In contrast, the second paper shows three
examples with no evidence for interaction
with a surviving companion. This supports
a “double degenerate” origin, which leaves
no material for subsequent interaction (Figure 10). NASA’s Kepler satellite provided the
first observations of these supernovae. The
ground-based spectra, using GMOS on both
Gemini North and South, showed that the
hosts are passive galaxies at redshifts around
0.1. The two papers appear in the journal Nature, volume 521, pages 328 and 332.
Figure 10.
Light curves of
three of the doublydegenerate SNe
Ia, from the Kepler
satellite (filled points
and error bars),
compared with
models (blue lines).
April 2015
Clarity and Change in an
Explosive Stellar Outflow
The outflow that emerges from the Orion
Molecular Cloud 1 (OMC1) offers a rare opportunity to observe a catastrophic episode
in a massive star-forming region. The outflow’s large scale, and the common dynamical age of its many high-velocity knots (in the
region known as the “Orion Fingers”), point
to an explosive origin. Observations using
the Gemini Multi-conjugate adaptive optics System (GeMS), and the Gemini South
Adaptive Optics Imager (GSAOI), have provided the sharpest views ever obtained of
the large region, nearly reaching the diffraction limit with a resolution of 0.08 to
0.1 arcsecond.
The narrow-band images show [Fe II] emission at the fingertips, where the material
is ionized and excited at the leading shock
fronts (Figure 11). Additional shocks excite
molecular hydrogen in the wakes of the
trailing regions. John Bally (University of
Colorado) and collaborators directly measure the motion of specific fingers in the
outflow and their morphological changes.
They also compare the current data with
earlier observations, especially those ob-
January 2016
2015 Year in Review
GeminiFocus
Figure 11.
The outflow of the
“Orion Fingers” is
evident in this highresolution image. The
leading fingertips
appear in [Fe II] (cyan),
and the trailing
fingers are evident in
molecular hydrogen
emission (orange).
Comparison with
earlier observations
shows the motion and
morphological changes
of the emitting knots.
27