ACIS Focal Plane Temperature Limit Violations

Focal-plane temperature-limit violations across approved observing programs
Generated
Violation log

Most recent violations

Individual focal-plane limit violation events, most recent first.
Obsid Violation start Violation end Duration (ks) Max temp (°C) Limit (°C)
Violation Statistics

Time-weighted histogram of violations per cycle

Each 0.1°C bin of violation above the ACIS focal-plane limit (ΔTviol), weighted by the share of a cycle's total observing time that program consumed. Restricted to programs that have < 90% good time.
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Time-weighted histogram of violations by focal-plane limit

Cycle 24 onward pooled together, grouped by the ACIS focal-plane limit in force for each violating observation instead of by cycle. Every violating observation counts here, regardless of its program's overall good-time fraction.
Show focal plane limits:
Good-time fraction by program
Fraction of approved exposure time in observing programs / sequence numbers (t / tapp) which is "good", e.g. under the ACIS FP limit. The fraction does not account for approved exposure time that has not yet been observed in a sequence. The fraction can be larger than 1.0 in such cases, due to the fact that exposure times for individual OBSIDs can exceed the approved exposure time. The dashed line at 0.9 marks the good-time threshold.
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All approved programs

Peak violation ≥ 0.0°C

Peak violation ≥ 0.5°C

Peak violation ≥ 1.0°C