Gamma-ray Burst 051006

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 06 Oct 05 20:31:20 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     158593,   Seg_Num: 0
GRB_RA:          110.830d {+07h 23m 19s} (J2000),
                 110.909d {+07h 23m 38s} (current),
                 110.145d {+07h 20m 35s} (1950)
GRB_DEC:          +9.531d {+09d 31' 50"} (J2000),
                  +9.519d {+09d 31' 09"} (current),
                  +9.628d {+09d 37' 41"} (1950)
GRB_ERROR:       4.00 [arcmin radius, statistical only]
GRB_INTEN:       13937 [cnts]    Image_Peak=254 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   307     E_range: 50-350 keV
BKG_INTEN:       113142 [cnts]
BKG_TIME:        73776.00 SOD {20:29:36.00} UT
BKG_DUR:         40 [sec]
GRB_DATE:        13649 TJD;   279 DOY;   05/10/06
GRB_TIME:        73833.25 SOD {20:30:33.25} UT
GRB_PHI:         120.81 [deg]
GRB_THETA:        35.80 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     17.14 [sigma]
IMAGE_SIGNIF:    7.25 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +3  +6  +0  +0 -12  +1 
SUN_POSTN:       192.59d {+12h 50m 22s}   -5.40d {-05d 23' 54"}
SUN_DIST:         82.74 [deg]
MOON_POSTN:      230.83d {+15h 23m 18s}  -22.10d {-22d 05' 50"}
MOON_DIST:       121.20 [deg]
MOON_ILLUM:      12 [%]
GAL_COORDS:      207.96, 11.37 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      111.04,-12.40 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.

red DSS finding chart ps-file

GCN/SWIFT NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 06 Oct 05 20:32:29 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     158593,   Seg_Num: 0
POINT_RA:        110.847d {+07h 23m 23s} (J2000)
POINT_DEC:        +9.525d {+09d 31' 30"} (J2000)
GRB_DATE:        13649 TJD;   279 DOY;   05/10/06
GRB_TIME:        73941.46 SOD {20:32:21.46} UT
COUNTS:          17    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN/SWIFT NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 06 Oct 05 20:33:56 UT
NOTICE_TYPE:     Swift-XRT Spectrum
TRIGGER_NUM:     158593,   Seg_Num: 0
SPEC_START_DATE: 13649 TJD;   279 DOY;   05/10/06
SPEC_START_TIME: 73946.23 SOD {20:32:26.23} UT
SPEC_STOP_DATE:  13649 TJD;   279 DOY;   05/10/06
SPEC_STOP_TIME:  74017.47 SOD {20:33:37.47} UT
LIVETIME:         70.45 [sec]
POINT_RA:        110.85d {+07h 23m 24s} (J2000)
POINT_DEC:        +9.52d {+09d 31' 23"} (J2000)
MODE:            6, Windowed Timing mode
WAVEFORM:        60
LRPD_BIAS:       84  (this value is valid only when in LRPD mode)
TERM_COND:       5
SPEC_URL:        sw00158593000msx.pha
SUN_POSTN:       192.59d {+12h 50m 22s}   -5.40d {-05d 23' 56"}
SUN_DIST:         82.72 [deg]
MOON_POSTN:      230.84d {+15h 23m 22s}  -22.10d {-22d 06' 10"}
MOON_DIST:       121.19 [deg]
MOON_ILLUM:      12 [%]
GAL_COORDS:      207.97, 11.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      111.06,-12.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-XRT Spectrum.
COMMENTS:        This spectrum accumulation was terminated by the 'WT-to-LRorPC Transition' condition.

