TheThe BroadBroad--BandBand XX--rayray SpectrumSpectrumofof CygnusCygnus XX--1 1 MeasuredMeasured by by

INTEGRALINTEGRAL

Marion Cadolle BelService d’Astrophysique, CEA-Saclay, France

Internal INTEGRAL Workshop, Noordwijk, 18 - 21 January 2005

P. Sizun, A. Goldwurm, P. Laurent, A. Zdziarski, J. Malzac, E. Jourdain, J-P. Roques, P. Goldoni, J. Rodriguez, C. Gouiffès & L. Foschini

CygnusCygnus XX--11Bright Bright XX--rayray emissionemission (1964)(1964)

High mass XHigh mass X--ray binaryray binary-- 2 2 kpckpc-- orbital period: 5.6 days orbital period: 5.6 days -- wind accretionwind accretion10 M¤ black hole18 M¤ giant (09.7 I) companion

Complex spectral-timing behaviour- incoherent fast X-ray variability- hard spectrum above 100 keV- persistent X-ray emission

First black hole prototypeFirst black hole prototype

Two Main Spectral StatesTwo Main Spectral States

High/SoftDominant soft X-ray thermal component; photon spectral index = 2.2

Low/Hard (90% time)Low flux for soft X-rays, strong flux for hard photons (keV)Photon spectral index 1.5-2, cut-off at E = 100 keV: comptonization

Low/Hard

High/Soft

McConnell et al. 2002

0,1

0,5

Spec

tral

inde

x

Truncated Julian Days (TJD)Flux

-1,5

-4

8500 10000 11500

Cts

s-1

20

100

BATSE index (20-100 keV)BATSE flux

RXTE counts (1.5-12 keV)

High/Soft Low/Hard

Observation LogObservation Log

PVPV--PhasePhase ((27th November - 15th December, 2002)

GPS (GPS (betweenbetween 2003, March 2003, March andand 2004, 2004, SeptemberSeptember))

Open Open TimeTime ((7 - 11th June, 2003)

Calibration in 2004, Calibration in 2004, NovemberNovember 2222ndnd

ASM Light ASM Light CurveCurve

Spectral transitions Spectral transitions probablyprobably occurringoccurring

1: 1: PVPV--phasephase2: Open 2: Open TimeTime3: GPS3: GPS4: 4: calibratcalibrat..

52600

ASM

Cou

nt R

ate

(cts

s-1)

1.5-

12 k

eV

50

0

100

150

52800 53000 53200 53400Universal Time (MJD)

SimultaneousSimultaneous ASM ASM andand IBIS/ISGRI IBIS/ISGRI LightLight CurvesCurves

Changes in IBIS/ISGRIChanges in IBIS/ISGRI CorrespondingCorresponding hardnesshardness ratio ?ratio ?

52600

ASM

Cou

nt R

ate

(cts

s-1) 1.

5-12

keV

50

0

100

100

52800 53000

200

53200 53400Universal Time (MJD)

ISGR

I Co

unt

Rate

(cts

s-1) 20

-200

keV

This work

52610

200

0

100

300

IBIS

/ISG

RI C

ount

Ra

te (ct

s s-

1 )20

-200

keV

52615 52620

Har

dnes

s ra

tio

20-3

0/30

-40

keV 0.64

0.620.600.580.56

Universal Time (MJD)

Bazzano et al. 03

Time bins ~ 0.15 d

100

050

150

IBIS

/ISG

RI C

ount

Ra

te (ct

s s-

1 )20

-300

keV

Har

dnes

s ra

tio

20-3

0/30

-40

keV

0.60

0.55

0.50

0.45

200

52798 52799 52800Universal Time (MJD)

52801

Zooms on IBIS/ISGRI Light Zooms on IBIS/ISGRI Light CurvesCurvesandand HardnessHardness RatioRatio

CorrespondingCorresponding HardnessHardness RatioRatioHar

dnes

s Ra

tio

40-1

00/2

0-30

keV

1

0.8

0.6

Universal Time (MJD)

1.2

1.4

1.6

52600 52800 53000 53200 53400

1.91.9

2.32.2

1.9

2.32.2

Hard state

Soft state

Photon index

DecemberDecember 02 02 SpectraSpectra

IBIS/ISGRI (128 ks)3% systematics

JEMX (31 ks)3% systematics

SPI (156 ks)3% systematics

kT = 93 +18 keV weak disc component ~ 0.2 Ltot

t = 1.5 ± 0.2 L 0.5-10 keV: 3.8 1036 ergs s-1

Fe line 6.4 ± 0.4 keV not well constrained?2

réd = 1.70 (dof = 219) EW = 223 eV; reflection 0.38 ± 0.05

-12Model = absorbed black body disc + comptonizationAdding then reflection + gaussian components

JuneJune 03 03 SpectraSpectra

kT = 104 ± 16 keV disc: kTin = 1.22 keV, comp. ~ 0.4 Ltott = 0.3 ± 0.1 L 0.5-10 keV: 6.6 1036 ergs s-1

Fe line 7.1 ± 0.1 keV well defined?2

réd = 1.88 (dof = 230) EW = 190 eV; reflection 0.58 ± 0.05

JEMX (200 ks)1% systematics

IBIS/ISGRI (219 ks)3% systematics

SPI (306 ks)3% systematics

IBIS/PICsIT (200 ks)no systematics

GPS 03GPS 03--04 04 SpectraSpectraHar

dnes

s Ra

tio

40-1

00/2

0-30

keV

1

0.8

0.6

Universal Time (MJD)

