skip to main content

Search for: All records

Creators/Authors contains: "Orquera-Rojas, Carlos"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.


    We present broad-band radio flux-density measurements supernova (SN) 1996cr, made with MeerKAT, ATCA, and ALMA, and images made from very long baseline interferometry (VLBI) observations with the Australian Long Baseline Array. The spectral energy distribution of SN 1996cr in 2020, at age t ∼8700 d, is a power-law, with flux density, S ∝ ν−0.588 ± 0.011 between 1 and 34 GHz, but may steepen at >35 GHz. The spectrum has flattened since t = 5370 d (2010). Also since t = 5370 d, the flux density has declined rapidly, with $S_{\rm 9 \, GHz} \propto t^{-2.9}$. The VLBI image at t = 8859 d shows an approximately circular structure with a central minimum reminiscent of an optically-thin spherical shell of emission. For a distance of 3.7 Mpc, the average outer radius of the radio emission at t = 8859 d was (5.1 ± 0.3) × 1017 cm, and SN 1996cr has been expanding with a velocity of 4650 ± 1060 km s−1 between t = 4307 and 8859 d. It must have undergone considerable deceleration before t = 4307 d. Deviations from a circular shell structure in the image suggest a range of velocities up to ∼7000 km s−1, and hint at the presence of a ring- or equatorial-belt-like structure rather than a complete spherical shell.

    more » « less