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The Suzaku PV observation of the Planetary Nebula BD+30°3639

Mio MURASHIMA , Motohide KOKUBUN ( U-Tokyo ), Hiroshi MURAKAMI ( ISAS ), Kiyoshi HAYASHIDA ( Osaka-U ), Kyoko MATSUSHITA ( Tokyo-U.Sci ), Jun'ichi KOTOKU ( Titech ), Keith ARNAUD, Kenji HAMAGUCHI ( GSFC ), Kazuo MAKISHIMMA ( U-Tokyo/RIKEN ).

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The Suzaku PV observation of the Planetary Nebula BD+30°3639

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  1. Mio MURASHIMA, Motohide KOKUBUN (U-Tokyo), Hiroshi MURAKAMI (ISAS), Kiyoshi HAYASHIDA (Osaka-U), Kyoko MATSUSHITA (Tokyo-U.Sci), Jun'ichi KOTOKU (Titech), Keith ARNAUD, Kenji HAMAGUCHI (GSFC), Kazuo MAKISHIMMA (U-Tokyo/RIKEN) The Suzaku PV observation of the Planetary Nebula BD+30°3639 • Mostly based on the PhD Thesis by Mio Murashima • “X-ray Study of Planetary Nebulae” • Nov. 2005: Approved by SWG to use the Suzaku data, on condition that the results be published by the end of March. • Dec. 20, 2005: Thesis submitted to Dept. Astronomy, U.Tokyo. • Jan. 26, 2006: Thesis defense completed successfully. • Feb. 14, 2006: Thesis accepted. • March, 2006: Degree to be awarded. To be submitted to ApJL as Murashima et al.

  2. 1. Qualification of Mio Murashima (Guideline set by the Steering Comm. on Jan. 13, 2006) 1. Contributed to R&D and pre-launch tests of the HXD. 2. Explored X-ray emission from pl. nebulae (with Dr. Kokubun). 3. Proposed and planned the PV observation of BD+30 3639 (accepted on Sept. 10, 2005). 4. Contributed to quantification of the XIS low-E QE change (on xoops). 5. Lead data analysis, and discovered a very high C/O ratio. 6. Accomplished a fine PhD thesis in only half a year after the launch (perhaps the quickest record among Japanese astro-satellites). 7. Her results selected as one of three press-releasetopics at the JAS meeting in March 2006. 8. Presently, serving as a duty scientist atUSC.

  3. 2.5 arcsec color: H-alpha contours: X-ray 2. The target (2-1) Basic information • BD+30°3639 / HD184738 / V1966 Cyg • One of the most well studied planetary nebulae (PNe) • (α,δ)=(19 34 45.23, +30 3058.9) ; (l,b)= (64.79,+5.02) • Distance 1.3±0.2 kpcNH ~ 1e21 cm-2 • The X-ray brightest PN. • X-rays are emitted from inside the optical shell. • Similar shapes in C- and O-bands. 0.3–0.5 keV 0.5–0.7 keV Suzaku SWG

  4. Ne (H) assumed • Responses to 0.37 keV monoenergetic X-rays Newton Chandra C N O XIS-BI XIS-FI (2-2) Previous X-ray spectroscopy • Extreme abundances suggested ASCA Arnaud et al. (1996) 0.5 1.0 1.5 keV Chandra Kastner et al. (2000) Mannes et al. (2003) Suzaku SWG

  5. XIS field of view 3. The Suzaku Observation • PV-phase observation on 2005 September 21-22 • Exposure 34.3 ks • 0.033 c/s/XIS-FI, 0.089 c/s/XIS1 SNR G65.2+5.7 18 arcmin 1 deg. SDSS optical image Gray scale: [OIII] Contours: X-rays(ROSAT) Mavromatakis et al. (2002) Suzaku SWG

  6. bkgd region source region XIS-1: 0.3–0.5 keV XIS-1: 0.5–0.7 keV 5. The XIS Images XIS-0 (0.3-0.7 keV) XIS-1 (0.3–0.7 keV) Suzaku SWG

