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Dust and PAHs in X-ray Plasma of Elliptical Galaxies Hidehiro Kaneda （ Nagoya U. ） , et al.

Dust and PAHs in X-ray Plasma of Elliptical Galaxies Hidehiro Kaneda （ Nagoya U. ） , et al. Ellipticals: ▪ old stars not productive of dust ▪ hot plasma destructive to dust BUT, dust still exists despite harsh environments. X-ray. visible. IR. AKARI 3 m m. d = 1 arcmin.

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Dust and PAHs in X-ray Plasma of Elliptical Galaxies Hidehiro Kaneda （ Nagoya U. ） , et al.

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  1. Dust and PAHs in X-ray Plasma of Elliptical GalaxiesHidehiro Kaneda（Nagoya U.）, et al. Ellipticals: ▪ old stars not productive of dust ▪hot plasma destructive to dust BUT, dust still exists despite harsh environments X-ray visible IR

  2. AKARI 3 mm d = 1 arcmin Dust and PAHs in X-ray Plasma of Elliptical GalaxiesHidehiro Kaneda（Nagoya U.）, et al. AKARI + Spitzer SED (d < 30”) NGC4125 PAH PAH Dust Stars Kaneda et al. 2011 10 Wavelength (mm) 100

  3. Balance between supply and destruction of dust P+ P+ AKARI 24 mm Stellar mass loss（gas-to-dust ratio: 100） LB / LSun (MSun yr-1) 1.5×10-13 Faber ＆ Gallagher 1976, Knapp +, 1992 Arimatsu et al. 2011 Sputtering destruction in hot plasma of Te≥107K C Si,, Draine ＆ Salpeter 1979 Tielens et al. 1994 Typical lifetime: ～107 yr PAH lifetime: ～1000 yr Micelotta et al.2010 PAHs are much more easily destroyed! << Galaxy evolution timescale(at least, a few Gyr since merger)

  4. Motivations There exist much larger amounts of dust than expected for the balance. Even PAHs exist? Knapp et al. 1989 Goudfrooij & de Jong 1995 Mdust vs. LB (IRAS) Xilouris et al. 2004 What are their origins? How can they survive? • Possible origins • (0) stellar mass loss, • cooling flow, • merger origin, • others? Goudfrooij & de Jong 1995 dust lifetime 107yr

  5. Infrared observations by AKARI & Spitzer We observed 18 nearby IRAS-detected elliptical galaxies with AKARIand Spitzer. AKARI:NIR-FIR 9-band images fromthe nearby galaxy project Spitzer : MIR spectra from GO1 + GO3 + GO5 Blue: 90 mm Red: 15 mm Grey image: 3 mm

  6. Detection of PAHs & unusual PAH band ratios • PAH features detected from spectra of elliptical galaxies with Spitzer: 14 out of 18 galaxies. • PAH7.7 is unusually weak relative to PAH11.3 & 17. (Kaneda et al. 2005; 2008) (Kaneda et al. 2010) NGC4125 NGC4589 5mm 40mm 5mm 40mm

  7. Detection of PAHs & unusual PAH band ratios • PAH features detected from spectra of elliptical galaxies with Spitzer: 14 out of 18 galaxies. • PAH7.7 is unusually weak relative to PAH11.3 & 17. (Kaneda et al. 2005; 2008) C-C stretching：<10mm、C-H bending:>10mm Neutral PAHs are dominant. Very inactive in galaxies. Not as tracers of star formation (Kaneda et al. 2010) NGC4125 NGC4589 5mm 40mm 5mm 40mm Smith et al. 2007

  8. PAH vs FIR Relation among PAHs, dust, and hot plasma PAHs correlate well with dust. Dust & PAHs do not correlate with X-ray intensity. PAH-bright They are supplied not continuously, rather sporadically? FIR-bright PAH11.3 EW vs. LX / LB FIR/11mm vs. LX / LB PAH-bright FIR-bright X-ray-bright X-ray-bright Kaneda et al. 2008

