Transcript Northern rim

Japanese historical
records of SNRs and
SUZAKU observation
of SN1006
2006/05/16
国宝「明月記」（冷泉家時雨亭文庫）
One Millennium after SN 1006? @Hangzhou
Hiroya Yamaguchi (Kyoto Univ., Japan)
Katsuji Koyama (Kyoto Univ.)
Junko Hiraga (RIKEN),
Aya Bamba (RIKEN)
My talk plan
• The Japanese historical records of SN1006
and other supernova remnants.
• Introduction of Japanese satellite “Suzaku”.
• Report of the Suzaku observation of
SN1006.
• Summary
Historical record of SNRs
Ancient China and Japan
Astronomical records (auroras, eclipse, shooting star and etc.)
were frequently appeared after 7th century.
The exchange between China and Japan was very active.
遣隋使 (Kenzuishi)
The mission
to China
煬帝 Yang Di
Astronomical
knowledge
and thought
聖徳太子 Shotoku-taishi
(assistance of emperor)
In 12-13th century, Teika Fujiwara (Japanese noble and poet)
collected the ancient astronomical records, and noted them in
his diary “Meigetsuki（明月記）”.
He started to write the diary
when he was 19 years old,
and continued for 56 years.
In those days, diaries had
the role of the records of
the ceremony, political affairs,
and disasters.
藤原定家 Teika Fujiwara (1162-1241)
Unusual astronomical phenomena (supernovae, eclipses,
comets, and shooting stars) were believed as the predictions of
famines, epidemics, and floods.
Japanese historical record of SNR
“Meigetsuki” (This page was written in 11/8, 1230.)
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Crab Nebula
「客星古現例」
the ancient samples of
“guest stars”.
Guest stars = comets, novae, and supernovae
3C58
SN1006
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
Chandra image of SN1006
In the reign-period of Ichijo-In, April 2nd, 3rd year of Kanko
(= May 1st, 1006), a great guest star appeared within
the constellation “Kikan”
騎官 (kikan) (=Imperial Guards).
It was very bright like Mars,
and visible in the southern sky
every night.
One possibility was the star of
“Kijin-Shogun” (= Chariots and
General) suddenly lighten?
騎陣将軍 (Kijin-Shogun)
Lupusκ
Crab nebula
後冷泉院 天喜二年 四月中旬以降 丑時
客星觜参度 見東方 孛天関星 大如歳星
Chandra image of Crab
In the reign-period of Goreizei-In, after the middle of April,
2nd year of Tenki (= May-June, 1054), a guest star appeared
nearby “Shi” and “Shin”
(= Orion) in eastern sky
天関 (Tenkan)
at 2:00. It shined near to the
Taurusζ
star of “Tenkan”, and its size
was comparable
to Jupiter.
觜, 参 = Orion
3C58
高倉院 治承五年 六月廿五日 庚午 戌時
客星見北方 近王良 守伝舎星
Chandra image of 3C58
王良 (Oh-Ryo)
Cassiopeiaβ
伝舎 (Densya) = Camelopardalis
In the reign-period of
Takakura-In, June 25th,
5th year of Jisyou
(= August 7th, 1181),
a guest star appeared
in northern sky at 20:00.
It was near to the star of
“Oh-Ryo” (= real person’s
name of ancient China)
and “Densya”.
“Meigetsuki” was designated as a national treasure in 2000.
It is preserved by Reizei-ke（冷泉家）,
descendant of Teika Fujiwara.
Kyoto Univ.
Reizei-ke
Kyoto Gyoen
Very near !
(～2km)
Kamo river
Introduction of Suzaku
Introduction of Suzaku
The 5th Japanese X-ray astronomical satellite.
It was launched on July 10th 2005.
朱雀 (Suzaku)
Suzaku is “Red Chinese Phoenix”,
the protector God of the South.
The wall painting of Suzaku
in “Kitora” tomb
Instrument
XRT (X-Ray Telescope)
Large effective area
450cm2 @1.5keV per 1 unit
XRT
XIS (X-ray Imaging Spectrometer)
Improved X-ray CCD with high efficiency
and good energy resolution
Low Background
Energy band : 0.2-12keV
HXD (Hard X-ray Detector)
Wide energy band
Si-PIN (8-50keV) & Scintillator (50-600keV)
Non-imaging detector, but low background
XIS
HXD
XIS
4 units
3 Front-illuminated (FI) CCD ‥ high efficiency for hard X-ray
1 Back-illuminated (BI) CCD ‥ high efficiency for soft X-ray
XRT
XRT
FI CCD
BI CCD
DE
PPU
to DP
MPU
PPU
Bonnet
AE/TCE
Base
Sensor
XIS
Quantum Efficiency of XIS
XIS
Comparison of efficiency and energy resolutions
O VIII
Suzaku XIS-FI
Suzaku XIS-BI
O VII
Ne IX
Ne X
Spectra of E0102-72
XIS
Comparison of background levels
BGD spectra normalized by solid angle of FOV and effective area
Suzaku XIS-FI
Suzaku XIS-BI
XMM EPIC-MOS
XMM EPIC-pn
Suzaku observation
of SN1006
Cosmic ray accelerator
Koyama et al. (1995) discovered
synchrotron X-ray from the shell of SN1006.
