Japanese historical records of SNRs and SUZAKU observation

of SN10062006/05/16 One Millennium after SN 1006? @Hangzhou

Hiroya Yamaguchi (Kyoto Univ., Japan) Katsuji Koyama (Kyoto Univ.)

Junko Hiraga (RIKEN),

Aya Bamba (RIKEN)

国宝「明月記」（冷泉家時雨亭文庫）

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

Astronomical records (auroras, eclipse, shooting star and etc.)were frequently appeared after 7th century.

The exchange between China and Japan was very active.

煬帝 Yang Di

聖徳太子 Shotoku-taishi(assistance of emperor)

遣隋使 (Kenzuishi)The mission to China

Astronomical knowledge and thought

Ancient China and Japan

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）” .

藤原定家 Teika Fujiwara (1162-1241)

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.

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.)

「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

Chandra image of 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

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” (=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

騎官 (kikan)

Crab nebula

Chandra image of Crab

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

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 at 2:00. It shined near to the star of “Tenkan”, and its size was comparable to Jupiter.

觜 , 参 = Orion

天関 (Tenkan)Taurusζ

3C58

Chandra image of 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

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”.

王良 (Oh-Ryo)Cassiopeiaβ

伝舎 (Densya) = Camelopardalis

Kyoto Gyoen

Reizei-ke

Kamo river

Kyoto Univ.

Very near ! (～ 2km)

“Meigetsuki” was designated as a national treasure in 2000.

It is preserved by Reizei-ke （冷泉家） , descendant of Teika Fujiwara.

Introduction of Suzaku

Introduction of SuzakuThe 5th Japanese X-ray astronomical satellite.

It was launched on July 10th 2005.

Suzaku is “Red Chinese Phoenix”, the protector God of the South. The wall painting of Suzaku

in “Kitora” tomb

朱雀 (Suzaku)

Instrument

XRT (X-Ray Telescope)Large effective area 450cm2 @1.5keV per 1 unit

XIS (X-ray Imaging Spectrometer)Improved X-ray CCD with high efficiency

and good energy resolutionLow BackgroundEnergy 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

XRT

XIS

HXD

XIS4 units3 Front-illuminated (FI) CCD high efficiency for hard X-ray‥1 Back-illuminated (BI) CCD high efficiency for soft X-ray‥

XRT

SensorAE/TCE

to DP

MPU

PPU

PPU

Bonnet

Base

DE

XRT

XIS

FI CCDBI CCD

Quantum Efficiency of XIS

Suzaku XIS-FISuzaku XIS-BI

Spectra of E0102-72

XIS

O VII

O VIII

Ne IX

Ne X

Comparison of efficiency and energy resolutions

XISComparison of background levels

BGD spectra normalized by solid angle of FOV and effective area

Suzaku XIS-FISuzaku XIS-BIXMM EPIC-MOSXMM EPIC-pn

Suzaku observationof SN1006

Cosmic ray acceleratorKoyama et al. (1995) discovered synchrotron X-ray from the shell of SN1006.

→ Indication of ～ 100TeV electrons

SNRs are cosmic ray accelerator !

Unsolved problem The environment of accelerating place ‥ Plasma temperature, density, and so on. Essential information to understand the acceleration mechanism.

Temperature 0.1 - 1 keV‥ We don’t know accurate value, Density 0.1 - 10 cm‥ -3 nor positional dependence.

Suzaku XIS-BI (high efficiency and good energy resolution) is the best instrument to resolve this problem !

ASCA image of SN1006

10’

Thermal X-ray from SNRsWe 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) ・ nenpVLine: Iz n∝ enzV

ne = electron density, np = proton densitynz = ion density, V = volume of emission region

Thermal X-ray from SNRs

He-like ion H-like ion

IonizationHe-like H-like Fully ionized

1 10 100 103 104

Electron temperature (eV)

Oxygen ionization fraction vs. electron temp.

Non-equilibrium ionization (NEI)

At low density, Te ≠ Tz

Ionization equilibrium requires ～ 103 years !

He-like H-like Fully ionized

106 107 108 109 1010 1011 1012

net (cm-3 s)

Oxygen ionization fraction vs. net (for kTe=1.5keV)

Higher temperatureHigher density Higher ionized state

Neutral

Neutral

XIS image of SN1006

XIS-BI 0.3 - 5.5 keV image

43.5ksec

62.4ksec

59.1ksec 61.6ksec

Suzaku observed SN1006 by 6pointing on 2005/9 and 2006/2.

4 pointing on source2 pointing for background

Extract spectrum from whole northeast region.

Spectra of whole NE region

Black : XIS-BIRed : average of 3 XIS-FIs

He-O

H-O

Non-thermal emission

Successfully divided oxygen lines and synchrotron component !

He-O band

3 - 5 keV band

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

He-O line band 3 - 5 keV band

NE rim of SN1006

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 regionWe divided NE region into 8x8 region, and extracted spectra from each square region.

Northern rim

Eastern rim

Inner region

Compared the fluxes of O lines and 3-5keV band.

Used region: in the YELLOW frame

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

Eastern rim

Inner region

Similar distribution to He-O vs. hard X-ray

Northern rim

Eastern rim

These regions are correspond to 2 Chandra filaments in NE shell.

Chandra image with Suzaku FOV.

Northern rim

Eastern rim

The first result: We distinguished the spectral properties of two filaments !

Chandra image of SN1006

Inner region

More detailed analysis and discussion

He-O

H-O

Northern rim

Eastern rimInner region

Black: NH=1x1021cm-2

Red: NH=2x1021cm-2

Blue: NH=3x1021cm-2

H-O/He-O ～ 0.2 in all regions !

High Temp.

Hig

h D

ens

ity

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

Black: Northern rimRed: Eastern rim

Γ ～ 2.7

Γ ～ 3.1

Higher energy electrons exist in Northern rim ?

Emax ∝ V ρ∝ -1/5

Low density → High shock speed→ High acceleration efficiency

Non-thermal emission

Future workQuantitative 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?

HXDComparison of background levelsBGD spectra normalized by effective area

1Crab

RXTE-PCA/HEXTEBeppoSAX-PDS

Suzaku HXD-PIN/GSO

Energy (keV)10 100 500

Cou

nts

sec-1

keV

-1 c

m-2

Discussions

Density of ISM ? ‥ Line intensity ρ∝ 2

‥ Radius ρ∝ -1/3

rnorth > reast (Rothenflug et al. 2004)

Line Non-thermalNorth rim weak intense hardEast rim intense intense softInner region middle weak

VLA (1518MHz)image of SN1006