transient x-ray binaries in centaurus a

Transient X-ray Binaries In Centaurus A

July 15, 2010: Accretion WorkshopCambridge, Massachusetts

Gregory R. Sivakoff (UVa)Chandra Cen A-Very Large Project Team

A Galaxy’s CookbookA Population of X-Ray Binaries• Start With A Galaxy’s Stellar IMF

– # NSs/BHs• Stir In Stellar Dynamics

– # Binaries Form• Bake With Stellar Evolution & Binary

Evolution For A Few Million/Billion Years– # HMXBS/LMXBs Form

• Top With Accretion Physics– # XRBs Emitting At A Given LX

July 15, 2010: Accretion WorkshopCambridge, Massachusetts

July 15, 2010: Accretion WorkshopCambridge, Massachusetts

King 2006

X-ray Binary Variability Soft X-ray Transients

Disk Instability + Irradiation + Disk Size

Mar. 4, 2010: HEAD Meeting, Waikoloa, Hawaii

X-ray Binary Variability Soft X-ray Transients

Disk Instability + Irradiation + Disk Size Most Outbursts Are Short, But Some > 10 yr

(e.g., GRS1915, KS1731)

Aql X1 EXO1745-248GX339-4

2001 2003 2001 2003 2001 2003YearL X

,0.3

-10

kev (

erg/

s)

5×1037

1×1038

Galactic/Extragalactic Studies ofXRBs are Complementary

Galactic Extragalactic

Sensitivity For Quiescent XRBSActive XRBs Active XRBs

Orbital Param. Some Known Mostly Unknown

Absorption Variable Column Constant Column

Distance ~1/3 Known Same / gal.

Field-Of-View All-Sky Chandra-Sized

Sample Size Limited 10s – 100s per gal.

July 15, 2010: Accretion WorkshopCambridge, Massachusetts

July 15, 2010: Accretion WorkshopCambridge, Massachusetts

Mar. 4, 2010: HEAD Meeting, Waikoloa, Hawaii

1999 Dec 052000 May 172002 Sep 032003 Sep 142007 Mar 272007 Mar 222007 Mar 302007 Apr 172007 May 082007 May 30

The Importance Of Being Variable

Sivakoff et al. 2008 + Updates

Steep Power Law StateThermal State

July 15, 2010: Accretion WorkshopCambridge, Massachusetts

GX 339-4 Like Sources?

July 15, 2010: Accretion WorkshopCambridge, Massachusetts

But, Persistence Dominates

July 15, 2010: Accretion WorkshopCambridge, Massachusetts

NGC 4697: Sivakoff et al. NGC 4365: Sivakoff et al.

… In Many Galaxies

Accretion Processes in X-Rays:From White Dwarfs to Quasars

… In Many Galaxies

Accretion Processes in X-Rays:From White Dwarfs to Quasars

Where Do We Go From Here?

Fainter Sources, Month-Year Timescales

Brighter Sources, Decade Timescales

Accretion Processes in X-Rays:From White Dwarfs to Quasars

XLF of 14 E/SOs: Kim & Fabbiano 2003

Where Do We Go From Here?

Fainter Sources, Month-Year Timescales

Brighter Sources, Decade Timescales

Accretion Processes in X-Rays:From White Dwarfs to Quasars

Chandra X-ray Observatory

Where Do We Go From Here?

Fainter Sources, Month-Year Timescales

Bright Sources, Decade Timescales

Week Timescales

Accretion Processes in X-Rays:From White Dwarfs to Quasars

L

X,0.

3-10

kev

(erg

/s)

5×1037

1×1038

20032001 Year

AQL X-1

Where Do We Go From Here?

Fainter Sources, Month-Year Timescales

Bright Sources, Decade Timescales

Week Timescales

Accretion Processes in X-Rays:From White Dwarfs to Quasars

Wide FieldX-ray Telescope

Take-Away Points There Is A Wealth Of XRB Data In Cen A Variability Reveals Black Hole Candidates Sources Largely Persistent

Sources Largely NS XRBs? Missing Short Timescale Transient XRBs? BH XRBs Are Long Timescale Transients? Accretion Theory Is Missing Something?

July 15, 2010: Accretion WorkshopCambridge, Massachusetts

Thank You

Thank You

July 15, 2010: Accretion WorkshopCambridge, Massachusetts