학술논문
JWST NIRSpec observations of Supernova 1987A -- from the inner ejecta to the reverse shock
Document Type
Working Paper
Author
Larsson, J.; Fransson, C.; Sargent, B.; Jones, O. C.; Barlow, M. J.; Bouchet, P.; Meixner, M.; Blommaert, J. A. D. L.; Coulais, A.; Fox, O. D.; Gastaud, R.; Glasse, A.; Habel, N.; Hirschauer, A. S.; Hjorth, J.; Jaspers, J.; Kavanagh, P. J.; Krause, O.; Lau, R. M.; Lenkic, L.; Nayak, O.; Rest, A.; Temim, T.; Tikkanen, T.; Wesson, R.; Wright, G. S.
Source
Subject
Language
Abstract
We present initial results from JWST NIRSpec integral field unit observations of the nearby Supernova (SN) 1987A. The observations provide the first spatially-resolved spectroscopy of the ejecta and equatorial ring (ER) over the 1-5 \mu m range. We construct 3D emissivity maps of the [Fe I] 1.443 \mu m line from the inner ejecta and the He I 1.083 \mu m line from the reverse shock (RS), where the former probes the explosion geometry and the latter traces the structure of the circumstellar medium. We also present a model for the integrated spectrum of the ejecta. The [Fe I] 3D map reveals a highly-asymmetric morphology resembling a broken dipole, dominated by two large clumps with velocities of ~2300 km/s. We also find evidence that the Fe-rich inner ejecta have started to interact with the RS. The RS surface traced by the He I line extends from just inside the ER to higher latitudes on both sides of the ER with a half-opening angle ~45 degrees, forming a bubble-like structure. The spectral model for the ejecta allows us to identify the many emission lines, including numerous H_2 lines. We find that the H_2 is most likely excited by far-UV emission, while the metal lines ratios are consistent with a combination of collisional excitation and recombination in the low-temperature ejecta. We also find several high-ionization coronal lines from the ER, requiring a temperature > 2 \times 10^6 K.
Comment: Accepted for publication in ApJL
Comment: Accepted for publication in ApJL