The Fermi LAT In Relation To All-sky Monitors: A New Approach To Multi-wavelength Correlations

The Fermi Gamma-ray Space Telescope Large Area Telescope (LAT) can be regarded as an all-sky monitor, the first such monitor (as distinguished from survey) in high energy gamma-rays and a powerful one in that it reaches the lowest flux levels yet achieved for its band. The LAT has a need for multi-wavelength context information, both to secure source identifications and develop physical understanding. Multi-wavelength campaigns can be pursued in a new way - on an all-sky and all-source basis - provided the LAT can be correlated with other all-sky monitors with comparably powerful sky coverage and sensitivity characteristics. We demonstrate this with a pilot study based on the RXTE ASM. The recently-launched MAXI on the ISS can continue the X-ray capability into the future. We further discuss how the new Pan-STARRS 1 (PS1) optical survey can be regarded as the first high-sensitivity all-sky monitor in visible wavelengths. Details of cross-correlation methodologies are presented along with preliminary results. The techniques are applicable to the variability method for establishing true identifications (as distinguished from associations) for Fermi LAT sources. Future capabilities for all-sky coverage in all wavelengths will be discussed.