- ID:
- ivo://nasa.heasarc/at20g1fgl
- Title:
- AT20G/Fermi 1FGL Source Catalog
- Short Name:
- AT20G1FGL
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The high-frequency radio sky, like the gamma-ray sky surveyed by the Fermi satellite, is dominated by flat-spectrum radio quasars and BL Lac objects at bright flux levels. To investigate the relationship between radio and gamma-ray emission in extragalactic sources, the authors have cross-matched the Australia Telescope 20-GHz survey catalog (AT20G: Murphy et al. 2010, MNRAS, 402, 2403, available as a HEASARC Browse table) with the Fermi-LAT 1-year Point Source Catalog (1FGL: Abdo et al. 2010, ApJS, 188, 405, also available as the HEASARC Browse table FERMILPSC). The 6.0 sr of sky covered by both catalogs (Declination < 0 degrees, |b| > 1.5 degrees) contains 5890 AT20G radio sources and 604 1FGL gamma-ray sources. The AT20G source positions are accurate to within ~1 arcsec and, after excluding known Galactic sources, 43% of Fermi 1FGL sources have an AT20G source within the 95% Fermi confidence ellipse. Monte Carlo tests imply that at least 95% of these matches are genuine associations. Only five gamma-ray sources (1% of the Fermi catalog) have more than one AT20G counterpart in the Fermi error box. The AT20G matches also generally support the active galactic nucleus (AGN) associations in the First LAT AGN Catalog. The authors find a trend of increasing gamma-ray flux density with 20 GHz radio flux density. The Fermi detection rate of AT20G sources is close to 100% for the brightest 20 GHz sources, decreasing to 20% at 1 Jy, and to roughly 1% at 100 mJy. Eight of the matched AT20G sources have no association listed in 1FGL and are presented here as potential gamma-ray AGNs for the first time. The authors also identify an alternative AGN counterpart to one 1FGL source. The percentage of Fermi sources with AT20G detections decreases toward the Galactic plane, suggesting that the 1FGL catalog contains at least 50 Galactic gamma-ray sources in the southern hemisphere that are yet to be identified. This table contains the complete list of all 233 Fermi-AT20G matches. This table was created by the HEASARC in August 2010 based on the electronic version of Table 4 obtained from the ApJ web site. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/fermi2favs
- Title:
- Fermi All-Sky Variability Analysis Second Catalog of Flaring Gamma-Ray Sources
- Short Name:
- FERMI2FAVS
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi All-sky Variability Analysis (FAVA) is an analysis technique that searches for flaring sources in data collected by the Large Area Telescope (LAT) onboard NASA's Fermi Gamma-ray Space Telescope. It uses a photometric approach to blindly search for flares over the entire sky, and a likelihood analysis to precisely locate them and to measure their spectra. This catalog contains the flares and sources detected by running FAVA over the first 7.4 years of Fermi mission, from Modified Julian Date (MJD) 54682 (2008-08-04) to 57391 (2016-01-04). The analysis has been run in weekly time bins and in two independent energy bands, 100-800 MeV and 0.8-300 GeV. The detection threshold applied to the catalog flares is equivalent to 6 sigma (pre trials). The sources in the 2FAV are identified as clusters of flares. Their position and the corresponding error are derived from a weighted average of the best localized flares in the cluster. Likely gamma-ray counterparts, based on positional coincidence, are provided for the sources. This database table was first ingested by the HEASARC in July 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/fava_catalog/">http://fermi.gsfc.nasa.gov/ssc/data/access/lat/fava_catalog/</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fer2fusrid
- Title:
- Fermi 2FGL Unassociated Gamma-Ray Sources Possible Radio Identifications
- Short Name:
- FER2FUSRID
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the results from an all-sky radio survey between 5- and 9-GHz of sky areas surrounding all unassociated gamma-ray objects listed in the Fermi Large Area Telescope (LAT) Second Source Catalog (2FGL). The goal of these observations is to find all new gamma-ray active galactic nucleus (AGN) associations with radio sources > 10 mJy at 8GHz. The authors observed with the Very Large Array (VLA) and the Australia Telescope Compact Array (ATCA) the areas around unassociated sources, providing localizations of weak radio point sources found in 2FGL fields at arcminute scales. They then followed up a subset of these with the Very Long Baseline Array (VLBA) and the Long Baseline Array (LBA) in order to confirm detections of radio emission on parsec-scales. The authors quantified association probabilities based on known statistics of source counts and assuming a uniform distribution of background sources. In total, they found 865 radio sources at arcsecond scales as candidates for association and detected 95 of 170 