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Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes Feeding The Beast: Infall, Mergers or Starbursts? Mike Dopita (ANU)

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Presentation on theme: "Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes Feeding The Beast: Infall, Mergers or Starbursts? Mike Dopita (ANU)"— Presentation transcript:

1 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes Feeding The Beast: Infall, Mergers or Starbursts? Mike Dopita (ANU)

2 Research School of Astronomy & Astrophysics Fluorescent Processes Topics to be Covered: What is the nature of “cooling flow Elliptical Galaxies”? How do Luminous IR galaxies (LIRGS) evolve and feed their Black Holes? What can we learn from IR spectroscopy of LIRGS? How do AGNs feed back on their hosts in the hi-Z Universe? (the revenge of the AGNs!) How do starbursts blow winds? (the revenge of the massive stars!)

3 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes 1. “Cooling Flow” Elliptical Galaxies collaborators Catherine Farage ANU (Thesis Project), Peter McGregor ANU

4 Research School of Astronomy & Astrophysics Fluorescent Processes “Cooling flows” According to the Fabian/Nulsen model, the hot X-ray emitting plasma in Elliptical Galaxies cools and falls into the galactic core, feeding the supermassive Black Hole. Is this model correct? Consider first the southern “poster child” of cooling flows, NGC 4696...

5 Research School of Astronomy & Astrophysics Fluorescent Processes NGC4696 (Crawford 2005)

6 Research School of Astronomy & Astrophysics Fluorescent Processes NGC4696 (Crawford 2005) Note close correlation of X-ray and H- alpha

7 Research School of Astronomy & Astrophysics Fluorescent Processes NGC4696 (Crawford 2005) Note close correlation of X-ray and H- alpha Radio emission morphology is determined by gas, not vice- versa.

8 Research School of Astronomy & Astrophysics Fluorescent Processes NGC4696 (Crawford 2005) Note close correlation of X-ray and H- alpha Radio emission morphology is determined by gas, not vice- versa. Where would dust come from in a cooling flow?

9 Research School of Astronomy & Astrophysics Fluorescent Processes..so, make WiFeS Observations of NGC 4696 Farage, Dopita & McGregor B 7000 R 7000

10 Research School of Astronomy & Astrophysics Fluorescent Processes [N II] Brightness Distribution (note strong central concentration)

11 Research School of Astronomy & Astrophysics Fluorescent Processes [N II] Velocity Dispersion (note low velocity dispersion) [N II] Velocity Centroid (note evidence for rotation)

12 Research School of Astronomy & Astrophysics Fluorescent Processes

13 Research School of Astronomy & Astrophysics Fluorescent Processes LINER spectrum. Strong [NII] and [N I] and weak [O III]] imply low shock velocities ~ 80km/s Compare with the Herbig-Haro spectrum of DG Tau

14 Research School of Astronomy & Astrophysics Fluorescent Processes Conclusion on NGC 4696 The presence of dust implies we see matter from a minor merger, not a cooling flow. This is supported by: Rotational support rather than infall Low velocity dispersion in filaments “Liner” Spectrum characteristic of low velocity (<100km/s) shocks.

15 Research School of Astronomy & Astrophysics Fluorescent Processes A much larger and more luminous source: Abell 2204

16 Research School of Astronomy & Astrophysics Fluorescent Processes

17 Research School of Astronomy & Astrophysics Fluorescent Processes..again, a LINER spectrum. Strong [NII] very strong [N I] and weak [O III]] again imply low shock velocities, despite a much larger total velocity dispersion.

18 Research School of Astronomy & Astrophysics Fluorescent Processes If either shocks or cooling flows, the X-ray is too strong for the observed H-alpha in emission line radio E galaxies T = 5E5 KT =2.5E6 K

19 Research School of Astronomy & Astrophysics Fluorescent Processes A Dynamical Model: Fragments of merger orbit through hot halo gas, and are shocked as a result. T ; c 0 1 T 0 n 0 V orb V s n c

20 Research School of Astronomy & Astrophysics Fluorescent Processes Implications of this “Heating Flow” model: Orbital Motion is transonic (weak shocks): Ram pressure drives cloud shock: Some likely parameters of the problem: Therefore we have:

21 Research School of Astronomy & Astrophysics Fluorescent Processes 2. Luminous IR Galaxy Mergers collaboratorsJeff Rich IFA, Hawaii (Thesis Project), Lisa Kewley & Dave Sanders IFA, Hawaii Lee Armus Spitzer Science Center and the GOALS team

22 Research School of Astronomy & Astrophysics Fluorescent Processes GOALS: Merging IR-Luminous Galaxies in the local Universe

