Aug. 21-23, 2006 KJYAM 2006 @ 慶州 1

SuzakuSuzaku Observation of Observation of Nearby Seyfert 2 GalaNearby Seyfert 2 Gala

xy NGC 4945xy NGC 4945

Naoki Isobe (RIKEN, Japan) Naoki Isobe (RIKEN, Japan) and and SuzakuSuzaku NGC 4945 team NGC 4945 team

Aug. 21-23, 2006 2KJYAM 2006 @ 慶州

Introduction ofIntroduction of Suzaku Suzaku ““ 朱雀”朱雀” The 5The 5thth Japanese X-ray observ Japanese X-ray observ

atory.atory. Launched in July 10, 2005 Launched in July 10, 2005 Investigation of Investigation of

structure formation of universestructure formation of universe Black holes (inclusding AGNs)Black holes (inclusding AGNs) etc.etc.

Scientific observationsScientific observations SWG phase from 2005/08SWG phase from 2005/08 AO-1 from 2006/04 AO-1 from 2006/04 Call for AO-2, this December Call for AO-2, this December

http://www.astro.isas.jaxa.jp/http://www.astro.isas.jaxa.jp/suzaku/index.html.ensuzaku/index.html.en

Suzaku

Launch of Suzaku(from Uchinoura Space Station)

Aug. 21-23, 2006 3KJYAM 2006 @ 慶州

Instrument on Instrument on SuzakuSuzaku XRTXRT (X-Ray Telescope) (X-Ray Telescope)

large effective arealarge effective area (450cm(450cm22 /1XRT@ 1.5 keV) /1XRT@ 1.5 keV)

XISXIS (X-ray Imaging Spectrometer) (X-ray Imaging Spectrometer) 4CCD cameras (0.2 – 12 keV)4CCD cameras (0.2 – 12 keV)

1 Back-illuminated (XIS1)1 Back-illuminated (XIS1) 3 Front-illuminated (XIS0,2,3)3 Front-illuminated (XIS0,2,3)

Low background, Good energy resLow background, Good energy resolution and high sensitivityolution and high sensitivity

HXDHXD (Hard X-ray Detector) (Hard X-ray Detector) Si-Si-PIN PIN diode (10-60 keV) and diode (10-60 keV) and GSGS

OO scintillator (30-600 keV) scintillator (30-600 keV) Wide energy band and low backgrWide energy band and low backgr

ound ound

SuzakuXRT

XIS

HXD

Aug. 21-23, 2006 4KJYAM 2006 @ 慶州

Seyfert 2 Galaxies with Seyfert 2 Galaxies with SuzakuSuzaku

Molecular Torus Hot gas

Super massive black holeAccretion disk

Seyfert 1Seyfert 2

Direct but absorbed

component

Scattered component

Reflected component

10 10010.1 E [keV]

Flux Suzaku is best Chandra/Newton

Aug. 21-23, 2006 5KJYAM 2006 @ 慶州

NGC 4945NGC 4945 Nearby edge-on spiral galaxy Nearby edge-on spiral galaxy (O(O

tt et al. 1995)tt et al. 1995) at 3.7 Mpc at 3.7 Mpc (Mauersberger et al. (Mauersberger et al. 1996)1996)

MMBHBH = 1.4x10 = 1.4x1066 MMsun sun (Greenhill et al. 199(Greenhill et al. 1997)7)

Starburst activity Starburst activity (Moorwood et al. 1996)(Moorwood et al. 1996)

The nucleus is heavily absorbThe nucleus is heavily absorbed (ed (NNHH ～～ 4x104x102424 cm cm-3-3; Compt; Compton-thick) on-thick)

The brightest Seyfert 2 above The brightest Seyfert 2 above 20 keV 20 keV (Done et al. 1996; Madejski et al. 2000)(Done et al. 1996; Madejski et al. 2000)..

