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XMM-Newton Science Analysis System

phasecalc (dscalc-2.9) [xmmsas_20211130_0941-20.0.0]


Given an ephemeris and a list of event tables, phasecalc calculates the phase of each event in each of the tables. The calculated values are stored in a column named PHASE. If the column exists it is overwritten.

phasecalc relies on the event table having a TIME column and the two attributes MJDREF and TIMEZERO.

The time of event n is then:

t(n) = \texttt{MJDREF} * 86400 + \texttt{TIMEZERO} + \texttt{TIME}[n]
$ (1)

where $\texttt{TIME}[n]$ is the value stored in the TIME column.

An ephemeris is specified in terms of four quantities:

The phase of event n is defined as:

\phi(n) = \phi_0 + \{ t(n) - t_0 \} \times \nu + \frac{1}{2} \{ t(n) - t_0 \}^2 \times \dot{\nu}\,.
$ (2)

XMM-Newton SOC -- 2021-11-30