2011/04/26 by Sangwook Park, Svetozar A. Zhekov, D. N. Burrows +5 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Flux (metallurgy) #Gamma-ray bursts and supernovae #Light curve #Mechanics #Phase (matter) #Physics #Shock (circulatory) #Shock wave #Supernova #Supernova remnant #astro-ph.HE
paper · pdf · doi:10.1088/2041-8205/733/2/l35
11 pages, 2 tables, 1 color figure, Accepted by ApJ Letters
arxiv created 2011/04/26 · openalex publication_date 2011/05/10 · arxiv updated 2015/05/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have been monitoring the supernova remnant (SNR) 1987A with Chandra observations since 1999. Here we report on the latest change in the soft X-ray light curve of SNR 1987A. For the last ∼1.5 yr (since day ∼8000), the soft X-ray flux has significantly flattened, staying (within uncertainties) at f X ∼ 5.7 × 10 −12 erg cm −2 s −1 (corresponding to L X ∼ 3.6 × 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 ∼10 yr prior to day ∼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 Chandra monitoring observations.