Skylook | Astronomy | Eclipses | Telescopes » foreground galaxy

NGC 3314 When Galaxies Overlap

Father Sky — Sat, 16 Jul 2011 21:44:07 +0000

NGC 3314
is actually two large spiral
galaxies which just happen to almost exactly line up.

The foreground spiral is viewed nearly
face-on, its
pinwheel shape defined by young bright star clusters.

But against the glow of the background galaxy, dark swirling lanes of
interstellar dust appear to
dominate the face-on spiral's structure.

The dust lanes are
surprisingly pervasive, and this remarkable
pair of
overlapping galaxies is one of a small number of systems in which
absorption of light from beyond a galaxy's own stars
can be used to directly
explore
its distribution of dust.

NGC 3314 is
about 140 million light-years (background galaxy) and 117 million
light-years (foreground galaxy) away in the multi-headed
constellation
Hydra.

The background galaxy would span nearly 70,000
light-years at its estimated distance.

A synthetic third channel was created to
construct this dramatic
new
composite of the overlapping galaxies
from two color image data in the Hubble Legacy Archive.

Read the full story:
NGC 3314: When Galaxies Overlap

Tags: foreground spiral, foreground galaxy, Milky Way, dust lanes, bright star clusters

The Einstein Cross Gravitational Lens

Father Sky — Mon, 28 Feb 2011 15:34:23 +0000

Most galaxies have a single nucleus -- does this galaxy have four?

The strange answer leads
astronomers
to conclude that the nucleus of the surrounding galaxy is not even visible in
this image.

The central
cloverleaf is rather light emitted from a background

quasar.

The gravitational field of the visible foreground
galaxy
breaks light
from this distant
quasar
into four distinct images.

The quasar must be
properly aligned behind the center of a massive galaxy for a
mirage like this to be evident.

The general effect is known as
gravitational lensing, and this specific case is known as the
Einstein Cross.

Stranger still, the images of the
Einstein Cross vary in relative brightness,
enhanced occasionally by the additional
gravitational microlensing
effect of specific stars in the foreground galaxy.

Tags: einstein cross, galaxy, foreground galaxy, Einstein, Gravitational

Stephan's Quintet

Father Sky — Sun, 21 Nov 2010 00:04:26 +0000

The first identified compact galaxy group,
Stephan's Quintet is featured in
this
eye-catching image constructed with data drawn from
the extensive Hubble Legacy Archive.

About 300 million light-years away, only four galaxies of the group
are actually locked in a cosmic dance of repeated close encounters.

The odd man out is
easy to spot, though.

The four
interacting galaxies
(NGC 7319, 7318A, 7318B, and 7317)
have an overall yellowish cast
and tend to have distorted
loops and tails, grown under the
influence of disruptive gravitational tides.

But the larger bluish galaxy, NGC 7320,
is much closer than the others.

Just 40 million light-years distant, it isn't part of the
interacting group.

In fact, individual stars in the foreground galaxy can be seen in
the sharp Hubble view, hinting that it is much closer than
the others.

Stephan's Quintet lies within the boundaries of the high flying
constellation
Pegasus.

Tags: million light years, hubble view, Archive, Hubble, foreground galaxy

Skylook | Astronomy | Eclipses | Telescopes » foreground galaxy

NGC 3314 When Galaxies Overlap

Related Skylook Posts:

The Einstein Cross Gravitational Lens

Related Skylook Posts:

Stephan's Quintet

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