SN 2018gjx reveals that some SNe Ibn are SNe IIb exploding in dense circumstellar material

Abstract

We present the data and analysis of SN 2018gjx, an unusual low-luminosity transient with three distinct spectroscopic phases. Phase I shows a hot blue spectrum with signatures of ionised circumstellar material (CSM), Phase II has the appearance of broad SN features, consistent with those seen in a Type IIb supernova at maximum light, and Phase III is that of a supernova interacting with helium-rich CSM, similar to a Type Ibn supernova. This event provides an apparently rare opportunity to view the inner workings of an interacting supernova. The observed properties can be explained by the explosion of a star in an aspherical CSM. The initial light is emitted from an extended CSM (~ 4000 Rsun), which ionises the exterior unshocked material. Some days after, the SN photosphere envelops this region, leading to the appearance of a SN IIb. Over time, the photosphere recedes in velocity space, revealing interaction between the supernova ejecta and the CSM that partially obscures the supernova nebular phase. Modelling of the initial spectrum reveals a surface composition consistent with compact H-deficient Wolf-Rayet and LBV stars. Such configurations may not be unusual, with SNe IIb being known to have signs of interaction so at least some SNe IIb and SNe Ibn may be the same phenomena viewed from different angles or, possibly with differing CSM configurations.

arXiv commentAccepted for publication in MNRAS

References in corpus (115)

