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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Ultra-long gamma-ray bursts (ulGRBs) are a new population of GRBs withextreme durations of $\sim 10^{4}$ s. Leading candidates for their origin areblue supergiant collapsars, magnetars, and white dwarf tidal disruption events(WD-TDEs) caused by massive black holes (BHs). Recent observations ofsupernova-like (SN-like) bumps associated with ulGRBs challenged both theWD-TDE and the blue supergiant models because of the detection of SNe and theabsence of hydrogen lines, respectively. We propose that WD-TDEs canaccommodate the observed SN-like bumps if the fallback WD matter releasesenergy into the unbound WD ejecta. The observed ejecta energy, luminosity, andvelocity are explained by the gravitational energy, Eddington luminosity, andescape velocity of the formed accretion disk, respectively. We also show thatthe observed X-rays can ionize the ejecta, eliminating lines. The SN-like lightcurves (SN 2011kl) for the ulGRB 111209A are consistent with all three models,although a magnetar model is unnatural because the spin-down time required topower the SN-like bump is a hundred times longer than the GRB. Our resultsimply that TDEs are a possible energy source for SN-like events in general andfor ulGRBs in particular.

Are Ultra-Long Gamma-Ray Bursts Caused by Blue Supergiant Collapsars, Newborn Magnetars, or White Dwarf Tidal Disruption Events?