The Fermi-LAT Light Curve Repository

The Fermi Large Area Telescope (LAT) light curve repository (LCR) is a publicly available, continually updated library of gamma-ray light curves of variable Fermi-LAT sources generated over multiple timescales. The Fermi-LAT LCR aims to provide publication-quality light curves binned on timescales of 3 days, 7 days, and 30 days for 1525 sources deemed variable in the source catalog of the first 10 years of Fermi-LAT observations. The repository consists of light curves generated through full likelihood analyses that model the sources and the surrounding region, providing fluxes and photon indices for each time bin. The LCR is intended as a resource for the time-domain and multi-messenger communities by allowing users to quickly search LAT data to identify correlated variability and flaring emission episodes from gamma-ray sources. We describe the sample selection and analysis employed by the LCR and provide an overview of the associated data access portal.Comment: Accepted for publication in ApJ Supplement Serie

The Fermi-LAT Light Curve Repository

The Fermi Large Area Telescope (LAT) light curve repository (LCR) is a publicly available, continually updated library of gamma-ray light curves of variable Fermi-LAT sources generated over multiple timescales. The Fermi-LAT LCR aims to provide publication-quality light curves binned on timescales of 3 days, 7 days, and 30 days for 1525 sources deemed variable in the source catalog of the first 10 years of Fermi-LAT observations. The repository consists of light curves generated through full likelihood analyses that model the sources and the surrounding region, providing fluxes and photon indices for each time bin. The LCR is intended as a resource for the time-domain and multi-messenger communities by allowing users to quickly search LAT data to identify correlated variability and flaring emission episodes from gamma-ray sources. We describe the sample selection and analysis employed by the LCR and provide an overview of the associated data access portal

The Fermi-LAT Lightcurve Repository

The Fermi Large Area Telescope (LAT) lightcurve repository (LCR) is a publicly available, continually updated library of gamma-ray lightcurves of variable Fermi-LAT sources generated over multiple timescales. The Fermi-LAT LCR aims to provide publication-quality lightcurves binned on timescales of 3, 7, and 30 days for 1525 sources deemed variable in the source catalog of the first 10 yr of Fermi-LAT observations. The repository consists of lightcurves generated through full likelihood analyses that model the sources and the surrounding region, providing fluxes and photon indices for each time bin. The LCR is intended as a resource for the time-domain and multimessenger communities by allowing users to search LAT data quickly to identify correlated variability and flaring emission episodes from gamma-ray sources. We describe the sample selection and analysis employed by the LCR and provide an overview of the associated data access portal

The Fermi-LAT Light Curve Repository

The Fermi Large Area Telescope (LAT) light curve repository (LCR) is a publicly available, continually updated library of gamma-ray light curves of variable Fermi-LAT sources generated over multiple timescales. The Fermi-LAT LCR aims to provide publication-quality light curves binned on timescales of 3 days, 7 days, and 30 days for 1525 sources deemed variable in the source catalog of the first 10 years of Fermi-LAT observations. The repository consists of light curves generated through full likelihood analyses that model the sources and the surrounding region, providing fluxes and photon indices for each time bin. The LCR is intended as a resource for the time-domain and multi-messenger communities by allowing users to quickly search LAT data to identify correlated variability and flaring emission episodes from gamma-ray sources. We describe the sample selection and analysis employed by the LCR and provide an overview of the associated data access portal

