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A Dyson’s Dream - Dusty Early-Type Galaxies

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. Breakdown. Intro: Early-Type Galaxies ( ETGs ) Intro: Early-Types with dust GAMA and Herschel-ATLAS

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A Dyson’s Dream - Dusty Early-Type Galaxies

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

  3. Old vs. New Tuning Forks Credit: http://www.sdss.org How can we differentiate between galaxy types? Cappellariet al (2011) Nicky Agius Jeremiah Horrocks Institute, UCLan

  4. Early-Type Galaxies Late-Type Galaxies Classification and Morphology of External Galaxies – G. de Vaucouleurs CenA – Marina Rejkuba (ESO-Garching) M87 – David Malin (AAO) M86 –NOAO/SCIENCE PHOTO LIBRARY M74 - NASA - Hubble

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

  6. Adding some stardust Ellipticals: originally no observed cold gas – hot (106 - 107K) ionised gas – dust destroyed in situ (sputtering) (EINSTEIN, ROSAT, ASCA observations) APOD – dust lane Knapp (1999) – connects cold gas and dust Nicky Agius Jeremiah Horrocks Institute, UCLan

  7. 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) Planck Function: Nicky Agius Jeremiah Horrocks Institute, UCLan

  8. Hierarchical Formation? Scenario: Elliptical with no interactions within sputtering timescale ≈ 107 – 108 years = no dust!! Georgakakiset al (2001) – dust masses don’t come from old stars Shabala et al (2012) – dusty ETGs have higher SFRs Questions: E’s with significant dust masses not yet achieved massive end-stage Elliptical status? Can dust be used as a smoking gun? Nicky Agius Jeremiah Horrocks Institute, UCLan

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

  10. Herschel-ATLAS • Largest Open-Time Key Project with Herschel • PACS – 100μm & 160μm • SPIRE – 250μm, 350μm & 500μm • Full survey: 550 deg2, ~200,000 detections, zmed~1 • Source extraction described in Rigby et al, 2011 • ~66,500 Phase 1 detections: • =10,000 GAMA matches over 160 deg2 Credit: esa.org Parallel Mode Ealeset al (2010), Poglitschet al (2010), Griffin et al (2010) Nicky Agius Jeremiah Horrocks Institute, UCLan

  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 GAMA CAT 0.013<z<0.06 rpet ≤ 19.8 mag Mr ≤ -17.4 mag Nicky Agius Lunchtime Talk – St-Andrews Jeremiah Horrocks Institute

  13. Kelvin et al (in prep) Nicky Agius Lunchtime Talk – St-Andrews Jeremiah Horrocks Institute

  14. 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 Nicky Agius Jeremiah Horrocks Institute, UCLan

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

  16. Sample Properties Nicky Agius Jeremiah Horrocks Institute, UCLan

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

  18. Nicky Agius Lunchtime Talk – St-Andrews Jeremiah Horrocks Institute

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

  20. Dust in Galaxies Dust Mass: Nicky Agius Jeremiah Horrocks Institute, UCLan • Single component – isothermal fitting • Modified BB equation with β=2.0 (Draine & Li, 2007) • Fit galaxies with SPIRE emission ≥ 3σ • Dust mass and temperature • K = k-correction • DL = luminosity distance • κ250 = absorption coefficient = 0.89m2kg-1 (Dunne et al, 2011)

  21. Modified Blackbody Fits

  22. Isothermal Fitting Results Nicky Agius Jeremiah Horrocks Institute, UCLan

  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 Fischeraet al (2011), Nataleet 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 Fischeraet al (2011), Nataleet al (2010)

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

  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 • Popescuet al (2011) for more details • Template: MW SF region fit + Groves et al (2008) model

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

  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: χcoland χUV • compute energy density (Urad,gal ) of dust disk • Assume dust in ETGs is localised in a central disk • Use RT spheroidal models to find radius of disk • Match Urad,gal with Urad,mod(R)

  30. z rscale = 5670 pc zscale = 90 pc Model: Q=r/R R r Varying parameters: τB = 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) Nicky Agius Lunchtime Talk – St-Andrews Jeremiah Horrocks Institute

  31. Test Galaxies Nicky Agius Jeremiah Horrocks Institute, UCLan

  32. Preliminary Results Nicky Agius Lunchtime Talk – St-Andrews Jeremiah Horrocks Institute

  33. In Conclusion Nicky Agius Jeremiah Horrocks Institute, UCLan • Two groups of ETGs: • 1. High Md/M, low n, blue NUV-r • 2. Low Md/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 Lackner & Gunn (2012) 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

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

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