1. Virgo update: VSR1 analysis
Analysis of VSR1 started using first 10 days of data
SFDB and peak-map produced using both “old” and “new” method (see Pia’s presentation)
Cleaning of the peak-map
Faster procedure to extract input files
Hough step
C. Palomba on behalf of Rome group

2. Cleaning of the peak-map
In Virgo data there are many lines of clear instrumental origin: “known” lines (e.g. violin modes), “unknown” lines but easily identifiable (e.g higher order violin modes) and “unknown” (mainly harmonics) .

3. 10 Hz harmonics (up to 2kHz): likely due to a camera clock
1Hz harmonics (up to ~60Hz): coherence with WE magnetometers

4. Hz: 55 harmonics found
0.33Hz (up to ~45Hz): sidebands of 1Hz?
Hz: 67 harmonics found
Hz: 36 harmonics found, of which 22 around 250Hz

6. Violin modes not in the list:
BS 5th order, around 836Hz,
mirrors 5th order around 1675Hz and 6th order around 1997Hz

9. In the analysis of WSR data we have noticed a reduction in the number of candidates of 20-50% after peak-map cleaning.

10. Input file extraction
From the peak-map we extract “slices” (e.g. each covering 1Hz) that are the input of the Hough step. These slices are submitted with the job or, better, are copied to the SEs before job submission.
We have modified the old program for file extraction making it faster: few minutes to extract 2000 files each covering 1Hz and 10 days of time.

11. Hough step
We have found Hough candidates over the band Hz, maximum spin-down age 4000yrs.
Strange behaviour in the candidates frequency distribution, suggesting something wrong.
Under investigation.