Catalog of Long-term Transient Sources in the First 10 yr of Fermi-LAT Data

none118siFermi-Lat Collaboration T.; Baldini L.; Ballet J.; Bastieri D.; Becerra Gonzalez J.; Bellazzini R.; Berretta A.; Bissaldi E.; Blandford R.D.; Bloom E.D.; Bonino R.; Bottacini E.; Bruel P.; Buson S.; Cameron R.A.; Caraveo P.A.; Cavazzuti E.; Chen S.; Chiaro G.; Ciangottini D.; Cibario N.; Ciprini S.; Cristarella Orestano P.; Crnogorcevic M.; Cutini S.; D'Ammando F.; De La Torre Luque P.; De Palma F.; Digel S.W.; Di Lalla N.; Dirirsa F.; Di Venere L.; Dominguez A.; Fiori A.; Fleischhack H.; Franckowiak A.; Fukazawa Y.; Funk S.; Fusco P.; Gargano F.; Gasparrini D.; Germani S.; Giglietto N.; Giordano F.; Giroletti M.; Green D.; Grenier I.A.; Griffin S.; Guiriec S.; Gustafsson M.; Hewitt J.W.; Horan D.; Imazawa R.; Johannesson G.; Kerr M.; Kocevski D.; Kuss M.; Larsson S.; Latronico L.; Li J.; Liodakis I.; Longo F.; Loparco F.; Lovellette M.N.; Lubrano P.; Maldera S.; Manfreda A.; Marti-Devesa G.; Matake H.; Mazziotta M.N.; Mereu I.; Meyer M.; Mirabal N.; Mitthumsiri W.; Mizuno T.; Monzani M.E.; Morselli A.; Moskalenko I.V.; Nagasawa S.; Negro M.; Ojha R.; Orienti M.; Orlando E.; Palatiello M.; Paliya V.; Paneque D.; Pei Z.; Persic M.; Pesce-Rollins M.; Petrosian V.; Poon H.; Porter T.A.; Principe G.; Racusin J.L.; Rain S.; Rando R.; Rani B.; Razzano M.; Razzaque S.; Reimer A.; Reimer O.; Saz Parkinson P.M.; Scotton L.; Serini D.; Sgr C.; Siskind E.J.; Spandre G.; Spinelli P.; Suson D.J.; Tajima H.; Tak D.; Torres D.F.; Tosti G.; Troja E.; Wood K.; Yassine M.; Zaharijas G.; Cavazzuti E.Fermi-Lat Collaboration, T.; Baldini, L.; Ballet, J.; Bastieri, D.; Becerra Gonzalez, J.; Bellazzini, R.; Berretta, A.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Bruel, P.; Buson, S.; Cameron, R. A.; Caraveo, P. A.; Cavazzuti, E.; Chen, S.; Chiaro, G.; Ciangottini, D.; Cibario, N.; Ciprini, S.; Cristarella Orestano, P.; Crnogorcevic, M.; Cutini, S.; D'Ammando, F.; De La Torre Luque, P.; De Palma, F.; Digel, S. W.; Di Lalla, N.; Dirirsa, F.; Di Venere, L.; Dominguez, A.; Fiori, A.; Fleischhack, H.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Green, D.; Grenier, I. A.; Griffin, S.; Guiriec, S.; Gustafsson, M.; Hewitt, J. W.; Horan, D.; Imazawa, R.; Johannesson, G.; Kerr, M.; Kocevski, D.; Kuss, M.; Larsson, S.; Latronico, L.; Li, J.; Liodakis, I.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Maldera, S.; Manfreda, A.; Marti-Devesa, G.; Matake, H.; Mazziotta, M. N.; Mereu, I.; Meyer, M.; Mirabal, N.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Nagasawa, S.; Negro, M.; Ojha, R.; Orienti, M.; Orlando, E.; Palatiello, M.; Paliya, V.; Paneque, D.; Pei, Z.; Persic, M.; Pesce-Rollins, M.; Petrosian, V.; Poon, H.; Porter, T. A.; Principe, G.; Racusin, J. L.; Rain, S.; Rando, R.; Rani, B.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Saz Parkinson, P. M.; Scotton, L.; Serini, D.; Sgr, C.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Tak, D.; Torres, D. F.; Tosti, G.; Troja, E.; Wood, K.; Yassine, M.; Zaharijas, G.; Cavazzuti, E

Catalog of Long-term Transient Sources in the First 10 yr of Fermi-LAT Data

We present the first Fermi Large Area Telescope (LAT) catalog of long-term \u3b3-ray transient sources (1FLT). This comprises sources that were detected on monthly time intervals during the first decade of Fermi-LAT operations. The monthly timescale allows us to identify transient and variable sources that were not yet reported in other Fermi-LAT catalogs. The monthly data sets 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\u3c3 in at least one monthly bin were listed in the final catalog. The 1FLT catalog contains 142 transient \u3b3-ray sources that are not included in the 4FGL-DR2 catalog. Many of these sources (102) have been confidently associated with active galactic nuclei (AGNs): 24 are associated with flat-spectrum radio quasars, 1 with a BL Lac object, 70 with blazars of uncertain type, 3 with radio galaxies, 1 with a compact steep-spectrum radio source, 1 with a steep-spectrum radio quasar, and 2 with AGNs of other types. The remaining 40 sources have no candidate counterparts at other wavelengths. The median \u3b3-ray spectral index of the 1FLT-AGN sources is softer than that reported in the latest Fermi-LAT AGN general catalog. This result is consistent with the hypothesis that detection of the softest \u3b3-ray emitters is less efficient when the data are integrated over year-long intervals

Fermi-GBM Discovery of GRB 221009A: An Extraordinarily Bright GRB from Onset to Afterglow