SuzakuSuzaku observations observations 2005 Aug. 22 (25 ksec)2005 Aug. 22 (25 ksec) 2006 Jan. 15 (100 ksec) 2006 Jan. 15 (100 ksec)

Chandra Image

5”

Chandra + RXTE

Aug. 21-23, 2006 6KJYAM 2006 @ 慶州

SuzakuSuzaku XIS image of NGC 4945 XIS image of NGC 4945

The X-ray peak coincides wiThe X-ray peak coincides with the center of the host galth the center of the host galaxyaxy

X-ray emission is elongated X-ray emission is elongated along the host galaxy.along the host galaxy.

Some point sources are detSome point sources are detected.ected.

A new transient source (ULA new transient source (ULX) is found at the south-weX) is found at the south-west arm in the 2st arm in the 2ndnd exposure. exposure. (Isobe et al. in prep.)(Isobe et al. in prep.)

XIS FI image in 0.5 – 10 keV, with IR (Jarette et al. 2003) contours overlaid

2005/8/22-23

+ X-ray sources detected with XMM-Newton

2006/1/15-17

Aug. 21-23, 2006 7KJYAM 2006 @ 慶州

SuzakuSuzaku X-ray Lightcurve X-ray Lightcurve The XIS lightcurves show almost nThe XIS lightcurves show almost n

o significant variability both in 0.5 o significant variability both in 0.5 – 2 keV and 2 – 10 keV (< 20 %).– 2 keV and 2 – 10 keV (< 20 %).

The Fe KThe Fe K band (6.2 – 6.6 keV) li band (6.2 – 6.6 keV) lightcurve shows significant variatioghtcurve shows significant variation, with a time scale of 10 ksec.n, with a time scale of 10 ksec.

The HXD PIN lightcurve shows a fThe HXD PIN lightcurve shows a factor of 3 variability, with a time sactor of 3 variability, with a time scale of cale of ～ ～ 10 ksec.10 ksec.

The HXD PIN hardness ratio stays The HXD PIN hardness ratio stays relatively constant, indicating almrelatively constant, indicating almost no spectral change.ost no spectral change.

Time [ksec]

Aug. 21-23, 2006 8KJYAM 2006 @ 慶州

SuzakuSuzaku HXD Spectra HXD Spectra X-ray signals are detected X-ray signals are detected abab

ove 100 keVove 100 keV with HXD. with HXD. Spectral fittingSpectral fitting

PL model PL model NNHH = (4.6±0.5) = (4.6±0.5) xx 10 102424 cm cm-2-2

= 1.83 ± 0.08= 1.83 ± 0.08 Cutoff PL model Cutoff PL model

EEcutcut > 100 keV > 100 keV = 1.4 ± 0.4 = 1.4 ± 0.4

The HXD data is dominated bThe HXD data is dominated by y the absorbed nucleus, the absorbed nucleus, has has no significant contribution frono significant contribution from the m the reflection componentreflection component..

PIN

GSO

Energy [keV]

Flux

Aug. 21-23, 2006 9KJYAM 2006 @ 慶州

Suzaku XIS spectraSuzaku XIS spectra

The XIS spectra The XIS spectra below 2 keV show a thermal below 2 keV show a thermal

nature.nature. avobe 2 keV show a hard speavobe 2 keV show a hard spe

ctrum ctrum show significant Fe linesshow significant Fe lines

Fe lines are clearly resolveFe lines are clearly resolved.d. 6.39 keV : Fe Ka6.39 keV : Fe Ka 7.05 keV : Fe Kb7.05 keV : Fe Kb 6.68 keV : Fe XXV (He-like)6.68 keV : Fe XXV (He-like)

Fe lines

Thermal

XIS FI / BI

Hard spectrum

Reflection

Aug. 21-23, 2006 10KJYAM 2006 @ 慶州

Wide-band X-ray SpectrumWide-band X-ray Spectrum Absorbed nucleusAbsorbed nucleus

