The
most
massive
galaxies
in
the
universe
are
rare,
but
because
of
this,
their
formation
history
imposes
some
of
the
strongest
constraints
on
our
models
of
galaxy
formation.
In
the
local
universe,
massive
galaxies
like
M87
appear
relatively
dull,
with
elliptical
morphologies,
old
stars,
and
little
ongoing
star
formation.
For
decades,
archeological
studies
predicted
that
most
of
the
action
during
these
galaxies’
formation
must
have
occurred
at
much
higher
redshift
(z
>
2).
With
the
first
deep
and
wide
field
surveys
of
the
near
infrared
sky
coming
online,
we
can
now
directly
observe
the
progenitors
of
local
massive
galaxies
as
they
are
forming.
I
will
show
state-of-the-art
observations
of
this
process
up
to
z
~
4,
where
we
are
finding
that
the
early
stages
of
massive
galaxy
formation
are
in
fact
extremely
dynamic,
with
huge
bursts
of
dust-obscured
star
formation,
ubiquitous
AGN
activity,
and
significant
structural
transformations.
I
will
also
discuss
what
we
are
learning
at
z
~
6-7
from
ongoing
deep/wide
surveys
such
as
UltraVISTA,
and
what
we
expect
to
learn
in
the
JWST
era,
when
we
may
be
able
to
observe
the
process
of
massive
galaxy
formation
right
out
to
its
initial
stages
at
z
~
10-20.