  9. Spatial distributions of PAHs & dust NGC4589 NGC4125 one slit aperture one slit aperture ~1’x1’ Color: 2MASS J Kaneda et al. 2011 Kaneda et al. 2010 Spitzer/IRS spectral mapping observations

  10. Spatial distributions of PAHs & dust NGC4589 NGC4125 ~1’x1’ PAH11.3 mm emission: compact distributions near the centers, predominantly from the dust lanes

  11. Spatial distributions of PAHs & dust NGC4125 NGC4589 B：90 mm dust (AKARI) R：PAH 11.3 mm (Spitzer) W：3mm starlight (AKARI) G: diffuse X-ray (Chandra), point sources removed ~1’x1’ PAHs are more centrally-concentrated than dust. Dust and PAHs are distributed differently from stars.

  12. Comparison between X-ray and FIR distributions Color: AKARI 90 mm Contours: Chandra0.3-7 keV NGC4125 E6pec、 Lx = 1×1041 erg s-1(0.6-2.4 keV) 6-8 Gyr old major merger? Schweizer&Seitzer 1992 2 kpc < r < 10 kpc ・dust mass： ~7x105 M⊙ ・X-ray plasma： ~3x108 M⊙ Fukazawa et al. 2006 LFIR=5x108L⊙ LX=2x107L⊙ 3nkT/(n2L) = (2 - 9)x107 yr～ dust lifetime <<a few Gyr L: cooling function of dusty plasma by gas-grain collision Dwek 1987

  13. Comparison between X-ray and FIR distributions Color: AKARI 90 mm Contours: Chandra0.3-7 keV Color: Herschel/PACS 70 mm NGC4125 E6pec、 Lx = 1×1041 erg s-1(0.6-2.4 keV) 6-8 Gyr old major merger? Schweizer&Seitzer 1992 2 kpc < r < 10 kpc ・dust mass： ~7x105 M⊙ ・X-ray plasma： ~3x108 M⊙ Fukazawa et al. 2006 NGC4125 LFIR=5x108L⊙ LX=2x107L⊙ 3nkT/(n2L) = (2 - 9)x107 yr～ dust lifetime <<a few Gyr L: cooling function of dusty plasma by gas-grain collision Dwek 1987

  14. Comparison between X-ray and FIR distributions Color: AKARI 90 mm Contours: Chandra0.3-7 keV 0.3-0.8 keV / 0.8-7 keV 2 kpc < r < 10 kpc ・dust mass：~7x105 M⊙ ・X-ray plasma：~3x108 M⊙ NGC4125 Fukazawa et al. 2006 LFIR=5x108L⊙ LX=2x107L⊙ 3nkT/(n2L) =(2 - 9)x107 yr～ dust lifetime<<a few Gyr L: cooling function of dusty plasma by gas-grain collision Dwek 1987

  15. Comparison between X-ray and FIR distributions PAH 11.3 mm Color: AKARI 90 mm Contours: Chandra0.3-7 keV Color: Herschel/PACS 70 mm 2 kpc < r < 10 kpc ・dust mass：~7x105 M⊙ ・X-ray plasma：~3x108 M⊙ NGC4125 Fukazawa et al. 2006 LFIR=5x108L⊙ LX=2x107L⊙ 3nkT/(n2L) = (2 - 9)x107 yr～ dust lifetime <<a few Gyr L: cooling function of dusty plasma by gas-grain collision Dwek 1987

  16. AKARI FIR all-sky survey Log(Mdust) [M⊙] Log(LB) [L⊙] ~1 Jy detection limit E&S0 complete sample F90mm/F140mm ⇒ Mdust Presence of excess dust is clear. Mdust increases with LB ! dust lifetime dust lifetime stellar mass loss If mergers are important, didmergers increase both stars and dust?

