discovery and evolution of a new galactic black hole candidate xte j1752-223 discovery and evolution...

Discovery and Evolution of aNew Galactic Black Hole Candidate

XTE J1752-223

N. Shaposhnikov1,2,3, J. Swank3, C. Markwardt1,2,3, H. Krimm2,3,4

The Astrophysical Journal, 723, 2,1817 1University of Maryland, Astronomy Department2Center for Research and Exploration in Space Science & Technology (CRESST)3NASA/Goddrd Space Flight Center4Universities Space Research Association

4th MAXI Workshop 2010, Tokyo, November 29, 2010

Discovery

XTE J1752-223

• RXTE/PCA Galactic Bulge Scans showed an unidentified new source on October 21, 2009. Scans on October 23 fully confirmed a new source (Atel #2258)

• Subsequent Swift/XRT observation showed bright point source with very hard non-thermal spectrum with index Γ = 1.2 and NH =0.47×1022 cm-2 (Atel #2261)

October, 21 2009

October 20, 2009

October, 23 2009

Discovery and Evolution of a New Galactic Black Hole Candidate XTE J1752-223

4th MAXI Workshop 2010, Tokyo, November 29, 2010Shaposhnikov, Swank, Markwardt &Krimm

XTE J1752-223 Evolution



Shaposhnikov, Swank, Markwardt &Krimm

Hardness – Intensity Diagram

Data modeling:Energy spectral model• Comptonization (BMC)• Gaussian for the iron line

at ~6.5 keV• Modified by interstellar

absorption (measured by Swift/XRT)

• High energy cutoff

Power Density Spectra• Power law or broken

power law for the broad band variability

• Loretzians for QPOs

RXTE Data Spectral Analysis




QPO

Shaposhnikov et al. ApJ,2010

XTE J1752-223 Variability Evolution




LHS HIMS SIMS HSS IS LHS

Low Hard State in XTE J1752-223




XTE J1752-223

GX 339-4

Power Spectra

Fourier Resolved Spectroscopy (FRS)




XTE J1752-223

Low Hard State

GX 339-4

Fourier Resolved Spectroscopy (continued)




State Transition

HIMS SIMS

Lowest QPOs during the beginning of the transition are softer than the time averaged spectrum. As the transition evolves they quickly become harder (Sobolewska & Zycki 2006). QPO spectrum is always harder that

the broad band noise.

Fourier Resolved Spectroscopy (HIMS)




FRS normalized by total spectrum

FRS normalized by the non-thermal

spectral component

(Shaposhnikov et al. 2010)

Disk black body spectral component is stable!RMS ratio normalized on the power law component alone is decreasing

from the level of 50% (LHS!).

What can we learn from spectral data?Nature of the power law

E- Thermal Comptonization:

€

Nsc ~ τ 2,

€

η =4kT /mec2

€

α ~ [(4kT /mec2)2τ 2]−1

(Rubicki & Lightman, 79)

Bulk Motion Comptonization:

(S & Titarchuk, 2009)




(Laurent & Titarchuk 2010)

€

η∝τ −1, Nsc ∝ τ ⇒ α ≈ const

Thermal versus Bulk motion Comptonization




(S & Titarchuk 2010)

XTE J1550-564

Thermal

BMC

High Energy Cutoff Evolution

Thermal

BMC

XTE J1550-564 (1998 ouburst) Index vs Luminosity

On the behavior of RMS spectrum



Shaposhnikov, Swank, Markwardt &Krimm €

F(v) = (1− fC )B(v) + fC ⋅ B(v')0

∞

∫ C(v ',v)dv'

LHS HIMS

€

C = Cthermal

€

C = Cthermal + CBMC

Thermal Comtonization is variable, BM Comptonization is not!

Correlation scaling: BH mass estimate




Scaling Laws GX 339-4 vs XTE J1752-223 GRO J1655-40 vs XTE J1752-223

sv = 0.88 sn=0.41GX 339-4:

M=12.5 M ,d=5.7 kpc (S & Titarchuk 2009)

M1752≅11M d≅3.5 kpc

S & Titarchuk 2009, ApJ

sv = 1.5 sn=0.96GRO J1655-40:

M=12.5 M, d=5.7 kpc (Hjellming & Rupen 1995)

M1752≅9.5M d≅3.8 kpc

MAXI J1659-152




Evolution Index – QPO Frequency during the rise episode

sv = 1.62 +/- 0.04GX 339-4:

M=12.5 M ,d=5.7 kpc (S & Titarchuk 2009)

M1659≅20+/-3 M

Hardness-Intensity Diagram

SUMMARY • On October 21 RXTE discovered a new X-ray transient source

XTE J1752-223• Spectral and variability properties and the evolutionary

pattern are consistent with other Galactic BH candidates• XTE J1752-223 exhibited a uniquely stable prolonged low-

hard state• RXTE data allows spectral, timing analysis and Fourier

resolved spectroscopy revealing a new phenomenology. This helps to identify sources of different types of variability (noise, QPOs). QPO seems to be produced in the Compton Corona.

• Bulk Motion Comptonization in the converging flow provides a very promising framework for explaining different observational aspects of accreting BHs

• We estimated BH masses in XTE J1752-223 and MAXI J1659-152 of about 10 and 20 solar masses correspondingly

• The presented results are entirely due to unique RXTE capabilities, large collection area, high time and moderate spectral resolution and unmatched monitoring capabilities.


4th MAXI Workshop 2010, Tokyo, November 29, 2010Shaposhnikov, Swank, Markwardt &Krimm

discovery and evolution of a new galactic black hole candidate xte j1752-223 discovery and evolution...

Documents

evolution xte j1752

discovery xte j1752

markwardt krimm xte

th maxi workshop

new source atel

variability evolution

markwardt krimm slide

unidentified new source