= 1.64= 1.64 NNHH = 4.1 x 10 = 4.1 x 102424 cm cm-2-2

LL20-100keV20-100keV ～ ～ 10104343 ergs s ergs s-1-1

Reflection componentReflection component Continuum : about 1 % of aContinuum : about 1 % of a

bsorbed nucleus bsorbed nucleus Fe lines : EWFe lines : EWKK = 1.2 keV = 1.2 keV EWEWKbKb = 0.2 keV = 0.2 keV

Hot thermal emissionHot thermal emission kTkT = 5.5 keV = 5.5 keV

Soft thermal emissionSoft thermal emission fro from the host galaxy m the host galaxy kTkT = 0.3 keV = 0.3 keV

XIS

PIN GSO

Spectral Energy Distribution of NGC 4945

Aug. 21-23, 2006 11KJYAM 2006 @ 慶州

Comparison with previous Comparison with previous observations observations

The nucleus of NGC 4945 shows only a factor of The nucleus of NGC 4945 shows only a factor of 2 variation in its activity.2 variation in its activity.

The spectral parameters stay relatively constant. The spectral parameters stay relatively constant.

Ginga : Iwasawa et al. 1993BeppoSAX : Guainazzi et al. 2000RXTE : Madejski et al. 2000RXTE/Chandra : Done et al. 2003

Aug. 21-23, 2006 12KJYAM 2006 @ 慶州

SummarySummary SuzakuSuzaku observed the nearby Seyfert 2 galaxy NGC 4945 observed the nearby Seyfert 2 galaxy NGC 4945

on 2005/08/22 and 2006/01/15.on 2005/08/22 and 2006/01/15. The X-ray signals are significantly detected in the 0.5 – 2The X-ray signals are significantly detected in the 0.5 – 2

00 keV range.00 keV range. The wide band X-ray spectrum of NGC 4945 is decomposThe wide band X-ray spectrum of NGC 4945 is decompos

ed into the absorbed nucleus, reflection and scattered coed into the absorbed nucleus, reflection and scattered component including significant Fe lines, and thermal emissmponent including significant Fe lines, and thermal emission from the host galaxies.ion from the host galaxies.

The absorbed nucleus shows a factor of 3 intensity variatThe absorbed nucleus shows a factor of 3 intensity variation, without any spectral change. ion, without any spectral change.

However, in order to finalize our result, the HXD backgrouHowever, in order to finalize our result, the HXD background improved accuracy will be required. nd improved accuracy will be required.

A new transient source was discovered in the second expA new transient source was discovered in the second exposure. osure.

Aug. 21-23, 2006 13KJYAM 2006 @ 慶州

Suzaku NGC 4945 teamSuzaku NGC 4945 team R. E. Griffith (leader), G. C. Dewangan (CMU) R. E. Griffith (leader), G. C. Dewangan (CMU) N. Isobe (Co-leader, RIKEN)N. Isobe (Co-leader, RIKEN) K. Makishima, T. Itoh (Tokyo U)K. Makishima, T. Itoh (Tokyo U) N. Anabuki (Osaka U)N. Anabuki (Osaka U) H. Awaki (Ehime U)H. Awaki (Ehime U) G. M. Madejski (SLAC)G. M. Madejski (SLAC) T. Okajima, J. N Reeves (NASA/GSFC)T. Okajima, J. N Reeves (NASA/GSFC) T Takahashi (JAXA/ISAS)T Takahashi (JAXA/ISAS) Y. Ueda (Kyoto U)Y. Ueda (Kyoto U) T. Yaqoob (JHU)T. Yaqoob (JHU)

Aug. 21-23, 2006 14KJYAM 2006 @ 慶州

Introduction of myself Introduction of myself Name : Naoki IsobeName : Naoki Isobe Date of Birth : April 10, 1974 (32 years old)Date of Birth : April 10, 1974 (32 years old) Nationality : JapaneseNationality : Japanese Institute : Cosmic Radiation Laboratory, RIKENInstitute : Cosmic Radiation Laboratory, RIKEN Position : Post. Doc.Position : Post. Doc. Research field : X-ray Astronomy, AGNResearch field : X-ray Astronomy, AGN