UNVEILING THE SUPER ORBITAL UNVEILING THE SUPER ORBITAL UNVEILING - - PowerPoint PPT Presentation

4th FAN workshop, Hong Kong

UNVEILING THE SUPER ORBITAL UNVEILING THE SUPER ORBITAL UNVEILING THE SUPER-ORBITAL MODULATION OF LS I +61 303 IN X-RAYS UNVEILING THE SUPER-ORBITAL MODULATION OF LS I +61 303 IN X-RAYS

Jian Li (李劍)

Special thanks to Shu Zhang Diego F Torres Daniela Hadasch Jianmin Wang et al Special thanks to Shu Zhang, Diego F. Torres, Daniela Hadasch, Jianmin Wang et al. Institute of High Energy Physics , Chinese Academy of Sciences Institut de Ciencies de l’Espai (IEEC-CSIC)

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Outline Out e

• Introduction
• Introduction
• Evidence of super-orbital modulation

b d i X & M d l i li ti

• bserved in X-ray & Model implication
• Summary

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• 1. Introduction of LSI +61 303

LSI +61 303: HMXB, 2±1 kpc,

• r Blackhole
• rbit period: 26.496±0.0028 days.

Companion: B0 Ve star M 12 5±2 5 M Mass: ~12.5±2.5 M⊙ Radius: ~10 R⊙ Compact object: 1 4 M with Compact object: 1-4 M⊙with unknown nature.

Conventional model for Conventional model for a Be/X-ray binary

The picture is based on a diagram from Snow (1987, in Physics of Be stars, Cambridge University Press).

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• 1. Introduction of LSI +61 303
• r Blackhole

Conventional model for Conventional model for a Be/X-ray binary

The picture is based on a diagram from Snow (1987, in Physics of Be stars, Cambridge University Press).

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• 1. Introduction of LSI +61 303

Orbital geometry (26.5 days period) of LS I +61 303 Apastron Superior conjunction LS I +61 303 is visible in radio X-ray to very high radio, X ray to very high energy (GeV and TeV) Inferior conjunction Periatron V.Zabalza et al. 2011 A&A

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• 1. Introduction of LSI +61 303

C t 26 5 d bit i d 1667 d bit l i d i Compare to ~26.5 days orbit period, a 1667 days super-orbital period is detected first in radio (Gregory 2002) and then in Hα emission lines (Zamanov et al. 1999) 1667 days ~ 63 orbits~ 4.6 years

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• 1. Introduction of LSI +61 303

Hα emission comes mainly from the Be star disk (Hunushik Hα emission comes mainly from the Be star disk (Hunushik, Kozok & Kaizer 1988) and its equivalent width stands for the size of the disk.

• r Blackhole

Hα emission line of LSI + 61 303 (Liu & yan, 2005 New Astronomy)

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• 1. Introduction of LSI +61 303
• Super-orbital modulation in radio and Hα promotes us to find

p p similar modulation evidence in X-ray and link it to the mass loss rate of the Be star.

• J. Li et al. 2012
• M Chernyakova et al 2012
• M. Chernyakova et al. 2012

In soft X-ray: RXTE/PCA, more than 4 years (2007-08-28 till 2011-09-15) In hard X-ray: INTEGRAL/ISGRI, 10 years (2002-12-28 till 2012-11-24)

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3-30keV

0.2 0.6 1.0 1.4 1.8 Orbital Phase

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• Image of LSI + 61 303 by

INTEGRAL/ISGRI in 18- INTEGRAL/ISGRI in 18 60 keV.

• 12.45 sigma detection

12.45 sigma detection under 807ks exposure time 200 d

• 200 days

binned light curve curve

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• 2. Evidence of super-orbital

d l ti i X

• Super-orbital

modulation in X-ray

Super orbital lightcurve in hard X-ray hard X ray

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• 2. Evidence of super-orbital

d l ti i X modulation in X-ray

3-30keV PCA results

• Super-orbital modulation in hard X-ray is in

phase with soft X-ray

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Radio(1977-2000)

• ptical

X-ray X Optical(1989-1999) X-ray (2007-2011, soft) (2002 2012 hard) p ( ) radio (2002-2012, hard) X-ray super-orbital modulation is in phase with Hα, lagged by radio at about Li et al, 2012，ApJL p , gg y 300 days, 0.2 super-orbital phase

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io TeV P k fl bit i radi Peak flux per orbit in TeV shown in red (all

• f them happening in

the 0 6 1 0 Hα the 0.6–1.0

• rbital phase range)

as a function of super-orbital phase H super-orbital phase, together with radio, Hα, GeV and X-ray data GeV data G X-ray

• J. Li et al, 2012

Super-orbital phase (0-2) 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

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• 2. Model implications

p But could LS I + 61 303 be different ?

• J. Li et al, 2012

But could LS I + 61 303 be different ?

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• 2. Model implications

p

In 2008, a very short (0.16s) X-ray burst detected from it by Swift/BAT, lead to the suggestions that the system may contain a magnetar. (Torres et al, 2012, ApJ ) If it is a magnetar, it is likely subject to a flip-flop behavior and shift from behaving as a pulsar being rotationally powered near apastron to g p g y p p being a propeller near periastron, along each of the system’s orbit ( Torres et al. 2012; Zamanov et al. 1995, 2001 ).

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• 2. Model implications

p

A sketch of the Ejector Propeller model Ejector-Propeller model. The dashed lines indicates The dashed lines indicates the orbit of the neutron star.

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• 2. Model implications

p

• TeV

radio Hα V GeV X-ray Super-orbital phase (0-2)

0 0.4 0.8 1.2 1.8 2.0

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• 2. Model implications

p

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• 2. Model implications

p

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io TeV P k fl bit i radi Peak flux per orbit in TeV shown in red (all

• f them happening in

the 0 6 1 0 Hα the 0.6–1.0

• rbital phase range)

as a function of super-orbital phase H super-orbital phase, together with radio,

• Ha. GeV and X-ray

data GeV data G X-ray

• J. Li et al, 2012

Super-orbital phase (0-2) 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

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• 3. Summary

Summary:

y

• 1. We found evidence for super-orbital variability in X-rays

3 Th i h hift b t 300 d i bit l d l ti

• 3. There is a phase shift about 300 days in super-orbital modulation

between radio and X-ray.

• 4. The equivalent width of the Hα emission line is in phase with X-ray

variation

• 5. TeV emissions seems to be related to the super-orbital variability,

but because of limited data, it is still unconfirmed.

Thanks! Thanks! Thanks! Thanks!