A puzzle solved after two decades: SN 2002gh among the brightest of superluminous supernovae

Abstract

We present optical photometry and spectroscopy of the superluminous SN 2002gh from maximum light to $+204$ days, obtained as part of the Carnegie Type II Supernova (CATS) project. SN 2002gh is among the most luminous discovered supernovae ever, yet it remained unnoticed for nearly two decades. Using Dark Energy Camera archival images we identify the potential SN host galaxy as a faint dwarf galaxy, presumably having low metallicity, and in an apparent merging process with other nearby dwarf galaxies. We show that SN 2002gh is among the brightest hydrogen-poor SLSNe with $M_V=-22.40\pm 0.02$, with an estimated peak bolometric luminosity of $2.6\pm 0.1\times 10^{44}$ erg s${}^{-1}$. We discount the decay of radioactive nickel as the main SN power mechanism, and assuming that the SN is powered by the spin down of a magnetar we obtain two alternative solutions. The first case, is characterized by significant magnetar power leakage, and $M_{\mathrm{ej}}$ between 0.6 and 3.2 $M_{\odot }$, $P_{\mathrm{spin}}=3.2$ ms, and $B=5\times 10^{13}$ G. The second case does not require power leakage, resulting in a huge ejecta mass of about 30 $M_{\odot }$, a fast spin period of $P_{\mathrm{spin}}\sim 1$ ms, and $B\sim 1.6\times 10^{14}$ G. We estimate a zero-age main-sequence mass between 14 and 25 $M_{\odot }$ for the first case and of about 135 $M_{\odot }$ for the second case. The latter case would place the SN progenitor among the most massive stars observed to explode as a SN.

25 pages, 18 figures, accepted for publication in MNRAS

References in corpus (19)

• Pulsational pair instability as an explanation for the most luminous supernovae
• SN 2006gy: An extremely luminous supernova in the galaxy NGC 1260
• The magnetar model for Type I superluminous supernovae I: Bayesian analysis of the full multicolour light curve sample with MOSFiT
• SN 2005ap: A Most Brilliant Explosion
• The Evolution of Massive Helium Stars Including Mass Loss
• Spectroscopy of superluminous supernova host galaxies. A preference of hydrogen-poor events for extreme emission line galaxies
• The Unique Type Ib Supernova 2005bf at Nebular Phases: A Possible Birth Event of A Strongly Magnetized Neutron Star
• Optical Spectra of 73 Stripped-Envelope Core-Collapse Supernovae
• Hydrogen-Poor Superluminous Supernovae from the Pan-STARRS1 Medium Deep Survey
• The hydrogen-poor superluminous supernova iPTF13ajg and its host galaxy in absorption and emission
• Zooming In on the Progenitors of Superluminous Supernovae With the HST
• Superluminous supernova 2015bn in the nebular phase: evidence for the engine-powered explosion of a stripped massive star
• Superluminous Supernovae Powered by Magnetars: Late-time Light Curves and Hard Emission Leakage
• Gamma-ray Thermalization and Leakage from Millisecond Magnetar Nebulae: Towards a Self-Consistent Model for Superluminous Supernovae
• Discovering extremely compact and metal-poor, star-forming dwarf galaxies out to z ~ 0.9 in the VIMOS Ultra-Deep Survey
• A Type Ia supernova at the heart of superluminous transient SN 2006gy
• SN 2017gci: a nearby Type I Superluminous Supernova with a bumpy tail
• The nature of PISN candidates: clues from nebular spectra
• Understanding the extreme luminosity of DES14X2fna

Cited by in corpus (4)

• The Large Array Survey Telescope -- Science Goals
• Deciphering the unusual stellar progenitor of GRB 210704A
• Supernovae double-peaked light curves from double-nickel distribution
• Feeding post core collapse supernova explosion jets with an inflated main sequence companion