Time evolution of the line emission from the inner circumstellar ring of SN 1987A and its hot spots

Abstract

We present seven epochs between October 1999 and November 2007 of high resolution VLT/UVES echelle spectra of the ejecta-ring collision of SN 1987A. The fluxes of most of the narrow lines from the unshocked gas decreased by a factor of 2-3 during this period, consistent with the decay from the initial ionization by the shock break-out. However, [O III] in particular shows an increase up to day ~6800. This agrees with radiative shock models where the pre-shocked gas is heated by the soft X-rays from the shock. The line emission from the shocked gas increases rapidly as the shock sweeps up more gas. We find that the neutral and high ionization lines follow the evolution of the Balmer lines roughly, while the intermediate ionization lines evolve less rapidly. Up to day ~6800, the optical light curves have a similar evolution to that of the soft X-rays. The break between day 6500 and day 7000 for [O III] and [Ne III] is likely due to recombination to lower ionization levels. Nevertheless, the evolution of the [Fe XIV] line, as well as the lines from the lowest ionization stages, continue to follow that of the soft X-rays, as expected. There is a clear difference in the line profiles between the low and intermediate ionization lines, and those from the coronal lines at the earlier epochs. This shows that these lines arise from regions with different physical conditions, with at least a fraction of the coronal lines coming from adiabatic shocks. At later epochs the line widths of the low ionization lines, however, increase and approach those of the high ionization lines of [Fe X-XIV]. The H-alpha line profile can be traced up to ~500 km/s at the latest epoch. This is consistent with the cooling time of shocks propagating into a density of (1-4)x10^4 cm-3.

arXiv comment25 Pages, 12 Figures, accepted for publication in A&A

References in corpus (20)

• The Triple-Ring Nebula around SN1987A: Fingerprint of a binary merger
• The Line Emission from the Circumstellar Gas Around SN 1987A
• Spatially Resolved STIS Spectroscopy of SN 1987A: Evidence for Shock Interaction with Circumstellar Gas
• SN 1987A After 18 Years: Mid-Infrared GEMINI and SPITZER Observations of the Remnant
• Modelling the Hubble Space Telescope Ultraviolet and Optical Spectrum of Spot 1 on the Circumstellar Ring of SN 1987A
• Infrared and X-Ray Evidence for Circumstellar Grain Destruction by the Blast Wave of Supernova 1987A
• The X-ray Spectrum of Supernova Remnant 1987A
• On the Emergence and Discovery of Hot Spots in Supernova Remnant 1987A
• SN 1987A's Circumstellar Envelope, II: Kinematics of the Three Rings and the Diffuse Nebula
• Evolution and Geometry of Hot Spots in Supernova Remnant 1987A
• Limits from the Hubble Space Telescope on a Point Source in SN 1987A
• Chandra LETG Observations of Supernova Remnant 1987A
• The Optical-Radio Mapping: the kinetic efficiency of Radio-Loud AGNs
• Chandra HETG Spectra of SN 1987A at 20 years
• Chandra Observations of Shock Kinematics in Supernova Remnant 1987A
• A New View of the Circumstellar Environment of SN 1987A
• Coronal emission from the shocked circumstellar ring of SN 1987A
• Fifteen Years of High-Resolution Radio Imaging of Supernova 1987A
• Chandra Observations of Supernova 1987A
• The Reverse Shock of SNR 1987A

Cited by in corpus (34)

• Herschel Detects a Massive Dust Reservoir in Supernova 1987A
• High angular resolution ALMA images of dust and molecules in the SN 1987A ejecta
• Modelling supernova line profile asymmetries to determine ejecta dust masses: SN 1987A from days 714 to 3604
• NTT, Spitzer and Chandra spectroscopy of SDSSJ095209.56+214313.3: the most luminous coronal-line supernova ever observed, or a stellar tidal disruption event ?
• X-ray illumination of the ejecta of Supernova 1987A
• The 3-D Structure of SN 1987A's inner Ejecta
• Abundances and density structure of the inner circumstellar ring around SN 1987A
• The Destruction of the Circumstellar Ring of SN 1987A
• Three-dimensional distribution of ejecta in Supernova 1987A at 10 000 days
• The morphology of the ejecta in Supernova 1987A: a study over time and wavelength
• SOFIA mid-infrared observations of Supernova 1987A in 2016 --- forward shocks and possible dust re-formation in the post-shocked region?
• Late Spectral Evolution of the Ejecta and Reverse Shock in SN1987A
• HST-COS Observations of Hydrogen, Helium, Carbon and Nitrogen Emission from the SN 1987A Reverse Shock
• Emission lines due to ionizing radiation from a compact object in the remnant of Supernova 1987A
• ALMA spectral survey of Supernova 1987A --- molecular inventory, chemistry, dynamics and explosive nucleosynthesis
• The 30-Year Search for the Compact Object in SN 1987A
• Infrared Continuum and Line Evolution of the Equatorial Ring around SN 1987A
• The matter beyond the ring: the recent evolution of SN 1987A observed by the Hubble Space Telescope
• JWST NIRSpec observations of Supernova 1987A -- from the inner ejecta to the reverse shock
• The outer rings of SN1987A
• Evolution of the Chandra CCD Spectra of SNR 1987A: Probing the Reflected-Shock Picture
• High Resolution X-Ray Spectroscopy of SN 1987A: Monitoring with XMM-Newton
• XMM-Newton observations of SNR 1987A. II. The still increasing X-ray light curve and the properties of Fe K lines
• Thermal Emission and Radioactive Lines, but No Pulsar, in the Broadband X-Ray Spectrum of Supernova 1987A
• A New Evolutionary Phase of Supernova Remnant 1987A
• Spectral Evolution of the X-Ray Remnant of SN 1987A: A High-Resolution $Chandra$ HETG Study
• The Post-impact Evolution of the X-ray Emitting Gas in SNR 1987A Viewed by XMM-Newton
• The blue supergiant MN18 and its bipolar circumstellar nebula
• X-Ray and Gamma-Ray Emission From Core-collapse Supernovae: Comparison of Three-dimensional Neutrino-driven Explosions With SN 1987A
• A 3D view of molecular hydrogen in Supernova 1987A
• The morphology of the ejecta of SN 1987A at 31 years from 1150 to 10000 Å
• Near-infrared evolution of the equatorial ring of SN 1987A
• A real-time search for Type Ia Supernovae with late-time CSM interaction in ZTF
• The position of SN 1987A