Suzaku Results of SN 1006: Chemica l abundances of the youngest Galactic Type Ia Supernova Remnant Katsuji Koyama Department of physics, Kyoto Universit y, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 “youngest ”
Dec 14, 2015
Suzaku Results of SN 1006: Chemical abundances of the youngest Galactic
Type Ia Supernova Remnant
Katsuji Koyama
Department of physics, Kyoto University, Kitashirakawa,
Sakyo-ku, Kyoto 606-8502
“youngest”
Japanese historical record of SNROn 8 Nov. 1230, Teika Fujiwara wroteguest star events in his diary “Meigetsuki”
「客星古現例」the ancient samples of “guest stars”.
Guest stars = comets, novae, and supernovae
8 7 6 5 4 3 2 1
SN10063C58
Crab Nebula
SN1006一條院 寛弘三年 四月二日 葵酉 夜以降 騎官中 有大客星 如螢惑 光明動耀 連夜正見南方 或云 騎陣将軍星本体 増変光
騎官 (kikan)
如螢惑( Mars )
On May 1st 1006, a great guest star appeared in “Kikan” (the Oriental name of the constellations Lupus and Centaurus).It was very bright like Mars, and visible in the southern sky in every night.
Old records from Asia and Arabia
明月記( Kyoto ):寛弘三年四月二日 (= 5/1) 如螢惑( like Mars )
Ibn al-Jawzi ( Baghdad ) : A large star similar to Venus
appeared to the left of qibla. at the beginning of the month
of Sha’ban (= 5/3).
Ali ibn Ridwan ( Egypt ) : 2.5 to 3 times as large as Venus.
The intensity of its light was a littlemore than a quarter of that moonlight.(5/5?)
宋史天文志( China ) :景徳三年四月戊寅 (=5/6) 如半月 ( half moon)
-2 Mag
-4 Mag
-8 Mag
-10 Mag
Ref : Full Moon = -12.6 Mg 、 Venus= -4.6 Mag
SN1006 : Historical Galactic SNR Type Ia SN
Distance = 2.2 kpcMaximum Mag = -20 Mag
Days after 1006/05/01
Mag
nit
ud
e-12
-10
-8
-6
-4
-2
0
2
4
2006 was one millennium after SN1006memory X-ray picture of SN1006 by Suzaku
Suzaku The 5th Japanese X-ray astronomical Satellite, lauched on July 10th 2005
Suzaku: “red angel bird” of the Oriental Mythology, living in the Southern Sky of the Palace
Suzaku
Wall painting in the old tomb“Kitora Kofun”
XIS (X-ray Imaging Spectrometer: CCD)
XRT
XIS
XRT (X-Ray Telescope)
In 2006, Suzaku saw a southern sky, and took a millennium-memorial X-ray picture of SN1006
High Temperature Plasmas in SN1006
Black : FI-CCDRed : BI-CCD
Discovery of Ar, Ca and Fe Lines
In normal cases, we can determine the chemical compositions using the conventional plasma code. The plasma code has been made based on the laboratory plasma physics. However,
This spectrum is very unusual, hence can notbe applied by the conventional plasma code.What is unusual, what is the difference between this plasma and those in the other SNRs ?
He-Kβat 670 eV
575eV672eV
820eV
730eV 920eV
He-like Kα: 570eVH-like Ly α :650eV
H-like oxygen
He-likeoxygen
If we see this spectrum in the other SNRs, most of the X-ray Astronomers believe that these two-lines are He-like and H-like Ka. This is true for any SNRs other than SN1006 .
We found Kγ 、 Kδ lines at 730 eV and 820 eV This is very surprising (no plasma code !) High electron temperature (kTe ~ 1.5 [keV] ), butHe-like is in low ionization states (kTi ~ 0.15 [keV])
↑ ↑ ↑ nt SN1987A Cas A CygnusLoop Kepler&Tycho
The plasma evolution in SNRs
Tpn
Te
Ti
Tp:proton temp.
Te: Electron temp
Ti: Ionization temp.
Shock by Velocity (V) kTp=mpV2, kTe=meV2
Tp ~ 1000*Te (mp/me =1000)kTp kTe , kTe kTi
Energy Transfer ∝ nt
Thermal ages ∝ nt
SN1006 is the “youngest” SNR in our Galaxy!
SN1006
Taking these non-equilibrium effects into account, we modified the conventional plasma codes, and fit the spectrum . It was very complicated job, hence
1) kTe=0.54 (0.52-0.58) keV, net= 6.7×109 :solar abundance
2) kTe = 1.2 (1.1-1.3) keV, net = 1.3×1010 :over abundance
3) kTe = 1.5 (1.5-1.6) keV, net = 7.4×108 : over abundance
Ejecta1: Reverse shock of Early heating (Outer Shell)Ejecta2: Reverse shock of Recent heating (Inner Shell)
Ejecta 2
CO
Mg
Si S
C
Fe
Large Ca, Fe (Nomoto el al. 1984)
Ejecta 1
Large Si, S
2) kTe = 1.2 (1.1-1.3) keV, net = 1.3×1010 = Ejecta1
3) kTe = 1.5 (1.5-1.6) keV, net = 7.4×108 = Ejecta2
Conclusion
(1) We discovered Ar, Ca and Fe Lines for the first time
(2) We found extremely non-equilibrium between electron temperature and ionization temperature.
(3) The ejecta consists of two plasma components: One has almost identical abundance profile to that of the theoretical prediction of type Ia SNR, and the other has lower abundance in Fe.
The former would be due to an inner part of the SNR and the latter is due to an outer part.