23 Research School of Astronomy & Astrophysics Fluorescent Processes IRAS 18293-3413 He I + Na I [S II] H-alpha + [N II]

24 Research School of Astronomy & Astrophysics Fluorescent Processes Galaxy Image Velocity Field H-Alpha Image Line Ratio Map

25 Research School of Astronomy & Astrophysics Fluorescent Processes The Merger Scenario Sanders & Mirabel (1996); Banes & Hernquist (1996) etc. Starburst Phase First Passage: Formation of Tidal Tails

26 Research School of Astronomy & Astrophysics Fluorescent Processes The Merger Scenario Sanders & Mirabel (1996); Banes & Hernquist (1996) etc. First Passage: Formation of Tidal Tails Second Passage & Merging Phase AGN Phase Starburst Phase

27 Research School of Astronomy & Astrophysics Fluorescent Processes The Merger Scenario Sanders & Mirabel (1996); Banes & Hernquist (1996) etc. First Passage: Formation of Tidal Tails Second Passage & Merging Phase Abundance Gradients Normal Abundance Gradients Disrupted Abundance Gradients Disrupted Abundance Gradients Disrupted Abundance Gradients Mixed, gas flows lower nuclear abundance

28 Research School of Astronomy & Astrophysics Fluorescent Processes Gas flows from Abundance Measurements: Kewley Geller & Barton 2006, AJ, 131,2004 Nuclear Abundance Lower in Merging Galaxies: Implies Gas flows to nucleus

29 Research School of Astronomy & Astrophysics Fluorescent Processes Gas flows from Abundance Measurements: Kewley Geller & Barton 2006, AJ, 131,2004..and Abundance Gradient is disrupted Nuclear Abundance Lower in Merging Galaxies: Implies Gas flows to nucleus (Keck LRIS Spectroscopy)

30 Research School of Astronomy & Astrophysics Fluorescent Processes Amount of Gas Inflow to Nucleus in Mergers Assuming gas inflow ~7 M_sun/yr and an initially normal metallicity gradient We need 50-60% dilution in nucleus c.f. Merger models, which predict 60% and we need an infall timescale of 10-100 Myr c.f. merger models, which predict 100 Myr.

31 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes Excitation Conditions

32 Research School of Astronomy & Astrophysics Fluorescent Processes Spectral Classification: Yuan, Kewley & Sanders (2009) IRGs LIRGs ULIRGs logL>8 logL >12 10.5 { "@context": "http://schema.org", "@type": "ImageObject", "contentUrl": "http://images.slideplayer.com/12/3441312/slides/slide_32.jpg", "name": "Research School of Astronomy & Astrophysics Fluorescent Processes Spectral Classification: Yuan, Kewley & Sanders (2009) IRGs LIRGs ULIRGs logL>8 logL >12 10.58 logL >12 10.5

33 Research School of Astronomy & Astrophysics Fluorescent Processes Old Classifications:

34 Research School of Astronomy & Astrophysics Fluorescent Processes New Classifications: Yuan, Kewley & Sanders (2009) Note how Seyfert activity is at first hidden, then becomes dominant both at late phases and in ULIRGs

35 Research School of Astronomy & Astrophysics Fluorescent Processes What is the Nature of Transition Objects? Do all (or any of) the transition objects contain an AGN? For: Their line ratios are shifted in the direction of AGN. Against: No radio point sources are detected in these objects. Could this be the result of high free-free optical depth in the radio? Answer: Only if surface rate of SF is rather extreme, or if the AGN has a very strong ionized wind. If so, why are the ULIRGS more LINER-like than Seyfert II -like? Could this indicate a role for distributed shock emission? Could the IMF in these objects be unusually flat?

36 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes 3. Infrared Modelling of LIRGS

37 Research School of Astronomy & Astrophysics Fluorescent Processes Analytic Modelling (Dopita et al. 2004-8) Use STARBURST 99 to provide the intrinsic stellar SEDs. Use MAPPINGS IIIq to compute HII region temperature, ionisation, emission line spectrum, dust and PAH absorption, dust re-emission in the mid- and far-IR. Dust model includes grain shattering size spectrum, quantum fluctuations of the dust temperature & PAH photodissociation. Ensure that any cluster of a given age is placed in its self- consistent evolving HII region. Add the contribution of the old (10-100Myr) stars. Put the whole lot behind a dusty turbulent foreground screen.

38 Research School of Astronomy & Astrophysics Fluorescent Processes Our Model Starburst: HII Regions of all ages and many cluster masses evolve in an ISM of a given pressure & chemical abundance

39 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes Fits to SEDs of “template” starburst galaxies.