1.2

1.4

1.6

52800 53000 53200

1.9

1.9

2.3 2.2

1.9

2.3

2.2

Hard state

Soft state

PreliminaryPreliminary Spectral Spectral ParametersParametersin GPS 03in GPS 03--0404

1.451.450.780.781.021.021.081.081.021.02?2réd

(dof=185)

0.4±0.20.3±0.10.3±0.10.8±0.20.4±0.1ReflectionReflectionangleangle

7±2(bad)469

6.0±0.5(bad)721

7.1±0.1(good)

89

6.7±0.8(bad)297

6.3±0.3(bad)557

FeFe lineline(keV)(keV)

EW (EW (eVeV))

1.4 keV0.5 Ltot

weak0.4 Ltot

1.1 keV0.4 Ltot

1.5 keV0.4 Ltot

weak0.2 Ltot

DiscDisc ((kTkTinin))LL0.5-10 keV

113±720.2±0.1

57±102.5±0.1

61±200.6±0.3

106±490.3±0.2

59±202.5±0.5

kT (keV)kT (keV)t

Gr. 5Gr. 5Gr. 4Gr. 4Gr. 3Gr. 3Gr. 2Gr. 2Gr. 1Gr. 1GroupGroupParametersParameters

HARD HARDSOFT SOFT SOFT

NovemberNovember 04 04 SpectraSpectra

kT = 94 ± 44 keV disc: kTin = 1.27 keV, comp. ~ 0.4 Ltott = 0,4 ± 0.2 L 0.5-10 keV: 6.8 1036 ergs s-1

Fe line 7.8 ± 0.6 keV well defined?2

réd = 1,05 (dof = 209) reflection 0.35 ± 0.15

JEMX (6 ks) no systematics

IBIS/ISGRI (8 ks)3% systematics

SPI (8 ks)no systematics

Spectra comparisons in ESpectra comparisons in E22 f(Ef(E))December 02 and June 03December 02 and June 03

SOFTHARD

ConclusionsConclusionsEvolutions from hard (December 02, GPS) to soft states (June 03,Evolutions from hard (December 02, GPS) to soft states (June 03,GPS) thanks to combined JEMX, IBIS and SPI spectraGPS) thanks to combined JEMX, IBIS and SPI spectra

Probably intermediate states instead of real soft statesProbably intermediate states instead of real soft states(conclusion also supported by radio observations, see Malzac(conclusion also supported by radio observations, see Malzac et al.et al. 04)04)

ComptonizationComptonization models work well (typical for such a black hole)models work well (typical for such a black hole)

Fe lines and reflection values consistent with precedent studiesFe lines and reflection values consistent with precedent studies

Future work: Future work: -- Other models (Other models (eqpaireqpair, , comppscompps, , ……) to be tested on all available data) to be tested on all available data-- SPI highSPI high--energy data significance requires investigationenergy data significance requires investigation-- Study of fast variability (QPOs)Study of fast variability (QPOs)

Thanks for your attention !

Spectra comparisons in ESpectra comparisons in E22 f(Ef(E))December 02 and June 03December 02 and June 03

LHS

E2f(

E) k

eV c

m-2

s-1

Energy (keV)20 50 100 200 500

1

10-1

10

HSS

McConnellet al. 02(CGRO,

BeppoSAX)

Har

dnes

s ra

tio

40-1

00/2

0-30

keV

1

0.8

0.6

Universal Time (MJD)

1.2

1.4

1.6

52800 53000 53200

1.9

1.9

2.3 2.2

1.9

2.3

2.2

Hard state

Soft state

TheThe INTEGRAL SatelliteINTEGRAL Satellite

INTERnational Gamma Ray Astrophysical Laboratory (ESA)Imager IBIS (2 detectors ISGRI, PICsIT): 13 keV to 10 MeVSpectrometer (SPI): 20 keV to 8 MeVLarge energy coverage

Spectral Spectral ParametersParametersGr. 1Gr. 1 ?2

réd = 1.02 (dof = 185) HARDkT = 59 ± 20 keV, t = 2.5 ± 0.5, weak disc component ~ 0.3 LtotFe line 6.3 ± 0.3 keV not well defined, reflection ~ 0.35 ± 0.07

Gr. 2Gr. 2 ?2réd = 1.08 (dof = 185) SOFT

kT = 106 ± 49 keV, t = 0.3 ± 0.2, kTin = 1.46 keV, comp. ~ 0.5 LtotFe line 6 ± 2 keV not well defined, reflection ~ 0.8 ± 0.2

Gr. 3Gr. 3 ?2réd = 1.02 (dof = 185) SOFT

kT = 61 ± 20 keV, t = 0.6 ± 0.3, kTin = 1.11 keV, comp. ~ 0.5 LtotFe line 7.1 ± 0.1 keV well constrained, reflection ~ 0.3 ± 0.1

Gr. 4Gr. 4 ?2réd = 0.78 (dof = 185) HARD

kT = 57 ± 10 keV, t = 2.5 ± 0.05, weak disc component ~ 0.3 LtotFe line 6.0 ± 0.5 keV not well defined, reflection ~ 0.28 ± 0.04

Gr. 5Gr. 5 ?2réd = 1.45 (dof = 185) SOFT

kT = 113 ± 72 keV, t = 0.2 ± 0.1, kTin = 1.41 keV, comp. ~ 0.6 LtotFe line 6 ± 2 keV not well defined, reflection ~ 0.36 ± 0.21