Beyond X-ray timing I: Using reprocessing to map the geometry of - - PowerPoint PPT Presentation

Beyond X-ray timing I: Using reprocessing to map the geometry

• f X-ray binaries

Teo Muñoz-Darias

INAF-OSSERVATORIO ASTRONOMICO DI BRERA (OAB)

University of Southampton, Black hole variability 2010

Monday, June 7, 2010

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OUTLINE

1. Why could you be interested in optical/infrared timing?

• 2. How can we do it?
• OIR timing instruments
• 3. A science case:
• Echo-tomography of Low mass X-ray binaries

Monday, June 7, 2010

LMXBs: interacting binaries with “normal” star transfering matter at ~ 10-9 M yr-1 onto a compact object (BH or NS)

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WHY? 1. Multiwavelength sources

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LMXBs: interacting binaries with “normal” star transfering matter at ~ 10-9 M yr-1 onto a compact object (BH or NS)

Credit: Rob Hynes

Companion star Accretion disc Corona Jet

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WHY? 1. Multiwavelength sources

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WHY? 1. Multiwavelength sources

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Radio IR Opt. X

Fν ν

Disc Jets Corona

Credit: Mickaël Coriat

Fast variability observed from IR to X-rays Full accretion picture MW view companion

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WHY? 2. Interesting science cases

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Complex X-ray/optical cross correlations: Contributions from jet or the corona Kanbach et al., Nature, 2001

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WHY? 2. Interesting science cases

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Casella et al. 2010, MNRAS Lett. Fast infrared variability from the jet Piergiorgio’s talk

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WHY? 2. Interesting science cases

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Optical echoes: binary geometry and neutron star masses In few minutes...

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WHY? 2. Interesting science cases

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Optical echoes: binary geometry and neutron star masses In few minutes...

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WHY? 2. Interesting science cases

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Pulsed optical emission from Magnetars: testing models See e.g. Dhillon 2005, 2009, 2010

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WHY? 3. Maybe it is the right time

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Science with ULTRACAM

accreting white dwarfs/cataclysmic variables 20% black-hole/neutron star X-ray binaries 16% sdB stars/asteroseismology 12% eclipsing, detached white-dwarf/red-dwarf binaries 11% extrasolar planet transits and eclipses 9%

• ccultations by Titan, Pluto, Uranus, Kuiper Belt Objects

6% flare stars 6% pulsars 5% isolated white dwarfs 5% ultra-compact binaries 4% isolated brown dwarfs 3% GRBs 2% Miscellaneous objects (AGN, contact binaries, etc) 1%

220 nights 16 runs 50+ papers 8.2m VLT 4.2m WHT 3.5m NTT since 2002

Credit: Vik Dhillon

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How? Optical: ULTRACAM at ING and ESO

High temporal resolution (>100Hz) Triple beam CCD (3x1024x1024) Cover 3 different bands simoustanealy Pipeline: data on real time!

See Dhillon et al. 2007

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How? Optical: ULTRACAM at ING and ESO

High temporal resolution (>100Hz) Triple beam CCD (3x1024x1024) Cover 3 different bands simoustanealy Pipeline: data on real time!

See Dhillon et al. 2007

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How? IR: ISAAC at ESO VLT

See Dhillon et al. 2007

• ‘Burst’ and ‘fastjitter’ modes
• up to 3 ms ! ...but you have to stop for reading at some point
• J, K, H bands

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How? IR: ISAAC at ESO VLT

See Dhillon et al. 2007

• ‘Burst’ and ‘fastjitter’ modes
• up to 3 ms ! ...but you have to stop for reading at some point
• J, K, H bands

★ Other Instruments

• OPTIMA

small telescope but nice results!

• Also fast modes in e.g. VLT and Keck instruments

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HOW?. New things comings

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EMCCDs at help... They are becoming popular

• Fast optical spectroscopy with ULTRASPEC

Visitor instrument at ESO telescope

• Fast optical spectroscopy with ISIS/EMCCD

4.2m WHT at La Palma

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MY SCIENCE CASE:

constraining fundamental parameters with Echo-tomography

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Persistent / Transient

bright disc Companion not detected

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Distribution of NS and BH masses

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Monday, June 7, 2010

Distribution of NS and BH masses

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Monday, June 7, 2010

Distribution of NS and BH masses

Is there a real gap in the distribution? Which is the maximum mass for a NS? 15

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Bowen emission from the companion

Steeghs & Casares 2002 ApJ 568 273

 Discovery of narrow (FWHM ≈ 50 km/s) high excitation

emission lines from the irradiated companion in Sco X-1.

Most intense in Bowen blend:

• NIII 4634, 4641-2
• CIII 4647, 4650-1

Powered by fluorescence resonance triggered by cascade recombination of HeII Ly α photons

Monday, June 7, 2010

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Bowen emission from the companion

Steeghs & Casares 2002 ApJ 568 273

 Discovery of narrow (FWHM ≈ 50 km/s) high excitation

emission lines from the irradiated companion in Sco X-1.

Most intense in Bowen blend:

• NIII 4634, 4641-2
• CIII 4647, 4650-1

Powered by fluorescence resonance triggered by cascade recombination of HeII Ly α photons

Monday, June 7, 2010

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Bowen emission from the companion

Steeghs & Casares 2002 ApJ 568 273

 Discovery of narrow (FWHM ≈ 50 km/s) high excitation

emission lines from the irradiated companion in Sco X-1.

Most intense in Bowen blend:

• NIII 4634, 4641-2
• CIII 4647, 4650-1

Powered by fluorescence resonance triggered by cascade recombination of HeII Ly α photons

Monday, June 7, 2010

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Bowen emission from the companion

Steeghs & Casares 2002 ApJ 568 273

 Discovery of narrow (FWHM ≈ 50 km/s) high excitation

emission lines from the irradiated companion in Sco X-1.

