title: Observing supernova 1987A with the refurbished Hubble Space Telescope.
abstract: Observations with the Hubble Space Telescope (HST), conducted since 1990, now offer an unprecedented glimpse into fast astrophysical shocks in the young remnant of supernova 1987A. Comparing observations taken in 2010 with the use of the refurbished instruments on HST with data taken in 2004, just before the Space Telescope Imaging Spectrograph failed, we find that the Lyα and Hα lines from shock emission continue to brighten, whereas their maximum velocities continue to decrease. We observe broad, blueshifted Lyα, which we attribute to resonant scattering of photons emitted from hot spots on the equatorial ring. We also detect N v λλ1239, 1243 angstrom line emission, but only to the red of Lyα. The profiles of the N v lines differ markedly from that of Hα, suggesting that the N4+ ions are scattered and accelerated by turbulent electromagnetic fields that isotropize the ions in the collisionless shock.
authors.affiliation: Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309-0389, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: France
authors.forename: Richard
authors.initials: R
authors.lastname: McCray
authors.forename: Kevin
authors.initials: K
authors.lastname: Heng
authors.forename: Robert P
authors.initials: RP
authors.lastname: Kirshner
authors.forename: Peter
authors.initials: P
authors.lastname: Challis
authors.forename: Patrice
authors.initials: P
authors.lastname: Bouchet
authors.forename: Arlin
authors.initials: A
authors.lastname: Crotts
authors.forename: Eli
authors.initials: E
authors.lastname: Dwek
authors.forename: Claes
authors.initials: C
authors.lastname: Fransson
authors.forename: Peter M
authors.initials: PM
authors.lastname: Garnavich
authors.forename: Josefin
authors.initials: J
authors.lastname: Larsson
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Lawrence
authors.forename: Peter
authors.initials: P
authors.lastname: Lundqvist
authors.forename: Nino
authors.initials: N
authors.lastname: Panagia
authors.forename: Chun S J
authors.initials: CS
authors.lastname: Pun
authors.forename: Nathan
authors.initials: N
authors.lastname: Smith
authors.forename: Jesper
authors.initials: J
authors.lastname: Sollerman
authors.forename: George
authors.initials: G
authors.lastname: Sonneborn
authors.forename: John T
authors.initials: JT
authors.lastname: Stocke
authors.forename: Lifan
authors.initials: L
authors.lastname: Wang
authors.forename: J Craig
authors.initials: JC
authors.lastname: Wheeler