• The chemical composition of the Sun
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• The Origin of the Mass--Metallicity Relation: Insights from 53,000 Star-Forming Galaxies in the SDSS
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• ATLAS: A High-Cadence All-Sky Survey System
• Las Cumbres Observatory Global Telescope Network
• Mass Loss: Its Effect on the Evolution and Fate of High-Mass Stars
• The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment
• Physical Properties of Wolf-Rayet Stars
• Pre-Supernova Evolution of Massive Single and Binary Stars
• HyperLEDA. III. The catalogue of extragalactic distances
• The Zwicky Transient Facility: Science Objectives
• Empirical Color Transformations Between SDSS Photometry and Other Photometric Systems
• Determining the Type, Redshift, and Age of a Supernova Spectrum
• Cosmicflows-3
• The Arecibo Legacy Fast ALFA Survey: The ALFALFA Extragalactic HI Source Catalog
• A giant outburst two years before the core-collapse of a massive star
• Confined Dense Circumstellar Material Surrounding a Regular Type II Supernova: The Unique Flash-Spectroscopy Event of SN 2013fs
• A Wolf-Rayet-like progenitor of supernova SN 2013cu from spectral observations of a wind
• PESSTO : survey description and products from the first data release by the Public ESO Spectroscopic Survey of Transient Objects
• The Unprecedented 2012 Outburst of SN 2009ip: A Luminous Blue Variable Becomes a True Supernova
• SN 2006jc: A Wolf-Rayet Star Exploding in a Dense He-Rich Circumstellar Medium
• Oxygen and nitrogen abundances in nearby galaxies. Correlations between oxygen abundance and macroscopic properties
• Evidence for Asphericity in the Type IIn Supernova 1998S
• The ATLAS All-Sky Stellar Reference Catalog
• Interacting Supernovae and Supernova Impostors. SN 2009ip, is this the end?
• An embedded X-ray source shines through the aspherical AT2018cow: revealing the inner workings of the most luminous fast-evolving optical transients
• Detailed Analysis of Early to Late-Time Spectra of Supernova 1993J
• A panchromatic view of the restless SN2009ip reveals the explosive ejection of a massive star envelope
• Asphericity in Supernova Explosions from Late-Time Spectroscopy
• The Broad-lined Type Ic SN 2003jd
• Flash Spectroscopy: Emission Lines from the Ionized Circumstellar Material around $<10$-Day-Old Type II Supernovae
• The Type IIb Supernova 2011dh from a Supergiant Progenitor
• Optical Spectroscopy of Type Ib/c Supernovae
• The Cow: discovery of a luminous, hot and rapidly evolving transient
• The Most Luminous Supernovae
• PTF11eon/SN2011dh: Discovery of a Type IIb Supernova From a Compact Progenitor in the Nearby Galaxy M51
• The Yellow Supergiant Progenitor of the Type II Supernova 2011dh in M51
• The Galactic WC stars: Stellar parameters from spectral analyses indicate a new evolutionary sequence
• Unifying Type II Supernova Light Curves with Dense Circumstellar Material
• Broad emission lines from opaque electron-scattering environment of SN 1998S
• Optical Spectra of 73 Stripped-Envelope Core-Collapse Supernovae
• An Asymmetric, Energetic Type Ic Supernova Viewed Off-Axis, and a Link to Gamma-Ray Bursts
• Massive stars exploding in a He-rich circumstellar medium. I. Type Ibn (SN 2006jc-like) events
• Coronal lines and dust formation in SN 2005ip: Not the brightest, but the hottest Type IIn supernova
• Dust Formation and He II 4686 emission in the Dense Shell of the Peculiar Type Ib Supernova 2006jc
• Ejection of the massive Hydrogen-rich envelope timed with the collapse of the stripped SN2014C
• Nebular emission-line profiles of Type Ib/c Supernovae - probing the ejecta asphericity
• Revisiting the Lick Observatory Supernova Search Volume-Limited Sample: Updated Classifications and Revised Stripped-Envelope Supernova Fractions
• Interacting Supernovae: Types IIn and Ibn
• PTF11iqb: Cool supergiant mass loss that bridges the gap between Type IIn and normal supernovae
• The bolometric light curves and physical parameters of stripped-envelope supernovae
• The delay of shock breakout due to circumstellar material seen in most Type II Supernovae
• Late-time spectral line formation in Type IIb supernovae, with application to SN 1993J, SN 2008ax, and SN 2011dh
• Fundamental properties of core-collapse Supernova and GRB progenitors: predicting the look of massive stars before death
• Yellow supergiants as supernova progenitors: an indication of strong mass loss for red supergiants?
• A Fully Automated Integral Field Spectrograph Pipeline for the SEDMachine: pysedm
• Metamorphosis of SN 2014C: Delayed Interaction Between a Hydrogen Poor Core-collapse Supernova and a Nearby Circumstellar Shell
• Optical Spectroscopy of Supernova 1993J During Its First 2500 Days
• Type IIB Supernovae with Compact and Extended Progenitors
• The type IIb SN 2008ax: spectral and light curve evolution
• Investigating the properties of stripped-envelope supernovae, what are the implications for their progenitors?
• ESC Supernova spectroscopy of non-ESC targets
• The Type IIb Supernova 2013df and Its Cool Supergiant Progenitor
• Panchromatic Observations of SN 2011dh Point to a Compact Progenitor Star
• 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
• The Koala: A Fast Blue Optical Transient with Luminous Radio Emission from a Starburst Dwarf Galaxy at $z=0.27$
• Thermal and non-thermal emission from circumstellar interaction
• Nearby supernova host galaxies from the CALIFA Survey: I. Sample, data analysis, and correlation to star-forming regions
• Doublets and Double Peaks: Late-Time [O I] 6300, 6364 Line Profiles of Stripped-Envelope, Core-Collapse Supernovae
• Dissecting the Homunculus nebula around Eta Carinae with spatially resolved near-infrared spectroscopy
• Early-time spectra of supernovae and their precursor winds: the luminous blue variable/yellow hypergiant progenitor of SN 2013cu
• Early Emission from the Type IIn Supernova 1998S at High Resolution
• Late-Time Optical Emission From Core-Collapse Supernovae
• Short-Lived Circumstellar Interaction in the Low-Luminosity Type IIP SN 2016bkv
• The He-rich Stripped-Envelope Core-Collapse Supernova 2008ax
• Constraints on core-collapse supernova progenitors from explosion site integral field spectroscopy
• SN 2013df, a double-peaked IIb supernova from a compact progenitor and an extended H envelope
• Massive stars exploding in a He-rich circumstellar medium. IV. Transitional Type Ibn Supernovae
• Massive stars exploding in a He-rich circumstellar medium - IX. SN 2014av, and characterization of Type Ibn SNe
• Constraints on the Progenitor of SN 2016gkg From Its Shock-Cooling Light Curve
• SN 2011hw: Helium-Rich Circumstellar Gas and the Luminous Blue Variable to Wolf-Rayet Transition in Supernova Progenitors
• The progenitor and early evolution of the Type IIb SN 2016gkg
• Asphericity, Interaction, and Dust in the Type II-P/II-L Supernova 2013ej in Messier 74
• SN 2017ens: The Metamorphosis of a Luminous Broad-lined Type Ic Supernova into an SN IIn
• Circumstellar interaction in type Ibn supernovae and SN 2006jc
• A physically motivated classification of stripped-envelope supernovae
• Stripped-envelope supernova SN 2004dk is now interacting with hydrogen-rich circumstellar material
• SN 2011fu: A type IIb Supernova with a luminous double-peaked light curve
• A Spectroscopic Study of Mass Outflows in the Interacting Binary RY Scuti
• Type IIb Supernova SN 2011dh: Spectra and Photometry from the Ultraviolet to the Near-Infrared
• The long-lived Type IIn SN 2015da: Infrared echoes and strong interaction within an extended massive shell
• Origins of Type Ibn SNe 2006jc/2015G in interacting binaries and implications for pre-SN eruptions
• On type IIn/Ia-CSM supernovae as exemplified by SN 2012ca
• The Physics of Flash (Supernova) Spectroscopy
• Massive stars exploding in a He-rich circumstellar medium. V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006
• Progenitors of early-time interacting supernovae
• The Nearby Type Ibn Supernova 2015G: Signatures of Asymmetry and Progenitor Constraints
• Optical and IR observations of SN 2013L, a Type IIn Supernova surrounded by asymmetric CSM
• Massive stars exploding in a He-rich circumstellar medium. VI. Observations of two distant Type Ibn supernova candidates discovered by La Silla-QUEST
• PTF 13efv - An outburst 500 days prior to the SNHunt 275 explosion and its radiative efficiency
• Near-Infrared Spectroscopy of SN2009ip's 2012 Brightening Reveals a Dusty Pre-Supernova Environment
• Flash ionization signatures in the type Ibn supernova SN 2019uo
• Disentangling Dust Components in SN 2010jl: The First 1400 Days
• Detection of Late-Time Circumstellar Interaction of SN 2017eaw in NGC 6946
• 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
• Discovery and Rapid Follow-up Observations of the Unusual Type II SN 2018ivc in NGC 1068
• Constraining GRB progenitor models by probing Wolf-Rayet wind geometries in the Large Magellanic Cloud
• Massive stars exploding in a He-rich circumstellar medium - VIII. PSN J07285387+3349106, a highly reddened supernova Ibn
• LSQ13ddu: A rapidly-evolving stripped-envelope supernova with early circumstellar interaction signatures
• A new and unusual LBV-like outburst from a Wolf-Rayet star in the outskirts of M33
• A luminous stellar outburst during a long-lasting eruptive phase first, and then SN IIn 2018cnf
• Early Ultra-Violet observations of type IIn supernovae constrain the asphericity of their circumstellar material

