Secondary Calibrators

The primary calibrators used at the IRAM 30m telescope are Mars, Uranus and Neptune. Here we propose some secondary calibrators to observe when these planets are not visible.

Fluxes of the secondary calibrators

The IRAM DataBase for Pooled Observations provides MAMBO fluxes for a list of secondary bolometer calibrators (ask Israel Hermelo for the login information). To access the list of calibrators go to Astro -> Calib Sources.

See also the secondary calibrators for continuum measurements report by Lisenfeld et al. (2000).

Asteroids

Some asteroids have quite excentric orbits, and their temperatures thus vary quite a bit. In addition, the smaller ones have non-circular shapes and thus also rotational variability on scales of few hours. However, the four largest asteroids (Ceres, Pallas, Vesta, and Lutetia) present a flux accuracy better than 5% and therefore, they can be used as reliable calibrators for the IRAM 30m continuum cameras (see the poster courtesy of Thomas Mueller).

Thomas Mueller provided flux predictions at different wavelengths for these four asteroids until 2020:

The following figure summarizes the flux predictions at 1.3 mm for the period 2014-2015:

Ceres

SOURCE Body Ceres 2456551.202069534158 80.32764144660911  72.29215117844517 10.59398142371781 2.557090856996202 .07579725984872261    

Pallas

SOURCE Body Pallas 2456634.320680106518 173.1023717671647 309.9337060321055 34.83625656930519 2.130435195136733 .2315650120848084

Vesta

SOURCE Body Vesta 2456923.695134388993 103.8514828145328 151.1995756082146 7.140518203879475 2.152395790927782 .08850244223456388

Lutetia

SOURCE Body Lutetia 2457274.428494472523 80.88533411704726 250.2363739926752 3.06386567315565 2.034005484901541 .1644593151184061  

Author: Israel Hermelo (IRAM 30m continuum pool manager)

email: hermelo@iram.es

Created: 2014.01.14

Last update: 2014.01.25