Transcript Hubble Deep Field Image

Hubble Deep Field
Daniel Hazard
Background
 The Hubble Deep Field (HDF) is a composite
picture of 342 different images.
 The HDF covers an area of 144 arc seconds.
 Taken by the Hubble Space Telescope (HST)
over a period of 10 consecutive days in
December of 1995.
 Taken by the Wide Field and Planetary
Camera 2.
 Total exposure time was more than 100
hours.
… the telescope and its
origins
 Astronomer Lyman Spitzer calls
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for space-based observatory in
1946; designing of HST begun in
1978; launched in 1990.
NASA and ESA funded, NASA
built.
Named after astronomer Edwin
Hubble.
Total costs to date have been
estimated to be close to
$14,000,000,000.
May be replaced by James
Webb Space Telescope in 2013.
Selecting the HDF
 HDF is but a tiny, tiny portion of the sky seen in the
Northern Hemisphere; more specifically: a small
section which lies within the Ursa Major
constellation.
 Field was selected by the following criteria
 Needed to be outside of the Milky Way’s disk of
dust
 Could not contain very bright objects or anything
that emitted too much infrared, x-ray, or UV
 In addition, field could never be occulted by the
Earth or Moon.
… HDF within the sky
Describing the HDF
 As a result of the field’s size, it is thought to
display less than 10 stars from our galaxy.
 Most of the objects seen are distant
galaxies--nearly 3,000 of them.
 There are also a number of bluish objects
and regions. They might be:
 Regions of intense star formation
 Faint quasars
 White dwarfs
Initial implications of HDF
 HDF looks into space, and, in effect, back in time
 Large number of galaxies with unforeseen redshift
values; prior to the HDF no galaxies with a redshift
value higher than 1
 Helped in debate over the missing mass of the
universe. Prior to the HDF there were theories of faint
yet massive objects in the outer regions of galaxies
such as red dwarves and planets making up this
missing, non visible mass. The HDF proved that this
wasn’t the case, as these proposed faint objects did
not exist. Thus, the mass must exist in other non
visible forms such as dark matter and dark energy.
A second HDF
 Named Hubble Deep Field South (HDF-
S); very similar to original HDF, now
named Hubble Deep Field North (HDFNorth).
 Same criteria, only now in Southern
Hemisphere, within the Tucana
constellation.
 Taken over in 1998 over 10 days.
Content of HDF-S
 Remarkably
similar to HDF-N.
 One major
difference is the
existence of a
known quasar.
Implications of HDF-S
 In general, HDF-S confirmed many
findings of HDF-N.
 Evidence for cosmological principle:
correlations between HDF-N and HDF-S
help support the idea that the universe
is homogenous and isotropic.
… one more image
 Hubble Ultra Deep Field (HUDF) is
appropriately titled: taken over a period of
several months in 2003 and 2004, the HUDF
is the deepest image ever taken in visible
light.
 Taken within the constellation of Fornax
 Also looks back into time: 13 billion years
 Evidence for Big Bang, and finite age of
universe
 Contains perhaps as many as 10,000 galaxies
Works Cited
 http://en.wikipedia.org/wiki/Hubble_
Deep_Field
 http://en.wikipedia.org/wiki/Hubble_
Space_Telescope
 http://oposite.stsci.edu/pubinfo/PR/9
7/hdf-key-findings.html