Mass Estimate of Black Hole Candidates GRS and GX339-4 Based on a Transition Layer Model of the Accretion Disk and a Search for X-ray Jets in GRS Santa Cruz Institute for Particle Physics Seminar May 23, 2006 Nathan D. Bezayiff, David M. Smith University of California Santa Cruz
GX and GRS are Low Mass X-Ray Binary Systems I.Companion Star is smaller than or equal to our sun. II.Roche Lobe is the most common type of accretion. III.If the point where the gravitational attraction between the two stars is equal (Inner Lagrange Point) occurs near the surface of the Companion Star, matter will be stripped from the Companion Star into an Accretion Disc that forms around the Compact Object. IV.Matter falling into the black hole converts about half its graviational binding energy to radiation via viscosity; the other half will be released near the surface of the star.
From Companion Star Compact Object Jets Accretion Disc Gravitational Attraction Between Both Stars equal ↑
Motivation For Development of the Transition Layer Model to Determine the Mass of Black Holes 1. In a Low-Mass X-Ray Binary System, no knowledge of any of the parameters of the companion are required. 2. The parameters required to determine the mass of a black hole only depend on the Energy Spectrum Power Law Index and Power Density Quasi Periodic Oscillation Frequency. 3. GRS , 1E , and GX are black holes where companion information does not exist. Hence their mass must be determined by another method. 4. May help to classify objects as neutron stars or black holes easier. If saturation of the Power-Law Indices is observed, the object is a black hole. If no saturation of the Power-Law Indices are observed, the object may be a neutron star.
Proportional Counter Array of Rossi X-Ray Timing Explorer Provides Timing, Energy Spectra Energy range: keV Energy resolution: < 18% at 6 keV Time resolution: 1 microsec Spatial resolution: collimator with 1 degree FWHM Detectors: 5 proportional counters Collecting area: 6500 square cm Layers: 1 Propane veto; 3 Xenon, each split into two; 1 Xenon veto layer
Obtaining the PLI and QPO from a given observation for GRS Power Law Component ↓ ↑ Interstellar Absorption First, Get the Power Law Index Channel Energy (keV) Residuals Normalized counts/sec/keV
Obtain the Quasi Periodic Oscillation Frequency in the Power Density Spectra Frequency (Hz) Power Density [(Rms/Mean)^2/Hz] QPO
(PLI) Power Law Index-Quasi Periodic Oscillation (QPO) curve Power Law Index Quasi-Periodic Oscillation (QPO) freq (Hz) Harmonic Pair? ↑
(33 kB) TRANSITION LAYER MODEL (VERY BASIC) 1. The Optical Depth (τ) is related to the accretion rate (dM/dt) 2. The Power Law Index, is related to the Optical Depth,τ. 3. The Power Law Index is related to dM/dt 4. The QPO frequency is related to the Transition Layer Outer Radius 5. The Transition Layer is Related to dM/dt 6. Thus, sine both and are both related to dM/dt, they are related to each other.
QuasiPeriodic Oscillation Correlations of two black holes related by shift in QPO frequency, 2 =(m 1 /m 2 ) 1 Best Fit Mass GRS ±.00m GRS GRS
1.The Fit is Poor and the Curve is the Wrong Shape 2. There are two more free parameters we can adjust A, They are found from the relation between and the Reynold’s number =A 3. We Can Allow A, and the mass to Vary and fit them freely for the Black Hole as done for GRS (TF04)
1. If we assume GRS and GRS have the same =A (A=1.0, = 1.25) then the best fit mass is m=2.3±.0m 3. If ( ) is different for GRS , our best fits have A=1.0, is 0.95), and the best fit mass is m= m
A, are clearly important in the shift between QPO-PLI Correlations from one black hole to another. A, , and the mass are not orthogonal. Below, curve families of A, m, . “δ” varies A, mass constant “Mass” varies“A” varies Mass, δ constantA, δ constant
Reduced chi square space for GX339-4 One of A,m,d is held constant at best fit parameters. Mass (M) δ A constant, M- δ varied δ A Mass constant, δ-A varied δ,Constant, Mass-A varied A Mass (M )
Transition Layer Model More Complicated for GX Power Law Index Quasi-Periodic Oscillation (QPO) freq (Hz)
GX Blue Count Rate > 500 cts/sec Red < 500 Cts/sec Blue 2002 Outburst, Red is 2004, 2003, 2005 Outburst Power Law Index Quasi-Periodic Oscillation (QPO) freq (Hz)
GX Low, Best Fit Parameters A= 0.75, Mass=2.68M, δ=1.6 Quasi-Periodic Oscillation (QPO) freq (Hz) Power Law Index 2.05 ± 0.0 M
GX High, Best Fit Parameters A=0.65, Mass=2.35 M, δ=2.35 Power Law Index Quasi-Periodic Oscillation (QPO) freq (Hz) – 0.05 M
CONCLUSIONS FOR TRANSITION LAYER MODEL 1. Certain parameters need to be better constrained in the TL model, i.e., A, , saturation 2. We’d like to do the analysis considering the other harmonics as the fundamental frequency. 3. GRS appears to be the type of black hole that the transition layer model may apply to. 4. The Transition Layer Model predicts a possible neutron star mass for GX Better fits and saturation are required to support this prediction.
Part II: Search For X-Ray Jets in GRS
Motivation For X-Ray Jet Search For GRS Persistent Radio Jets Have Been Seen in GRS A Persistent Extension Has Been Seen in Cygnus X Might GRS have X-ray jets too? Extension
The Chandra HRC-I is excellent for Imaging X-Ray Sources ” per pixel Resolution 2. Large uniform field of view (31 x 31 arc minutes) 3. Large uniform field of view (31 x 31 arc minutes) 4. High time resolution over the entire field of view (16 microseconds) 5. Low background (4 x 10^-6 cts/s/arcsec) High Resolution Camera HRC-I Chandra Satellite
Raw Data From HRC-I GRS Observation 2718 Each Pixel is 0.13“
Fit Gaussians to Slices, Look For Unusual Standard Deviations Heindl Astrophys J. 578,2 L125 Slice Angle (Degrees) Point Spread Function Sigma
Gaussian Fits of Slices Through Center Yield No X-Ray Jets 1E ♦ GRS X Cygnus X-3 ■ AR Lacertae ▲
Radio Jets Have Been Seen in GRS Thus, We Looked For X-Ray Jets in Radio Centers
No Jets Found In Regions Corresponding To, or Perpendicular To Radio Jets South Lobe North Lobe Signal/Noise Ratio Counts/Area % of GRS e-3 %9. 6e-3 % Core Brightness Needed for 3-Sigma Detection Counts/Area % of GRS e-3 % 9. 9e-3 % Core Brightness
Finally, We Took Azimuthal Slices Around GRS |18 “arcsecs |
We Found An Extension... Signal/Noise Counts in Counts/Area 12.2 arcsec^2 region 136 Degrees Degrees Avg Background
…But It Is A Detector Artifact 1.The spacecraft orientation is 90 or 270 degrees. If the extension was real, it should be present no matter how I orient the Satellite. 2. Upon rotating the satellite, the extension rotates also, so the extension must be part of the satellite. 3. From the Chandra Handbook, a “ghost” artifact, a secondary image, appears on one side of every source, due to the Saturation of the High Gain Amplifiers. The brightness of the ghost image is reported to be 0.1% of the source. 4. The fake jet is about 0.01% of the brightness of the center of the source. 5. Thus we conclude the extension is an artifact of the satellite. Merged Data; Roll Angle=90° Merged Data; Roll Angle=270°
Expected Signals if GRS Was Similar to Other Black Holes What Would The Size of the Jet Be? What Would The Flux of the Jet Be? BH= Black Hole GRS is being compared to, PS=Point Source or Central Compact Region, R=Radius, D=Distance to compact object, J=size of Jet in Arcsecs, F=Flux of Jet in ergs/sec/cm^2
Black Holes Most Similar to GRS XTE J H Cygnus X-3 M87
GRS width X height comments H X 1.88 ejected Cygnus X X 2.35 persistent/ continuous XTE J X 2.55 ejected M87 (with BH mass scaled) 1.48E-4 X 1.4E-5 persistent/ continuous M87 (without BH mass scake) 44,470 X 4,447 persistent/ continuous GRS_jet_flux WebPimms cts/ Could we X-Ray Jet Flux ergs/sec/cm^2 cts/sec arcsec^2 detect this? H e e No Cygnus X e Yes XTE J e e Yes M87 6e e16 Yes Radio Jet Flux H ~e e-8 1.0e-3 No Cygnus X e Yes XTE J e e Yes M87 (no radio data) Persistent=appeared in all observations, continuous=connected to central source, ejected=separated from central source
Conclusions For X-Ray Jet Search of GRS No Jets Were Found With Chandra Observations. 2. If GRS Was Similar to Black Holes M87, Cygnus X-3, or XTE J , We Should Have Seen X-Ray Jets Based on Rough Estimates. If GRS is More Similar to H , We Would Not Have Seen X-Ray Jets. 3. The Extension We Found Was a Property of the Chandra HRC-I Detector.