Welcome to the web site of the Planck - HFI consortium.

Planck is an ESA satellite aimed at providing a final mapping of the cosmological anisotropies of temperature and to foray deeply into their polarisation properties. Launch was on May 14th 2009. Two instruments are onboard, the LFI and HFI.

The HFI (High Frequency Instrument) is built by a French-led international consortium which will provide maps of the sky at 100, 143, 217, 353, 545 and 857 GHz. The first 3 channels will be the most sensitive to cosmological information (the peak of emission of a black body at 2.728K is around 100Ghz, i.e. 3mm), while the higher frequency channels will be very precious to trace the emission of some contaminating foregrounds (like the emissions from dust in galaxies, including our own, or the effect from clusters).

The LFI (Low Frequency Instrument) is built by an Italian-led international consortium. It will provide maps of the sky at 33, 44 and 70 GHz, which will be very precious to trace the emission of some other contaminating foregrounds (like the synchrotron emission of our Galaxie, or that of radio sources).

The HFI is a very powerful instrument by itself. But Planck has been conceived as a whole, such that the combination of the data from the two instruments should allow mining essentially all the cosmological information contained in the CMB (Cosmic Microwave Background), by minimizing astrophysical limitations. Parenthetically, it shows that spin-off science from Planck (concerning the CMB "contaminants") will be extremely interesting per se. Global information on Planck may be found in the Planck web site at ESA (see also the science team pages).

Navigating the site

This site may be viewed as a federation of sites, each of these sites corresponding to one of the tabs within the top row. For each of those, there is a home page (like this one) and a number of sub-sites selectable by the second row of tabs. Note that the clickable navigation bar below which shows where you are within the global site tree. Once within a sub-site, one can hide everything above the navigation bar with the top left button and navigate within that sub-site with its menu on the left. Note that a number of sub-sites have aliases for direct access (e.g. Data Processing > L2 can be accessed directly via http://l2.iap.fr), in which case the upper part is initially closed.

Within this part of the site (Home), you shall find only very global information (e.g. on the consortium itself, the Master schedule of the project, an historical overview, or the site credits).

The Outreach part provides useful background information. Please refer to the Science section for a description of our scientific goals, to the Instrument section for information on the technical design, and to the Data Processing section for information on data analysis. The Links offers a selection of links for Cosmologists in general, and CMB-ers in particular, while Hosted sites contains various sub-sites of related interest which are not specifically HFI, like some Planck-wide Working groups.

Nota Bene: links internal to the site are in blue, while the external ones are in red and open in a separate window. Underlined words signal a tooltip with extra information like the meaning of an acronym. In addition, this icon