1 / 33

I. Origin of the dust emission from Tycho’s SNR

AKARI infrared observations of SNRs. Ishihara Daisuke (Nagoya Univ.). I. Origin of the dust emission from Tycho’s SNR. II. Mapping observations of [Fe II] lines and dust emission of IC443 by IRSF & AKARI. III. Summary.

niles
Télécharger la présentation

I. Origin of the dust emission from Tycho’s SNR

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. AKARI infrared observations of SNRs Ishihara Daisuke (Nagoya Univ.) I. Origin of the dust emission from Tycho’s SNR II. Mapping observations of [Fe II] lines and dust emission of IC443 by IRSF & AKARI III. Summary

  2. I. Origin of the dust emission from Tycho’s SNR Ishihara, D., et al. 2010

  3. 1. Tycho’s SNR - introduction Tycho’s SNR • Type Ia • Observed in 1572 by Tycho Brahe - Distance = 1.5～3.1 kpc • Size = 8’ (5.3pc) • Extensively studied in X-ray, Radio and Optical • Detection of IR emissioin + IRAS (Schwaltz 1995) + ISO/ISOCAM (Douvion+ 2001) Tycho’s SNR • Type Ia • Observed in 1572 by Tycho Brahe - Distance = 1.5～3.1 kpc • Size = 8’ (5.3pc) • Extensively studied in X-ray, Radio and Optical • Detection of IR emissioin + IRAS (Schwaltz 1995) + ISO/ISOCAM (Douvion+ 2001) 4.1 -6.1 keV1.63-2.26 keV0.95-1.26 keV, (Warren+ 2005)

  4. 1. Tycho’s SNR - introduction Fastexpansion(0.45”/yr) Tycho’s SNR • Type Ia • Observed in 1572 by Tycho Brahe Slowexpansion(0.15”/yr) - Distance = 1.5～3.1 kpc • Size = 8’ (5.3pc) • Extensively studied in X-ray, Radio and Optical • Detection of IR emissioin + IRAS (Schwaltz 1995) + ISO/ISOCAM (Douvion+ 2001) X-ray (Suzaku 0.1-12 keV) Expansion velocity from VLA 1375 Hz(Reynoso+ 1997) Molecular cloud (12CO) Hot dust (AKARI 18um)

  5. 2. AKARI infrared observations Tycho’s SNR • Type Ia • Observed in 1572 by Tycho Brahe - Distance = 1.5～3.1 kpc • Size = 8’ (5.3pc) • Extensively studied in X-ray, Radio and Optical • Detection of IR emissioin + IRAS (Schwaltz 1995) + ISO/ISOCAM (Douvion+ 2001) X-ray (Suzaku 0.1-12 keV) Expansion velocity from VLA 1375 Hz(Reynoso+ 1997) We investigated physical state and origin of the MIR emissionusing AKARI (9, 15, 18, 24, 65, 90, 140, 160um) images. Molecular cloud (12CO) Hot dust (AKARI 18um)

  6. 3. Overall picture Infrared SED of dust emission Flux (Jy) AKARI 9mm band AKARI 18mm band 15/24mm intensity ratio (PAH) (Hot dust) (100～136 K) 0.3 0.2 Infrared SED of dust emission Total SED (AKARI+IRAS) is characterized by two temperatures MIR map limb-brightened shell structure T1～25 KISM Flux (Jy) T2～95 KShock heateddust Dust temperature ⇒ higher at outer edge (shock front) ⇒ Shock heated dust of IS origin

