Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
FERMI LAT STACKING ANALYSIS OF SWIFT LOCALIZED GRBs
KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik. Tokyo Metropolitan University, Japan.ORCID-id: 0000-0003-4378-8785
Rekke forfattare: 1122016 (engelsk)Inngår i: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 822, nr 2, artikkel-id 68Artikkel i tidsskrift (Fagfellevurdert) Published
Resurstyp
Text
Abstract [en]

We perform a comprehensive stacking analysis of data collected by the Fermi. Large Area Telescope (LAT) of gamma-ray bursts (GRBs) localized by the Swift. spacecraft, which were not detected by the LAT but which fell within the instrument's field of view at the time of trigger. We examine a total of 79 GRBs by comparing the observed counts over a range of time intervals to that expected from designated background orbits, as well as by using a joint likelihood technique to model the expected distribution of stacked counts. We find strong evidence for subthreshold emission at MeV to GeV energies using both techniques. This observed excess is detected during intervals that include and exceed the durations typically characterizing the prompt emission observed at keV energies and lasts at least 2700 s after the co-aligned burst trigger. By utilizing a novel cumulative likelihood analysis, we find that although a burst's prompt gamma-ray and afterglow X-ray flux both correlate with the strength of the subthreshold emission, the X-ray afterglow flux measured by Swift's X-ray Telescope at 11 hr post trigger correlates far more significantly. Overall, the extended nature of the subthreshold emission and its connection to the burst's afterglow brightness lend. further support to the external forward shock origin of the late-time emission detected by the LAT. These results suggest that the extended high-energy emission observed by the LAT may be a relatively common feature but remains undetected in a majority of bursts owing. to instrumental threshold effects.

sted, utgiver, år, opplag, sider
Institute of Physics Publishing (IOPP), 2016. Vol. 822, nr 2, artikkel-id 68
Emneord [en]
gamma-ray burst: general, gamma rays: general, methods: data analysis, X-rays: bursts
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-189726DOI: 10.3847/0004-637X/822/2/68ISI: 000377204900011Scopus ID: 2-s2.0-84969543427OAI: oai:DiVA.org:kth-189726DiVA, id: diva2:948396
Merknad

QC 20160711

Tilgjengelig fra: 2016-07-11 Laget: 2016-07-11 Sist oppdatert: 2017-11-28bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekstScopus

Søk i DiVA

Av forfatter/redaktør
Axelsson, Magnus
Av organisasjonen
I samme tidsskrift
Astrophysical Journal

Søk utenfor DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric

doi
urn-nbn
Totalt: 30 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf