrocks Institute, UCLan Photodissociation (PDR/HII) Region Contribution Diffuse Contribution

29. Testing the Dust Distribution Nicky Agius Jeremiah Horrocks Institute, UCLan  Fit MIR/FIR/sub-mm data – diffuse + PDR fit  WISE: 12μm & 24μm  H-ATLAS: 100μm, 160μm, 250μm, 350μm & 500μm  Use output fit parameters: χ col and χ UV  compute energy density (U rad,gal ) of dust disk  Assume dust in ETGs is localised in a central disk  Use RT spheroidal models to find radius of disk  Match U rad,gal with U rad,mod (R)

30. Nicky AgiusLunchtime Talk – St-AndrewsJeremiah Horrocks Institute z r scale = 5670 pc z scale = 90 pc Varying parameters: τ B = 0.1, 0.3, 0.5, 1.0, 2.0, 4.0, 8.0 n = 1.0, 2.0, 4.0, 8.0 Dust model: Weingartner & Drain (2001) r Q=r/R Model: R

31. Nicky Agius Jeremiah Horrocks Institute, UCLan Test Galaxies

32. Preliminary Results Nicky AgiusLunchtime Talk – St-AndrewsJeremiah Horrocks Institute

33. In Conclusion Nicky Agius Jeremiah Horrocks Institute, UCLan  Two groups of ETGs: – 1. High M d /M , low n, blue NUV-r – 2. Low M d /M , high n, red NUV-r  Suggests younger population of ETGs which will continue to evolve – but no M * diff.  The geometrical distribution of dust in these ETGs could help identify how they are evolving.

34. Bulge-Disk Decomposition Nicky Agius Jeremiah Horrocks Institute, UCLan  Ideal for separating Es from S0s  Lackner & Gunn (2012) performed B+D for SDSS galaxies up to z=0.05  SDSS image quality not high enough for B+D up to z=0.4 - Waiting for VST/VISTA Lackner & Gunn (2012)

35. Centrally concentrated Elliptical Galaxy Artist’s Impression (sort of) CenA – Marina Rejkuba (ESO-Garching) M87 – David Malin (AAO) M86 –NOAO/SCIENCE PHOTO LIBRARY Nicky Agius Jeremiah Horrocks Institute, UCLan Dark Matter Halo Many globular clusters Mostly Red