The multi-wavelength context of the future gamma-ray instruments: X-rays

T. Dotani1), A. Bamba2), T. Fujinaga3,1)

1) ISAS/JAXA2) Aoyama Gakuin Univ.3) Tokyo Institute of Technology

Joint Discussion on the Highest-Energy Gamma-Ray Universe observed with Cherenkov Telescpe Arrays

CONTENTS

1. Current/Future X-ray missions– NuSTAR, ASTROSAT, eROSITA, LOFT– ASTRO-H

2. Science cases : X-ray studies of VHE -ray sources

– Shell-type SNRs– PWNe– Blazars

Complementarity of X-ray & VHE -ray bands

Examples of SEDs from mono-energetic electrons/protons(Hinton, J.A., Hofmann, W., 2009. ARAA, 47, 523)

E2 d

N/d

E (

erg/

cm2 /

sec)

1-10 keV 1-10 TeV

CTA schedule2010 2015 2020

Preparatory phase

Construction/Deployment

Partial Operation

Full Operation

X-ray satellites in these 10 years

2010 2015 2020

ChandraXMM-NewtonSuzaku

NuSTAR

ASTROSAT

eROSITA/SRG

ASTRO-H

LOFT

CTA

NuSTAR• Launched successfully on June 13th, 2012.• The first satellite-based focusing X-ray telescope

operating in the hard X-ray band, 5-80 keV.

Leading institution : CaltechMission life : 2 years baseline Integral

NuSTAR

Deployable mastFocal length 10m

ASTROSATThe first dedicated astronomy mission in India for multi-wavelength astronomy.

Launch : 2013Main instrument : large area proportional counter (6000 cm2)

LAXPC

eROSITA / SRGeROSITA will be the primary instrument on-board the Russian "Spectrum-Roentgen-Gamma" (SRG) satellite.

Purpose : First imaging all-sky survey up to 10 keV

Launch : 2013Leading institution : MPE

LOFT : the Large Observatory For X-ray Timing

One of the four candidates selected for the next M-class mission in ESA’s Cosmic Vision.

Launch period : 2020-2022 (if selected)

Instruments• The Large Area

Detector (10m2@8 keV)

• The Wide Field Monitor

Current status : Assessment phase

ASTRO-H

14m

6.5m

Suzaku

• Length :14 m• Weight : 2.7 t• Power : 3500 W• Telemetry : 8Mbps (X-band)• Data Recorder : 12 Gbits• Launch : 2014• Life : 3 year (requirement) 5 year (goal) H2A

ASTRO-H mission instruments

Filter wheel

SXS: cooling chain

• 3 years with LHe• 2 more years without LHe

Life

SXS performance compared with existing observatories

Effective area

Figure of merit

SXI: an X-ray CCD camera

Hood

FrontendElectronicsbox

Engineering model• 4 CCD chips with 31x31mm• Depletion layer: 200m• Type: Back-illumination• Operating temp.: -120 - -100 degC• Exposure time: 4 sec• FOV: 38x38 arcmin

A focal plane assembly

SXI

Hard X-ray telescopes & imagers

HXT principle

HXI: hard X-ray imagers

BGO scintillaters

Engineering model

principle

SGD

BGO fov

Fine collimator fov

PrincipleNarrow field Compton camera

BGO

Fine collimator

Sat

ellit

e si

de p

anel

AE

BGO

Compton camera

SGD

ASTRO-H sensitivities in hard X-ray band

10 100 1000Energy (keV)

10-8

10-4

HXI

SGD

Suzaku

INTEGRAL

104 106 1010 1012

Energy (eV)

keV MeV GeV TeV

HXI

SGD

CTA

VHE -ray sky

http://www.mpp.mpg.de/~rwagner/sources/

Galactic (61): PWN (19), -ray binary (4), SNR(10), GC (1), Pulsar (1), OC (1), unID (24)Extra-galactic (46) : Blazar (37), FSRG (2), Radio galaxy (5), SB galaxy (2)

Origin of cosmic rays below ~1015 eV− Particle acceleration in shell type SNRs? −

Contours : ASCA

G347.3-0.5 (RX J1713.7-3946): shell-type SNR

TeV image with HESS

Yuan, Q. et al. 2011, ApJ, 735, 120

Model spectrum for the hadronic scenario

Acceleration in thin filaments

Red : 0.5-0.91 keVCyan : 0.91-1.34 keVBlue : 1.34-3.0 keV

SN1006 Chandra

Uchiyama et al. 2007, Nature, 449, 576

G347.3-0.5 Chandra

Expected image with A-H/HXIStructure of the particle acceleration site in the filaments may be studied with NuSTAR and A-H/HXI at an order of magnitude higher energies.

Simulated image of A-H/SXI(9x9 arcmin2)

Measuring the ion temperature in shell type SNR

SN1006 NW shell : thermal X-rays

Kinematic energy of unshocked plasma

Kinematic energy of shocked plasma

Thermal energy of shocked plasma

Particle acceleration

ASTRO-H SXS can measure the thermal energy (ion temp) of shocked plasma

Measure the particle acceleration efficiency

Shock velocity is known(2890 km/s)

Evolution of particle acceleration in the shell-type SNRs

Stefan Funk, August 5th 2011, TeVPA

<1000 years

1000-3000 years

>3000 years

Evolution of Synchrotron X-rays in SNRs

Synchrotron X-rays tends to drop for SNRs with >5pc.