→ Indication of ～100TeV electrons
SNRs are cosmic ray accelerator !
10’
Unsolved problem
ASCA image of SN1006
The environment of accelerating place
‥ Plasma temperature, density, and so on.
Essential information to understand the acceleration mechanism.
Temperature ‥ 0.1 - 1 keV
Density ‥ 0.1 - 10 cm-3
We don’t know accurate value,
nor positional dependence.
Suzaku XIS-BI (high efficiency and good energy resolution)
is the best instrument to resolve this problem !
Thermal X-ray from SNRs
We can get the information of temperature and density
from thermal X-ray spectrum of SNR !
Shock front of SNR heats the matter up to a temperature of a few keV
(～107 K), and emits X-rays (bremsstrahlung and line emissions).
Electron temperature ‥ the shape of the bremsstrahlung continuum
Density ‥ the flux of the continuum and the line emissions
Brems: I(ν) ∝ (hν)-0.4 exp(-hν/kTe)・nenpV
Line: Iz∝ nenzV
ne = electron density,
np = proton density
nz = ion density,
V = volume of emission region
Thermal X-ray from SNRs
Ionization
Oxygen ionization fraction vs. electron temp.
He-like H-like
Neutral
He-like ion
H-like ion
Fully ionized
10
100
103
Electron temperature (eV)
1
104
Higher temperature
Higher ionized state
Higher
density
Non-equilibrium ionization (NEI)
Oxygen ionization fraction vs. net (for kTe=1.5keV)
At low density,
Te ≠ Tz
He-like H-like
Neutral
Fully ionized
Ionization equilibrium
requires ～103 years !
106
107
108
109
net (cm-3 s)
1010
1011
1012
XIS image of SN1006
43.5ksec
Suzaku observed SN1006
by 6pointing on 2005/9
and 2006/2.
62.4ksec
4 pointing on source
2 pointing for background
Extract spectrum from
whole northeast region.
59.1ksec
61.6ksec
XIS-BI 0.3 - 5.5 keV image
Spectra of whole NE region
H-O
He-O
He-O
band
Non-thermal
emission
Black : XIS-BI
Red : average of 3 XIS-FIs
3 - 5 keV band
Successfully divided oxygen lines and synchrotron component !
Narrow band images of XIS-BI
He-O line band
3 - 5 keV band
Distributions of thermal plasma (line emission) and
non-thermal electron (synchrotron emission) are different !
Narrow band images of XIS-BI
NE rim of SN1006
He-O line band
3 - 5 keV band
Easthern rim emits X-rays in the He-O band (soft thermal X-rays),
and northern rim emits hard X-rays ??
Spectral analysis of NE region
We divided NE region into 8x8 region,
and extracted spectra
from each square region.
Northern rim
Compared the fluxes of
O lines and 3-5keV band.
Used region:
in the YELLOW frame
Inner region
Eastern rim
He-O line vs. hard X-ray emission
Northern rim
Eastern rim
Inner region
Consistent with
imaging analysis !
H-O line vs. hard X-ray emission
Northern rim
Similar distribution to
He-O vs. hard X-ray
Eastern rim
Inner region
Chandra image of SN1006
These regions are correspond to
2 Chandra filaments in NE shell.
Northern rim
Northern rim
Inner region
Eastern rim
The first result:
We distinguished the spectral
properties of two filaments !
Eastern rim
Chandra image
with Suzaku FOV.
Inner
region
Eastern rim
Black: NH=1x1021cm-2
Red: NH=2x1021cm-2
Blue: NH=3x1021cm-2
H-O/He-O～0.2
in all regions !
Northern rim
He-O
High Density
H-O
More detailed analysis and discussion
High Temp.
kTe vs. net (for H-O/He-O=0.2)
Line intensity: Eastern rim > Northern rim
→ Density: Eastern rim > Northern rim
H-O/He-O ratio: Eastern rim = Northern rim
→ Temperature: Eastern rim < Northern rim
More detailed analysis and discussion
Non-thermal emission
Γ～ 2.7
Higher energy electrons
exist in Northern rim ?
Emax ∝ V ∝ρ-1/5
Γ～ 3.1
Black: Northern rim
Red: Eastern rim
Low density
→ High shock speed
→ High acceleration efficiency
Future work
Quantitative decision of temperature, density,
and maximum energy of accelerated electrons
by spectral fitting with precise response of XIS.
Summary
• We observed SN1006 with Suzaku.
• We succeed to divide two oxygen lines
from continuum spectrum.
• We discovered positional dependence of
line intensities in the NE region of SN1006.
• E rim = High density and low temperature,
N rim = low density and high temperature?
HXD
Comparison of background levels
Counts sec-1 keV-1 cm-2
BGD spectra normalized by effective area
1Crab
BeppoSAX-PDS
RXTE-PCA/HEXTE
Suzaku HXD-PIN/GSO
10
Energy (keV)
100
500
Discussions
North rim
East rim
Inner region
Line
weak
intense
middle
Non-thermal
intense hard
intense
soft
weak
Density of ISM ?
‥ Line intensity ∝ ρ2
‥ Radius ∝ ρ-1/3
rnorth > reast (Rothenflug et al. 2004)
VLA (1518MHz)
image of SN1006