selected for follow-up observations at milliarcsecond resolution. Based on this, they obtained firm associations for 76 previously unknown gamma-ray AGNs. Comparison of these new AGN associations with the predictions from using the Wide-field Infrared Survey Explorer (WISE) color-color diagram shows that half of the associations are missed. The authors found that in 129 out of 588 gamma-ray sources observed at arcminute scales not a single radio continuum source was detected above their sensitivity limit within the 3-sigma gamma-ray localization. These "empty" fields were found to be particularly concentrated at low Galactic latitudes. The nature of these Galactic gamma-ray emitters is not yet determined. A list of 216 target fields were observed with the VLA. The instantaneous bandwidth was split into two parts, with one half centered at 5.0 GHz (4.5 - 5.5 GHz) and the other centered at 7.3 GHz (6.8 - 7.8 GHz). The observations were made on 2012 October 26 and 2012 November 3. See section 2.1 of the reference paper for more details. These data are included in this HEASARC table. During the first campaign with the ATCA from 2012 September 19-20, the authors observed 411 2FGL unassociated sources in a Declination range of -90 degrees to +10 degrees at 5.5 and 9 GHz. The details of this observing campaign and results have been reported by Petrov et al. (2013, MNRAS, 432, 1294: available at the HEASARC as the AT2FGLUS table). The authors detected a total of 424 point sources. In a second ATCA campaign on 2013 September 25-28, the authors re-observed sources that were detected at 5 GHz, but were not detected at 9 GHz. See section 2.2 of the reference paper for more details. These data are included in this HEASARC table. Follow-up observations of 149 targets selected from the VLA and ATCA surveys above -30 degrees Declination were conducted with the VLBA between 2013 Feb-Aug (VCS7 project; 4.128 - 4.608 and 7.392 - 7.872 GHz simultaneously) and in 2013 Jun-Dec (campaign S5272; 7.392 - 7.872 GHz only). See section 2.3 of the reference paper for more details. These data are NOT included in this HEASARC table. For sources with Declination below -30 degrees, the authors added 21 objects to the on-going LCS campaign being conducted using the LBA (Petrov et al. 2011, MNRAS, 414, 2528) in 2013 Mar-2013 Jun at 8.200 - 8.520 GHz. See section 2.4 of the reference paper for more details. These data are NOT included in this HEASARC table. This table was created by the HEASARC in May 2015 based on the union of CDS Catalog J/ApJS/217/4/ files table2.dat (the 148 'Category I' objects that were detected at 5.0/5.5 and/or 7.3/9.0 GHz within 2.7' of the 2FGL counterpart localization), table3.dat (the 501 'Category II' objects that were detected at 5.0/5.5 and/or 7.3/9.0 GHz between 2.7' and 6.5' of the 2FGL counterpart localization) and table4.dat (the 216 'Category III' objects that were detected outside of the 6.5 arcminutes but still within the 99% positional uncertainty of the 2FGL counterpart localization). It thus contains a total of 865 objects. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermigdays
- Title:
- Fermi GBM Daily Data
- Short Name:
- FERMIGDAYS
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi GBM Daily Data database table contains entries for each day for which GBM data has been processed. The daily data products consist of GBM data that are produced continuously regardless of whether a burst occurred. Thus these products are the count rates from all detectors, the monitoring of the detector calibrations (e.g., the position of the 511 keV line), and the spacecraft position and orientation. Some days may also have event lists known as time-tagged event (TTE) files associated with them. These TTE files have the same format as those produced for bursts. Due to the large data volume associated with TTE files, only certain portions of the day considered of scientific interest to the instrument team will have TTE data. The underlying Level 0 data arrive continuously with each Ku band downlink. However, the GBM Instrument Operations Center (GIOC) will form FITS files of the resulting Level 1 data covering an entire calendar day (UTC); these daily files are then sent to the FSSC. Consequently, the data latency is about one day: the first bit from the beginning of a calendar day may arrive a few hours after the day began while the last bit will be processed and added to the data product file a few hours after the day ended. These data products may be sent to the FSSC file by file as they are produced, not necessarily in one package for a given day. Note that the data may include events from slightly before and slightly after the day official boundaries, which will be reflected in the start and stop times in the table. Consequently, some events may be listed in files for two consecutive days (e.g., at the end of one and the beginning of the next). Due to the continuous nature of GBM processing, new data files may arrive after the day has been included in Browse and reprocessed version may also arrive at any time. The reprocessed data will have the version number incremented (see file name conventions below). Browse will automatically download the latest versions of the data files. This database table was created by and is updated by the HEASARC based on information supplied by the Fermi Project. It is updated on a daily basis. The tte_flag parameter was added to the table in July 2010. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermigsol
- Title:
- Fermi GBM Solar Flare Catalog
- Short Name:
- FERMIGSOL
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- These data represent the Fermi GBM Solar Flare Catalog. Data in this catalog are targeted specifically at Fermi observations of high-energy solar phenomena, primarily solar flares, in order to facilitate the use of Fermi data by the international solar physics community. This table catalogs Fermi Gamma-Ray Burst Monitor (GBM) triggers associated with known solar flares. The Fermi GBM Solar Flare Catalog is supported by a Fermi Guest Investigator program and maintained at <a href="http://hesperia.gsfc.nasa.gov/fermi_solar">http://hesperia.gsfc.nasa.gov/fermi_solar</a>. Please include the following acknowledgment if you use these facilities in a paper or presentation: "We acknowledge the use of the Fermi Solar Flare Observations facility funded by the Fermi GI program (<a href="http://hesperia.gsfc.nasa.gov/fermi_solar/">http://hesperia.gsfc.nasa.gov/fermi_solar/</a>)." The information in this table is provided independently by a Fermi Guest Investigator grant. The tabulated data come from <a href="http://hesperia.gsfc.nasa.gov/fermi/gbm/qlook/fermi_gbm_flare_list.txt">http://hesperia.gsfc.nasa.gov/fermi/gbm/qlook/fermi_gbm_flare_list.txt</a>. This table is updated automatically within a day or so of a new data file being made available. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermigtrig
- Title:
- Fermi GBM Trigger Catalog
- Short Name:
- FERMIGTRIG
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table lists all of the triggers observed by one or more of the 14 GBM detectors (12 NaI and 2 BGO). Note that there are two Browse catalogs resulting from GBM triggers. All GBM triggers are entered in the Trigger Catalog, but only those triggers classified as bursts are entered in the <a href="/W3Browse/fermi/fermigbrst.html">Fermi GBM Burst Catalog</a>. Thus, a burst will be found in both the Trigger and Burst Catalogs. The Burst Catalog analysis requires human intervention; therefore, GRBs will be entered in the Trigger Catalog before the Burst Catalog. The latency requirements are 1 day for triggers and 3 days for bursts. The GBM consists of an array of 12 sodium iodide (NaI) detectors which cover the lower end of the energy range up to 1 MeV. The GBM triggers off of the rates in the NaI detectors, with some Terrestrial Gamma-ray Flash (TGF)-specific algorithms using the bismuth germanate (BGO) detectors, sensitive to higher energies, up to 40 MeV. The NaI detectors are placed around the Fermi spacecraft with different orientations to provide the required sensitivity and FOV. The cosine-like angular response of the thin NaI detectors is used to localize burst sources by comparing rates from detectors with different viewing angles. The two BGO detectors are placed on opposite sides of the spacecraft so that all sky positions are visible to at least one BGO detector. The signals from all 14 GBM detectors are collected by a central Data Processing Unit (DPU). This unit digitizes and time-tags the detectors' pulse height signals, packages the resulting data into several different types for transmission to the ground (via the Fermi spacecraft), and performs various data processing tasks such as autonomous burst triggering. The information in this table is provided by the Fermi Gamma-ray Burst Monitor Instrument Operations Center (GIOC) and the Fermi Science Support Center (FSSC). The values come from a trigger catalog entry file or a burst catalog entry file provided by the GIOC. These are FITS files which may contain additional data in extensions for bursts (see the spectrum_flag and fit_flag columns) and are available for download. This table is updated automatically within a day or so of new data files being processed and made available. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermilbsl
- Title:
- Fermi LAT Bright Source List
- Short Name:
- FERMILBSL
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi LAT table of bright sources is a list of bright LAT sources that have statistical significances of 10 sigma or higher, based on the first three months of survey data. The primary purpose of this list is to assist proposers for Guest Investigator Cycle 2 (due date 6 March). This list will eventually be superseded by the LAT Source Catalog, to be released about one year after launch. This database table was created by the HEASARC in February 2009 based on the electronic data obtained from the Fermi Science Support Center (FSSC) available at <a href="http://fermi.gsfc.nasa.gov/ssc/data/access/lat/bright_src_list/">http://fermi.gsfc.nasa.gov/ssc/data/access/lat/bright_src_list/</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermilac
- Title:
- Fermi LAT Fourth AGN Catalog
- Short Name:
- FERMILAC
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is the third update to the fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Large Area Telescope (LAT). This version (4LAC-DR3) derives from the third data release of the 4FGL catalog based on 12 years of gamma-ray data with energies greater than 50 MeV. The spectral parameters, spectral energy distributions (SEDs), yearly light curves, and associations have been updated for all sources. The catalog contains includes 3407 AGN located at high Galactic latitudes (|b| > 10 degrees). This database table was first ingested by the HEASARC in February 2010. It was last updated (to the 4LAC-DR3 version) in June 2023 using electronic data obtained from the Fermi Science Support Center (FSSC). That data is available at <a href="https://fermi.gsfc.nasa.gov/ssc/data/access/lat/4LACDR3/">https://fermi.gsfc.nasa.gov/ssc/data/access/lat/4LACDR3/</a>. Note that this table does not contain the low-latitude sources given in a separate file there, which are not formally a part of the catalog. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermilblaz
- Title:
- Fermi LAT Gamma-Ray Blazar Classification Catalog
- Short Name:
- FERMILBLAZ
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table contains a catalog of classifications for blazar candidates of uncertain type (BCU) detected by the Fermi Large Area Telescope gamma-ray instrument. These classifications have been determined by an Artificial Neural Network machine learning method. The aim of the authors' study was to develop an optimized version of this Artificial Neural Network machine learning method for classifying these blazar candidates. The final result of this study increased the classification performance by about 80% with respect to the method previously used for the classification of uncertain blazars in Chiaro et al. (<a href="https://ui.adsabs.harvard.edu/abs/2016MNRAS.462.3180C">2016MNRAS.462.3180C</a>, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/462/3180/">CDS Cat. J/MNRAS/462/3180</a>), leaving only 15 unclassified blazars out of 573 blazar candidates of uncertain type listed in the Fermi LAT 4-Year Source Catalog. Looking beyond the gamma-ray features of blazars, interesting information can be obtained from a multiwavelength study of the sources and particularly from X-ray and radio flux. In this study the authors tested the possibility to use those two parameters to improve the performance of the network. They did not consider any optical spectroscopy data because, when considering uncertain sources, optical spectra are very often not available or not sufficiently descriptive of the nature of the source. The gamma-ray flux was obtained by adding five time-integrated fluxes in five bands (0.1-0.3, 0.3-1, 1-3, 3-10, 10-100 GeV) from the <a href="/W3Browse/fermi/fermi3fgl.html">3FGL Catalog</a> (Acero et al. <a href="https://ui.adsabs.harvard.edu/abs/2015ApJS..218...23A">2015ApJS..218...23A</a>, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/218/23/">CDS Cat. J/ApJS/218/23</a>). Radio and X-ray data were obtained from the Fermi LAT 4-Year AGN Catalog 3LAC (Ackermann et al. <a href="https://ui.adsabs.harvard.edu/abs/2015ApJ...810...14A">2015ApJ...810...14A</a>, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/810/14/">CDS Cat. J/ApJ/810/14</a>). Radio fluxes used were measured at frequencies of 1.4 and 0.8 GHz; the X-ray fluxes were measured in the 0.1-2.4keV range. The complete list of 567 classified BCUs is presented in this table in which sources are ordered by increasing likelihood of a source being a BL Lac. This database table was ingested by the HEASARC in May 2023 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/490/4770">CDS Catalog J/MNRAS/490/4770</a> file table1.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermilhesc
- Title:
- Fermi LAT High-Energy Source Catalog (1FHL)
- Short Name:
- FERMILHESC
