X-ray Observations of Supernova Remnants

YITP
My oﬃce:
Room 336, Bldg. No.5

Hiroyuki Uchida（Kyoto University）

Conference on SNe, YITP, Kyoto, 1 November 2013

Motivation
SN1006W44~30 light-year

Mixed-morphology SNR	~30 light-year

Shell-like SNR	Why do these SNRs have quite diﬀerent morphologies?
How can we trace the histories from SNe to SNRs?

Diﬀerent Spectra for Diﬀerent Types of SNRs
Suzaku XIS

W44high energy-resolution, low backgroundsuitable for extended sources~30 light-year

SN1006Countss-1 keV-1
スペクトル強度酸素O10SN1006
W44S硫黄アルゴンAr

1Ca
カルシウム

0.1

0.01~30 light-year

マグネシウム
Mg
Si硅素
Neネオン

Fe
鉄W44: Recombining Plasma
SN1006: Ionizing Plasma	0.512

エネルギー（キロ電子ボルト）
Energy(keV)

5

New Type of SNR Spectra Discovered with Suzaku
middle-aged SNR: W49B
Fe Kα

Fe Kβ

Radiative Recombination
Continuum (RRC)

Collisional Ionization
Equilibrium (CIE)

Cascade Lines
Ozawa+2009

RRC(→n=1)
Cascade (→n=1)
RRC(→n=2)
RRC(→n=1)

free electron

Fe+26

excited state

Cascade (Kα)
ground stateelectrontemperature
89

Energy (keV)

10Two Diﬀerent Types of SNR Evolutions

Standard EvolutionofMost SNRs

Temperature

TeTe: Electron TemperaturekH
ShocTzIonization
Equilibriumgeatin

Tz: Ionization TemperatureRadioX-ray

Time since Explosion

Non-standardEvolution

Temperature

Te < Tz
TeTz

Over-ionization→ Recombining Plasma→ enhancement of RRC

Time since Explosion

Recombining plasmas found only from mixed-morphology SNRs
IC443
Yamaguchi et al. 2009
(discovery, suggestinga rarefaction scenario)

W28
Sawada & Koyama
2012 (multi-Tz)

W49B

W44

Ozawa et al. 2009
(discovery)

Uchida et al. 2012b(spatial analysis, NEIJ)

G359.1-0.5
Ohnishi et al. 2011
(prominent RRC)

G346.6-0.2
Yamauchi et al. 2013

Mixed-morphology SNRRadioX-rayp shell-like (asymmetric) morphology in the radio
band and centrally peaked thermal emission in the
X-ray band (Rho et al. 1998).
p The morphology is associated with the origin of RP.

3D Hydrodynamical Simulationp Simulation of rarefaction had predicted
recombining plasma (Itoh & Masai 1987).
p Advanced simulation; Shimizu+2012.
p Disk-like CSM (e.g., Be stars) well explains“belt-like” structure such as W49B (alsomaybe G292.0+1.8).

equator viewpolar view

Shimizu+2012

W49B

ne t~10 12

G292.0+1.8

A possible scenario leading to over-ionization: Rarefactionp “Rarefaction scenario is plausible” (Yamaguchi+2009; Sawada &Koyama 2012; HU+2012b)
Rareﬁed Ambient Medium
Stellar Wind

Forward ShockDense CSM

SN explosion

1. Before SNe, stellar
wind forms dense
CSM around theprogenitor.

Rarefaction

2. After SNe, forward shockpropagates into dense
CSM.
3. Due to a large net, theejecta rapidly comes tothe collisional ionization
equilibrium (Te=Tz).

4. When the forward shock runs
over the dense CSM, theplasma rapidly expands into a
rareﬁed ambient medium.
5. The electron temperature
decreases adiabatically,hence Te<Tz.

Dense CSM is required: Type IIn SNe origin? → Future workMotivation
SN1006

W44

Core-collapse SNRinteracted with dense CSM
in the past	~30 light-year

Mixed-morphology SNR	Type Ia SNR
evolved in low-density ISM	~30 light-year

Shell-like SNR	As for SN1006, it is easier to date back to the time of explosion,and thus to get to its explosion mechanism itself.

