Figure 3.
The position and
velocity offsets
between the merging
components observed
in the SMGs compared
to the offsets within
galaxy halos of varying
mass ranges extracted
from the Millennium
Simulation database
(orange dashed lines).
The SMG offsets are best
described by the halo
masses between 1013
and 1014 solar masses.
paring the observations to the properties
of simulated galaxy halos extracted from
the Millennium Simulation database. Within
each halo we identify the constituent subhalos, then measure the average offset between the most bound subhalo and the other subhalos. We therefore derive spatial and
velocity offsets for simulated galaxy halos
in various mass ranges. Figure 3 compares
our observed offsets to the simulated ones
and shows that the SMG offsets are best described by the simulated galaxy halo masses
between 1013 and 1014 solar masses, which
is more massive than previous measures of
SMG halo masses.
The Future
The arrival of telescopes capable of millimeter interferometry has enabled the study
of the fuel for rapid star formation in early
galaxies. It also allows us to trace their molecular gas in the same detail as their ionized gas. By combining these observations,
it will be possible, to probe the complicated
gas processes in great detail. We can then
better constrain the progenitor systems of
the mergers, understand the triggering pro-
16
GeminiFocus
cess of the prodigious star formation, and
also explore the evolution of these systems
towards the massive elliptical galaxies observed in the local universe.
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Alaghband-Zadeh, S., et al., Monthly Notices of
the Royal Astronomical Society, 424: 2232, 2012
Forster-Schreiber, N. M., et al., The Astrophysical
Journal, 706: 1364, 2009
Shapiro, K. L., et al., The Astrophysical Journal,
682: 231, 2008
Krajnović, D., et al., Monthly Notices of the Royal
Astronomical Society, 366: 787, 2006
Bothwell, M. S., et al., Monthly Notices of the Royal
Astronomical Society, 405: 219, 2010
Narayanan, D., et al., Monthly Notices of the Royal
Astronomical Society, 400: 1919, 2009
Davé, R., et al., Monthly Notices of the Royal Astronomical Society, 404: 1355, 2010
Springel, V., et al., Nature, 435: 629, 2005
Susannah Alaghband-Zadeh is a Ph.D. student
at the Institute of Astronomy, University of Cambridge. She can be reached at: [email protected]
December2012