From Planck Legacy Archive Wiki
Revision as of 21:28, 20 October 2012 by Fbouchet (talk | contribs) (LS)
Jump to: navigation, search

The PSM or "Planck Sky Model" is an updated version (using knowledge derived from Planck observations) of the software tool described in Ref to the PSM paper of 2012. This can take in actual band-passes (in a RIMO) and create sky maps and catalogues at the specified frequencies. It can be supplemented by ad-hoc simulation software for particular (theoretical) CMB maps

The Level S (LS in short) is a generic simulation tool common to HFI and LFI. One version was described in ref to the old LS paper. It can take in input the output of the PSM, a pointing and beam description in order to generate the infalling power on detectors as a function of time. It can additionnaly create some noise realisation as a very simplified version of the actual instruments. Alternatively, the output can be used as input to a detailed simulation of the instrumental behaviour.

The PSM together with the LS therefore provide two basic bricks of a more extensive instrument specific simulation environment. For HFI, see HFI-Validation#sims.

Joint simulations provides an environment for checking algorithms in a realistic context. The latest series is the "FFP6", which provides a Full Focal Plane simulation of the DPC maps in the 2013 data release. They were initially provided (partially) "blind", ie without knowledge of the actual sky components used, but with an exact description of the Bandpasses, beams, and calibration.

CMB maps simulations[edit]

The basis is simple Gaussian realisation given a power spectrum, as given by, eg., CAMB external Ref Here.

Several non-Gaussian signatures can also be generated by dedicated software, like the lensing-induced deformations, which is included in the standard PSM package. But other cases have been developped within Planck as part of the scientific preaparation, in particular the $f_{NL}$ and $g_{NL}$ maps of Ref to Elzner and Wandelt paper and string maps of ref to Ringeval and Bouchet paper }}. For convenience, they are available through the PLA Link here to PLA once ESA has finsihed developing the interface .

Planck Sky Model PSM[edit]

(this is the abstract of the pre-launch PSM paper, arXiv:1207.3675)

The Planck Sky Model (PSM) is a parametric model for the generation of all-sky, few arcminute resolution maps of sky emission at submillimetre to centimetre wavelengths, in both intensity and polarisation. Several options are implemented to model the cosmic microwave background, Galactic diffuse emission (synchrotron, free-free, thermal and spinning dust, CO lines), Galactic H-II regions, extragalactic radio sources, dusty galaxies, and thermal and kinetic Sunyaev-Zeldovich signals from clusters of galaxies. Each component is simulated by means of educated interpolations/extrapolations of data sets available at the time of the launch of the Planck mission, complemented by state-of-the-art models of the emission.

Distinctive features of the simulations are: spatially varying spectral properties of synchrotron and dust; different spectral parameters for each point source; modeling of the clustering properties of extragalactic sources and of the power spectrum of fluctuations in the cosmic infrared background.

The PSM enables the production of random realizations of the sky emission, constrained to match observational data within their uncertainties, and is implemented in a software package that is regularly updated with incoming information from observations. The model is expected to serve as a useful tool for optimizing planned microwave and sub-millimetre surveys and to test data processing and analysis pipelines. It is, in particular, used for the development and validation of data analysis pipelines within the planck collaboration. A version of the software that can be used for simulating the observations for a variety of experiments is made available on a dedicated website.

Level S LS[edit]

The LS software package simulates the incoming sky radiation on detectors as a function of time. ref to LS docs , paps

FFP6 set[edit]

This sixth round of simulations of the "Full Focal Plane" of Planck encompasses the basic characteristics of Planck (Temperature) maps in support of scientific analyses, from component separation and power spectrum estimation to measures of non-gaussianity. They are simplified/idealsized in the sense that TOI processing is considered perfect. (For HFI for instance, there are no transfer function nor pointing error, no 4K nor glitch residuals, no noise correlation, etc). But the actual pointing, spectral banpasses, beams, noise determinations were used.

The basis sky maps are available here - link to PLA, including for convenience the individual components (which were initially hidden to the Planck collaboration, but for the generators :-) ).

Planck Sky Model

reduced IMO

Cosmic Microwave background

(Planck) High Frequency Instrument

(Planck) Low Frequency Instrument

Data Processing Center

Planck Legacy Archive