5.12 Testing the Production Pipe-Line

The production PL can produce data in one of 3 ways, specified at the start of the reduction, these are (i) optimal photometry magnitudes, produced using airmass curves generated from optimal photometry (opt-opt). (ii) optimal photometry magnitudes, produced using airmass curves generated from aperture photometry (opt-apt), and (iii) aperture photometry magnitudes, produced using airmass curves generated from aperture photometry (apt-apt).

Tables 5.7, 5.8 & 5.9 show the low mass star data of Chapter 4. The tables show (i) the production PL reduction, (ii) the prototype PL reduction and also in the case of the R and I band data, (iii) photographic magnitudes extracted from Hambly et al. (1995).

Star	R opt-opt	Error	R opt-apt	Error	R apt-apt	Error	R ptype	R photo








hshj22	16.939	0.025	16.868	0.025	16.865	0.009	17.005	17.610






hshj25	16.857	0.021	16.791	0.021	16.798	0.009	16.892	17.320






hshj29	17.073	0.022	17.009	0.022	17.015	0.011	17.383	17.950






hshj37	16.733	0.016	16.670	0.016	16.667	0.008	16.993	17.550






hshj38	16.705	0.017	16.642	0.017	16.636	0.008	16.908	17.380






hshj42	17.168	0.020	17.105	0.020	17.106	0.010	17.459	17.990






hshj48	16.787	0.006	16.725	0.006	16.744	0.008	16.900	17.440






hshj60	16.481	0.013	16.419	0.013	16.421	0.007	16.791	17.310






hshj64	17.110	0.020	17.049	0.020	17.047	0.009	17.256	17.740






hshj74	17.125	0.019	17.064	0.019	17.060	0.010	17.415	17.950






hshj91	16.873	0.015	16.812	0.015	16.820	0.008	17.196	17.580






hshj102	17.225	0.021	17.165	0.021	17.160	0.010	17.515	17.960






hshj108	16.853	0.017	16.793	0.017	16.792	0.008	17.144	17.550






hshj125	16.906	0.020	16.847	0.020	16.843	0.008	16.704	17.540






hshj126	16.786	0.018	16.727	0.018	16.723	0.008	17.017	17.390











continued on next page



Star	R opt-opt	Error	R opt-apt	Error	R apt-apt	Error	R ptype	R photo




hshj136	16.781	0.018	16.721	0.018	16.729	0.008	16.978	17.300






hshj165	16.819	0.021	16.759	0.021	16.762	0.008	16.894	17.280






hshj185	17.033	0.025	16.973	0.025	16.970	0.010	17.128	17.670






hshj187	16.501	0.016	16.441	0.016	16.445	0.007	16.684	17.070






hshj186	16.636	0.017	16.576	0.017	16.578	0.008	16.839	17.180






hshj191	16.924	0.022	16.864	0.022	16.869	0.010	17.107	17.470






hshj194	17.241	0.021	17.180	0.021	17.180	0.014	17.504	17.930






hshj195	17.811	0.003	17.750	0.003	17.731	0.017	17.657	17.910






hshj229	17.105	0.030	17.043	0.030	17.027	0.014	17.273	17.660






hshj230	17.034	0.002	16.971	0.002	16.980	0.012	16.858	17.190






hshj242	16.693	0.024	16.628	0.024	16.642	0.013	16.713	17.040






hshj246	17.440	0.059	17.375	0.059	17.390	0.022	17.613	17.950

Table 5.7:

The low mass star sample of Chapter 4 showing; pure optimal photometry (opt-opt), combined optimal and aperture photometry (opt-apt) and pure aperture photometry(apt-apt) and their associated errors, all derived from the production PL. Also shown is the prototype PL reduction (ptype) and photographic magnitudes (photo). This table shows the R band magnitudes