  7. 3. Overall picture Time scale of the dust destruction by sputtering in hot plasma (Draine & Salpeter 1979, Tielens et al. 1994) 500 yr 150 yr ⇔ 500 yr(Age of the SNR) ⇒150 yr Time scale of PAH destruction is 1/100～1/1000 faster ⇒ < 1 yr . . . vanished -3 -3 6 6 C=0.79 (silicate), a=1nm, T=8.4x10 K、nH=10 cm C=0.79 (silicate), a=1nm, T=8.4x10 K、nH=10 cm AKARI 9mm band AKARI 18mm band 15/24mm intensity ratio atom (PAH) (Hot dust) (100～136 K) ISM dust is heated at the shock front and destructed by the sputtering in the post-shock hot-plasma ⇒ Shell structure of ～100 K 0.3 0.2 Time scale of the dust destruction by sputtering in hot plasma Infrared SED of dust emission T1～25 KISM Flux (Jy) (Draine & Salpeter 1979, Tielens et al. 1994) T2～95 KShock heateddust ⇔ 500 yr(Age of the SNR) ⇒150 yr Time scale of PAH destruction is 1/100～1/1000 faster ⇒ < 1 yr . . . vanished

  8. 3. Overall picture AKARI 9mm band AKARI 18mm band 15/24mm intensity ratio (PAH) (Hot dust) (100～136 K) NE NW ISM dust is heated at the shock front and destructed by the sputtering in the post-shock hot-plasma ⇒ Shell structure of ～100 K 0.3 0.2 Time scale of the dust destructionby sputtering in hot plasma Infrared SED of dust emission We focus on the two bright spots at NE and NW boundaries. Flux (Jy) (Draine & Salpeter 1979, Tielens et al. 1994) -3 6 C=0.79 (silicate), a=1nm, T=8.4x10 K、nH=10 cm ⇔ 500 yr(Age of the SNR) ⇒150 yr Time scale of PAH destruction is 1/100～1/1000 shorter ⇒ < 1 yr . . . vanished

  9. 4.1. Origin of NE and NW emission NE NW Gas (H2) 2M -60～-63 km/s Ratio Hot dust Gas/dust ～100 K 20M - 4 - 4 2x10 M 2x10 M 5 10 4 10 (cold dust) (cold dust) AKARI AKARI Infrared SED of dust emission Flux (Jy) NE NW Local SED for NE region - Large amount of cold dust at NE Spatial distribution of molecular gas, cold dust ⇒ SNR is interacting with dense medium at NE boundary ⇒ NW is relatively rich in warm dust compared with amount of molecular gas

  10. 4.2. Origin of dust emission at NW boundary HeatedISM Ejectafrom SNR ColdISM Contactdiscontinuity Ejecta origin Blast wave Schematic view around blast wave ISM origin AKARI 18μm intensity mapー Blast waveー Conduct discontinuity (Warren+ 2008) ⇒ The NW warm dust could have an SN ejecta origin

  11. 4.3. Composition of newly formed dusts Spitzer / IRS 5~36μm spectrum Image : AKARI mid-IR (15μm)Contour: Hα • Featureless continuum(No lines, dust features) • Composed of pure Fe? IRS spectrum of Cas A (Rho+ 2008)

  12. 5. Summary • Infrared observations of Tycho’s SNR(AKARI 9-160μm)⇒ Physical state (temperature, heating source) and origin of hot dusts • Overall picture: Dusts of an ISM origin are heated and destroyed in the hot plasma • NEregion: Interaction with dense ISM • NW region: Hot dusts without dense ISM- small gas/hot dust mass ratio- located inside the contact discontinuity ⇒ SN ejecta origin？ • First suggestion of dust formation in Type Ia SNR → impact on the transmigration of the ISM in our galaxy and early universe. • Demonstrates advantage of AKARI diffuse mapscombined with X-ray and 12CO maps.