Radius : indicator of ageNakamura et al. 2012, ApJ, 746, 134

Evolution of Synchrotron X-rays in SNRs

5 cm-3

1 cm-3

0.1 cm-3

protons

electrons

Assumption (electrons) acceleration time = synchrotron cooling time

TeV

Assumption (protons)Acceleration time = SNR age

Diffusion of energetic electrons in PWNe

Produced by S. Funk and O.C. de Jager for the H.E.S.S. collaboration

G18.0-0.7 (HESS J1825-137) : spectral steepening away from the pulsar

An example of X-ray observations

The Kookaburra complex

H.E.S.S. contours

Suzaku X-ray image

HESS J1420-607

HESS J1418-609

PSR J1420-6048(P=68ms)

R1 & R2

K3

Rabbit

Spatial dependence of the X-rays in the PWN

K3 Rabbit

Energy spectra tend to become softer according to the distance from the X-ray peaks (pulsars).

Energy loss of electrons/positrons due to the synchrotron radiation (Compton scattering) as they propagate.

Spatial dependence of the X-rays in the PWN (2)

HESS J1846-029(Kes75)

HESS J1747-281(G0.9+0.1)

HESS J1804-216

HESS J1809-193HESS J1833-105(G21.5-0.9)

(G18.0-0.7)HESS J1825-137HESS J1837-069

• 　 Radio pulsar (82.7 ms) at the cross.• 　 Spatial variation of the VHE photon

index is suggested by H.E.S.S.

AB

CD

A

B

C

D

Photon index2 2.5

HESS

HESS J1809-193

Suzaku observations of HESS J1809-193

0.4-1 keV

2-10 keV

Energy spectra were calculated for annular regions (A through D)

Suzaku

HESS

• 　 X-ray source at the position of the pulsar

• 　 Different spatial distribution between thermal （ 0.4-1 keV ） and non-thermal X-ray emission.

HESS J1809-193 : spectral analysis

ABCD

NH = 7.1 ×1021 cm-2

kT = 0.18 keV

1.5 2.0

Photon index

Spectral model : Power-law + thin thermal X-ray emission

No spatial dependence was found in the spectral shape

Pulsar

Far

HESS J1809-193 : spatial extent

０ ５ １０ １５ ２０ Distance from the pulsar (arcmin)

Measure the extension of non-thermal X-ray emission around the pulsar

Pseudo-color map : 2-10 keV X-ray intensityYellow contours : HESS image

σ = 6’.8 ± 1’.0

1. Projected intensity profile in the rectangle region2. Fit with a gaussian + constant

Suzaku

0.5

１

Rel

ativ

e in

tens

ity 2-10 keV

pul

sar

Spatial extent of the non-thermal emission

35

HESS J1825-137

σ = 3’.5 ± 0’.4

Vela X MSH 15-52

PSR J1420-6049

σ = 1’.5 ± 0’.4

σ = 23’.5 ± 2’.6 σ = 1’.6 ± 0’.1

Suzaku

ASCA

Chandra

Chandra

Spatial extent of the non-thermal emission

Kes 75

G21.5-0.9

HESS J1718-385

HESS J1616-508

σ = 0’.63 ± 0’.05

σ = 0’.91 ± 0’.05

σ = 4’.2± 0’.5

σ = 1’.8 ± 0’.5

Chandra

Chandra XMM-Newton

Suzaku

Spatial extent of the non-thermal diffuse X-ray emission vs pulsar ages

X-ray emitting electrons

Energy loss time scale

Accelerated electrons up to ~80 TeV can escape from the PWNe without losing most of the energies.

VHE -ray sky

http://www.mpp.mpg.de/~rwagner/sources/

Galactic (61): PWN (19), -ray binary (4), SNR(10), GC (1), Pulsar (1), OC (1), unID (24)Extra-galactic (46) : Blazar (37), FSRG (2), Radio galaxy (5), SB galaxy (2)

Multi-frequency studies of Blazars

X-ray GeV TeV　　 Optical

SSC

LE HELow-energy peak(Synchrotron)

High-energy peak（ Inverse Compton ）

Kataoka 02 Kubo+ 98

ERC

Flat Spectrum Radio Quasars(= FSRQ, e.g. PKS0528-134)

Low-frequency peaked BL Lac 　(= LBL e.g., 0716+714)

High-frequency peakedBL Lac 　(= HBL e.g., Mrk421)

　　 Radio

Sync

1-10 keV 1-10 TeV

X-ray band is suited to detect luminous FSRQs

Blazar sequence

High power jets : Luminous FSRQ

PKS 2149-306

Sof

t X-r

ay

Har

d X

-ray

Ghisellini et al. 2010, MNRAS, 405, 387

CTA

Fer

mi L

AT

HXI 100ks

The best-fit synchrotron-Compton model for PKS 2149-306.

The model is shifted to z~8.

Astro-H can detect wide-band spectrum of effectively all the luminous FSRQs.

LX > 2x1047 erg/sec(>109 Msolar SMBH)

Evolution of FSRQs

CXB and contribution of the FSRQs

Ajello, M. et al. 2009, ApJ, 699, 603

Seyfert-like AGNs

FSRQs(double power-law is assumed)

FSRQs may explain the CXB at >500 keV solving the mystery of generation of the MeV background.

Summary

• ASTRO-H may be the only observatory-class X-ray satellite operating simultaneously with CTA.

• Combining ASTRO-H and CTA data, we may be able to trace history of particle acceleration, acceleration efficiency, and diffusion of energetic particles in SNRs and PWNe.

• HXI on board ASTRO-H may be powerful telescopes to observe luminous FSRQs, which are key to understand CXB in the MeV band.