* Astronomy

Blobrana · L

RE: Allan Sandage (1926 - 2010)

Blobrana · L

Title: Allan Sandage and the Cosmic Expansion
Authors: G. A. Tammann, B. Reindl (Department of Physics and Astronomy, Univ. of Basel)

This is an account of Allan Sandage's work on (1) The character of the expansion field. For many years he has been the strongest defender of an expanding Universe. He later explained the CMB dipole by a local velocity of 220 ±50 km/s toward the Virgo cluster and by a bulk motion of the Local supercluster (extending out to ~3500 km/s) of 450-500 km/s toward an apex at l=275, b=12. Allowing for these streaming velocities he found linear expansion to hold down to local scales (~300 km/s). (2) The calibration of the Hubble constant. Probing different methods he finally adopted - from Cepheid-calibrated SNe Ia and from independent RR Lyr-calibrated TRGBs - H_0 = 62.3 ±1.3 ±5.0 km/s/Mpc.

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Title: Allan R. Sandage, 18 June 1926 - 13 November 2010
Authors: Donald Lynden-Bell (IoA, Cambridge), Francois Schweizer (OCIS, Pasadena)

Allan Sandage was an observational astronomer who was happiest at a telescope. On Hubble's sudden death Allan Sandage inherited the programmes using the world's largest optical telescope at Palomar to determine the distances and number counts of galaxies. Over many years he greatly revised the distance scale and, on re-working Hubble's analysis, discovered the error that had led Hubble to doubt the interpretation of the galaxies' redshifts as an expansion of the universe. Sandage showed that there was a consistent age of Creation for the stars, the elements, and the Cosmos. Through work with Baade and Schwarzschild he discovered the key to the interpretation of the colour-magnitude diagrams of star clusters in terms of stellar evolution. With others he founded Galactic Archaeology, interpreting the motions and elemental abundances of the oldest stars in terms of a model for the Galaxy's formation. He published several fine atlases and catalogues of galaxies and a definitive history of the Mount Wilson Observatory.

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Allan Sandage, Astronomer, Dies at 84; Charted Cosmoss Age and Expansion

Allan R. Sandage, who spent his life measuring the universe, becoming the most influential astronomer of his generation, died Saturday at his home in San Gabriel, Calif. He was 84.
The cause was pancreatic cancer, according to an announcement by the Carnegie Observatories, where he had spent his whole professional career.
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Blobrana · L

Allan Rex Sandage (born June 18, 1926 in Iowa City, Iowa, died November 13, 2010) was an American astronomer. He is Staff Member Emeritus with the Carnegie Observatories in Pasadena, California. He is best known for determining the first reasonably accurate value for the Hubble constant and the age of the universe.
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