A New Evolutionary Phase of Supernova Remnant 1987A

Abstract

We have been monitoring the supernova remnant (SNR) 1987A with {\it Chandra} observations since 1999. Here we report on the latest change in the soft X-ray light curve of SNR 1987A. For the last $\sim$1.5 yr (since day $\sim$8000), the soft X-ray flux has significantly flattened, staying (within uncertainties) at $f_{\mathrm{X}}$ $\sim$ 5.7 $\times$ 10${}^{-12}$ erg cm${}^{-2}$ s${}^{-1}$ (corresponding to $L_{\mathrm{X}}$ $\sim$ 3.6 $\times$ 10${}^{36}$ erg s${}^{-1}$) in the 0.5--2 keV band. This remarkable change in the recent soft X-ray light curve suggests that the forward shock is now interacting with a decreasing density structure, after interacting with an increasing density gradient over $\sim$10 yr prior to day $\sim$8000. Possibilities may include the case that the shock is now propagating beyond a density peak of the inner ring. We briefly discuss some possible implications on the nature of the progenitor and the future prospects of our {\it Chandra} monitoring observations.

11 pages, 2 tables, 1 color figure, Accepted by ApJ Letters

References in corpus (12)

• Discovery of a nearby twin of SN1987A's nebula around the luminous blue variable HD168625: Was Sk--69 202 an LBV?
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• Chandra LETG Observations of Supernova Remnant 1987A
• XMM-Newton observations of SN1987A
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• 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
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• Chandra Observations of Supernova 1987A

Cited by in corpus (14)

• Chandra Observes the End of an Era SN 1987A
• The morphology of the ejecta in Supernova 1987A: a study over time and wavelength
• Chandra observations of SN 1987A: the soft X-ray light curve revisited
• High-resolution radio observations of SNR 1987A at high frequencies
• 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
• The 30-Year Search for the Compact Object in SN 1987A
• Recovery of the Historical SN1957D in X-rays with Chandra
• 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
• Spectral Evolution of the X-Ray Remnant of SN 1987A: A High-Resolution $Chandra$ HETG Study
• High-cadence Dispersed Spectral Analysis of Supernova Remnant 1987A
• Latest Evolution of the X-Ray Remnant of SN 1987A: Beyond the Inner Ring
• Polarized radio emission unveils the structure of the pre-supernova circumstellar magnetic field and the radio emission in SN1987A