Useful information for observations

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List of Astronomical Targets for NIKA2 (from NIKA2R1.sou)

last edited by PG 02-FEB-2017 (Previous editing by XD, LP, CK)

Here is the full detailed formatted list Full list with some fluxes. Rename it to NIKA2R5.sou to use it in Pako.

For Run6 onward, there is the detailed list file which is converted to a source file in the pako directory as NIKA2R6.sou .

LST coverage created for FEB-2017

1. Planets planets

2. Strong Galactic sources Strong Gal. Sources

3. Strong pointing sources Strong Pointing Sources

4. Secondary Calibrators (from Lisenfeld+2000) Secondary Calibrators

5. Radio sources from IRAM catalog nika2-radio

6. Planets, Asteroids, and Secondary Calibrators (from Lisenfeld+2000) nika2-secondaries

7. Strong Galactic sources nika2-galactic

8. Weak Galactic sources nika2-weak-galactic

9. Nearby galaxies nika2-nearby-galaxies

10. Distant galaxies or faint quasars nika2-distant

11. NIKA list of faint sources nika-faint-sources

Details on planets and asteroids

Uranus and Neptune are well known primary calibrators for photometric calibration and for beam maps. Mars, Jupiter, Saturn can be used for the errorbeams or to map the satellites.

Rough fluxes from Gildas (as for the 10th of October), FXD 14/9/2016

The following table gives only rough numbers for the fluxes. Note that some are varying in R.A./Dec, distance, flux and brightness temperature.

Accurate fluxes

For accurate fluxes, use the following predictions from recent 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 Lelloche. It will ask for the HPBW at 300 GHz which is ~8" at the 30m.

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 can be found here. 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 

Fluxes of quasars used as pointing source

IRAM conducts several observatory programs at the 30-m Pico Veleta telescope to monitor the time variability of extragalactic continuum sources. A webpage dedicated to these flux monitoring programs has been created. The fluxes are mainly monitored at 3 and 2 mm, but there's also several 1 mm measurements.

Interface with the telescope: Pako

Short manual on useful "Pako for Nika" see on Granada computers on the NIKA directory Pako_helpv??.txt ==> Obsolete. Has been replaced by much simpler procedures listed on the control computers screen wallpaper:

NIKA2_Wallpaper.PNG

- Pako scripts are in the Pako subdirectory

- Before starting the pointing session, we may be requested to move the azimuth by 60deg to reset the inclinometer of the az axis.

- The sun avoidance radius is 1deg and there are internal safeties that prevent the antenna to point to the Sun, but we may not get error messages.

- The antenna can point between 60 and 460 degrees in azimuth, between less than 15 and 83 degrees in elevation.

- If a source is available both at low and high azimuth, use command SET TOPO LOW (or SET TOPO HIGH) to stay on the source without moving.

- The minimum number of sources to observe for the pointing model is 15. 30 is good enough.

- the pointing sources should be observed on 'short' period, e.g. 3-4 hours to avoid daily pointing variations.

Commissioning requirements and observation plan

Below is a summary of the observation plan as discussed at the NIKA2 meeting on Feb. 9.

1. Check alignment on Tuesday during maintainance
2. Pointing session
   • use Samuel's excell file to check the coverage in azymuth and elevation
3. Beammap at optimal axial and lateral focus,
   • perform beammap sequence: pointing+focus+pointing+ beammap
   • span various elevation
   • use lateral focus corrections from the maps of the residual after subtraction of a Gaussian beam
4. Beammap defocused on purpose by z=[-1.2, -0.3, 0.3, 1.2]mm.
   • Center the focus on the best "average" focus, not the best focus computed with central kids only;
   • This z focus sequence is needed at least at low and high elevations (extreme values).
   • Need at least 4 maps, in the sequence, 3 is not enough.
5. Calibration
   • Monitor primary and secondary calibrators. Few of them but repeatedly along the run and at various elevations.
   • Check the kid responsivity [Hz/Jy] both in TOI and map
6. Opacity
   • several skydips a day in all possible weather conditions
   • checks on f_tone values

7. Opacity check using EMIR. The PaKo scripts for the EMIR skydip observations are found in the ~/pako/EMIR_SCRIPTS/ folder in the t22 account. A detailed description of the observing procedure can be found here. The observing strategy for the skydips is:

   • (1.) configure EMIR to the desired frequency (tuning takes ~ 1/2 hour. The 1.15 mm and 2.0 mm frequencies (bands E1 & E2) can no be observed simultaneously with EMIR. The NIKA2 frequencies set to the EMIR's USBs). (1.) perform a pointing measurement in a strong continuum source and introduce the pointing corrections. (1.) perform a focus measurement in the same strong continuum source and introduce the focus correction. (1.) run the skydip. (1.) calibrate the measurement sin MIRA to obtain opacities.

8. Dark tests on a daily basis
9. Noise integration of faint sources for a few hours both for noise integration and photometry qualification

   • use prioritary the NIKA1 faint sources (item 11 in LST ephemerides)

10. Gain elevation correction
    • measure the flux of a source (after focus correction) at the optimum elevation near 50deg, and at extreme elevations, e.g. 20deg and 70deg.
11. If we have time, it would be good to have a few polarization observations, even only maps on Uranus to recheck the entire system.
12. If we have time, it would be good to have a few observations using the external calibrator

see also the private wiki