the xmm-newton survey of the smc: the be/x-ray binary ... · the be/x-ray binary population richard...

XMM-NewtonSMC survey:

The Be/X-raybinary population

Richard Sturm

The XMM-Newton survey of the SMC:The Be/X-ray binary population

Richard Sturmon behalf of the SMC XMM-Newton large project collaboration

Max-Planck-Institut fur extraterrestrische Physik

The X-ray Universe 2011Berlin, 27.06.2011



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Neutron Star X-ray Binaries – Classification

X-ray binaries

High Mass X-ray Binary

early type OB companion starM∗ > 8M�

trace recent star formation

Low Mass X-ray Binary

late type companionM∗ < 2M�

number ∝ galaxy massnone known in the SMC

Supergiant systems

Supergiant I-II

Be/X-ray Binaries

V–III emission line stardecretion disk of Be star

Disk fed

1038 erg s−1Wind fed

1037 erg s−1Persistent

1034−35 erg s−1

small long term variabilitylong puls periods

low or no Fe Kα emission

Transient

Type I outburst: 1036−37 erg s−1

Type II outburst: >1037 erg s−1

quiescence: ∼1033 erg s−1



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Be/X-ray Binaries – Phenomenology

X-rays powered by accretion of matter from companion staronto a compact object:

high variability possiblepowerlaw like (Γ ∼ 0.8) spectrumsoft excesspulsations

optical & infrared emission dominated by Be star:spectral types O9e–B4evariable emission lines (e.g. Hα)variable IR excess

Credit: Walt Feimer, NASA/Goddard Space Flight Center



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

HMXBs in the Milky Way and nearby galaxies

227 HMXBs and candidates – 130 pulsars

MW: Liu et al. (2006)

SMC: Haberl & Pietsch (2004); Coe et al. (2005) + new discoveries

LMC: Negueruela & Coe (2002); Shtykovskiy & Gilfanov (2005) + new discoveries



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

The Be/X-ray binary population in the SMC

Galaxy

1%

25%

74%

SG HMXB diskSG HMXB windBe/X-ray binary

SMC

1%

25%

99%

Over-abundance of HMXBsNo wind accretion poweredsupergiant system



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Why observe HMXB in the SMC?

Galaxy – Physics ofindividual systems

high-resolutionspectroscopy andtimingaccretion processwind structure

SMC – Statisticalstudies

Observations ofmany systemssimultaneously atsimilar distancelow foregroundabsorptionglobal propertiespopulation studies

5.1×104 5.2×104 5.3×104 5.4×104

340

342

344

346

348

puls

e pe

riod

(s)

time (modified JD)

SAX J0103.2−7209

5.1×104 5.2×104 5.3×104 5.4×104

0.1

110

lum

inos

ity (

1035

erg

s−1)

time (modified JD)

SAX J0103.2−7209

Eger & Haberl (2008)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

HMXBs and Star Formation History

N

E

20’

HI map Stanimirovic et al. (1999)

HMXBs in regions with starformation bursts 25-60 Myrago

number of HMXBs correlateswith SFR at 42 Myr

Antoniou et al. (2010)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

The SMC in HI

HI (Stanimirovic et al. 1999)

20’

N

E

-1s 22.07s

0.72s

31.03s

-1s

65.78s

-1s

726s

3.34s

11.48s

-1s

1323s

-1s

-1s

345.2s

6.85s

-1s

967s

-1s

7.92s

-1s

455s

304.5s

8.02s-1s

-1s

202.52s

201.9s

2.76s

291.33s

152.34s

280.4s

565s

101.16s

-1s

-1s

140.1s

644.6s

701.6s

59.07s

499.2s

2.37s

-1s

341.9s46.63s

-1s

-1s

138s

169.3s

-1s

325.4s

-1s

-1s15.3s

82.4s

-1s

7.78s

8.9s

172s

91.12s

323.2s

214.03s

755.5s

-1s

894s9.13s-1s

18.37s74.67s

-1s

-1s

25.55s

11.87s

263s

-1s



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

The SMC in X-ray

(2.0-4.5) keV

(1.0-2.0) keV

(0.2-1.0) keV

N

E

20’

