Evidence for GeV emission of the superluminous supernova SN 2017egm

Abstract

Superluminous supernovae (SLSNe) are a new class of transients with luminosities $\sim 10-100$ 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.

Accepted for publication in PRL

References in corpus (16)

• Gaia Data Release 3: Summary of the content and survey properties
• The Last of FIRST: The Final Catalog and Source Identifications
• The Unique Type Ib Supernova 2005bf at Nebular Phases: A Possible Birth Event of A Strongly Magnetized Neutron Star
• A Quick Look at the $3$GHz Radio Sky I. Source Statistics from the Very Large Array Sky Survey
• Super-luminous supernovae at redshifts of 2.05 and 3.90
• A radio spectral index map and catalogue at 147-1400 MHz covering 80 per cent of the sky
• Gamma-Ray and Hard X-Ray Emission from Pulsar-Aided Supernovae as a Probe of Particle Acceleration in Embryonic Pulsar Wind Nebulae
• Gamma-ray Thermalization and Leakage from Millisecond Magnetar Nebulae: Towards a Self-Consistent Model for Superluminous Supernovae
• The superluminous supernova SN 2017egm in the nearby galaxy NGC 3191: a metal-rich environment can support a typical SLSN evolution
• ALMA and NOEMA constraints on synchrotron nebular emission from embryonic superluminous supernova remnants and radio-gamma-ray connection
• A Quick Look at the 3GHz Radio Sky. II. Hunting for DRAGNs in the VLA Sky Survey
• SN2017egm: A Helium-rich Superluminous Supernova with Multiple Bumps in the Light Curves
• Radio Counterpart Candidates to 4FGL-DR2 Unassociated Sources
• An update on Fermi-LAT transients in the Galactic plane, including strong activity of Cygnus X-3 in mid-2020
• Search for gamma rays from SNe with a variable-size sliding-time-window analysis of the Fermi-LAT data
• VERITAS and Fermi-LAT constraints on the Gamma-ray Emission from Superluminous Supernovae SN2015bn and SN2017egm