The Nearby Type Ibn Supernova 2015G: Signatures of Asymmetry and Progenitor Constraints

Abstract

We present the results of an extensive observational campaign on the nearby Type Ibn SN 2015G, including data from radio through ultraviolet wavelengths. SN 2015G was asymmetric, showing late-time nebular lines redshifted by ~1000 km/s. It shared many features with the prototypical SN In 2006jc, including extremely strong He I emssion lines and a late-time blue pseudocontinuum. The young SN 2015G showed narrow P-Cygni profiles of He I, but never in its evolution did it show any signature of hydrogen - arguing for a dense, ionized, and hydrogen-free circumstellar medium moving outward with a velocity of ~1000 km/s and created by relatively recent mass loss from the progenitor star. Ultraviolet through infrared observations show that the fading SN 2015G (which was probably discovered some 20 days post-peak) had a spectral energy distribution that was well described by a simple, single-component blackbody. Archival HST images provide upper limits on the luminosity of SN 2015G's progenitor, while nondetections of any luminous radio afterglow and optical nondetections of outbursts over the past two decades provide constraints upon its mass-loss history.

19 pages, 13 figures. Published in MNRAS

References in corpus (32)

• Modules for Experiments in Stellar Astrophysics (MESA)
• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• Binary interaction dominates the evolution of massive stars
• Determining the Type, Redshift, and Age of a Supernova Spectrum
• A giant outburst two years before the core-collapse of a massive star
• An Open Catalog for Supernova Data
• SN 2006jc: A Wolf-Rayet Star Exploding in a Dense He-Rich Circumstellar Medium
• SOUSA: the Swift Optical/Ultraviolet Supernova Archive
• Asphericity in Supernova Explosions from Late-Time Spectroscopy
• Massive stars exploding in a He-rich circumstellar medium. I. Type Ibn (SN 2006jc-like) events
• Luminous Blue Variables are Antisocial: Their Isolation Implies that they are Kicked Mass Gainers in Binary Evolution
• Ejection of the massive Hydrogen-rich envelope timed with the collapse of the stripped SN2014C
• Revisiting the Lick Observatory Supernova Search Volume-Limited Sample: Updated Classifications and Revised Stripped-Envelope Supernova Fractions
• From Spitzer Galaxy Photometry to Tully-Fisher Distances
• Metamorphosis of SN 2014C: Delayed Interaction Between a Hydrogen Poor Core-collapse Supernova and a Nearby Circumstellar Shell
• Double-peaked Oxygen Lines Are not Rare in Nebular Spectra of Core-Collapse Supernovae
• Type Ibn Supernovae Show Photometric Homogeneity and Spectral Diversity at Maximum Light
• Massive stars exploding in a He-rich circumstellar medium. II. The transitional case of SN 2005la
• Dead or Alive? Long-term evolution of SN 2015bh (SNhunt275)
• Massive stars exploding in a He-rich circumstellar medium. IV. Transitional Type Ibn Supernovae
• On the Social Traits of Luminous Blue Variables
• E-BOSS: An Extensive stellar BOw Shock Survey. II. Catalogue second release
• SN 2015bh: NGC 2770's 4th supernova or a luminous blue variable on its way to a Wolf-Rayet star?
• SN 2015U: A Rapidly Evolving and Luminous Type Ibn Supernova
• Properties of newly formed dust by SN2006jc based on near-to-mid infrared observation with AKARI
• The possible detection of a binary companion to a Type Ibn supernova progenitor
• Constraints on Type IIn Supernova Progenitor Outbursts from the Lick Observatory Supernova Search
• Massive stars dying alone: The extremely remote environment of SN 2009ip
• Massive stars exploding in a He-rich circumstellar medium - VII. The metamorphosis of ASASSN-15ed from a narrow line Type Ibn to a normal Type Ib Supernova
• Massive stars exploding in a He-rich circumstellar medium - VIII. PSN J07285387+3349106, a highly reddened supernova Ibn
• SuperNova IDentification spectral templates of 70 stripped-envelope core-collapse supernovae
• The Radio Properties of Type Ibc Supernovae

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• The changing-type SN 2014C may come from an 11-$M_{\odot }$ star stripped by binary interaction and violent eruption
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• Wave-Driven Shocks in Stellar Outbursts: Dynamics, Envelope Heating, and Nascent Blastwaves
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• Massive stars exploding in a He-rich circumstellar medium $-$ X. Flash spectral features in the Type Ibn SN 2019cj and observations of SN 2018jmt
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