Star	I opt-opt	Error	I opt-apt	Error	I apt-apt	Error	I ptype	I photo








hshj22	15.895	0.037	15.757	0.030	15.611	0.009	15.342	15.620






hshj25	15.551	0.015	15.621	0.014	15.614	0.007	15.195	15.450






hshj29	16.121	0.016	16.217	0.014	16.219	0.007	15.690	15.930






hshj37	15.608	0.047	15.724	0.045	15.705	0.023	15.232	15.490






hshj38	15.859	0.015	15.986	0.005	15.846	0.008	15.158	15.490






hshj42	16.139	0.024	16.271	0.019	16.260	0.010	15.746	16.090






hshj48	15.482	0.021	15.619	0.013	15.623	0.008	15.100	15.330






hshj60	15.479	0.023	15.623	0.013	15.628	0.008	15.130	15.350






hshj64	16.306	0.021	16.454	0.008	16.350	0.010	15.438	15.670






hshj74	15.952	0.023	16.090	0.015	16.092	0.009	15.628	15.820






hshj91	15.769	0.023	15.906	0.014	15.907	0.009	15.428	15.570






hshj102	16.013	0.022	16.145	0.016	16.149	0.009	15.675	15.900






hshj108	15.712	0.020	15.833	0.014	15.843	0.008	15.326	15.560






hshj125	15.904	0.020	16.012	0.016	16.008	0.008	15.493	15.550






hshj126	15.836	0.020	15.928	0.018	15.931	0.008	15.320	15.530






hshj136	15.821	0.015	15.886	0.015	15.893	0.007	15.405	15.580






hshj165	15.642	0.003	15.689	0.002	15.945	0.007	15.339	15.480






hshj185	15.946	0.018	15.985	0.018	15.987	0.008	15.461	15.610






hshj187	15.376	0.012	15.384	0.012	15.383	0.006	15.070	15.150






hshj186	15.494	0.013	15.502	0.013	15.496	0.006	15.180	15.260






hshj191	15.775	0.017	15.735	0.017	15.726	0.008	15.305	15.290






hshj194	15.931	0.016	15.859	0.016	15.860	0.009	15.809	15.910






hshj195	16.151	0.037	16.051	0.036	16.065	0.015	15.995	15.920






hshj229	15.818	0.056	15.590	0.033	15.602	0.016	15.483	15.470






hshj230	15.437	0.076	15.145	0.018	15.554	0.021	15.270	15.310






hshj242	15.270	0.151	14.862	0.043	14.871	0.037	15.051	15.090






hshj246	16.354	0.198	15.885	0.049	15.856	0.053	15.853	15.920

Table 5.8:

Star	Z opt-opt	Error	Z opt-apt	Error	Z apt-apt	Error	Z ptype








hshj22	16.884	0.049	16.891	0.006	15.807	0.012	14.865






hshj25	15.412	0.009	15.370	0.004	15.371	0.008	14.689






hshj29	15.988	0.016	15.940	0.005	15.934	0.011	15.227






hshj37	14.906	0.026	14.853	0.011	14.852	0.007	14.652






hshj38	15.302	0.028	15.246	0.004	15.302	0.008	14.589






hshj42	16.060	0.031	16.002	0.006	15.977	0.011	15.215






hshj48	15.228	0.038	15.169	0.019	15.173	0.008	14.571






hshj60	14.968	0.039	14.907	0.012	14.899	0.007	14.630






hshj64	15.408	0.043	15.346	0.018	15.357	0.009	14.883






hshj74	15.478	0.038	15.418	0.016	15.424	0.009	15.094






hshj91	15.296	0.037	15.236	0.015	15.237	0.008	14.910






hshj102	15.551	0.035	15.492	0.017	15.479	0.009	15.140






hshj108	13.207	0.027	13.150	0.006	13.151	0.004	14.821






hshj125	15.356	0.026	15.301	0.016	15.297	0.008	14.982






hshj126	15.256	0.021	15.205	0.015	15.208	0.007	14.842






hshj136	15.433	0.019	15.389	0.018	15.392	0.008	14.985






hshj165	15.687	0.004	15.647	0.002	15.704	0.010	14.850






hshj185	15.847	0.005	15.808	0.004	15.809	0.010	14.930






hshj187	14.909	0.013	14.878	0.013	14.889	0.007	14.574






hshj186	15.037	0.014	15.006	0.014	15.011	0.007	14.676






hshj191	15.079	0.018	15.059	0.016	15.067	0.009	14.783






hshj194	15.604	0.030	15.592	0.024	15.598	0.012	15.309






hshj195	15.651	0.041	15.645	0.028	15.658	0.012	15.477






hshj229	15.337	0.133	15.361	0.037	15.376	0.018	0.000






hshj230	15.191	0.219	15.232	0.022	15.999	0.029	14.867






hshj242	14.896	0.394	14.963	0.039	15.072	0.041	14.563






hshj246	15.772	0.524	15.854	0.068	15.852	0.057	15.330

Table 5.9:

To verify the data reduction carried out by the PL the reduced data will be compared with the data produced by the prototype PL, shown in Chapter 4 to fit the Chabrier et al. (1996) models. Figures 5.8, 5.9 & 5.10 show the R band, I band and Z band comparison of the prototype PL reduction and the production PL respectively. Each plot shows the production PL optimal reduction (y-axis) against the prototype PL reduction (x-axis) in red and the production PL aperture reduction (y-axis) against the prototype PL reduction (x-axis) in blue. The green lines indicate a one-to-one correspondence. Best fit lines are plotted using a least-squares-fits technique, Table 5.10 presents all fits and indicates the standard deviation of the points about the fitted line.

Plot	sd.	Gradient	Intercept


R production_optimal vs R prototype	0.14	0.853	2.360
R production_aperture vs R prototype	0.14	0.844	2.445
I production_optimal vs I prototype	0.16	0.921	1.601
I production_aperture vs I prototype	0.22	0.818	3.207
Z production_optimal vs Z prototype	0.50	1.040	-0.126
Z production_aperture vs Z prototype	0.50	1.031	-0.040

Table 5.10:

Showing the collated results of all bands used in comparing the prototype and production PLs.

R-band data comparison of prototype and production pipe-lines

Figure 5.8:

All data is compared with the prototype PL reduction (x-axis). The red symbols indicate the the production PL optimal photometry and the blue the production PL aperture photometry. The red and blue solid lines indicate a least-squares-fit applied to the data, the green line is a one-to-one indicator. This plot shows R band data

Figure 5.8 shows the R band data: Evident from the plot is that the optimal photometry and aperture photometry describe the same form. The aperture photometry has smaller errors than the optimal, this is due to the additional step of aperture correction in the optimal photometry reduction. The two methods discussed do however describe slightly different distributions, because of this whilst the aperture photometry may be more precise (i.e., have a smaller error), the optimal photometry may be more accurate (i.e., be nearer the true answer).

I-band data comparison of prototype and production pipe-lines

Figure 5.9:

All data is compared with the prototype PL reduction (x-axis). The red symbols indicate the production PL optimal photometry and the blue the production PL aperture photometry. The red and blue solid lines indicate a least-squares-fit applied to the data, the green line is a one-to-one indicator. This plot shows I band data

Figure 5.9 shows the I band data: The distribution of points, both optimal and aperture, is closely interlaced as is evident from the fits. The fits are very close and intersect each other, at the graph’s mid-point. The errors are again smaller on the aperture photometry than the optimal photometry.

Z-band data comparison of prototype and production pipe-lines

Figure 5.10:

Figure 5.10 shows the Z band data: The fits again describe the same gradient with an offset between the two of ~0.05 magnitudes. Three points from the optimal distribution exhibit relatively large errors, when compared to the rest of the distribution. The Z band data were noted during the prototype PL construction to be low quality, however the reason why these three particular points exhibit such errors is not evident.

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