- ID:
- ivo://nasa.heasarc/fermilasp
- Title:
- Fermi LAT Monitored Source List
- Short Name:
- FERMILASP
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi LAT table of monitored sources provides daily and weekly fluxes for sources of interest as described in <a href="http://fermi.gsfc.nasa.gov/ssc/data/policy/LAT_Monitored_Sources.html">http://fermi.gsfc.nasa.gov/ssc/data/policy/LAT_Monitored_Sources.html</a>. In addition, similar information will be released for any source which flares above 2x10<sup>-6</sup> photons cm<sup>-2</sup> s<sup>-1</sup> until the flux drops below 2x10<sup>-7</sup> photons cm<sup>-2</sup> s<sup>-1</sup>. 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 this 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 multi-wavelength observations of flaring sources. The table of released fluxes will be updated as analysis and calibrations improve. <b>These early flux estimates do not include systematic uncertainties and do not</b> <b>have an absolute flux calibration</b>. 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. 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. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/fermil2psr
- Title:
- Fermi LAT Second Catalog of Gamma-Ray Pulsars (2PC)
- Short Name:
- FERMIL2PSR
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog summarizes 0.1 GeV gamma-ray pulsar detections using data acquired by the Large Area Telescope (LAT) on the Fermi satellite. These pulsars are neutron stars identified using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The catalogued pulsars are divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. This catalog summarizes results of the analysis of pulse profiles and energy spectra, and analysis of the off-peak phase intervals, and compares the gamma-ray properties with those in the radio, optical, and X-ray bands. Flux limits for pulsars with no observed gamma-ray emission are provided. This database was constructed by the HEASARC by combining the tabulated data in the psrcat.dat, spec.dat, offpk.dat and refs.dat obtained from <a href="http://adsabs.harvard.edu/abs/2013yCat..22080017A">http://adsabs.harvard.edu/abs/2013yCat..22080017A</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermilgrb
- Title:
- Fermi LAT Second Gamma-Ray Burst Catalog
- Short Name:
- FERMILGRB
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The LAT routinely observes high-energy emission from gamma-ray bursts (GRBs). Here we present the second catalog of LAT-detected GRBs. Initially, the second catalog covered the only the first 10 years of operations, from 2008 August 4 to 2018 August 4. The table given here has been supplemented to add later GRBs that were analyzed using the same procedure as the original catalog. It will be updated periodically with new GRBs. This database table was last updated by the HEASARC in April 2022 using electronic data obtained from the Fermi Science Support Center (FSSC). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermilatra
- Title:
- Fermi LAT Sources Refined Associations Catalog
- Short Name:
- FERMILATRA
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi-Large Area Telescope (LAT) First Source Catalog (1FGL: Abdo et al. 2010, ApJS, 188, 405) was released in 2010 February and the Fermi-LAT 2-Year Source Catalog (2FGL: Nolan et al. 2012, ApJS, 199, 31) appeared in 2012 April, based on data from 24 months of operations. Since they were released, many follow up observations of unidentified gamma-ray sources have been performed and new procedures for associating gamma-ray sources with potential counterparts at other wavelengths have been developed. In the reference paper, the authors review and characterize all of the associations as published in the 1FGL and 2FGL catalogs on the basis of multi-frequency archival observations. In particular, they locate 177 spectra for the low-energy counterparts that were not listed in the previous Fermi catalogs, and in addition they present new spectroscopic observations of eight gamma-ray blazar candidates. Based on their investigations, the authors introduce a new counterpart category of "candidate associations" and propose a refined classification for the candidate low-energy counterparts of the Fermi sources. They compare the 1FGL-assigned counterparts with those listed in 2FGL to determine which unassociated sources became associated in later releases of the Fermi catalogs. The authors also search for potential counterparts to all of the remaining unassociated Fermi sources. Finally, they prepare a refined and merged list of all of the associations of 1FGL plus 2FGL that includes 2219 unique Fermi objects. This is the most comprehensive and systematic study of all the associations collected for the gamma-ray sources available to the date of this study. The authors conclude that 80% of the Fermi sources have at least one known plausible gamma-ray emitter within their positional uncertainty regions. This table was created by the HEASARC in May 2015 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/217/2">CDS Catalog J/ApJS/217/2</a> file table4.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermi3fgl
- Title:
- Fermi LAT 4-Year Point Source Catalog
- Short Name:
- FERMI3FGL