-1s 22.07s

0.72s

31.03s

-1s

65.78s

-1s

726s

3.34s

11.48s

-1s

1323s

-1s

-1s

345.2s

6.85s

-1s

967s

-1s

7.92s

-1s

455s

304.5s

8.02s-1s

-1s

202.52s

201.9s

2.76s

291.33s

152.34s

280.4s

565s

101.16s

-1s

-1s

140.1s

644.6s

701.6s

59.07s

499.2s

2.37s

-1s

341.9s46.63s

-1s

-1s

138s

169.3s

-1s

325.4s

-1s

-1s15.3s

82.4s

-1s

7.78s

8.9s

172s

91.12s

323.2s

214.03s

755.5s

-1s

894s9.13s-1s

18.37s74.67s

-1s

-1s

25.55s

11.87s

263s

-1s



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Discovery of the 11.866 s Be/X-ray binary pulsar

New X-ray transientLX = 3.97 ×1036 erg s−1

variability of >560

Spectrum:absorbed power-lawΓ = 0.53± 0.08indication of soft excess

Spin period:(11.86642± 0.00017) s

Be counterpart

Hα emissionEW = (−3.5± 0.6) A

NIR excess and variability

Sturm et al. (2011)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography



variability of >560


Spin period:(11.86642± 0.00017) s

Be counterpart



Sturm et al. (2011)

10−3

0.01

0.1

Cou

nts

s−1

keV

−1

−4

−2

0

2

χ

1 100.5 2 5−4

−2

0

2

4χ

Channel energy (keV)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography



variability of >560


Spin period:(11.86642± 0.00017) s

Be counterpart



Sturm et al. (2011)

0 0.05 0.1 0.15 0.2 0.25

020

4060

Pow

er

Frequency (Hz)

0.95

1.00

1.05

1.10

1.15

0.2-

1.0

keV

0.9

1.0

1.1

1.2

1.0-

2.0

keV

0.9

1.0

1.1

1.22.

0-4.

5 ke

V

0.900.95

1.00

1.05

1.10

4.5-

10.0

keV

0.0 0.5 1.0 1.5 2.0Phase (11.86642 s)

0.900.951.001.051.101.15

0.2-

10.0

keV

0.500.550.600.650.70

HR

1

0.35

0.40

0.45

0.50

HR

2

-0.020.000.020.040.060.080.100.12

HR

3

0.0 0.5 1.0 1.5 2.0Phase (11.86642 s)

-0.15

-0.10

-0.05

HR

4



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography



variability of >560


Spin period:(11.86642± 0.00017) s

Be counterpart



Sturm et al. (2011)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography



variability of >560


Spin period:(11.86642± 0.00017) s

Be counterpart



Sturm et al. (2011)

5000-17

-16

-15

-14

6200 6400 6600 6800

0.8

1

1.2

1.4

1.6



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography



variability of >560


Spin period:(11.86642± 0.00017) s

Be counterpart



Sturm et al. (2011)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Discovery of the 214 s Be/X-ray binary pulsar

40.0 20.0 0:50:00.0 49:40.0

-72:58:00

59:00

-73:00:00

01:00

02:00

03:00

Right Ascension

De

cli

na

tio

n

BG

MOS2

MOS1

pn

0.0

0.5

1.0

1.5

2.0

0.2-

1.0

keV

0.5

1.0

1.5

2.0

2.5

1.0-

2.0

keV

0.6

0.8

1.0

1.2

1.4

2.0-

4.5

keV

0.40.60.81.01.21.41.6

4.5-

10.0

keV

0.0 0.5 1.0 1.5 2.0Phase (214.045 s)

0.8

1.0

1.2

1.4

1.6

0.2-

10.0

keV

10−3

0.01

2×10−4

5×10−4

2×10−3

5×10−3

Cou

nts

s−1

keV

−1

1 100.5 2 5

−4

−2

0

2

4

χ

Channel energy (keV)

10−4 10−3 0.01 0.1

020

4060

Pow

er

Frequency (Hz)

TS_0601211401merged_sc4_200_10000.fits

Start Time 15139 22:01:52:914 Stop Time 15140 7:13:30:677

Bin time: 2.840 s

?



