Science Tools Working Group

Did not have a VRVS meeting this week, and with the ISOC workshop next week we won't meet again for 2 weeks.

The points of agreement and plan for near-term work (i.e., Action Items) that came out of GSSC-LAT Science Tools Meeting at SLAC, April 2007 have been added to that page.

The current version of ScienceTools remains v8r0p3. v8r0p4 will be on its way this afternoon, containing (at least) updates to PulsarSpectrum and gtmaketime.

Data products: No news yet this week

Databases and related utilities

No news

Likelihood analysis

No news. Work is continuing on understanding the differences in results (parameter values and TS values) between binned and unbinned likelihood analyses. Jean and Jim gave presentations on this at the Catalog VRVS meeting yesterday. Florien Kraft and Vincent Le Biez are running more simulations at SLAC like those Jim has made - in fact, starting with Jim's script. In the catalog analysis of the SC1 data, Jean is finding that binned likelihood analysis produces greater TS values and less biased results for source fluxes. In the simulations of point sources on isotropic backgrounds that Jim, Florian, and Vincent have made, the TS values from binned analyses are found to depend fairly strongly on the bin size - not a big surprise. So far the latter studies are finding that the unbinned likelihood analysis (on average) gives correct results, but Jean's studies using the SC1 data (which are much more complicated - including structured diffuse emission and faint sources and soures with a variety of spectra) appaear to find that unbinned results are biased.

GRB tools

No news

Pulsar tools

From Masa: "In the pulsar tools area, now gtpsearch and gtpspec are capable of creating a FITS file that contains a search result. They are available in the latest tagged version."

Observation simulation

Max has found a workaround to the problem of PulsarSpectrum sometimes wanting to look outside the time range of an FT2 file. This can happen owing to the nature of the arrival time corrections needed for pulsar simulations. He had worked out a way to catch this circumstance - as described before. The new method should be more robust.

User interface and infrastructure (& utilities)

I'll put it here: Jim has fixed a time precision problem with how gtmaketime defined starting and ending times when it operated on an FT1 file.

Source Catalog

Met this week; see above.

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