Casey Law edited untitled.tex  almost 10 years ago

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\section{Summary}  We report on the state of observing for the VLA FRB project, also known as 13B-409 and 14A-425. The We detected no FRBs in the  first 76 hours was observed under an approved DDT proposal (13B-409) and detected no FRBs. (13B-409).  Comparing our rate constraint to published rates revealed inconsistencies that led to an overestimate of the FRB rate. We discuss an improved rate estimate and find that completing the 147-hour campaign under program 14A-425 will give us a 50\% chance at detecting an FRB. Our first stage of VLA observations have already highlighted the value of using an interferometer to define a robust FRB rate limit. Raising the priority of Ensuring that  14A-425 is observed to completion  will help us complete observing and significantly  improve our chances of making the first interferometric detection of an FRB. FRB; an extremely exciting scientific result.  \section{Current Status} 

\label{fields}  \end{table}  All 63.3 hours of time on extragalctic fields has been searched for transients with dispersion measures from 0 to 3000 pc cm$^{-3}$ at a timescale of 5 ms. Figure \ref{snrhist} shows the typical SNR histogram of candidates greater than $6.5\sigma$, which are saved for analysis. Nearly all candidates are consistent with thermal noise. Fewer than 10 Eight  candidates deviated slightly from the thermal noise distribution and were inspected in detail. All of these candidates were found to be affected by RFI or were highly sensitive to flagging or imaging parameters. Our analysis shows that we can exclude the presence of astrophysical transients on timescales of 5 milliseconds and below. We measured data quality at regular intervals throughout the search and found that roughly 1\% of images had noise that was more than twice the median image noise. Our flux-calibrated observations have a median image noise of 12--14 mJy, as expected for 5-ms, L-band images made with data from 26 good antennas and 230 MHz of bandwidth. To include variance in the noise measurements, we define a 96\% completeness for a $1\sigma$ image sensitivity of 15 mJy or an $8\sigma$ flux limit of 120 mJy. Observations of pulsar B0355+54 at a range of offset positions shows that imaging sensitivity scales as expected for the VLA primary beam gain pattern. This end-to-end test also confirms that our transient search pipeline works as expeted.