NASA Planck Archive (NPA): Overview

The NASA Planck Archive (NPA) is the final United States repository for all of the data collected by the joint European Space Agency/NASA Cosmic Microwave Background Radiation mission, Planck. Only Planck data that have been released to the public are available via this interface.

The Spacecraft and Instruments

The Planck Telescope, consisting of a 1.5-meter telescope and two science instruments, was launched into an L2 orbit on May 14, 2009, and deactivated in October 2013. Planck performed a detailed study of the cosmic microwave background (CMB). The instruments aboard Planck --- the Low Frequency Instrument (LFI) and High Frequency Instrument (HFI) --- obtained images at wavelengths between 30 and 857 GHz, with spatial resolution ranging from 5 arcminutes at the shortest wavelengths to 33 arcminutes at the longest. More information on Planck can be found at http://planck.caltech.edu/ or http://planck.ipac.caltech.edu/ .

Planck Mission

Mission Milestones include: The primary sources of Planck data accessible by the NPA web tool are the Planck ERCSC Release (ER), Planck Public Data Release 1 (PR1), and the Planck Public Data Release 2 (PR2). The ERCSC Release is based on data acquired through 6 June 2010, Public Data Release 1 is based on the Nominal Mission data, and Public Data Release 2 is based on the complete mission data.

Searching, Results, and Filters

The NASA Planck Archive provides several options for searching its holdings. There are basically three kinds of searches in the NPA. (1) TOI (time ordered information); (2) Browse catalogs (single frequency but all positions); (3) cutout visualization (single position but all wavelengths). See the section on searching for more information.

The search results are displayed on the screen in three main regions: (1) upper left: up to a dozen tabs, one each for the nine Planck bands from 30-857 GHz and the remainder for the multifrequency (Cold Cores and/or SZ Cluster) catalogs. (2) upper right: details on the row selected in the tabs; (3) bottom: image cutouts for the row selected in the tabs. See the page on understanding your search results for more information.

Filters, either imposed on your initial search or via your results page, can provide a powerful tool for narrowing search results to the observations you want. For example, you can restrict your search based on source flux density or morphology, or you can restrict the entries in the tabs to be just those objects observed more than, say, three times.

Visualization

After searching the Time Ordered Information (TOI) data, you can combine subsets of the data into a new image. See the Results section for further details. You can explore the image in the same way as you can explore any other image in the NPA. (See the visualization section for more information.)

After searching by "Browse Catalogs" (search by wavelength) or "Cutout Visualization" (search by position), the NPA displays FITS images of a small area around each object. These are shown below the search results table, with the catalog entry highlighted in green and the object centered in the field of view for each wavelength. PR1 and PR2 visualization queries allows the image size to be set between 10 arcminutes and 2.0 degrees. WMAP and IRAS FITS images, where available, may also be shown for each table entry. (The original ERCSC images are JPGs, not FITS, but the WMAP and IRAS images returned for an ERCSC visualization search are indeed FITS files.) See the visualization section for more information.

Downloading Data

If you would like to download catalogs, click on the diskette icon in the upper right of the catalogs tab. It will save the file as an IPAC table file. The entire catalog will be saved if you are in the "browse catalog" kind of search; just the retrieved sources will be saved if you are in the "cutout visualization" kind of search.

If you'd like to download FITS data, click on the checkbox on the upper left side of the corresponding images or to the left of the corresponding row. Next, click "Prepare Download" to begin the packaging and data download process. The data will be made into a downloadable package by a background job, which can notify you via email when it's finished.

See the Downloads section for more specific information on how to select data for download. See the section on the Background Monitor for more information specifically on the background monitor.

User Login

The archive can remember you when you return. See the user registration section for more information.