GCN/SWIFT NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 06 Oct 05 20:34:13 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     158593,   Seg_Num: 0
GRB_RA:          110.830d {+07h 23m 19s} (J2000),
                 110.909d {+07h 23m 38s} (current),
                 110.145d {+07h 20m 35s} (1950)
GRB_DEC:          +9.531d {+09d 31' 50"} (J2000),
                  +9.519d {+09d 31' 09"} (current),
                  +9.628d {+09d 37' 41"} (1950)
GRB_DATE:        13649 TJD;   279 DOY;   05/10/06
GRB_TIME:        73833.25 SOD {20:30:33.25} UT
TRIGGER_INDEX:   307
GRB_PHI:         120.81 [deg]
GRB_THETA:        35.80 [deg]
DELTA_TIME:      57.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
LC_URL:          sw00158593000msb.lc
SUN_POSTN:       192.59d {+12h 50m 22s}   -5.40d {-05d 23' 54"}
SUN_DIST:         82.74 [deg]
MOON_POSTN:      230.83d {+15h 23m 18s}  -22.10d {-22d 05' 50"}
MOON_DIST:       121.20 [deg]
MOON_ILLUM:      12 [%]
GAL_COORDS:      207.96, 11.37 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      111.04,-12.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.

GCN/SWIFT NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 06 Oct 05 20:35:13 UT
NOTICE_TYPE:     Swift-XRT Lightcurve
TRIGGER_NUM:     158593,   Seg_Num: 0
POINT_RA:        110.848d {+07h 23m 23s} (J2000)
POINT_DEC:        +9.523d {+09d 31' 24"} (J2000)
LC_START_DATE:   13649 TJD;   279 DOY;   05/10/06
LC_START_TIME:   73944.22 SOD {20:32:24.22} UT
LC_STOP_DATE:    13649 TJD;   279 DOY;   05/10/06
LC_STOP_TIME:    74101.23 SOD {20:35:01.23} UT
LC_LIVE_TIME:    153.43 [sec], 97.7%
DELTA_TIME:      86242.99 [sec]
N_BINS:          100
TERM_COND:       0
LC_URL:          sw00158593000msx.lc
SUN_POSTN:       192.59d {+12h 50m 22s}   -5.40d {-05d 23' 56"}
SUN_DIST:         82.72 [deg]
MOON_POSTN:      230.84d {+15h 23m 22s}  -22.10d {-22d 06' 10"}
MOON_DIST:       121.19 [deg]
MOON_ILLUM:      12 [%]
GAL_COORDS:      207.97, 11.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      111.06,-12.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-XRT Lightcurve.

GCN/SWIFT NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 06 Oct 05 20:37:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     158593,   Seg_Num: 0
POINT_RA:        110.847d {+07h 23m 23s} (J2000)
POINT_DEC:        +9.525d {+09d 31' 30"} (J2000)
POINT_ROLL:      96.723d
GRB_DATE:        13649 TJD;   279 DOY;   05/10/06
GRB_TIME:        73940.60 SOD {20:32:20.60} UT
FILTER:          3, V
BKG_MEAN:        1.594
N_STARS:         145
X_OFFSET:        476 [pixels]
Y_OFFSET:        555 [pixels]
X_MAX:           1435 [pixels]
Y_MAX:           1514 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00158593000msufc.fits
SUN_POSTN:       192.59d {+12h 50m 22s}   -5.40d {-05d 23' 56"}
SUN_DIST:         82.72 [deg]
MOON_POSTN:      230.84d {+15h 23m 22s}  -22.10d {-22d 06' 09"}
MOON_DIST:       121.19 [deg]
MOON_ILLUM:      12 [%]
GAL_COORDS:      207.97, 11.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      111.06,-12.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN/SWIFT NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 06 Oct 05 20:39:06 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     158593,   Seg_Num: 0
POINT_RA:        110.847d {+07h 23m 23s} (J2000)
POINT_DEC:        +9.525d {+09d 31' 30"} (J2000)
ROLL:            96.723d
GRB_DATE:        13649 TJD;   279 DOY;   05/10/06
GRB_TIME:        73940.60 SOD {20:32:20.60} UT
FILTER:          3, V
EXPOSURE_ID:     150323540
X_OFFSET:        795 [pixels]
Y_OFFSET:        874 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       955
Y_GRB_POS:       1034
BINNING_INDEX:   1
IM_URL:          sw00158593000msuni.fits
SUN_POSTN:       192.59d {+12h 50m 22s}   -5.40d {-05d 23' 56"}
SUN_DIST:         82.72 [deg]
MOON_POSTN:      230.84d {+15h 23m 22s}  -22.10d {-22d 06' 09"}
MOON_DIST:       121.19 [deg]
MOON_ILLUM:      12 [%]
GAL_COORDS:      207.97, 11.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      111.06,-12.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN/SWIFT NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 06 Oct 05 20:33:56 UT
NOTICE_TYPE:     Swift-XRT Spectrum
TRIGGER_NUM:     158593,   Seg_Num: 0
SPEC_START_DATE: 13649 TJD;   279 DOY;   05/10/06
SPEC_START_TIME: 73946.23 SOD {20:32:26.23} UT
SPEC_STOP_DATE:  13649 TJD;   279 DOY;   05/10/06
SPEC_STOP_TIME:  74017.47 SOD {20:33:37.47} UT
LIVETIME:         70.45 [sec]
POINT_RA:        110.85d {+07h 23m 24s} (J2000)
POINT_DEC:        +9.52d {+09d 31' 23"} (J2000)
MODE:            6, Windowed Timing mode
WAVEFORM:        60
LRPD_BIAS:       84  (this value is valid only when in LRPD mode)
TERM_COND:       5
SPEC_URL:        sw00158593000msx.pha
SUN_POSTN:       192.59d {+12h 50m 22s}   -5.40d {-05d 23' 56"}
SUN_DIST:         82.72 [deg]
MOON_POSTN:      230.84d {+15h 23m 22s}  -22.10d {-22d 06' 10"}
MOON_DIST:       121.19 [deg]
MOON_ILLUM:      12 [%]
GAL_COORDS:      207.97, 11.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      111.06,-12.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-XRT Spectrum.  
COMMENTS:        This spectrum accumulation was terminated by the 'WT-to-LRorPC Transition' condition.