  17. Candidate for the origin of excess dust & PAHs AKARI3 mm 15 mm 90 mm ▪Central reservoirs of dust & PAHs Relics of mergers? Recycled products? ▪LLAGN-assisted energy feedback outflow in response to in-falling gas, distributing dust & PAHs from the center to the outer interstellar space. Mathew et al. 2004 1’ Cont.: 80- 10% Outflow velocity ~400 km/s　⇒ 　 Dust of 0.1 mm size reaches ~5 kpc in a sputtering lifetime of ~107 yr. NGC1052 LINER activity Temi et al. 2007 PAHs cannot be distributed because their destruction timescales are too short (~1000 yr). AKARI Spitzer Kaneda et al. 2011 2mm 100mm

  18. Summary 1. Large amounts of dust & PAHs exist in X-ray elliptical galaxies. Stellar mass loss cannot account for them. 2. For NGC4125 & 4589, PAH & dust emissions were spatially resolved; PAHs are centrally concentrated, while dust is more distributed. Signature of their interaction with X-ray plasma was obtained. 3. Reservoirs of dust and PAHs seem to exist near the center. Dust may be distributed by LLAGN-assisted outflow from the center to outer interstellar space, where hot plasma is cooled. PAHs cannot be distributed due to their short destruction timescales.

  19. SPICA (Japan-Europe collaboration) Launched around 2020 Core wavelengths: 5 – 200 mm Imaging spectroscopy with a 3-m cold (6 K) telescope Posters by Roelfsema et al. by Kaneda et al.

  20. Comparison between X-ray and FIR Color: AKARI 90 mm Contours: Spitzer [SiII]34.8 mm Chandra0.3-0.8 keV Kaneda et al. 2011 NGC4125 Color: AKARI 90 mm Contours: Chandra0.3-7 keV Chandra0.8-7 keV

  21. How do we sustain the X-ray plasma? Cooling function of a dusty plasma by gas-grain collision NGC4125 Gas-to-dust mass ratio = 200 ・dust mass： （2 kpc < r < 10 kpc） 7x105 M⊙ ・X-ray plasma： （3 kpc < r < 10 kpc） (0.2 – 1)x10-2 cm-3 0.36 - 0.44 keV 3x108 M⊙ LFIR=5x108 L⊙ LX=2x107 L⊙ dust emission Raymond Smith Fukazawa et al. 2006 Dwek 1987 3nkT/(n2L) = (2 - 9)x107 yr～ dust lifetime <<a few Gyr

  22. Interpretation of unusually low PAH7.7/11.3 neutral ionized Draine & Li 2007 C-C stretching：<10mm、C-H bending:>10mm Neutral PAHs are dominant. Very inactive in galaxies. Not as tracers of star formation

  23. NGC4125：Dust is distributed more widely than PAHs 1.0 PAH 11.3 mm PSF FIR 90 mm Encircled flux Kaneda et al. 2011 0.0 100” 0” Radius

  24. AKARIとSpitzerによる観測 We observed 20 nearby dusty elliptical galaxies with AKARIand Spitzer: NGC708, 1052, 1316, 1395, 1407, 1549, 2974, 3557, NGC3894, 3904, 3962, 4125, 4589, 4696, 5018, 5044, NGC5090, 7052, IC1459, IC3370. AKARI: NIR-FIR 10-band images + NIR spectra from the nearby galaxy project Spitzer: MIR spectra from GO1 + GO3 + GO5

  25. AKARI Near-IR spectra of NGC4125 & NGC4589 Heavily-smoothed high-resolution spectra Normalized to background spectrum Low-resolution spectra 3.4 3.5mm 3.4 3.5mm x1.1 x1.1 x1.6 x2.6 x2.3 x3.5 x4 3mm 4mm 3mm 4mm PAH11.3mm images NGC4589 NGC4125 Absorption due to aliphatic hydrocarbon groups. Abundant carbonaceous grains→ sources of PAHs?

  26. NGC5044 Temi et al. 2007 PAH Ha Kaneda et al. 2008 Contours：X-ray（Chandra） Gray: optical LLAGN-assisted energy feedback outflow? Outflow velocity ~400 km/s 　⇒　 Dust of 0.1 mm size reaches ~5 kpc in a sputtering lifetime of ~107 yr. Temi et al. 2007 Strong H2 lines, [SiII]

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