“Phillips relation” (Phillips et al. 1993, 1999)
Phillips et al. (1999)"Relationship between the peak luminosity and the speed of luminosity evolution after
maximum light Δm15(B) (Phillips et al. 1993）

Magnitude of a Type Ia SN:

m0 = [mobs – Am(Gal)] – Km – Am(host)	
observation value
Galactic extinction

host galaxy extinction
red shift

Why do Type Ia SNe have diversity?

Mn/Cr = Good Tracer of Metallicity of the Progenitor
Z=9 10-3

Z=2 10-4

CrCrMnMnPark+ Suzaku2011

Park et al. (2013)p 55Co (p=27, n=28) → 55Mn (p=25,n=30): Neutron-excess element.
p He-burning: 14N → 18F → 18O → 22Ne
(p=10, n=12; p<n).
p End products of CNO cycle: 14N.
p Total yield of 14N depends on initial
metallicity of the progenitor.

p Hence 55Mn/52Cr is sensitive tometallicity of the progenitor

“Super-solar Metallicity”: SN 1604（Park et al. 2013）
Keplerʼs SNRPark et al. (2013)p Deep observation for
Kepler SNR with Suzaku(660-690ks)
p Metallicity of theprogenitor is signiﬁcantly
higher than the solar
metallicity: Z~3Z8
p Suggesting a fainter TypeIa SN than that of normalluminosity?
p Can we observe light echo
in the future?

Example of Theoretical Simulations for Asymmetric Type Ia Explosion

White Dwarf

Asymmetric DeﬂagrationOﬀ-center ignition

supernova

Jordan IV + 2012

3D simulations have indicated that “asymmetry” is essential for Type Ia SNe.

Supportive Evidence from SN observations and Simulations
Maeda et al. 2010: “An asymmetric explosion as the origin ofspectral evolution diversity in type Ia supernovae”
Fe-rich core

The asymmetric explosion is common for extragalactic Type Ia SNe.
If so, clear evidence should also be found from nearby SNRs.

“Asymmetry” of Shell Structure or SNRs

Mirror AsymmetryCore-Collapsep Core-collapse SNRs are easy to
be distorted by dense
circumstellar gas.
p Type Ia SNRs have more “round”
shape (Lopez+2009).

Type Ia

Lopez+2009

Asphericity

Horizontal axis: asphericity
Vertical axis: mirror asymmetry

10SN1006
Keplerʻs SNRTychoʼs SNR
Hayato+2010

b = +14.6
Core-CollapseInner Region(Broad Lines)

G272.2-3.2

1

RCW 86

Cas A
G292.0+1.8

Tychoʼs SNR

RCW 103

G337.2-0.7

G11.2-0.3
W49B

Type Ia

0.1

Absolute Galactic Latitude |b| (degree)

Ejecta Distribution in Type Ia SNRs

G15.9+0.2

Outer Region(Narrow Lines)

Kes79
G0.9+0.1

Cassam-Chenai+2008p Low ambient density = Easier to go back to the time of SN.
Tychoʼs SNR (Hayato+2010): Discovery of the ”Onion-like
Structure” of ejecta. ”Si and S ejecta have higher velocities(~3500 km s-1) than Fe ejecta (~3000 km s-1).”
p SN1006: located at the highest Galactic latitude. → Good forapproaching the explosion mechanism of a Type Ia SN.

red: 0.5-0.8keV
green: 0.8-2.0keV
blue: 2.0-4.5keV

A thousand years ago SN1006 was observed in Kyoto

藤原定家（1162-1241）
Fujiwara no Teikap

In his diary ”Meigetsuki (明月記)”p
p

「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」“A large guest star (Supernova) appeared within the Kikan(Lupus) constellation.”“It was very bright like Mars, and visible in the southern sky
every night. “No obscuring dense dust along the line of sight:
SN1006 located at high Galactic latitude

“Millenium” Long-time Observation of SN1006 with Suzaku

NWNErimCenterSWrimp Located on relatively high galacticlatitude (b = 14.6 deg).
p The ambient density is extremely low.
Ø nH ~ 0.03 cm­3 at NE (Yamaguchi+2008)
Ø nH ~ 0.085 cm­3 at SE (Katsuda+2009)p Fairly uniform circumstellar matter(Dubner+2002).
p Various line emissions from heatedejecta (Yamaguchi+2009).