GCN/SWIFT NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 06 Oct 05 20:35:13 UT
NOTICE_TYPE:     Swift-XRT Lightcurve
TRIGGER_NUM:     158593,   Seg_Num: 0
POINT_RA:        110.848d {+07h 23m 23s} (J2000)
POINT_DEC:        +9.523d {+09d 31' 24"} (J2000)
LC_START_DATE:   13649 TJD;   279 DOY;   05/10/06
LC_START_TIME:   73944.22 SOD {20:32:24.22} UT
LC_STOP_DATE:    13649 TJD;   279 DOY;   05/10/06
LC_STOP_TIME:    74101.23 SOD {20:35:01.23} UT
LC_LIVE_TIME:    153.43 [sec], 97.7%
DELTA_TIME:      86242.99 [sec]
N_BINS:          100
TERM_COND:       0
LC_URL:          sw00158593000msx.lc
SUN_POSTN:       192.59d {+12h 50m 22s}   -5.40d {-05d 23' 56"}
SUN_DIST:         82.72 [deg]
MOON_POSTN:      230.84d {+15h 23m 22s}  -22.10d {-22d 06' 10"}
MOON_DIST:       121.19 [deg]
MOON_ILLUM:      12 [%]
GAL_COORDS:      207.97, 11.39 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      111.06,-12.40 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-XRT Lightcurve.