  13. II. Mapping observations of [Fe II] lines and dust emission of IC443by IRSF & AKARI Kokusho, T., et al. in prep.

  14. 1. Introduction □ IC443- Type II (Troja+ 2008)- Distance: ~1.5 kpc- Size: 45 amin (20 pc)- Age: ~104yr - Heavy interaction with the ISM (Saken+ 1992) - Over-ionized X-ray plasma Center-filled, rapid cooling? (Kawasaki+ 2002)- [Fe II] line emission in NE part of the remnant → J-shock (Graham+ 1987)- H2line emission in south part of the remnant → C-shock (Rho+ 2001) IC443 Hα image

  15. 1. Introduction □ IC443- Type II (Troja+ 2008)- Distance: ~1.5 kpc- Size: 45 amin (20 pc)- Age: ~104yr - Heavy interaction with the ISM (Saken+ 1992) - Over-ionized X-ray plasma Center-filled, rapid cooling? (Kawasaki+ 2002)- [Fe II] line emission in NE part of the remnant → J-shock (Graham+ 1987)- H2line emission in south part of the remnant → C-shock (Rho+ 2001) 30’ IC443 IRAS 100μm image Saken+1992

  16. 1. Introduction □ IC443- Type II (Troja+ 2008)- Distance: ~1.5 kpc- Size: 45 amin (20 pc)- Age: ~104yr - Heavy interaction with the ISM (Saken+ 1992) - Over-ionized X-ray plasma Center-filled, rapid cooling? (Kawasaki+ 2002)- [Fe II] line emission in NE part of the remnant → J-shock (Graham+ 1987)- H2line emission in south part of the remnant → C-shock (Rho+ 2001) 30’ IC443 ASCA 0.7-10 keV image Contours: softness ratio (Kawasaki+ 2002)

  17. 1. Introduction □ IC443- Type II (Troja+ 2008)- Distance: ~1.5 kpc- Size: 45 amin (20 pc)- Age: ~104yr - Heavy interaction with the ISM (Saken+ 1992) - Over-ionized X-ray plasma Center-filled, rapid cooling? (Kawasaki+ 2002)- [Fe II] line emission in NE part of the remnant → J-shock (Graham+ 1987)- H2line emission in south part of the remnant→ C-shock (Rho+ 2001) IC443 2MASS imageBlue: J, green: H, red: Ks-band(blue; [Fe II],Pβ, red: H2)

  18. 1. Introduction □ IC443- Type II (Troja+ 2008)- Distance: ~1.5 kpc- Size: 45 amin (20 pc)- Age: ~104yr - Heavy interaction with the ISM (Saken+ 1992) - Over-ionized X-ray plasma Center-filled, rapid cooling? (Kawasaki+ 2002)- [Fe II] line emission in NE part of the remnant → J-shock (Graham+ 1987)- H2line emission in south part of the remnant→C-shock (Rho+ 2001) Based on observations of [Fe II] line emissions and IR dust emissions,we discuss on supply of Fe element from SNRs to the ISM. IC443 2MASS imageBlue: J, green: H, red: Ks-band(blue; [Fe II],Pβ, red: H2)

  19. [OI] [CII] dust 65 90 140 160 l 2. FIR images from AKARI all-sky survey 90mm 65mm 90MJy/sr 110MJy/sr 140mm 160mm 300MJy/sr 240MJy/sr

  20. [OI] [CII] dust 65 90 140 160 l 2. FIR images from AKARI all-sky survey [OI] 90mm Contours: 140mm 110MJy/sr 140mm [CII] 240MJy/sr

  21. [OI] [CII] dust 65 90 140 160 l 2. FIR images from AKARI all-sky survey [OI] 90mm Contours: 140mm AKARI 2.5 – 5 mm spectra 110MJy/sr 140mm [CII] 240MJy/sr

  22. [OI] [CII] dust 65 90 140 160 l 2. FIR images from AKARI all-sky survey 90mm 65mm 90MJy/sr 110MJy/sr 140mm 160mm 300MJy/sr 240MJy/sr

  23. [OI] [CII] dust 65 90 140 160 l 2. FIR images from AKARI all-sky survey 90mm 65mm Broad bands tracing dust emissionwith small contribution of [OI] 63μm and [CII] 158μm line emissions. 90MJy/sr 110MJy/sr 140mm 160mm → Derive hot-dust mass distribution by fitting dust SEDs composed of Spitzer 24μm, AKARI 90μm, and 140μm intensities. 300MJy/sr 240MJy/sr

  24. 3. Observations of [Fe II] lines [Fe II] 1.256μm : 4D7/2 → 6D9/2 [Fe II] 1.644μm : 4D7/2 → 4F9/2 Transitions from same level.→ The intensity ratio is theoretically derived from Einstein A-coeffs.(Narayan+ 2010) → Accurate Av correction → Av-free [Fe II] intensity IRSF telescope of Nagoya Univ.(at South Africa)Nagayama+ 2008 1.644 1.256 Pβ (%) J H (μm) Narrow-band filters for [Fe II] 1.256μm & 1.644μm

  25. 3. Origin of [Fe II] emission • ISM: ~98 % of Fe is depleted on dust grains[Fe II] 1.64μm / Brγ~1 • SNRs: Fast shocks (~100 km/s)⇒ destruction of dust grains • [Fe II]1.64μm / Brγ~100 (Koo+ 2007) • [Fe II] IP: 7.9 eV(< 13.6 eV) • In equilibrium hot plasma (T=107K),most of Fe is Fe20+no Fe1+ atom → Tracers of fast shocks, young SNRs (Mazzotta+ 1998)

  26. 3. [Fe II] distribution → Derive Fe mass distribution from Av-free [Fe II] intensities assuming LTE with T~104 K. (erg/s/cm2/sr) IRSF[Fe II] 1.256μm IRSF[Fe II] 1.644μm 2MASS J, H, Ks

  27. 3. [Fe II] distribution AKARI 9μm(PAH, H2lines) atom [Fe II]1.644μm Contours: Hα+ [NII] AKARI 18μm(hot dust)

  28. 4. Comparison of dust mass and Fe mass □ Dust mass related to the SNR SED fitting by 2 temp. B.B. Hot dustcomponent - Hot dust … shock heated - Cold dust … (foreground or background ?) (μm) → Mdust assuming, a=0.1μm, Qabs=30cm2g-1 (Hildebrand 1983) □ Fe+ mass MFe = N・(unit mass)

  29. 4. Discussion AKARI IR SED IRSF [Fe II] 10’ Dust mass Fe+ mass - Fe / hot dust mass ratio shows excess in some regions. (excess amount ~106Msun) Solar abundance ~ 0.4 Fe / hot dust mass ratio

  30. 4. Comparison of time scales In the hot plasma of Te=107, ne=1.7 cm-1, adust=0.1μm(Yamaguchi+ 2009, Petre+ 1988) □ Life time of dust grains in hot plasma: (Darine+ 1979) ⇒ ~1x105yr □ Time scale to reach ionizationequilibrium : Fe1+disappears at ionization equilibrium (Te=107K) ⇒~ 2x104yr (yr) (Masai 1994) → [Fe II] line emissions attenuate faster than IR dust emission.

  31. 4. Discussion AKARI IR SED IRSF [Fe II] 10’ Dust mass Fe+ mass - Fe / hot dust mass ratio shows excess in some regions. (excess amount ~106Msun) - [Fe II] line emissions attenuate faster than IR dust emission. Solar abundance ~ 0.4 ⇒ Fe ejected from SNR ? Fe / hot dust mass ratio

  32. 5. Summary • AKARI mid-& far-infrared & IRSF near-IR observation of IC443 • Northern region: [Fe II] originated by dust sputtering in J-shock • Southern region: H2 and [O I] in C-shock • Accurate correction of extinction by observing two [Fe II] lines • Fe+ / hot dust mass ratio shows excessin some parts of IC443→ [Fe II] line emissions attenuate faster than IR dust emission→ Fe of an SN ejecta origin ?

  33. III. Summary • Interaction of SNRs with the dense ISM • → IR observations • Fe in ejecta of SNRsTycho’s SNR (10-4 Msun) … Type IaIC443 (10-6 Msun) … Type II • Utilization of AKARI All-Sky diffuse maps(shock tracer, past shock tracer, as well as indicators of dust temperature, dust mass, etc.)

More Related