40 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes Fits to SEDs of “template” starburst galaxies... Pretty good!

41 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes GOALS IRS Sample (Armus et al.) log C = 5.5A(v) = 8 mag A(v) = 19 magA(v) = 31 maglog C = 5.5 A(v) = 0 maglog C = 5.5

42 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes AGN +SB in GOALS Sample (Armus et al.) PAH Class C emission? see Tielens 2008, ARAA NLR dominated

43 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes..curiously enough, only 15-20% have AGN! PAH Class C emission? see Tielens 2008, ARAA NLR dominated

44 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes GOALS Sample - Silicate Absorption A(v) = 60 mag; SFR = 60 A(v) = 56 mag; SFR = 65 Draine “Astronomical” Silicate Opacity does not give a good fit to the 10 and 18 µm Si absorption. The 18 µm Si absorption is too weak, and the central wavelength of the 10 µm feature is too short.

45 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes 24 µm 18.4 µm 10.0 µm 9.3 µm 18.0 µm

46 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes...due to larger grain size (~1.5 µm) in the starburst region

47 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes 4. Radio Galaxy AGN Feedback (the revenge of the AGN) - Expelling the Interstellar Gas - The Transition to “red-and-dead”

48 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes The Evolution of a Radio Galaxy (Model by Sutherland)

49 Research School of Astronomy & Astrophysics Fluorescent Processes ACS Observations, Box: 2x2 arc sec. ~ 16x16 kpc Scale 0.05 arc sec/ pixel ~ 400 pc CIII] 1937Å 1513Å [O III] Galaxies around Radio Galaxy MRC 0316-257 (z=3.13) Maschietto et al. 2008 MNRAS

50 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes Example: 4C 41.17 Universe: 1.6 Gyr old Data By: van Breugel et al 2002 low freq. radio jet Feedback by AGN Jet Interaction

51 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes..forming stars at the rate of 5000 solar masses per year!

52 Research School of Astronomy & Astrophysics Fluorescent Processes..with shock excited jet emission

53 Research School of Astronomy & Astrophysics Fluorescent Processes Jet Hot-spot Colour: Ly−  Contours: H−  Nucleus

54 Research School of Astronomy & Astrophysics Fluorescent Processes Ly-Alpha  Halos associated with Hi-z Radio Galaxies are: Luminous: F = 10 -15 erg s -1 cm -2 or L = 10 44 erg sec -1 & Large: up to 200 kpc across or ~ 20 arc sec in diameter! Over 400 candidates remain unstudied. These Galaxies both represent truly galaxy-wide starbursts with chemical enrichment and “maximal” star formation extending over some 10-100 kpc 2. Such galaxies (and their radio-quiet counterparts) probably represent the dominant mode of star formation in the Universe at 4 > z > 2, forming typically 300-3000 solar masses per year.

55 Research School of Astronomy & Astrophysics Fluorescent Processes The Expanding Shell of 4C 60.07: Evidence for AGN Feedback Reuland et al. 2006 AJ

56 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes 4. Galactic Winds and Fountains (the revenge of the stars)

57 Fluorescent Processes Research School of Astronomy & Astrophysics Fluorescent Processes The Prototypical Superwind - M82 Chandra, HST, Spitzer http://chandra.harvard.edu/photo/2006/m82/m82_comp.jpg

58 Research School of Astronomy & Astrophysics Fluorescent Processes Condition to drive a Galactic Wind We need (at least) that the kinetic energy injection per unit area into a fraction of the disk gas will exceed its binding energy: Star formation follows the Kennicutt (1998) Law: So a wind becomes possible when: Therefore, a wind is driven when: Escape Velocity is Low (i.e. galaxy is small) Lifetime of Starburst is long Gas surface density is high

59 Research School of Astronomy & Astrophysics Fluorescent Processes Structure of a Superwind Cooper, Bicknell & Sutherland, RSAA: astro-ph 0710.5437

60 Research School of Astronomy & Astrophysics Fluorescent Processes The Movie of a Superwind Cooper, Bicknell & Sutherland, 2008

61 Research School of Astronomy & Astrophysics Fluorescent Processes Conclusions: Winds & Fountains Galactic winds can be driven when the collective effects of disk star formation become important, i.e. when hot bubbles can collide & merge in the halo. Starburst winds are driven when the star formation is of high concentration, long continued, and when the depth of the galaxian potential is sufficiently shallow. These conditions may be mutually exclusive, but are generally favoured in merging starburst galaxies.

62 Research School of Astronomy & Astrophysics Fluorescent Processes That’s All Folks!!


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