  7. He-like O-Kα 0.56 keV H-like C-Kα (0.37 keV) H-like O-Kα 0.65 keV C-Kβ (0.44 keV) He-like Ne-Kα 0.91 keV Inter-Stellar NH (1e21) × 0.4 × 0.4 Excess NH (1e21) XIS-BI response (initial) × 0.5 Decreasing relative QE × 0.75 source region, background region 6. Analysis of the XIS Spectra (6-1) Raw XIS-1 spectra [H-like C] / [He-like O] line ratio kT=0.2 keV 1 solar ~0.3 Expected count ratio : ~0.02 The observed C lines are much stronger! Suzaku SWG

  8. After correction XMM model XIS-1 XIS-023 (6-2) The XIS low-energy CAL (on xoops) • XIS gain: self-calibrated (2-3 %) using lines in the source spectra • Low-E QE: calibrated using RXJ 1856.5-3754 (2005 Oct. 24). Before correction XIS-1 XIS-023 • Energy dependence of excess absorption ⇒ modeled so that the XIS spectra of RXJ 1856 can be reproduced by the XMM-determined blackbody model. • Time evolution of the excess absorption ⇒ modeled so that the Chandra flux of BD+30 3639 agrees with that with Suzaku. • QE decrease from the launch at 0.37 keV is ~54% on Sept. 21, and ~30% on Oct. 24. Suzaku SWG

  9. OVIII NeIX CVI OVII 0.3 0.5 1.0 2.0 Energy (keV) Fiexed at solar ratios ⇒ kT ~ 0.23 keV, ab.~ 0.01 solar (χ2/dof = 296/78) (6-3) Simple model fits to the XIS-1 spectrum APEC, NH=1x1021 cm-2 1.5 0.3 0.5 1.0 2.0 Energy (keV) Fixed at 1 solar abundance ⇒ kT ~ 0.24 keV (χ2/dof = 648/79) The spectrum cannot be reproduced by isothermal solar-ratio IE models. Suzaku SWG

  10. (6-4) 1T analysis vAPEC, ACIS/XIS-1/XIS-023 joint NH = (2.1+0.2–0.4) e21 kT = 0.19 ± 0.01 keV C = 19+43-11 N = 0.67+0.25-0.20 O = 0.20+0.03-0.02 Ne = 1.1+0.2-0.1 Fe < 0.07 Others = 0 fixed χ2/dof = 312/229 XIS-1 ACIS XIS-023 0.3 0.5 1.0 1.5 Energy (keV) • Absolute abundances are highly uncertain because; • He/H ratio can be non-unity • Metals themselves emit continuum Suzaku SWG

  11. Confidence contours 68%, 90%, 99% (6-5) 1T abundance ratios C/O N/O Abundance ratios are well dtermined. Ne/O Suzaku SWG

  12. 1T: C/O = 75~110 2T: C/O = 35~120 10 20 30 50 100 200 Assumed C/O ratio • Lower-kT plasmas would emit stronger C-lines. What if there are mutiple kT’s (but with the same abundances)? • Test 2T-model fits (free kT’s and free norms), but asuuming the C/O ratio. ACIS XIS-1 XIS-023 (6-6) 2T analysis ACIS XIS-1 XIS-023 0.3 0.5 1.0 2.0 Energy (keV) The high C/O ratio remains unchanged even considering muti-kT condition.

  13. Masss loss conduciton He-burning shell H-rich env. convection Outer shock 7. Interpretation Shell (nebula) Contact discontinuity X-ray emission (size, kT,,..) Inner shock Interpretable in temrs of Interacting Stellar Wind model (Kwok et al. 1978; Volk & Kwok 1985) Hot gas Fast wid （700 km/s） Lx~ ~ 1.4×1033 erg s-1 only ~0.1% of kinetic luminosity supplied by the winds Central star Mass, density, and ionization equilibrium of the plasma Mx~4×10-4M◎ ； ne~100 cm-3 ; t~103 yr ; ne t~ 3×1012 We have successfully detected the He-burning products at the final evolutionary stage of a low-mass star! C/O ~ 60 (solar units) Typical in the He-burning layer; competition between 3α reaction and 12C(α,γ)16O (Suda et al. 2004) N/O ~ 3 (solar units) Remainder of CNO cycle 14N(α,γ)18F(β+ν)18O(α,γ)22Ne Ne/O ~ 7 (solar units) Suzaku SWG

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