XRF 060428B: Observational evidence for a strongly lensed burst

D. A. Perley, J. S. Bloom, N. R. Butler, W. Li, H. W. Chen

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations


Long-duration GRBs and X-ray flashes (XRFs; softer-spectrum brethren of long GRBs) are thought to occur following the core-collapse of massive stars. We report here on observations of a recent X-ray flash (XRF 060428B) that occurred 2.6 in projection from the center of a massive red galaxy at redshift z=0.348, well within its detectable light. While initial probabilistic arguments suggested a physical connection, deep Keck imaging reveals a compact blue source at the burst position, likely a higher-redshift host galaxy. Since the observed offset is approximately equal to the Einstein radius of the foreground elliptical, we suggest that XRF 060428B may have been strongly gravitationally lensed, allowing us to detect an underluminous burst at high-z. This would naturally explain the otherwise coincidental proximity to a nearby galaxy.

Original languageEnglish (US)
Title of host publicationSUPERNOVA 1987A
Subtitle of host publication20 YEARS AFTER: Supernovae and Gamma-Ray Bursters
Number of pages4
StatePublished - 2007
Externally publishedYes
EventSUPERNOVA 1987A: 20 YEARS AFTER: Supernovae and Gamma-Ray Bursters - Aspen, CO, United States
Duration: Feb 19 2007Feb 23 2007

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


OtherSUPERNOVA 1987A: 20 YEARS AFTER: Supernovae and Gamma-Ray Bursters
Country/TerritoryUnited States
CityAspen, CO


  • Gamma rays: bursts
  • Gamma-ray bursts: individual: 060428B
  • Gravitational lensing

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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