GCN notice #4061
J. Norris (GSFC), S. Barthelmy (GSFC), D. Burrows (PSU), M. Capalbi (ASDC), N. Gehrels (GSFC), S.T. Holland (GSFC), J. Kennea (PSU), C. Markwardt (GSFC/UMD), F. Marshall (GSFC), D. Morris (PSU), J. Nousek (PSU), C. Pagani (PSU), D. Palmer (LANL), P. Roming (PSU) on behalf of the Swift team:
At 20:30:33 UT, Swift-BAT triggered and located GRB051006 (trigger=158593). The spacecraft slewed immediately. The BAT on-board calculated location is RA,Dec 110.830d,+9.531d {07h 23m 19s,+09d 31' 50"} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve shows a multi-peak structure with a total duration of ~20 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~3 seconds after the trigger.
XRT began observing the field at 20:32:21.46, 108 seconds after the BAT trigger. No prompt X-ray position is available. The XRT lightcurve suggests a fading source is present in the field of view. The TDRSS downlinked spectrum is inconclusive. Further analysis of the XRT data will be reported when the full data set becomes available.
The UVOT began observing the position of trigger #158593 at 20:32:20.4 UT, 107 s after the BAT trigger. In the 200 s V-band image, no new source is detected with respect to the DSS down to a 3-sigma limiting mag of 18.8. The estimated extinction in this direction is A_V ~ 0.2 magnitudes. The UVOT image gives 25% coverage of the BAT error circle. The BAT source is located in a crowded star field.
GCN notice #4062
D. Morris (PSU), C. Pagani (PSU/OAB), M. Capalbi (ASDC), J. Kennea (PSU), D. Burrows (PSU) report on behalf of the Swift/XRT team:
The Swift XRT began observing GRB 051006 (trigger #158593, Norris et al., GCN 4061) at 20:32:21 UT, but was unable to obtain an on-board centroid. Analysis of the initial ground-processed data finds a faint, fading, and uncataloged source at coordinates:
```
RA(J2000) = 07 23 13.9
Dec(J2000) = +09 30 22.5
```
We estimate an uncertainty of 8 arcseconds (90% containment). This position lies 118 arcseconds from the BAT position reported in GCN 4061.
GCN notice #4063
D. Palmer (LANL), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), K. Gendreau (GSFC), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), P. Meszaros (PSU), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), J. Tueller (GSFC) on behalf of the Swift-BAT team:
Using the full data set from the recent telemetry downlink, we report further analysis of Swift-BAT Trigger #158593 (Norris, et al., GCN 4061). The ground-analysis position is RA,Dec 110.808,+9.510 {7h 23m 13.8s,+9d 30' 36.3"} (J2000) with an uncertainty of 1.7 arcmin (radius, 90%, stat+sys). T90 is 26 +- 1 sec. The lightcurve has an initial cluster of 3 overlapping peaks at T-5 to T+8 sec and a fourth peak at T+20 sec. Fitting a simple power law over the full interval from T-5.9 to T+24.7 sec, the photon index is 1.4 +/- 0.2 with a fluence of 1.28 +/- 0.13 X 10^-6 erg/cm^2. The peak flux in a 1-sec wide window starting at T+3.2 sec is 1.9 +/- 0.3 ph/cm^2/sec. All values are in the 15-150 keV band at the 90% confidence level.
GCN notice #4064
A. de Ugarte, A.J. Castro-Tirado, S. Guziy, V. Casanova, M. Jel=EDnek and J. Gorosabel (IAA-CSIC):
report:
"We have imaged a 7' x 7' region centred on the SWIFT/ BAT error box for GRB 051006 (Norris et al. GCNC 4061) with the 1.5-m OSN telescope at the Observatorio de Sierra Nevada starting on Oct 6.105 UT, i.e. 6.0 hours after the onset of the event) under fair meteorological conditions. Within the SWIFT/XRT error box (Morris et al. GCNC 4062), the co-added I-band image (10 x 300 s exposure time) shows three sources at the following coordinates (J2000):
```
ID       RA          Dec
#1   07 23 13.85 +09 30 28.3
#2   07 23 14.11 +09 30 20.4
#3   07 23 13.61 +09 30 23.7
```
with 0.4" error. Source 1 is a bright star present in the DSS-2. Source 2 is also present in the DSS-2 (blue). Source 3 is below the detection limit of the DSS-2.
Additional observations will continue tonight (if weather permits)."
GCN notice #4066
M. Capalbi, M. Perri (ASDC), J. Kennea, D.N. Burrows, D. Morris (PSU), L. Angelini (GSFC-JHU), J. Greiner (MPE) report on behalf of the Swift XRT team:
We have analyzed the first six orbits of the Swift XRT data for GRB 051006 ((trigger #158593, Norris et al., GCN 4061). The refined coordinates of the X-ray afterglow are:
```
RA(J2000) = 07 23 13.7
Dec(J2000) = +09 30 20.3
```
with an estimated uncertainty of 8 arcseconds radius (90% containment). This position is 16 arcseconds from the BAT refined position (Palmer et al., GCN 4063), 3.7 arcseconds from the early XRT position (Morris et al., GCN 4062) and 3.7 arcseconds from the optical source reported by de Ugarte et al. (GCN 4064).
Data in Windowed Timing (WT) mode starts at 20:32:26 UT, 113 seconds after the BAT trigger, then the XRT switched to Photon Counting mode.
The light curve shows a flaring behaviour in the first orbit, and has a decay index of -1.7 +/- 0.05 obtained excluding the flare time interval.
A preliminary spectral fit (simple absorbed power-law) to the WT data yields a photon index of 1.6 +/- 0.4 in the 0.7-10 keV band. The derived NH is (7 +/- 3)E21 cm^-2, which is higher than the Galactic value (8.6E+20 cm-2; Dickey & Lockman 1990).
GCN notice #4068
S. Bradley Cenko, Alicia M. Soderberg (Caltech) and Derek B. Fox (Penn State) report on behalf of a larger collaboration:
We have imaged the field of GRB 051006 (Norris et al., GCN 4061) with the automated Palomar 60-inch telescope. Observations consisted of 10 x 150 s R-band images taken at a mean epoch of approximately 9:20, 7 October UT (12.9 hours after the burst). In a co-addition of our images, we find no new sources inside the refined XRT error circle (Capalbi et al., GCN 4066). Using several Guide Star Catalog sources in the field, we estimate our limiting magnitude to be R > 21.0.
In particular, we do not detect source #3 identified by de Ugarte et al. (GCN 4064) to the magnitude limit quoted above.
GCN notice #4089
GRB 051006: Swift/UVOT Upper Limits
S. T. Holland (GSFC/USRA), J. Norris (GSFC), J. Greiner (MPE), D. Hinshaw (GSFC-SPSYS), and N. Gehrels (GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began observing the field of GRB 051006 107 seconds after the BAT trigger (Norris et al. GCN 4061). No new source is detected at the position of the XRT error circle (Capalbi et al. GCN 4066) in the initial 200 second V-band image down to a 5-sigma upper limit of 18.3, or in summed exposures with any of the filters down to the following 5-sigma magnitude upper limits.
```
Filter  T_range (s)     Exp (s)  5sig UL
V       107 - 98,547    12,033     20.5
B       474 - 68,573     4,111     20.9
U       420 - 64,478     3,846     20.4
UVW1    366 - 63,741     4,598     21.0
UVM2    311 - 73,819     4,179     21.3
UVW2    582 - 69,481     5,448     21.6
WHITE   527 -    577        50     18.5
```
These magnitudes have not been corrected for extinction.
GCN notice #4094
V.Rumyantsev (CrAO), V.Biryukov (SAI, MSU), A.Pozanenko (IKI), M. Ibrahimov (MAO) on behalf of larger GRB follow up collaboration report:
We have observed the GRB051006 error box (Norris et al., GCN4061) with 2.6 m Shajn telescope of CrAO on October 7 and 8 in R-band. On Oct.8 within XRT error circle (Capalbiet al., GCN4066) we detect source #3 quoted by Ugarte et al. (GCN 4064). The coordinate of the source is
```
RA(J2000) = 07 23 13.52
Dec          = +09 30 24.48
```
with uncertainty 0.4 arcsec in both coordinates. The photometry of the source against of USNO A2.0 is following
```
Mid time     Exposure    R
Oct.8 (UT)
  02:28      35x120 s   22.20 +/-0.15
```
The stacked image of the Oct.8 observation can be found in http://grb.rssi.ru/GRB051006/grb051006_051008_ZTSh_R.gif
Taking into account the upper limit of R>21.0 at 12.9 hours after the burst (Bradley Cenko at al., GCN 4068) and our result above one can estimate the power law decay index of possible afterglow source #3 as alpha >-1.37.
In our observation on Oct.7 between 02:23 - 02:44 (UT) due to unfavorable weather conditions the seeing was ~5 arcsec. At this time we could not confirm the presence of source #3 in the tail of nearby bright star. Detailed analysis in underway.
This message can be cited.
New/revised redshift from the TOUGH project, in particular: 1205.3162 1205.3490 1205.3779 1205.4036

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Jochen Greiner, last update: 08-Jul-2012 [Disclaimer]