First VLBI Detection of the Radio Remnant of Supernova 1987A: Evidence for Small-scale Features

TL;DR

This paper reports the first VLBI detection of supernova 1987A's radio remnant, revealing small-scale features and providing high-resolution images that enhance understanding of its structure.

Contribution

It presents the first high-resolution VLBI images of supernova 1987A's radio remnant, identifying small-scale features and setting limits on a central pulsar or nebula.

Findings

Detection of extended lobes consistent with lower-resolution observations.

Identification of small-scale clumps within the shell, less than 0.2" in size.

No central pulsar or nebula detected, with a flux limit of 0.3 mJy.

Abstract

We present a detailed analysis of the first very long baseline interferometry (VLBI) detection of the radio remnant of supernova 1987A. The VLBI data taken in 2007 and 2008 at 1.4 and 1.7 GHz, respectively, provide images sensitive to angular scales from 0.1" to 0.7", the highest resolution to date at radio frequencies. The results reveal two extended lobes with an overall morphology consistent with observations at lower resolutions. We find evidence of small-scale features in the radio shell, which possibly consist of compact clumps near the inner surface of the shell. These features have angular extent smaller than 0.2" and contribute less than 13% of the total remnant flux density. No central source is detected in the VLBI images. We place a 3-sigma flux density limit of 0.3 mJy on any pulsar or pulsar wind nebula at 1.7 GHz.