Pointing sources and calibrators

Ephemerides for the sources listed below are included in the IRAM 30m Catalog for Continuum Cameras (v beta). This catalog can be opened with XEphem.

Go to the GISMO |NIKA page.

Pointing Sources

The ongoing IRAM flux monitoring program provides flux estimates for most of the pointing sources included in the Catalog. These data are provided ONLY to help in the planning of observations, in particular to select pointing and focus sources at the IRAM 30-m telescope. They should not be used for any other purpose.

Primary Calibrators

The primary calibrators used at the IRAM 30m telescope are the planets Mars, Uranus and Neptune. The following table provides flux measurements taken at the IRAM 30m radiotelescope:

MAMBO fluxes were extracted from the IRAM DataBase for Pooled Observations (go to astro -> Calib Sources).

Please note that the fluxes measured depend on the date when the observations are done due to the distance and the orientation of their topological features. For example, note that the distance to Mars and hence its flux varies strongly! The fluxes measured at the 30m can be compared with theoretical predictions from planetary models:

• For Uranus and Neptune:

  • Download the templates of the model of Moreno 2010 ("Neptune and Uranus planetary brightness temperature tabulation. Technical report, ESA Herschel Science Center).

  • Download the templates of the model of Bendo et al. 2013 (Flux calibration of the Herschel-SPIRE photometer, MNRAS 433, 3062, 2013).

• For Mars:

  • Visit the web page of Emmanuel Lelloche. It will ask for the HPBW at 300 GHz which is ~8" at the 30m.

• See also:

  • Catalano et al. 2014, Performance and calibration of the NIKA camera at the IRAM 30 m telescope, arXiv

  • Adam et al. 2013, First observation of the thermal Sunyaev-Zel'dovich effect with Kinetic Inductance Detectors, arXiv

Secondary calibrators

The following list provides flux measurements for a list of secondary calibrators to be observerd when planets are not visible.

MAMBO fluxes were extracted from the IRAM DataBase for Pooled Observations (go to astro -> Calib Sources; positions there are given in the J2000 coordinate system, and not as indicated in the header as B1950.0!!). 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:

Ceres, Pallas, Vesta, Lutetia

Observers have to give the oribital elements of the asteroids to pako: perihelionEpoch, ascendingNode, argumentOfPerihelion, inclination, perihelionDistance, eccentricity. The elements listed below were extracted from the JPL Ephermides data base by X.Desert. Asteroids are on stable orbits. Their orbital elements are not expected to change.

   PAKO> SOURCE Body Ceres 2456551.202069534158 80.32764144660911  72.29215117844517 10.59398142371781 2.557090856996202 .07579725984872261    
   PAKO> SOURCE Body Pallas 2456634.320680106518 173.1023717671647 309.9337060321055 34.83625656930519 2.130435195136733 .2315650120848084
   PAKO> SOURCE Body Vesta 2456923.695134388993 103.8514828145328 151.1995756082146 7.140518203879475 2.152395790927782 .08850244223456388
   PAKO> SOURCE Body Lutetia 2457274.428494472523 80.88533411704726 250.2363739926752 3.06386567315565 2.034005484901541 .1644593151184061  

Polarized Calibrators

S(1mm), p(1mm), and x(1mm) are the flux density, the polarization fraction, and the polarization angle at 1 mm measured with the XPOL polarimeter at the IRAM 30m Telescope.

Author: Israel Hermelo (IRAM 30m Continuum Pool Manager)

email: hermelo@iram.es

Created: 2014.Jan.14

Last update: 2014.Feb.11