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FERMILASP - Fermi LAT Monitored Source List

HEASARC
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Overview

The Fermi LAT table of monitored sources provides daily and weekly fluxes for sources of interest as described in http://fermi.gsfc.nasa.gov/ssc/data/policy/LAT_Monitored_Sources.html. In addition, similar information will be released for any source which flares above 2x10-6 photons cm-2 s-1 until the flux drops below 2x10-7 photons cm-2 s-1. Fermi is currently in survey mode and observes the entire sky every day. However if a source does not exceed the detection threshold, no entry will appear in the catalog.

The tabulated fluxes are derived at the LAT Instrument Science Operations center in a 'quick look' analysis to produce results quickly to facilitate follow-up multiwavelength observations of flaring sources. The table of released fluxes will be updated as analysis and calibrations improve.

These early flux estimates do not include systematic uncertainties and do not have an absolute flux calibration. Use of these data as absolute flux measurements for constraining models or for comparison to other data is strongly discouraged at this time. In addition to overall normalization uncertainties, source fluxes may have variations of up to 10% due to currently-uncorrected dependencies of the gamma-ray detection efficiency on variations of the particle background in orbit. Please note that these results are produced using preliminary instrument response functions and calibrations. The quality and stability of these results will improve when updated calibrations become available over the coming months.


Bulletin

The FERMILASP database table was last updated on 16 April 2014.

References

The monitored source list is maintained at http://fermi.gsfc.nasa.gov/ssc/data/policy/LAT_Monitored_Sources.html.

Provenance

This database table is created by the HEASARC from FITS tables received from the Fermi Science Support Center (FSSC). The ASP FITS files are produced by the LAT Instrument Science Operations Center (LISOC) and transferred from the LISOC to the FSSC about once per week.

Parameters

MET_Start
This parameter is the observation start time given in Mission Elapsed Time (MET). Mission Elapsed Time is measured in seconds from 2001.0, not including leap seconds.

MET_End
This parameter is the observation stop time given in Mission Elapsed Time (MET). Mission Elapsed Time is measured in seconds from 2001.0, not including leap seconds.

Time
This parameter is the observation start time, in Universal Time (UT).

End_Time
This parameter is the observation start time, in Universal Time (UT).

Name
The designation of the source. Source names beginning with ASP are flaring sources (i.e. included in the table because the flux exceeded a threshold of 2x10-6 photons cm-2 s-1).

RA
The right ascension of the source. For cataloged sources, these are the cataloged values from an appropriate catalog. For new sources (names which begin with ASP), the RA is the value determined by the automated source detection and localization software and may have significant uncertainty.

Dec
The declination of the source. For cataloged sources, these are the cataloged values from an appropriate catalog. For new sources (names which begin with ASP), the Dec is the value determined by the automated source detection and localization software and may have significant uncertainty.

LII
This parameter is the Galactic Longitude, as derived from the source right ascension and declination.

BII
This parameter is the Galactic Latitude, as derived from the source right ascension and declination.

Flux_1_300_GeV_Limit
Upper limit flag for the 1-300 GeV band flux. The flag value is "<" (a "less than" symbol) if the flux is a 90%-confidence limit upper limit.

Flux_1_300_GeV
This parameter is the flux in the 1-300 GeV band, in photons/s/cm2, or the 90%-confidence limit flux if the limit flag is "<".

Flux_1_300_GeV_Error
This parameter is the 1-sigma uncertainty in the 1-300 GeV band flux. If the limit flag is "<", then the flux given is the 90% upper limit and the error flag can be ignored. If an upper limit, the value in the error column is the formal error estimate obtained from the best fit.

Flux_300_1000_MeV_Limit
Upper limit flag for the 300-1000 MeV band flux. The flag value is "<" (a "less than" symbol) if the flux is a 90%-confidence limit upper limit.

Flux_300_1000_MeV
This parameter is the flux in the 300-1000 MeV band, in photons/s/cm2, or the 90%-confidence limit flux if the limit flag is "<".

Flux_300_1000_MeV_Error
This parameter is the 1-sigma uncertainty in the 300-1000 MeV band flux. If the limit flag is "<", then the flux given is the 90% upper limit and the error flag can be ignored. If an upper limit, the value in the error column is the formal error estimate obtained from the best fit.

Flux_0p1_300_GeV_Limit
Upper limit flag for the 0.1-300 GeV band flux. The flag value is "<" (a "less than" symbol) if the flux is a 90%-confidence limit upper limit.

Flux_0p1_300_GeV
This parameter is the flux in the 0.1-300 GeV band, in photons/s/cm2, or the 90%-confidence limit flux if the limit flag is "<".

Flux_0p1_300_GeV_Error
This parameter is the 1-sigma uncertainty in the 0.1-300 GeV band flux. If the limit flag is "<", then the flux given is the 90% upper limit and the error flag can be ignored. If an upper limit, the value in the error column is the formal error estimate obtained from the best fit.

Duration
The duration (in MET seconds), calculated as MET_END - MET_START.

Test_Stat_0p1_300_GeV
The test statistic for flux variability in the 100-300000 MeV band. See Mattox et al. 1996 ApJ, 461, 396.


Contact Person

Questions regarding the FERMILASP database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 27-Mar-2009