High-resolution spectroscopy of SN 2017hcc and its blueshifted line profiles from post-shock dust formation

Abstract

SN2017hcc was remarkable for being a nearby and strongly polarized superluminous TypeIIn supernova (SN). We obtained high-resolution echelle spectra that we combine with other spectra to investigate its line profile evolution. All epochs reveal narrow P~Cygni components from pre-shock circumstellar material (CSM), indicating an axisymmetric outflow from the progenitor of 40-50 km/s. Intermediate-width and broad components exhibit the classic evolution seen in luminous SNe~IIn: symmetric Lorentzian profiles from pre-shock CSM lines broadened by electron scattering at early times, transitioning at late times to multi-component, irregular profiles coming from the SN ejecta and post-shock shell. As in many SNe~IIn, profiles show a progressively increasing blueshift, with a clear flux deficit in red wings of the intermediate and broad velocity components after day 200. This blueshift develops after the continuum luminosity fades, and in the intermediate-width component, persists at late times even after the SN ejecta fade. In SN2017hcc, the blueshift cannot be explained as occultation by the SN photosphere, pre-shock acceleration of CSM, or a lopsided explosion or CSM. Instead, the blueshift arises from dust formation in the post-shock shell and in the SN ejecta. The effect has a wavelength dependence characteristic of dust, exhibiting an extinction law consistent with large grains. Thus, SN2017hcc experienced post-shock dust formation and had a mildly bipolar CSM shell, similar to SN2010jl. Like other superluminous SNeIIn, the progenitor lost around 10Msun due to extreme eruptive mass loss in the decade before exploding.

21 pages, 16 figures, accepted in MNRAS

References in corpus (41)

• Binary interaction dominates the evolution of massive stars
• Pulsational Pair-Instability Supernovae
• Pulsational pair instability as an explanation for the most luminous supernovae
• Mass loss from hot massive stars
• SN 2006tf: Precursor Eruptions and the Optically Thick Regime of Extremely Luminous Type IIn Supernovae
• Shell-shocked diffusion model for the light curve of SN2006gy
• Rapid formation of large dust grains in the luminous supernova SN 2010jl
• Red supergiants as potential Type IIn supernova progenitors: Spatially resolved 4.6 micron CO emission around VY CMa and Betelgeuse
• Luminous Blue Variables are Antisocial: Their Isolation Implies that they are Kicked Mass Gainers in Binary Evolution
• A new mass-loss rate prescription for red supergiants
• PTF11iqb: Cool supergiant mass loss that bridges the gap between Type IIn and normal supernovae
• Luminous Blue Variables and superluminous supernovae from binary mergers
• A Massive Progenitor of the Luminous Type IIn Supernova 2010jl
• Numerical simulations of super-luminous supernovae of type IIn
• Binospec: A Wide-field Imaging Spectrograph for the MMT
• SN 2005 gj: Evidence for LBV supernovae progenitors?
• Discovery of a nearby twin of SN1987A's nebula around the luminous blue variable HD168625: Was Sk--69 202 an LBV?
• Numerical models of collisions between core-collapse supernovae and circumstellar shells
• Early Emission from the Type IIn Supernova 1998S at High Resolution
• High angular resolution ALMA images of dust and molecules in the SN 1987A ejecta
• Multi-epoch spectropolarimetry of SN 2009ip: direct evidence for aspherical circumstellar material
• Swift and Chandra Detections of Supernova 2006jc: Evidence for Interaction of the Supernova Shock with a Circumstellar Shell
• The UV Scattering Halo of the Central Source Associated with Eta Carinae
• Endurance of SN 2005ip after a decade: X-rays, radio, and H-alpha like SN 1988Z require long-lived pre-supernova mass loss
• Asphericity, Interaction, and Dust in the Type II-P/II-L Supernova 2013ej in Messier 74
• The Dual-Axis Circumstellar Environment of the Type IIn Supernova 1997eg
• New predictions for radiation-driven, steady-state mass-loss and wind-momentum from hot, massive stars. I. Method and first results
• MMT & Magellan Infrared Spectrograph
• Binospec Software System
• The impact of correlated noise on SuperWASP detection rates for transiting extra-solar planets
• Ancient eruptions of Eta Carinae: A tale written in proper motions
• Optical and IR observations of SN 2013L, a Type IIn Supernova surrounded by asymmetric CSM
• Near-Infrared observations of the type Ib Supernova SN2006jc: evidence of interactions with dust
• Disentangling Dust Components in SN 2010jl: The First 1400 Days
• SN2012ab: A Peculiar Type IIn Supernova with Aspherical Circumstellar Material
• On the observational behaviour of the highly polarized Type IIn supernova SN 2017hcc
• Near infrared spectroscopy of the type IIn SN 2010jl: evidence for high velocity ejecta
• A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA
• Multiwavelength Observations of NaSt1 (WR 122): Equatorial Mass Loss and X-rays from an Interacting Wolf-Rayet Binary
• SN 2014ab: An Aspherical Type IIn Supernova with Low Polarization
• Wind of presupernova IIn SN~1997eg

Cited by in corpus (16)

• Seven years of coordinated Chandra-NuSTAR observations of SN2014C unfold the extreme mass-loss history of its stellar progenitor
• A systematic reclassification of type IIn supernovae
• On the Kinematics of Cold, Metal-enriched Galactic Fountain Flows in Nearby Star-forming Galaxies
• The luminous Type IIN supernova SN 2017hcc: Infrared bright, X-ray and radio faint
• Asymmetries and Circumstellar Interaction in the Type II SN 2024bch
• Probing the Circumstellar Environment of highly luminous type IIn SN ASASSN-14il
• Luminous Blue Variables
• The bright long-lived Type II SN 2021irp powered by aspherical circumstellar material interaction (I): Revealing the energy source with photometry and spectroscopy
• The bright, dusty aftermath of giant eruptions & H-rich supernovae. Late interaction of supernova shocks & dusty circumstellar shells
• Massive stars dying alone: the remote environment of SN 2010jp and its associated late-time source
• ZTF-observed late-time signals of pre-ZTF transients
• The bright long-lived Type II SN 2021irp powered by aspherical circumstellar material interaction (II): Estimating the CSM mass and geometry with polarimetry and light curve modeling
• Spitzer's Last Look at Extragalactic Explosions: Long-Term Evolution of Interacting Supernovae
• A study on late time UV-emission in core collapse supernovae and the implications for the peculiar transient AT2018cow
• Late-time evolution of the interacting stripped-envelope supernova 2017dio
• A long life of excess: The interacting transient SN 2017hcc