The present version of the database contains 250 pulse profiles of PSR 0531+21, observed from 1967 to 1993 and published in the main astrophysical and astronomical journals and conference proceedings. Furthermore, a few profiles reported in Ph.D. theses or unpublished are also included.
The profiles are divided in five groups according to their energy ranges. The code of these groups, their energy intervals, the numbers of profiles and of used original papers are given in Table 1 (click here). Within each group the profiles are generally ordered by observation epoch and, for the same epoch, by increasing average energy. Each profile, in addition to the group code, is identified by two numbers: the first specifies either the observation epoch or the experiment, the second distinguishes the different energy ranges and/or phase binnings.
All the profiles in the Atlas and their relevant parameters are listed in Table 2. The identification code of each profile is reported in Col. 1, in Col. 2 there is the observation epoch, in cols. 3 and 4 the number of phase bins and the nominal energy ranges respectively, in Col. 5 the phase bin of the P1 centre (with the approximation of half a bin) in the original figure and, finally, in Col. 6 the paper code.
In order to make easier their use, we have for all the profiles: taken the phase of the P1 centre equal to 0; subtracted an off-pulse level, estimated by computing the mean in the phase interval (0.55-0.77), the most narrow of those used in the literature; normalized to unity the maximum of P1.
The accuracy of the profiles is good: digitization errors are usually much smaller than the statistical ones, with the only possible exception for those derived from very small or poor quality original figures.
The database is organized as follows. All the data and service files are written in ASCII to make simpler their examination, editing and transfer. General information on the content and use of the database and Atlas are given in the file CRPATL.INF and are updated when new data are available or when new consulting facilities are available. The list of all profiles can be found in the file CRPATL.IND, which is reproduced in Table 2. Another service file CRPATL.REF, containing all the bibliographical references, listed in alphabetical order according to the reference code reported in CRPATL.IND.
The data files are two for each profile; both files are named by the profile code but have different extensions: for example, SX01-1.CRP and SX01-1.NOR. The files with the CRP extension have records of 80 characters. The first two records are divided in four fields of 20 characters each, containing the file name, the reference code, the observation date or period, the energy interval and some other useful information. The third record contains the bin number and the off-pulse level evaluated in the original paper (a value equal to zero means this level is not indicated in the paper). The following records contain the values and the corresponding uncertainties of the signal in each phase bin: four couples of floating point numbers are written in each record, with the exception of the last one in which only the data necessary to complete the profile are written. When possible the scale of these quantities is the same as in the original paper, in a few case, however, they are given in arbitrary units. The files with the NOR extension contain the normalized profiles reported in the paper version of the Atlas. They do not have header and each record contains the phase of the bin centre, the normalized signal and its uncertainty.
The three service files are already accessible via Mosaic at the address given above; in a short time all the profiles and data files will also be available.
Figure 1: The energy dependence of P2/P1 and of Ip/P1,
panels a)
and b) respectively. The solid line in the panel a) is the
plot of the Eq. (1)