Archive

This guide describes the contents and organization of the Suzaku archive.

Overview of the Suzaku archive

The Suzaku archive contains all the information, data and software which are needed to analyze Suzaku data.

The Suzaku data are transferred from ISAS in its First FITS Files (FFF) format (e.g. telemetry converted into FITS standard format). The FFF are created by mk1stfits (FITS telemeter converter) using the Raw Packet Telemetry (RPT) as input. One observation can be made by one or more RPT. These files are the input to the processing pipeline which converts the FFF into calibrated event files (SFF Second FITS Format). These files are the Level 1 or unfiltered files. The pipeline also applies data screening generating the Level 2 or cleaned files, and if appropriate extracts the Level 3 or data products such as spectra light curves and others. It also creates the so-called 'make filter file'. All data files are in FITS format and the software and calibration data used in the pipeline are included in the standard Suzaku software package and the Suzaku CALDB distributed to the science community. The data files archived include the Level 1, 2 and 3 corresponding to the unfiltered, cleaned and products files, the housekeeping data, orbit and attitude and the make filter file. The FFF are not archived at the HEASARC. There is not loss of information between the FFF and SFF. The difference is that the FFFs have empty columns which are filled by software in the SFF. These columns in the SFF can be repopulated if necessary with the distributed software. The Suzaku archive is divided into three main areas which are populated on a routine basis.

Observation data

The Suzaku science data are organized in observations to which a specific sequence number is assigned. Each observation includes science, housekeeping, and orbit data from the HXD and XIS instruments on-board Suzaku taken during the time interval corresponding to the PI requested exposure. The content of an observation is produced within the processing pipeline. The data for an observation include the telemetry converted into FITS format with minimum processing (Level I), the calibrated and filtered data (Level II), and the results from the standard analysis carried out on the Level II data (Level III). The latter category provides a quick overview for the observed source. This includes: XIS light curves, images and spectra and HXD spectra. The products are not background subtracted. All data are in FITS format and follow the OGIP standards for high-energy astronomy data. In addition to the FITS files, each observation includes GIF plots which preview the FITS products, and an HTML file which records the processing history. The observation data populate the archive soon after the data are processed (see the section on the Suzaku data proprietary period).

Trend and Monitoring data

This data set is created as part of the reformatting process of the telemetry into FITS or generated during the pipeline processing. These data are mainly useful to the instrument teams for monitoring the instruments or to create high level calibration products.
The trend files are organized in directories, each dedicated to a specific trend type. Generally the trend files are not included with the sequence associated with an observation but there are few exeptions (see Chapter 4). All the trend data files are in FITS format.
Data taken during the slews will be archived in the trend area. The slew data are grouped in directories with a special sequence number and within divided in directories for each instrument. The slew data will be partially processed.

Archival calibration data

The calibration data necessary for data analysis are available in the calibration database (CALDB). The Suzaku instrument teams have the responsibility of providing the results of their calibration efforts to the Guest Observer Facility at GSFC, accompanied by the proper documentation. The files are delivered in FITS format, and follow the recommended CALDB standards. The GOF delivers the calibration data to the HEASARC in a form suitable for inclusion in the CALDB area. CALDB is populated one per month or in conjunction with the software releases if the files impact the software.

Database tables

Database tables recording high level information on the observation are used to browse the data. Suzaku has two database table: one table (suzamaster) gives general information on each observation and the other (suzaxislog) is specific for the XIS instrument describing the specific modes used during each observation.

Proprietary Data Rights

Data taken during the calibration and verification phase (about the first 9 months of the mission) are only available to the Suzaku Science Team. The proprietary period for all these data ends by the end of May 2007. Data taken in the normal Guest Investigator (GI) program have one year of proprietary period. These data are first distributed only to the Principal Investigator (PI) of the observation. After the proprietary period the data are part of the public archive. Calibration data taken during the mission and Target of Opportunity, outside of the Guest Observer program, are made public immediately.