Data model: thingIndex

General description: This file contains the full list of unique primary objects (called "things") in the SDSS imaging survey. Because of the large number of rows, we keep only the minimal required information for each object. The zero-indexed position of any primary object in this file is called its "THING_ID", and is included in the full resolve information in the reObjGlobal files (and also is stored in the photoObj files). This index file gives you the information to link any detection to all other detections of the object through its THING_ID. All the detections of the object associated with a certain "thing_id" can be found in these elements of thingList: thingList[thingIndex[thing_id].istart:thingIndex[thing_id].istart+thingIndex[thing_id].ndetect-1]. The thingList file tells you which field and which object id numbers those detections correspond to.

Naming convention: thingIndex.fits

Approximate size: 10 Gbytes.

File type: FITS

Read by products: photoop, sas

Written by products: photoop

Required column names:

• BALKAN_ID (int32): Index in the balkan list indicating which part of the geometry this primary object is in.
• IFIELD (int32): field of primary (or best) observation
• ID (int32): ID of object in field for primary (or best) observation
• ISPRIMARY (int8): Non-zero if there is a detection of this object in the primary field covering this balkan.
• ISTART (int32): First position in thingList of the detections associated with this primary object.
• NDETECT (int32): Number of detections of this object.
• NEDGE (int32): Number of fields in which this is a RUN_EDGE object (observation close to edge)
• RA (float64): Right ascension, J2000 deg
• DEC (float64): Declination, J2000 deg