International audienceWe report the discovery of GRB 221009A, the highest flux gamma-ray burst ever observed by the Fermi Gamma-ray Burst Monitor (GBM). This GRB has continuous prompt emission lasting more than 600 seconds, afterglow visible in the \gbm energy range (8 keV--40 MeV), and total energetics higher than any other burst in the GBM sample. By using a variety of new and existing analysis techniques we probe the spectral and temporal evolution of GRB 221009A. We find no emission prior to the GBM trigger time (t0; 2022 October 9 at 13:16:59.99 UTC), indicating that this is the time of prompt emission onset. The triggering pulse exhibits distinct spectral and temporal properties suggestive of shock-breakout with significant emission up to $\sim$15 MeV. We characterize the onset of external shock at \t0+600 s and find evidence of a plateau region in the early-afterglow phase which transitions to a slope consistent with \swift-XRT afterglow measurements. We place the total energetics of GRB 221009A in context with the rest of the GBM sample and find that this GRB has the highest total isotropic-equivalent energy ($\textrm{E}_{\gamma,\textrm{iso}}=1.0\times10^{55}$ erg) and second highest isotropic-equivalent luminosity ($\textrm{L}_{\gamma,\textrm{iso}}=9.9\times10^{53}$ erg/s) based on redshift of z = 0.151. These extreme energetics are what allowed GBMto observe the continuously emitting central engine from the beginning of the prompt emission phase through the onset of early afterglow

Fermi-GBM Discovery of GRB 221009A: An Extraordinarily Bright GRB from Onset to Afterglow

We report the discovery of GRB 221009A, the highest flux gamma-ray burst ever observed by the Fermi Gamma-ray Burst Monitor (GBM). This GRB has continuous prompt emission lasting more than 600 seconds which smoothly transitions to afterglow visible in the GBM energy range (8 keV--40 MeV), and total energetics higher than any other burst in the GBM sample. By using a variety of new and existing analysis techniques we probe the spectral and temporal evolution of GRB 221009A. We find no emission prior to the GBM trigger time (t0; 2022 October 9 at 13:16:59.99 UTC), indicating that this is the time of prompt emission onset. The triggering pulse exhibits distinct spectral and temporal properties suggestive of the thermal, photospheric emission of shock-breakout, with significant emission up to $\sim$15 MeV. We characterize the onset of external shock at t0+600 s and find evidence of a plateau region in the early-afterglow phase which transitions to a slope consistent with Swift-XRT afterglow measurements. We place the total energetics of GRB 221009A in context with the rest of the GBM sample and find that this GRB has the highest total isotropic-equivalent energy ($\textrm{E}_{\gamma,\textrm{iso}}=1.0\times10^{55}$ erg) and second highest isotropic-equivalent luminosity ($\textrm{L}_{\gamma,\textrm{iso}}=9.9\times10^{53}$ erg/s) based on redshift of z = 0.151. These extreme energetics are what allowed us to observe the continuously emitting central engine of GBM from the beginning of the prompt emission phase through the onset of early afterglow.Comment: 26 pages 7 figures - accepted for publication in ApJ

Fermi-GBM Discovery of GRB 221009A: An Extraordinarily Bright GRB from Onset to Afterglow

International audienceWe report the discovery of GRB 221009A, the highest flux gamma-ray burst ever observed by the Fermi Gamma-ray Burst Monitor (GBM). This GRB has continuous prompt emission lasting more than 600 seconds, afterglow visible in the \gbm energy range (8 keV--40 MeV), and total energetics higher than any other burst in the GBM sample. By using a variety of new and existing analysis techniques we probe the spectral and temporal evolution of GRB 221009A. We find no emission prior to the GBM trigger time (t0; 2022 October 9 at 13:16:59.99 UTC), indicating that this is the time of prompt emission onset. The triggering pulse exhibits distinct spectral and temporal properties suggestive of shock-breakout with significant emission up to $\sim$15 MeV. We characterize the onset of external shock at \t0+600 s and find evidence of a plateau region in the early-afterglow phase which transitions to a slope consistent with \swift-XRT afterglow measurements. We place the total energetics of GRB 221009A in context with the rest of the GBM sample and find that this GRB has the highest total isotropic-equivalent energy ($\textrm{E}_{\gamma,\textrm{iso}}=1.0\times10^{55}$ erg) and second highest isotropic-equivalent luminosity ($\textrm{L}_{\gamma,\textrm{iso}}=9.9\times10^{53}$ erg/s) based on redshift of z = 0.151. These extreme energetics are what allowed GBMto observe the continuously emitting central engine from the beginning of the prompt emission phase through the onset of early afterglow