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Detection of the 11.48 s Be/X-ray binary pulsar

0.0 0.3 0.8 1.8 3.9 8.0 16.2 32.4 65.3 130.3 259.7

EPIC MOS1

0601212601

0.0 0.3 0.8 1.9 4.1 8.5 17.3 34.7 69.8 139.3 277.7

EPIC MOS1

0301170501

10−3

0.01

0.1

1

Cou

nts

s−1

keV

−1

1 100.5 2 5 20

−2

0

2

χ

Channel Energy (keV)

0.70.80.91.01.11.21.3

0.2-

1.0

keV

0.6

0.8

1.0

1.2

1.41.

0-2.

0 ke

V

0.8

1.0

1.2

1.4

2.0-

4.5

keV

0.6

0.8

1.0

1.2

1.4

4.5-

10.0

keV

0.0 0.5 1.0 1.5 2.0Phase (11.49 s)

0.80.91.01.11.21.3

0.2-

10.0

keV

Townsend et al. (2011)

Discovered by INTEGRAL(IGR J01054-7253)

Swift follow up

RXTE found spin period

XMM-Newton confirmedposition and spin

Orbital solution

55000 55020 55040 55060DATE (MJD)

3.823

3.824

3.825

3.826

3.827

3.828

3.829

Obs

erve

d pe

riod

of H

arm

onic

(s)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

2 further transients in the survey data

2’

Γ = 0.79− 1.16NH = (8± 2)×1022 cm−2

LX = 5.6×1035 erg s−1

double peaked Hα lineEW = −(33± 3) A

10−3

5×10−4

2×10−3

5×10−3

Cou

nts

s−1

keV

−1

1 100.5 2 5

−1

0

1

χ


2’

Γ = 0.66− 0.83NH < 7×1020 cm−2

LX = 1.1×1035 erg s−1

correlating with early typeemission line star

10−3

2×10−4

5×10−4

2×10−3

5×10−3

Cou

nts

s−1

keV

−1

1 100.5 2 5

0

2

χ




Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

The search for new candidates



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography


The XMM-Newton point sourcecatalog of the SMC:(Sturm et al., in preperation)

3053 X-ray sources

5.7 deg2 total area

95 individual observations

astrometric improved positionsaccuracy ∼1.42′′

complete to 10−14 erg s−1 cm−2

in the (0.2–4.5) keV band4.3 ×1033 erg s−1 (for the SMC).

exposure: 10-30 ks (average),∼600 ks (maximum)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography


X-ray selection using hardness ratios:

−1 −0.5 0 0.5 1−1

−0.

50

0.5

1

HR

3

HR2

SXP8.02 (AXP?)SMC pulsars

−1 −0.5 0 0.5 1−1

−0.

50

0.5

1

HR

3

HR2

AGN

−1 −0.5 0 0.5 1−1

−0.

50

0.5

1

HR

3

HR2

stars



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography


Optical counterpart:

Magellanic Cloud PhotometricSurvey (Zaritsky et al. 2002)

16605 sources in theXMM-Newton field

position accuracy ∼0.3′′

−1 −0.5 0 0.5 1 1.5 2

2015

V (

mag

)

B−V (mag)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography


Result:

93 X-ray sources

51 known HMXB10 candidates from previousstudies32 new candidates

further investigation necessary...



