Detection of a Light Echo from the Otherwise Normal SN 2007af
D. Drozdov, M. D. Leising, P. A. Milne, J. Pearcy, A. G. Riess, L. M., Macri, G. L. Bryngelson, P. M. Garnavich

TL;DR
This paper reports the discovery of two light echoes from SN 2007af, a Type Ia supernova, revealing details about the surrounding interstellar dust and echo geometry using HST imaging.
Contribution
It provides the first detailed observation of multiple light echoes from SN 2007af, including their locations, colors, and implications for dust distribution.
Findings
Outer echo is ~800 pc in front of the SN
Inner echo is 0.45 to 90 pc from the SN
Echo characteristics resemble previous SN Ia echoes
Abstract
We present the discovery of a light echo from SN 2007af, a normal Type Ia supernova (SN Ia) in NGC 5584. Hubble Space Telescope (HST) images taken three years post explosion reveal two separate echoes; an outer echo and extended central region, which we propose as an unresolved inner echo. Multiple images were obtained in the F160W, F350LP, F555W, and F814W using the Wide Field Camera 3. If the outer echo is produced by an interstellar dust sheet perpendicular to the line of sight, it is located ~800 pc in front of the SN. The dust for the inner echo is 0.45 pc < d < 90 pc away from the SN. The inner echo color is consistent with typical interstellar dust wavelength-dependent scattering cross-sections, while the outer echo color does not match the predictions. Both dust sheets, if in the foreground, are optically thin for scattering, with the outer echo sheet thickness consistent with…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