SE0.4-1keV

1-3keVp SN1006 is a textbook sample for

3-5keV

investigating the origin of Type Ia
SNe.

2.31e-07 2.08e-07 1.85e-07 1.62e-07 1.39e-07 1.16e-07 9.23e-08 6.93e-08 4.61e-08 2.30e-0
2.31e-07 2.08e-07 1.85e-07 1.62e-07 1.39e-07 1.16e-07 9.23e-08 6.93e-08 4.61e-08 2.30e-08

1.30e-06 1.17e-06 1.04e-06 9.10e-07 7.80e-07 6.51e-07 5.20e-07 3.90e-07 2.59e-07 1.30e-07 3.91e-06 3.52e-06 3.13e-06 2.73e-06 2.34e-06 1.95e-06 1.56e-06 1.17e-06 7.79e-07 3.89e-07

p A total of ~400-ks observations (↓200ks for Center region) with Suzaku.
ObjectObs ID

RA NOM

DEC NOM

Exp. Time

Date

SN1006 Center502046010

225.7-41.9

211.7 ks

20090314

Spectral Analysis and Equivalent Width Maps
ONe
Mg

10S

1Counts sï1 keVï1

SiAr

0.1

Ca

Ejecta1
Ejecta2
ISM
PowerïlawCrOVII

NeSiS

Fe

0.01
10ï3r

50
ï50.5

1

2
Energy (keV)

5p Best-ﬁt model: two-component
ejecta with diﬀerent ionization
timescales plus power-law andISM components.
p Si and S are displaced toward
southeast. Shift velocity is
estimated to be ~3000 km/s

10

Radial Proﬁles of Ejecta Elements
10.1
0.01
10ï3Northwest

10ï410ï5
50
ï50.5

12
Energy (keV)

5

10.1
0.01
10ï310ï4Southeast

Southeast50
ï52.31e-07 2.08e-07 1.85e-07 1.62e-07 1.39e-07 1.16e-07 9.23e-08 6.93e-08 4.61e-08 2.3
0.5

12Energy (keV)

50.5

12
Energy (keV)

51

10.1

0.1

0.01

0.01

10ï310ï3

10ï410ï4

10ï5510ï5500ï5ï50.5

12Energy (keV)

5p Si, S, and Ar (yields fromincomplete Si-burninglayer) are displaced from
northwest to southeast.
p Fe distribution is also
asymmetric.
p Heavy elements distributeasymmetry.

Northwest

“3D” View of the Ejecta in SN1006
Frontal View

Side View
ObserverHamilton+1997

Several Observations ofbackground stars
suggest the line-of-sight
asymmetry of Fe basedon a Doppler shift ofabsorption lines of FeII.

Our result shows a clear
asymmetry of heavyelements (HU+2013).

Winkler+2005

Forward ShockNorthwest

Reverse ShockSoutheast+Observer

Geometric Center
Peak of the Proﬁlelight gray: Fe-rich coredark gray: Si-rich layer

Reverse-shock Heated Ejecta

Is the ambient density of SN1006 “Uniform”?

Cassam-Chenai+2008

red:
green:
blue:

0.5-0.8keV
0.8-2.0keV
2.0-4.5keV

Is the ambient density of SN1006 “Uniform”?

Line-of-sight Density Gradient (G299.2-2.9）
Park+2007

G299.2-2.9

SN1006 shows similar double-shell structure, also has density gradient?

Astro-H SXS Simulations for SN1006
O Heα
5000km/sCr KMn K

p Simulated SXS observations (200ks) ofa pointing the interior of SN1006.
p First estimation of Mn/Cr.
p Measuring line-of-sight expansion
velocity of some elements.
p ASTRO-H will provide new knowledge
concerning structures of SNRs andSNe.

6000km/s

Si Kα
4000km/s
5000km/s

Current Status of ASTRO-H
13m thermal-vacuum chamber at JAXA

System TTM (Thermal Test Model) test (Aug-Sep, 2012)

We will have some veriﬁcation tests in 2013-2015.
ASTRO-H will be launched in 2015!