Jennifer Andrews
Dusting the Universe
with Supernovae
Figure 1.
Long-term observations made with the Gemini Multi-Object
Spectrograph at Gemini South, combined with Spitzer space
telescope data, reveal how core collapse supernovae can make
an important, yet largely unrecognized, contribution to the
overall dust budget of the Universe.
GMOS-S g’, r’, and i’
color composite image
of SN 2011ja from April
2012 (day 112). In the
original image, the
supernova looks red
due to a combination
of bright hydrogen
(Hα) emission, strong
extinction around the
object, and new dust
formation.
Stars more than eight times the mass of our Sun end their lives
in fantastic explosions we call core collapse supernovae (CCSNe). Most common are Type II-Plateau (Type II-P) events, which
show broad hydrogen emission lines in their spectra along with
a near constant plateau of optical luminosity throughout the
first ~100 days.
It has long been known that heavy elements and dust grains can
be formed in the leftover material ejected in a CCSN explosion.
However, only recently have we recognized the importance of
this contribution to the overall dust budget in the Universe.
Generally we thought that asymptotic giant branch stars were
the main contributors of dust in galaxies; these low- to intermediate-mass stars form dust grains in their stellar winds over millennia and deposit them into the interstellar medium (ISM). But
this does not explain how high-redshift galaxies (z > 6) can have
more dust than their young ages should allow. Thus we began
to revisit the role that CCSNe play in dust production, especially
their ability to quickly return gas and dust to the ISM.
April 2016
GeminiFocus
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