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• Seven years of coordinated Chandra-NuSTAR observations of SN2014C unfold the extreme mass-loss history of its stellar progenitor
• Three Core-Collapse Supernovae with Nebular Hydrogen Emission
• Photometric and spectroscopic evolution of the interacting transient AT 2016jbu (Gaia16cfr)
• Mass-transferring binary stars as progenitors of interacting hydrogen-free supernovae
• A pre-explosion extended effervescent zone around core collapse supernova progenitors
• Oxygen and calcium nebular emission line relationships in core-collapse supernovae and Ca-rich transients
• Radio Analysis of SN 2004C Reveals an Unusual CSM Density Profile as a Harbinger of Core Collapse
• A pre-explosion effervescent zone for the circumstellar material in SN 2023ixf
• SN 2020bio: A Double-peaked, H-poor Type IIb Supernova with Evidence of Circumstellar Interaction
• Inferring CSM Properties of Type II SNe Using a Magnitude-Limited ZTF Sample
• Are stripped envelope supernovae really deficient in ${}^{56}$Ni?
• Massive stars exploding in a He-rich circumstellar medium. XI. Diverse evolution of five Ibn SNe 2020nxt, 2020taz, 2021bbv, 2023utc and 2024aej
• Understanding the extreme luminosity of DES14X2fna
• Massive stars exploding in a He-rich circumstellar medium $-$ X. Flash spectral features in the Type Ibn SN 2019cj and observations of SN 2018jmt
• Pre-supernova outbursts by core magnetic activity
• IIb or not IIb: A Catalog of ZTF Kilonova Imposters
• Fast and Not-so-Furious: Case Study of the Fast and Faint Type IIb SN 2021bxu
• ABC-SN: Attention Based Classifier for Supernova Spectra
• Modeling the Remnants of Core-collapse Supernovae from Luminous Blue Variable stars