Pointing sources and calibrators

Ephemerides for the sources listed below are included in the IRAM 30m Catalog for Continuum Cameras. This catalog is meant to be opened with XEphem.

Go to the NIKA2 main 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 former IRAM DataBase for Pooled Observations for that instrument.

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 ESA2 templates of the model of Moreno 2010 ("Neptune and Uranus planetary brightness temperature tabulation. Technical report, ESA Herschel Science Center).

  • Download the ESA4 templates of the models of Moreno and Orton described by Bendo et al. 2013 (Flux calibration of the Herschel-SPIRE photometer, MNRAS 433, 3062, 2013).

• For Mars:

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

Secondary calibrators

Ultra-compact HII regions, evolved stars, and others

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).

Visibilities of Calibrators

• An ASCII file (.sou) of the secondary calibrators is provided here: secondary calibrators

• An ASTRO command file to produce the visibilities of planets and secondary calibrators is provided here: ASTRO script

  • NOTE: The ASTRO script needs to have the date changed to the correct/relevant date for your observations
  • NOTE: The ASTRO script probably needs to have the full path for the secondary calibrator source file too.

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 of Thomas Mueller). See also Muller et al. 2014.

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

Flux predictions at 1.3 mm and 3.0 mm (and extrapolated fluxes at 1.2 mm and 2.0 mm) for the period 2017-2018 are:

In the plot, solid lines represent the predictions of T. Mueller, while dotted lines are an extrapolation to the exact NIKA2 wavelengths assuming BB radiation. The term <ΔT_RJ> represents the average of the percentage difference between the BB temperatures under Rayleigh-Jeans (RJ) approximation (with the corresponding standard deviation) obtained from the 1.3 mm and 3.0 mm specific intensity predictions. The smaller the <ΔT_RJ> term is, the closer are the flux values to be described by a BB (within the 3.0 mm - 1.2 mm wavelength domain), and hence, the more accurate is the extrapolation to the NIKA2 wavelengths.

Observers have to give the oribital elements of the asteroids to pako: perihelionEpoch, ascendingNode, argumentOfPerihelion, inclination, perihelionDistance, eccentricity. Asteroids are on stable orbits. Their orbital elements are not expected to change. Orbital parameters can be obtained from the following link: http://ssd.jpl.nasa.gov/sbdb.cgi with SOURCE Body Name tp node peri i q e

   *** Values for Ceres, Vesta, Lutetia, & Pallas (from jpl web site 03/02/17; orbital elements for 16-Feb-2017):
   PAKO> SOURCE Body Ceres 2458235.937196441384 80.30985818155804  72.90778936046735 10.59240162556512 2.558399943883621 .07568276766977486 
   PAKO> SOURCE Body Vesta 2458248.730549527339 103.8420858415193 151.0763599422539 7.140515813592748 2.150823811211408 .08913605302833576
   PAKO> SOURCE Body Lutetia 2457273.638883933000 80.88034501826424 250.0144262431933 3.063765292337028 2.033639660103867 .164587024192538      
   PAKO> SOURCE Body Pallas 2458320.692222709571 173.0884258274411 309.9972297543002 34.84038753772609 2.133254080983892 .2307043154546663 

Moons of Saturn and Jupiter

• Saturn
  • Titan
• Jupiter
  • Io
  • Europa
  • Callisto
  • Ganymede

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.

Created: 2013.OCT.25, by Isreal Hermelo

Last update: 2017.FEB.05, by Pablo García