English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In this work, we present a multi-wavelength study of XRF 040912, aimed atmeasuring its distance scale and the intrinsic burst properties. We performed adetailed spectral and temporal analysis of both the prompt and the afterglowemission and we estimated the distance scale of the likely host galaxy. We thenused the currently available sample of XRFs with known distance to discuss theconnection between XRFs and classical Gamma-ray Bursts (GRBs). We found thatthe prompt emission properties unambiguously identify this burst as an XRF,with an observed peak energy of E_p=17+/-13 keV and a burst fluence ratioS(2-30keV)/S(30-400keV)>1. A non-fading optical source with R~24 mag and withan apparently extended morphology is spatially consistent with the X-rayafterglow, likely the host galaxy. XRF 040912 is a very dark burst since noafterglow optical counterpart is detected down to R>25 mag (3 sigma limitingmagnitude) at 13.6 hours after the burst. The host galaxy spectrum detectedfrom 3800A to 10000A, shows a single emission line at 9552A. The lack of anyother strong emission lines blue-ward of the detected one and the absence ofthe Ly alpha cut-off down to 3800A are consistent with the hypothesis of the[OII] line at redshift z=1.563+/-0.001. The intrinsic spectral properties rankthis XRF among the soft GRBs in the E_peak-E_iso diagram. Similar results wereobtained for most XRFs at known redshift. Only XRF 060218 and XRF 020903represent a good example of instrinsic XRF(i-XRF) and are possibly associatedwith a different progenitor population. This scenario may calls for a newdefinition of XRFs.Comment: 10 pages, 7 figures, accepted for publication in Astronomy &  Astrophysic

X-ray flashes or soft gamma-ray bursts?. The case of the likely distant XRF 040912