Image Details
Caption: Figure 4.
Light curve of EP240414a in the observer frame in the g (blue), r (green), i (yellow) and z (red) bands (first panel) compared to the light curves of the prototypical LFBOT AT2018cow (second panel; S. J. Prentice et al. 2018), the prototypical GRB SN Ic-BL SN 1998bw (third panel; F. Patat et al. 2001), the X-ray flash GRB/XRF 060218 (fourth panel; A. M. Soderberg et al. 2006), and the LFBOT AT2018gep (fifth panel; A. Y. Q. Ho et al. 2020b). From the light curve in the top panel we distinguish what we refer to as the first, second, and third peaks at ~1, ~4, and ~10 days, respectively. The second panel shows the match between the steep decline in the light curve of AT2018cow and the second peak in the light curve of EP240414a. The timescale and steepness of the decline after this peak only matches AT2018cow in our selection of comparison objects. In the third panel we show that the third peak matches a prototypical GRB SN Ic-BL like SN 1998bw well, as is similarly true for our spectroscopy at this time. However, additional components to a SN are needed to explain the first and second peaks observed in EP240414a. The fourth panel compares EP240414a to X-ray flash GRB/XRF 060218 in which similarly no GRB was observed. This event shows two peaks, but at different timescales than EP2404141a. In the fifth panel we make a comparison to AT2018gep, where an SN Ic-BL appeared at late times (T. A. Pritchard et al. 2021), which shows that despite this LFBOT-SN Ic-BL connection, its light curve does not match that of EP240414a’s second and third peaks well.
© 2025. The Author(s). Published by the American Astronomical Society.