Open access
Datum
2017-06Typ
- Journal Article
ETH Bibliographie
yes
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Abstract
We report on the detection of a remarkable new fast high-energy transient found in the Chandra Deep Field-South, robustly associated with a faint (mR = 27.5 mag, zph ∼ 2.2) host in the CANDELS survey. The X-ray event is comprised of 115(+12)(−11) net 0.3–7.0 keV counts, with a light curve characterized by an ≈100 s rise time, a peak 0.3–10 keV flux of ≈5 × 10(−12) erg s(−1) cm(−2) and a power-law decay time slope of −1.53 ± 0.27. The average spectral slope is Γ=1.43(+0.23)(−0.13), with no clear spectral variations. The X-ray and multiwavelength properties effectively rule out the vast majority of previously observed high-energy transients. A few theoretical possibilities remain: an ‘orphan’ X-ray afterglow from an off-axis short-duration gamma-ray burst (GRB) with weak optical emission, a low-luminosity GRB at high redshift with no prompt emission below ∼20 keV rest frame, or a highly beamed tidal disruption event (TDE) involving an intermediate-mass black hole and a white dwarf with little variability. However, none of the above scenarios can completely explain all observed properties. Although large uncertainties exist, the implied rate of such events is comparable to those of orphan and low-luminosity GRBs as well as rare TDEs, implying the discovery of an untapped regime for a known transient class, or a new type of variable phenomena whose nature remains to be determined. Mehr anzeigen
Persistenter Link
https://doi.org/10.3929/ethz-b-000214966Publikationsstatus
publishedExterne Links
Zeitschrift / Serie
Monthly Notices of the Royal Astronomical SocietyBand
Seiten / Artikelnummer
Verlag
Oxford University PressThema
gamma-ray burst: general; galaxies: active; X-rays: bursts; X-rays: generalOrganisationseinheit
03968 - Schawinski (SNF-Professur) (ehemalig) / Schawinski (SNF-Professur) (former)
Förderung
138979 - From the Dawn of the Universe to Today: The Co-evolution of Galaxies and Black Holes (SNF)
166159 - From the Dawn of the Universe to Today: The Co-evolution of Galaxies and Black Holes (SNF)
Anmerkungen
It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.ETH Bibliographie
yes
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