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the catalog of gamma-ray sources at energies above 10 GeV based on data from the Large Area Telescope (LAT) accumulated during the first 3 years of the Fermi Gamma-ray Space Telescope mission. The first Fermi-LAT catalog of > 10 GeV sources (1FHL) has 514 sources. For each source, the authors present location, spectrum, a measure of variability,and associations with cataloged sources at other wavelengths. They found that 449 (87%) could be associated with known sources, of which 393 (76% of the 1FHL sources) are active galactic nuclei. Of the 27 sources associated with known pulsars, they find 20 (12) to have significant pulsations in the range > 10 GeV (> 25 GeV). In this work, the authors also report that, at energies above 10 GeV, unresolved sources account for 27% +/- 8% of the isotropic gamma-ray background, while the unresolved Galactic population contributes only at the few percent level to the Galactic diffuse background. The authors also highlight the subset of the 1FHL sources that are the best candidates for detection at energies above 50 - 100 GeV with current and future ground-based gamma-ray observatories. The time interval analyzed here is from the beginning of Fermi LAT science operations on 2008 August 4 (MET 239557447) to 2011 August 1 (MET 333849586), covering very nearly 3 years. In this work, the authors analyze gamma rays with energies in the range 10-500 GeV. To limit the contamination from gamma rays produced by cosmic-ray interactions in the upper atmosphere, gamma rays with zenith angles greater than 105 degrees were excluded. To further reduce the residual gamma rays from the upper atmosphere only data for time periods when the spacecraft rocking angle was less than 52 degrees were considered. See Section 2 of the reference paper for further explanations. This table was created by the HEASARC in April 2015 based on CDS Catalog J/ApJS/209/34/ files table3.dat and table7.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermiltrns
- Title:
- Fermi LAT Long-Term Transient Source Catalog
- Short Name:
- FERMILTRNS
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The First Catalog of Long-Term Transient Sources detected by Fermi Large Area Telescope (LAT) comprises of 142 unique, transient sources that were detected on monthly time intervals during Fermi-LAT operations. The monthly time scale allows to identify transient and variable sources that were not yet reported in other Fermi-LAT catalogs. The monthly datasets were analyzed using a wavelet-based source detection algorithm that provided the candidate new transient sources. The search was limited to the extragalactic regions of the sky to avoid the dominance of the Galactic diffuse emission at low Galactic latitudes. The transient candidates were then analyzed using the standard Fermi-LAT maximum likelihood analysis method. All sources detected with a statistical significance above 4 sigma in at least one monthly bin were listed in the final catalog. This database table was ingested by the HEASARC in September 2021 and is based upon file downloaded from the Space Science Data Center (SSDC) Fermi-1FLT <a href="https://www.ssdc.asi.it/fermi1flt/">website</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/fermille
- Title:
- Fermi LAT Low-Energy Events Catalog
- Short Name:
- FERMILLE
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- LAT Low-Energy events (LLE) are automatically produced for each GBM GRB in the GBM Trigger Catalog if the GBM GRB has a position within 90 degrees of the LAT boresight. LLE data are generated for a given position in the sky (RA, DEC) and for a given interval of time (T0, T1) corresponding to the GBM Burst. The standard LLE selection applied to the downloaded events is the following: (FswGamState==0 && TkrNumTracks>0 && (GltEngine==6 || GltEngine==7) && EvtEnergyCorr > 0) && (FT1ZenithTheta<90.0) && (FT1Theta<=90.0) && (((cos(FT1Dec*0.0174533)*(FT1Ra - (RA)))<sup>2</sup> + (FT1Dec - (DEC))<sup>2</sup>) < PSF(EvtEnergyCorr, Theta) where <pre> * FswGamState is the status of the Flight Sofware Gamma filter. We require that the event is a gamma-ray (FswGamState==0). * TkrNumTracks is the number of tracks in the tracker. We require that there is at least one track. This requires the event to have a reconstructed direction. * GltEngine is the status of the <a href="https://oraweb.slac.stanford.edu/pls/slacquery/DOCUMENTS.DetailedIndex?PROJECT=GLAST&P_DOC_ID=776972">Global LAT Trigger</a>. We require that GltEngine equals 6 or 7, which corresponds to taking all the events that trigger in the tracker TKR but did not have a region of interest (ROI) associated (GltEngine 7) or all the events that pass the CalHI (at least 1 GeV in one crystal). * EvtEnergyCorr is the best estimation of the reconstructed energy, especially at low energy. * Theta is the reconstructed source direction (Theta) with respect the LAT boresight. * PSF(EvtEnergyCorr, Theta) represents the functional form of the containment radius of the Point Spread Function (PSF) of the LAT. </pre> The exact cut used to select the events is saved in the keyword LLECUT in the primary header of each LLE file. If the GBM catalog position of the burst is updated (due to a refined localization from LAT or Swift or from subsequent on ground analysis), the LLE data are automatically updated and new versions of the LLE files are produced. In some cases, LLE data are manually generated (using a better localization which may or may not have been used in the GBM Trigger Catalog). For each updated position, the version of the corresponding LLE files increases by one. There are six FITS files provided for each entry: the LLE event file, the time-binned spectrum (CSPEC) file, the CSPEC response (RSP) file, and the extracted burst spectrum (the PHA-I file) for the entire duration of the burst, an LLE event file with same time cut as the RSP and PHA-I files, and a LAT pointing and livetime history file. There are six FITS files provided for each entry: the LLE event file (gll_lle_bnNNNNNNNNN_vMM.fit), the time-binned spectrum (CSPEC) file (gll_cspec_bnNNNNNNNNN_vMM.pha), the CSPEC response (RSP) file (gll_cspec _bnNNNNNNNNN_vMM.rsp), and the extracted burst spectrum (the PHA-I file) for the entire duration of the burst (gll_pha_bnNNNNNNNNN_vMM.fit), an LLE event file with same time cut as the RSP and PHA-I files (gll_selected_bnNNNNNNNNN_vMM.fit), and a LAT pointing and livetime history file (gll_pt_bnNNNNNNNNN_vMM.fit). The LLE event file format is similar to the LAT photon file format with some exceptions. Because the LLE data are tightly connected to a particular object (position and time), the FITS keyword OBJECT has been added to the file. Generally, OBJECT will correspond to the entry of the GBM Trigger Catalog used to generate LLE data and corresponds to the "name" column in the FERMILLE table (and in the GBM Trigger Catalog table). For similar reasons, the position of the object used to select LLE file is written in the header of each extension of each LLE file. PROC_VER corresponds to the iteration of the analysis of LLE data. PASS_VER corresponds to the iteration for the reconstruction and the general event classification (Pass6, Pass7, etc.). VERSION corresponds to the version of the LLE product for this particular event. The update of a location of a GRB will increase the number of VERSION in the file, but will leave the PASS_VER and PROC_VER unchanged. The CSPEC file is obtained from directly binning the TTE files. It provides a series of spectra, accumulated every second, from -1000 to 1000 seconds around the burst. Each spectrum is binned in 50 energy channels, ranging typically from 10 MeV to 100 GeV. The format of the CSPEC file is tailored to satisfy rmfit standards, and it is not directly usable in XSPEC. The CSPEC Response file (the RSP file) is the detector response matrix calculated from Monte Carlo simulation, and it corresponds to a single response matrix for each Gamma-Ray Burst or Solar Flare. The PHA-I file contains the count spectrum. The PHA-I file is created from the same time interval used to compute the response matrix. The selected events file is identical to the LLE event file with an additional time selection applied to match the cut used to compute response matrix and PHA-I files. The LAT pointing and livetime history file is identical to the standard LAT file but with entries every second (instead of every 30 seconds). It spans 4600 seconds before and 4600 after the trigger time. The information in this table is provided by the Fermi LAT Instrument Science Operations Center (LISOC) and the Fermi Science Support Center (FSSC). This is a service provided by NASA HEASARC .
- 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 .
- 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/fermilweek
- Title:
- Fermi LAT Weekly Data
- Short Name:
- FERMILWEEK
- Date:
- 10 May 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Fermi LAT Weekly Data database table provides access to LAT data binned into weekly files by the FSSC's data servers. For each week, the FSSC provides two FITS files: an all-sky file of photons containing positions, energies, etc. and a spacecraft pointing history file. The underscore separated fields in the file names indicate the file type (photon or spacecraft), the Fermi mission week (e.g., w009 = week 9), the processing version (which will change with each major reprocessing of LAT data), and a version number for the file itself. Note that currently the data may include events from slightly after the official week boundaries, which will be reflected in the start and stop times in the table. Any "run" of LAT data the FSSC receives that starts in a given week is put into the weekly file for that week and not broken up. Note additional selections must be applied to the weekly files prior to use in a data analysis. See <a href="http://fermi.gsfc.nasa.gov/ssc/data/analysis/documentation/Cicerone/Cicerone_Data_Exploration/Data_preparation.html">LAT Data Selection Recommendations</a> and <a href="http://fermi.gsfc.nasa.gov/ssc/data/analysis/LAT_caveats.html">Caveats About Analyzing LAT Data</a> for more information. For queries based on position, energy, and exact times, use the <a href="http://fermi.gsfc.nasa.gov/cgi-bin/ssc/LAT/LATDataQuery.cgi">FSSC's LAT data server</a>. This database table is created by the HEASARC from FITS tables received from the Fermi Science Support Center (FSSC). It is updated on a weekly basis. 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 .