First look at S5 data for pulsars - Line sensitivity
Vladimir Dergachev has run PowerFlux over the first seven weeks of
S5 data for H1 and L1, looking over the range 40-700 Hz. Results are
very preliminary and undigested, but there are a couple of noteworthy
points w.r.t. 1 Hz lines and 60 Hz lines:
- The 1 Hz lines that plagued us in S4 are not a problem at all in
S5 for PowerFlux. Greg Mendell had already reported in December on their absence
in looking over ~day-long averages of 30-minute SFT's.
The PowerFlux search too over seven weeks of SFT's shows little sign of
1 Hz contamination either. Here are preliminary S5 limits on circularly
polarized CW radiation (no spindown) on H1 and L1,
to be compared with corresponding
limits from S4 for H1 and L1. Note especially the dramatic improvement
in L1 from S4 to S5 w.r.t. the pervasive 1 Hz comb.
Color coding in upper limits plots:
- CYAN POINTS - 60 Hz +/- 1.25 Hz
- DARK BLUE POINTS - Non-Gaussian noise
- RED DIAMONDS - Wandering line
- GREEN CURVE - Upper limit
- RED POINTS - Upper limit with SNR>7
- PINK CURVE - Underlying noise scaled up arbitrarily
In contrast, the 60 Hz contamination of neighboring bands is
decidedly worse for S5 H1 than for S5 L1 or for S4 H1.
K. Riles 1/6/06
