Towards Nebular Spectral Modeling of Magnetar-Powered Supernovae

Abstract

Many energetic supernovae (SNe) are thought to be powered by the rotational-energy of a highly-magnetized, rapidly-rotating neutron star. The emission from the associated luminous pulsar wind nebula (PWN) can photoionize the SN ejecta, leading to a nebular spectrum of the ejecta with signatures possibly revealing the PWN. SN 2012au is hypothesized to be one such SN. We investigate the impact of different ejecta and PWN parameters on the SN nebular spectrum, and test if any photoionization models are consistent with SN 2012au. We study how constraints from the nebular phase can be linked into modelling of the diffusion phase and the radio emission of the magnetar. We present a suite of late-time (1-6y) spectral simulations of SN ejecta powered by an inner PWN. Over a large grid of 1-zone models, we study the behaviour of the SN physical state and line emission as PWN luminosity ($L_{\mathrm{PWN}}$), injection SED temperature ($T_{\mathrm{PWN}}$), ejecta mass ($M_{\mathrm{ej}}$), and composition (pure O or realistic) vary. We discuss the resulting emission in the context of the observed behaviour of SN 2012au, a strong candidate for a PWN-powered SN. The SN nebular spectrum varies as $T_{\mathrm{PWN}}$ varies, as the ejecta become less ionized as $T_{\mathrm{PWN}}$ increases. Low ejecta mass models at high PWN power obtain runaway ionization for O I and, in extreme cases, also O II, causing a sharp decrease in their ion fraction over a small change in the parameter space. Certain models can reproduce the oxygen lines luminosities of SN 2012au reasonably well at individual epochs, but we find no model that fits over the whole time evolution; this is likely due to the simple model setup. Using our derived constraints from the nebular phase, we predict that the magnetar powering SN 2012au had an initial rotation period $\sim$ 15 ms, and should be a strong radio source (F > 100 $\mu$Jy) for decades.

27 pages, 22 figures, accepted by A&A

References in corpus (34)

• Nucleosynthesis and Remnants in Massive Stars of Solar Metallicity
• The magnetar model for Type I superluminous supernovae I: Bayesian analysis of the full multicolour light curve sample with MOSFiT
• Spectroscopy of superluminous supernova host galaxies. A preference of hydrogen-poor events for extreme emission line galaxies
• The ultra-long Gamma-Ray Burst 111209A: the collapse of a blue supergiant?
• Superluminous supernova 2015bn in the nebular phase: evidence for the engine-powered explosion of a stripped massive star
• Spectropolarimetry of superluminous supernovae: insight into their geometry
• Gamma-Ray and Hard X-Ray Emission from Pulsar-Aided Supernovae as a Probe of Particle Acceleration in Embryonic Pulsar Wind Nebulae
• The braking index of millisecond magnetars
• Gamma-ray Thermalization and Leakage from Millisecond Magnetar Nebulae: Towards a Self-Consistent Model for Superluminous Supernovae
• Supernova ejecta with a relativistic wind from a central compact object: a unified picture for extraordinary supernovae
• NLTE Effects on Kilonova Expansion Opacities
• The Hydrogen-Poor Superluminous Supernovae from the Zwicky Transient Facility Phase-I Survey: II. Light Curve Modeling and Characterization of Undulations
• On the Validity of Steady-State for Nebular Phase Kilonovae
• Superluminous supernovae: an explosive decade
• Are Ultra-Long Gamma-Ray Bursts Caused by Blue Supergiant Collapsars, Newborn Magnetars, or White Dwarf Tidal Disruption Events?
• Luminous Late-time Radio Emission from Supernovae Detected by the Karl G. Jansky Very Large Array Sky Survey (VLASS)
• On the diversity of magnetar-driven kilonovae
• A Search for Late-Time Radio Emission and Fast Radio Bursts from Superluminous Supernovae
• Late-Time Radio and Millimeter Observations of Superluminous Supernovae and Long Gamma Ray Bursts: Implications for Obscured Star Formation, Central Engines, and Fast Radio Bursts
• 2D radiation-hydrodynamic simulations of supernova ejecta with a central power source
• Signatures of R-process Enrichment in Supernovae from Collapsars
• SN 2018bsz: a Type I superluminous supernova with aspherical circumstellar material
• Photometric, polarimetric, and spectroscopic studies of the luminous, slow-decaying Type Ib SN 2012au
• Dust masses for a large sample of core-collapse supernovae from optical emission line asymmetries: dust formation on 30-year timescales
• ALMA and NOEMA constraints on synchrotron nebular emission from embryonic superluminous supernova remnants and radio-gamma-ray connection
• Radio emission from a decade old Type I superluminous supernova, PTF10hgi: Comparison with FRB121102
• A Mid-infrared Study of Superluminous Supernovae
• Carbon monoxide formation and cooling in supernovae
• SN2020qlb: A hydrogen-poor superluminous supernova with well-characterized light curve undulations
• Late-Phase Spectropolarimetric Observations of Superluminous Supernova SN 2017egm to Probe the Geometry of the Inner Ejecta
• The interacting nature of dwarf galaxies hosting superluminous supernovae
• Optical polarization and spectral properties of the H-poor superluminous supernovae SN 2021bnw and SN 2021fpl
• Variability of Late-time Radio Emission in SLSN PTF10hgi
• Post maximum light and late time optical imaging polarimetry of type I superluminous supernova 2020znr

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• VLBI Observations of SN 2012au Reveal a Compact Radio Source a Decade Post Explosion
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