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Be/white dwarf systems

Population synthesis models predict for Be companions(Pols et al. 1991; Raguzova 2001)

10% neutron stars20% helium stars70% white dwarfs

expected X-ray properties:

Hard X-ray emission during accretion at 1029−33 erg s−1

Supersoft X-ray emission during thermonuclear surface burningBut: absorption and disc truncation

possible candidates:

γ Cas and γ Cas like objects (Haberl 1995; Lopes de Oliveira et al. 2006)

one SSS in the LMC (Kahabka et al. 2006)



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

A new candidate in the SMC?

New Discovery of a faint supersoft X-ray source(kT = 76+3

−6 eV, F(0.2−1.0)keV = 9.4×1033 erg s−1)

O7IIIe–B0Ie companion star in the SMC

(Sturm et al., in preperation)

10.2 0.5 2 5

02×

10−

34×

10−

36×

10−

3

Cou

nts

s−1

keV

−1




Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Spectral distributionof Be/X-ray binaries in the SMC

average photon index Γ = (0.79± 0.20)spectral confirmation of 3 HMXB candidates



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Absorption of Be/X-ray binaries in the SMC

0 2×1021 4×1021 6×1021 8×1021 1022 1.2×1022

02×

1022

4×10

226×

1022

8×10

2210

23

NH (

cm−

2 )

HI (cm−2)

HMXB

0 2×1021 4×1021 6×1021 8×1021 1022 1.2×1022

02×

1022

4×10

226×

1022

8×10

2210

23

NH (

cm−

2 )

HI (cm−2)

AGN



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Spin Period distribution

Bimodal distribution in the SMC?Comparing SMC and MW: KS-Test probability: 46%



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

The Corbet relation



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

Summary

4 new HMXB in the SMC found during the survey(SXP11.87, SXP214 and two transients)

XMM-Newton confirmed position and pulsation of SXP11.5

∼ 29 bright detections of known HMXBs in the survey data(144 in total)

Spectra of bright sources ⇒ confirmation of 3 HMXB candidates

Hardness ratio selection and correlation with optical catalogsresults in ∼ 30 new candidates

One candidate for a Be/white dwarf system found

to be continued...



Richard Sturm

Introduction

Classification

Phenomenology

HMXBs in theSMC

SF History

Discoveries

SXP11.87

SXP214

SXP11.5

Furthertransients

New candidates

Be/WD systems

Population

Bibliography

References

Antoniou, V., Zezas, A., Hatzidimitriou, D., & Kalogera, V. 2010, ApJ, 716, L140

Coe, M. J., Edge, W. R. T., Galache, J. L., & McBride, V. A. 2005, MNRAS, 356, 502

Eger, P. & Haberl, F. 2008, A&A, 491, 841

Haberl, F. 1995, A&A, 296, 685

Haberl, F. & Pietsch, W. 2004, A&A, 414, 667

Kahabka, P., Haberl, F., Payne, J. L., & Filipovic , M. D. 2006, A&A, 458, 285

Liu, Q. Z., van Paradijs, J., & van den Heuvel, E. P. J. 2006, A&A, 455, 1165

Lopes de Oliveira, R., Motch, C., Haberl, F., Negueruela, I., & Janot-Pacheco, E. 2006, A&A, 454, 265

Negueruela, I. & Coe, M. J. 2002, A&A, 385, 517

Pols, O. R., Cote, J., Waters, L. B. F. M., & Heise, J. 1991, A&A, 241, 419

Raguzova, N. V. 2001, A&A, 367, 848

Shtykovskiy, P. & Gilfanov, M. 2005, MNRAS, 362, 879

Stanimirovic, S., Staveley-Smith, L., Dickey, J. M., Sault, R. J., & Snowden, S. L. 1999, MNRAS, 302, 417

Sturm, R., Haberl, F., Coe, M. J., et al. 2011, A&A, 527, A131+

Townsend, L. J., Coe, M. J., Corbet, R. H. D., et al. 2011, MNRAS, 410, 1813

Zaritsky, D., Harris, J., Thompson, I. B., Grebel, E. K., & Massey, P. 2002, AJ, 123, 855

the xmm-newton survey of the smc: the be/x-ray binary ... · the be/x-ray binary population richard...

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