ISO Callibration

Model SEDs of asteroids from Mueller and Lagerros

Model SEDs of the asteroids used for the calibration of ISOPHOT were produced for specific dates during the ISO mission and are here available in FITS format. They are based on thermophysical models developed by Mueller and Lagerros (1998 AA 338, 340).

See explanatory file for the naming convention used.

• 1 Ceres
• 2 Pallas
• 3 Juno
• 4 Vesta
• 10 Hygiea
• 54 Alexandra
• 65 Cybele
• 106 Dione
• 313 Chaldaea
• 532 Herculina

The brightness range covered by the asteroids listed above is represented by the shaded area in this Figure.

An overview of the model parameters is shown in this Table.

Note that the predictable flux variations of the asteroid, due to rotation, are in the order of 5-30% on timescales of several hours. The changing earth-asteroid distance can cause an absolute flux in-/decrease of one order of magnitude on a yearly timescale, as is exemplified by the indicated flux range of Ceres.

From a comparison of the theoretical models used in the calibration of ISOPHOT with validated observations of the same targets with other ground-based and space facilities, we estimate that the accuracy of the models produced for our primary standards Ceres, Pallas, Vesta and Herculina is about 10%. For the rest of asteroids, the accuracy is only slightly worse but in all cases, except Dione and Cybele, better than 15%.

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Last update: 11-07-2000 by Pedro Garcia-Lario