Hubble upgrade beams first images

17 Jun 2002

The space telescope's new camera sends back some of the most detailed pictures ever taken of the Universe.

The Hubble Space Telescope (HST) has sent astronomers the first images taken with its recent camera upgrade, the Advanced Camera for Surveys (ACS). The camera was fitted during the HST upgrade two months ago.

A new set of optics has improved the detection range of the ACS and increased sensitivity by a factor of five, compared with the replaced instrument.

Holland Ford, the lead scientist on the ACS project, said: "These are among the best images of the distant Universe humans have ever seen. The ACS will allow us to enter the 'twilight zone' period when galaxies were just beginning to form after the Big Bang."

One picture shows two galaxies colliding, while another captures a celestial 'maternity ward' where starts and planets are created.

Behind a star system known as the Tadpole galaxy, 6000 other galaxies can now be seen. This is twice the number of galaxies seen in the HST's legendary "deep-field survey" performed in 1995, despite the ACS image taking less than one-tenth of the time to collect.

The ACS operates from the ultraviolet region, through the visible and into the near-infrared. It replaces the Faint Object Camera, which was the last of Hubble's original instruments.

With a new set of polarizers, filters and dispersers, the ACS can see deeper into the infrared region. This means that red-shifted light from very distant objects can now be detected, and that the HST can effectively look further back in time at a younger universe.

Author
Michael Hatcher is technology editor of Opto & Laser Europe magazine.