Observation General

Sequence number assignment

A pointed observation within Suzaku is identified by a contiguous view on a specific sky position. The start and end of an observation are defined when the source is entering or exiting the Field of View of the HXD. Each observation is identified by a sequence number. Beside the normal observation there are other data defined as non pointing data or not normal pointing that also are identified with a sequence number. The sequence is a 9 digit number whose form is defined belows

Sequence Number: normal observations

For normal observation the sequence number is defined as follows:

   CAAxxxyyz

where :

• C is the category code defined as :
  • 1 for calibration observations
  • 4 for Galactic Compact sources (stars, CVs, X-ray binaries, and isolated neutron stars)
  • 5 for Galactic Diffuse emission
  • 7 for Extragalactic Compact object
  • 8 for Extragalactic Diffuse object
  • 9 for Gamma-ray Bursts and other non-proposal TOOs

  Note : proposed TOO will not have C=9 but rather have the appropriate scientific category (C=4 or C=7).

• AA: is a two digits to identify the AO. 00 is for the SWG time, 01 for the A01 and so on.
• xxx: is the target number unique for a given C and AA. Multiple targets within the same proposal will have a different target number. The start value is 001.
• yy: multiple pointing number (planned multiple observations either specified within the proposal or due to operational needs). The start value is 01.
• z is used to divide long pointing into multiple sequence for processing purposes. Usually set to 0.

Please note: The sequence number is not related to the proposal number that get assigned at proposal submission. The proposal number is defined as a 6 digits string in the form of CCNzzz where the single digits are assigned accordingly with the following scheme:

• CC is the cycle number. This is set to 00 for the SWG time and to 01 for AO1 cycle proposal, 02 for the AO2 and so on.

• N defines the nationality of the proposal. This is set as :
  • N=0 Proposal from Japan
  • N=1 Proposal from USA
  • N=2 Proposal from Europe
  • N=3 Proposal merged with Japanese PI
  • N=4 Proposal merged with US PI
  • N=5 calibration proposal

• zzz is a sequential number set-up by each individual sites accepting proposals.

Sequence Number: Non pointing data

For non pointing data the sequence number is defined as follows :

    0Syymmddz

where :

• S is a code that specifies why this is not a normal pointing. The possible values are:
  • 0 for safe hold
  • 1 for accidental pointing
  • 2 for maneuver (slew)
  • 3 for step pointing
  • 7 for ground calibration

• yymmdd is the start date (last two digit year, month and day)
• z is used to distinguish multiple of such sequences for that day (e.g. multiple slews).

Data distribution

Data taken in response of Announcement Opportunity are distributed to the PI electronically. After the data arrive in the archive (about 7-10 days after the observation is concluded), a notification is sent to the PI together with the decryption key. These data remain encrypted in the archive until the proprietary period ends. If during the proprietary period data are re-processed with an upgraded pipeline, the PI will be notified that new version of the data are available. Data that are made public immediately are placed after processing non encrypted in the archive.

Keyword in the FITS file to ID an observation

All files that enter the archive have a number of keywords that identify the observation, the processing version, software and calibration files used in the pipeline. They are:

• OBS_ID contains the sequence number.

• PROCVER contains a string that identified the processing version.This is coded as MM.XX.YY.NN, where MM, XX, YY, and NN are set as follows:
  • MM.XX identify pipeline version changes. MM major changes, XX small changes.
  • YY identifies the version of Suzaku software used in the processing.
  • NN identifies the version of the calibration databases (CALDB) used in the processing.

• SEQPNUM gives the number of times a sequence has been processed across all processing versions.

• DATE gives the file creation date.

• SOFTVER is a string identifying the version of the Heasoft and Suzaku specific software used during the processing. This is defined as follows:

   Hea_DDMMMYYYY_Vxxxxx_Suzaku_DDMMMYYYY_Vyyy
  

  where DD is the day, MMM is the first 3 characters of the month name, YYYY the year and xxxxx and yyy are the version number as advertised in the software distribution for the Heasoft and Suzaku software.

• CALDBVER contains a strings which identifies the CALDB version used in the processing of a given observation. This is a string defined as follows:

  hxdYYYYMMDD_xisYYYYMMDD_xrtYYYYMMDD_xrsYYYYMMDD
  

  where the YYYYMMDD referenced to the latest CALDB version for that instrument.