Evidence for GeV emission of the superluminous supernova SN 2017egm

Evidence for GeV emission of the superluminous supernova SN 2017egm
Shang Li, Yun-Feng Liang, Neng-Hui Liao, Lei Lei, Yi-Zhong Fan
arXiv:2407.05968v2 Announce Type: replace
Abstract: Superluminous supernovae (SLSNe) are a new class of transients with luminosities $sim10 -100$ times larger than the usual core-collapse supernovae (SNe). Their origin is still unclear and one widely discussed scenario involves a millisecond magnetar central engine. The GeV-TeV emission of SLSNe has been predicted in the literature but has not been convincingly detected yet. Here we report the results of the search for $gamma$-ray emission in the direction of SN 2017egm, one of the closest SLSNe detected so far, using 15 years of {it Fermi}-LAT Pass 8 data. There is a transient $gamma$-ray source appearing about 2 months after this event and lasting a few months. Monte Carlo simulations show that the $gamma$-ray signal has a global significance of {it at least} 4$sigma$. Both the peak time and the luminosity of the GeV emission are consistent with the magnetar model prediction, suggesting that such a GeV transient is the high-energy counterpart of SN 2017egm and the central engine of this SLSNe is a young magnetar.arXiv:2407.05968v2 Announce Type: replace
Abstract: Superluminous supernovae (SLSNe) are a new class of transients with luminosities $sim10 -100$ times larger than the usual core-collapse supernovae (SNe). Their origin is still unclear and one widely discussed scenario involves a millisecond magnetar central engine. The GeV-TeV emission of SLSNe has been predicted in the literature but has not been convincingly detected yet. Here we report the results of the search for $gamma$-ray emission in the direction of SN 2017egm, one of the closest SLSNe detected so far, using 15 years of {it Fermi}-LAT Pass 8 data. There is a transient $gamma$-ray source appearing about 2 months after this event and lasting a few months. Monte Carlo simulations show that the $gamma$-ray signal has a global significance of {it at least} 4$sigma$. Both the peak time and the luminosity of the GeV emission are consistent with the magnetar model prediction, suggesting that such a GeV transient is the high-energy counterpart of SN 2017egm and the central engine of this SLSNe is a young magnetar.