ag2002hs

X-ray / optical correlations : 

X-ray / optical correlations G. Kanbach (MPE), H. Steinle (MPE), H.C. Spruit (MPA), C.Straubmeier (U. Köln), T. Belloni (Oss. di Brera) H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 in the transient black hole system KV UMa (J1118+48) 1

The year 2000 transient: XTE J1118+48 (=KV UMa): 

The year 2000 transient: XTE J1118+48 (=KV UMa) transient X-ray source during Jan – Jul 2000 nearby object (~ 2 kpc) at high galactic latitude estimated mass of compact star > 6 M Hard spectral state with high variability high optical / X-ray luminosity ratio Correlated observations using a RXTE-PCA ToO program and OPTIMA from Skinakas observatory, Crete were carried out during July 4-8, 2000 A total of 2.5 hours of coincident measurements were performed! (Kanbach, Straubmeier, Spruit, and Belloni, 2001, Nature 414, 180) H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 McClintock et al. 2

Optical-EUV-X-ray spectrum: 

Optical-EUV-X-ray spectrum Data from April 18, 2000 EUVE data from April 16, 2000 High optical / X-ray luminosity ratio! XTE J1118+48 (KV UMa) H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 thermal cyclo-synchrotron emission? Lopt-EUV ~ 1036 erg s-1 > LX  variable optical radiation can not be reprocessed X-rays Synchrotron emission? steep turn-over of spectrum at EUV is hard to explain with non-thermal synchrotron emission a thermal cyclo-synchrotron emission is more likely with Te ~ 200 keV, B~106 G, optical thickness up to ~ 100 log Fn log n non- thermal synch -(p-1)/2 therm CS 5/2 thick thin McClintock et al., 2001, ApJ, 555, 477 3

RXTE and OPTIMA Lightcurves: 

RXTE and OPTIMA Lightcurves Mean X-Ray and Optical „Flares“ H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 KV UMa KV UMa KV UMa KV UMa RXTE OPTIMA RXTE OPTIMA (~100) 4

´Reprocessing´ or ´Light-Echoes´: 

´Reprocessing´ or ´Light-Echoes´ X-ray pulse Optical pulse preceding delayed X-opt correlation Shadowing? Heating H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 5

X-ray optical correlations: 

X-ray optical correlations Positive correlation with short rise (~ 100ms) Maximum at ~ 500 ms; length ~ 5 sec; onset of sharp rise within 30 ms of X-ray peak; Anti-correlation at –2 sec:´precognition dip´ H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 6

Autocorrelation Functions: 

Autocorrelation Functions Time scales of the optical emission are much shorter than at X-rays. This is inconsistent with a reprocessing scheme! H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 7

Emission Models:: 

Emission Models: The brightness temperature and the SED indicate that self-absorbed cyclo-synchrotron emission causes the optical signal The size of the emitting region is < 30,000 km A ´quasi spherical´ slow outflow crossing photospheric surfaces: EUV @ 107- 108 G optical @ 106 G, r=20000 km EUV UV optical A ´jet-like´ slow outflow: X-ray and radio emission blobs fast jet ß ~ 0.5-0.9 slow outflow v < 30000 km/s optical emission @ d~ 20000 km , , H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 8

New Analysis: 

New Analysis H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 9 Principal Components Analysis Analysis of 250 events +/- 100 s results in 2 independent components: Shot Analysis (Spruit & Kanbach A&A 391, 225-233, 2002) (Malzac et al. Proc. Cargese WS „Black Holes“, 2002) no time-of-flight effect? both dip and peak are properties of optical light analysis of different (RXTE) X-ray spectral bands separate analysis of strong and weak events (shots) events similar in all spectral bands and correlated with optical; events similar Conclusion: one emission process that creates X-ray and optical emission. Similar structure on different time scales. C1 C2 C1 * C2 data anticorrelation of X-ray flux and hardnes ratio

Optical emission from slow outflow: 

Optical emission from slow outflow H. Steinle, MPE, AG Tagung Berlin, Splinter Meeting on Active Black Holes; September 26, 2002 10

The OPTIMA photometer: 

The OPTIMA photometer OPTIMA @ 1.3m Skinakas Focal Plane APD Photon Counters APD: high Q.E. ~60% (450-950 nm) Timing with GPS ~ 2 s Standby Mode Target Acquisition CCD Camera

Origin of Optical-EUV spectrum (continuum with weak lines): 

Origin of Optical-EUV spectrum (continuum with weak lines) Lopt-EUV ~ 1036 erg s-1 > LX  variable optical radiation can not be reprocessed X-rays Synchrotron emission? steep turn-over of spectrum at EUV is hard to explain with non-thermal synchrotron emission a thermal cyclo-synchrotron emission is more likely with Te ~ 200 keV, B~106 G, optical thickness up to ~ 100 log Fn log n non-thermal synch -(p-1)/2 therm CS 5/2 thick thin 3a