Most intense in Bowen blend:

• NIII 4634, 4641-2
• CIII 4647, 4650-1

Powered by fluorescence resonance triggered by cascade recombination of HeII Ly α photons

Monday, June 7, 2010

LMXB

PERIOD hours

Kem km s-1 M1 MSUN REFERENCE

J1808.4-3658 2.01 248±20 >0.13

Cornelisse et al. 2009

4U 1636-536 3.79 277±22 >0.62

Casares et al. 2006 EXO 0748-676

3.82 310±10 1.0-2.4

Muñoz-Darias et al. 2009

XB 1254-690 3.93 245±30 1.2-2.6

Barnes et al. 2007

J1814-338 4.2 345±19 >1

Casares et al. In prep

GX 9+9 4.2 230±35 >0.23

Cornelisse et al. 2007a

4U 1735-444 4.65 226±22 >0.32

Casares et al. 2006

X1822-371 5.57 280±3 1.5-1.9

Muñoz-Darias et al. In prep

LMC X-2 7.7 351±28 >1.2

Cornelisse et al. 2007c

Sco X-1 18.9 87±1 >0.24

Steeghs & Casares 2002

Aql X-1 18.97 247±8 >1.6

Cornelisse et al. 2007b

GX 339-4 42.14 317±10 >6 (BH)

Hynes et al. 2003; Muñoz- Darias et al. 2008

SUMMARY of results

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What is echo-tomography?

O(t) = X(t) * T(t-τ) Time delays between X-ray and optical variability to map reprocessing regions in a binary (O’Brien et al. 2001)

T(t-τ) depends on orbital phase and geometry:

• inclination i
• binary separation
• mass ratio q=M2/M1

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Monday, June 7, 2010

What is echo-tomography?

O(t) = X(t) * T(t-τ) Time delays between X-ray and optical variability to map reprocessing regions in a binary (O’Brien et al. 2001)

T(t-τ) depends on orbital phase and geometry:

• inclination i
• binary separation
• mass ratio q=M2/M1

We propose to apply echo-tomography using a narrow filter centered at the Bowen Blend.

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ULTRACAM+Narrow filters

Bowen + He II continuum subtracted lightcurves !!!

FLUX

WAVELENGTH

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Echo-tomography of Sco X-1

Goal: search for time delayed echoes of X-ray variability from the companion using Bowen lines.

Sco X-1 is the brightest LMXB in both, X-rays and optical wavelengths (V=12.9) Observational campaign with RXTE and WHT+ULTRACAM during 3 nights: 17-19 May 2004 full covering an orbital period (P=18.9 h)

0.00 0.50 0.25 0.75

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φ=0.42 φ=0.52 φ=0.60 φ=0.73

W5 W4 W1 W2 W3

SCO X-1 during flaring!

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φ=0.42 φ=0.52 φ=0.60 φ=0.73

W5 W4 W1 W2 W3

SCO X-1 during flaring!

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43s

Delay at orbital phase ~0.5

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43s

Delay at orbital phase ~0.5

Bowen+He II+Continuum~11-12 s Continuum ~9 s

DELAY (s)

CORRELATION LEVEL Continuum Monday, June 7, 2010

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Analysis of the delays

DELAY (s) MASS RATIO

DONOR DISK

CONTINUUM Text

Muñoz- Darias et al. 2007

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Analysis of the delays

M1 > 1.4 M

i > 50º

Bowen+He II CS

DELAY (s) MASS RATIO

DONOR DISK

CONTINUUM Text

Muñoz- Darias et al. 2007

Monday, June 7, 2010

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Analysis of the delays

M1 > 1.4 M

i > 50º However, we need phase dependent echoes

Bowen+He II CS

DELAY (s) MASS RATIO

DONOR DISK

CONTINUUM Text

Muñoz- Darias et al. 2007

Monday, June 7, 2010

Echo-tomography of 4U 1636-536

• Emission from the companion previously detected:

(Casares et al. 2006)

Kem=277 ± 22 km/s K1=90 -113 km/s

• Frequent Type I bursts

GOAL: using bursts to measure delays at different orbital phases

Observational campaign with RXTE and VLT+ULTRACAM during 2 consecutive nights in June 2007

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Monday, June 7, 2010

Phase-dependent echoes in 4U 1636-536

TIME (s) DELAY (s) FLUX CORRELATION LEVEL

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Monday, June 7, 2010

Phase-dependent echoes in 4U 1636-536

TIME (s) DELAY (s) FLUX CORRELATION LEVEL TIME (s) DELAY (s) CORRELATION LEVEL FLUX

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Monday, June 7, 2010

Phase-dependent echoes in 4U 1636-536

TIME (s) DELAY (s) FLUX CORRELATION LEVEL TIME (s) DELAY (s) CORRELATION LEVEL FLUX TIME (s) DELAY (s) FLUX CORRELATION LEVEL

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Monday, June 7, 2010

Analysis of the delays

q∼0.3 40°≤i≤60°

Casares et al. 2006

Text

Muñoz-Darias et al. in prep

Text M1=1.4-1.6 M

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Analysis of the delays

q∼0.3 40°≤i≤60°

Casares et al. 2006 New observations coming....

Text

Muñoz-Darias et al. in prep

Text M1=1.4-1.6 M

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SUMMARY

★ LMXBs are MW sources. They require of a MW approach

Interesting science cases

★ Things improving. For the first time, it seems we have the right

instruments to do OIR timing. ULTRACAM EMCCD technology

★ Indeed, it seems the right time. Field becoming popular

It is possible to use the optical echoes of the X-ray variability to constrain masses in LMXBs

Monday, June 7, 2010