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi LAT 4-Year Point Source Catalog (3FGL) is a catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (Fermi) mission during the first 48 months of the science phase of the mission, which began on 2008 August 4. Compared to the 2FGL catalog, the 3FGL catalog incorporates twice as much data as well as a number of analysis improvements, including improved calibrations at the event reconstruction level, an updated model for Galactic diffuse gamma-ray emission, a refined procedure for source detection, and improved methods for associating LAT sources with potential counterparts at other wavelengths. Sources were detected and characterized in the 100 MeV to 300 GeV range. Source detection was based on a threshold likelihood Test Statistic of 25, corresponding to a significance of just over 4 sigma. This catalog includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits with three different spectral forms; power-law for most sources, log-parabola for significantly curved sources, and power-law with exponential cutoff for known gamma-ray pulsars. It also includes flux measurements in 5 bands for each source. The Fermi LAT Team has evaluated the populations of gamma-ray sources that are represented in the catalog using a protocol defined before launch. Individual LAT-detected sources have been provided identifications or plausible associations with sources in other astronomical catalogs. Care was taken to characterize the sensitivity of the results to the model of interstellar diffuse gamma-ray emission used to model the bright foreground, and a number of sources at low Galactic latitudes and toward bright local interstellar clouds are flagged as having positions that are strongly dependent on the model or as potentially entirely due to incorrectly modeled structure in the Galactic diffuse emission. This catalog has been superseded by the <a href="fermilpsc.html">Fermi LAT 8-Year Point Source Catalog</a>, also known as 4FGL. Please refer to that if you want the latest version. This database table was originally ingested by the HEASARC in May, 2015, as FERMILPSC. With the release of the 4FGL catalog in March, 2019, this catalog was renamed FERMI3FGL. The electronic data for this catalog was obtained from the Fermi Science Support Center (FSSC) at <a href="http://fermi.gsfc.nasa.gov/ssc/data/access/lat/4yr_catalog/">http://fermi.gsfc.nasa.gov/ssc/data/access/lat/4yr_catalog/</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermilpsc
- Title:
- Fermi LAT 14-Year Point Source Catalog (4FGL-DR4)
- Short Name:
- FERMILPSC
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi Point Source Catalog (4FGL) is a catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope. The 14-year catalog is an incremental version (4FGL-DR4, for Data Release 4) of the fourth Fermi-LAT catalog of gamma-ray sources. Based on the first fourteen years of science data in the energy range from 50 MeV to 1 TeV, it uses the same analysis methods as the 4FGL- DR3 catalog did for 12 years of data. The spectral parameters, spectral energy distributions, light curves and associations are updated for all sources. This database table was last updated by the HEASARC in February 2024, using the latest electronic data obtained from the Fermi Science Support Center (FSSC) available at <a href="http://fermi.gsfc.nasa.gov/ssc/data/access/lat/14yr_catalog/">http://fermi.gsfc.nasa.gov/ssc/data/access/lat/14yr_catalog/</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermifhl
- Title:
- Second Catalog of Hard Fermi-LAT Sources (2FHL)
- Short Name:
- FERMIFHL
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is a catalog of sources detected above 50 GeV by the Fermi-Large Area Telescope (LAT) in 80 months of data. The newly delivered Pass 8 event-level analysis allows the detection and characterization of sources in the 50GeV-2TeV energy range. In this energy band, Fermi-LAT has detected 360 sources, which constitute the second catalog of hard Fermi-LAT sources (2FHL). The improved angular resolution enables the precise localization of point sources (~1.7-arcminutes radius at 68% confidence level) and the detection and characterization of spatially extended sources. The authors found that 86% of the sources could be associated with counterparts at other wavelengths, of which the majority (75%) are active galactic nuclei and the rest (11%) are Galactic sources. Only 25% of the 2FHL sources have been previously detected by Cherenkov telescopes, implying that the 2FHL provides a reservoir of candidates to be followed up at very high energies. This work closes the energy gap between the observations performed at GeV energies by Fermi-LAT on orbit and the observations performed at higher energies by Cherenkov telescopes from the ground. This database table was first ingested by the HEASARC in September 2015 using electronic data obtained from the Fermi Science Support Center (FSSC). That data is available at <a href="http://fermi.gsfc.nasa.gov/ssc/data/access/lat/2FHL/">http://fermi.gsfc.nasa.gov/ssc/data/access/lat/2FHL/</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermi3fhl
- Title:
- Third Catalog of Hard Fermi-LAT Sources (3FHL)
- Short Name:
- FERMI3FHL
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is a catalog of sources detected above 10 GeV by the Fermi-Large Area Telescope (LAT) in the first 7 years of data using the Pass 8 event-level analysis. It contains 1558 objects characterized in the 10 GeV to 2 TeV energy range. The sensitivity and angular resolution are improved by factors of 3 and 2 relative to the previous LAT catalog at the same energies (1FHL). The vast majority of detected sources (79%) are extragalactic, including 16 sources located at very high redshift (z > 2). Nine percent of the sources are Galactic and 12% are unassociated (or associated with a source of unknown nature). The high-latitude sky and the Galactic plane are observed with an average sensitivity of 0.5% and 1% of the Crab Nebula flux above 10 GeV, respectively. The catalog includes 225 new gamma-ray sources. The substantial increase in the number of photons (more than 4 times relative to the 1FHL and 10 times to the 2FHL) also allows us to characterize spectral curvature for 32 sources and flux variability for 163 of them. Furthermore, we estimate that for the same energy flux limit of 10<sup>-12</sup> erg cm<sup>2</sup> s<sup>-1</sup>, the energy range above 10 GeV has twice as many sources as the range above 50 GeV, which confirms and quantifies the importance of lowering the energy threshold of Cherenkov telescopes as much as possible in order to increase the number of available sources. This database table was first ingested by the HEASARC in December 2017 using electronic data obtained from the Fermi Science Support Center (FSSC). That data is available at <a href="http://fermi.gsfc.nasa.gov/ssc/data/access/lat/3FHL/">http://fermi.gsfc.nasa.gov/ssc/data/access/lat/3FHL/</a>. This is a service provided by NASA HEASARC .