## Appendix B: Euclid ERO data summary

<table><caption>**Table B.1.** Main characteristics and properties of the 17 ERO fields are consistent across the $Y_E$, $J_E$, and $H_E$ bands; therefore, we will report only on the $H_E$ band. The right ascension (RA) and declination (Dec) coordinates represent the centres of the stacks. The average colour excess $E(B-V)$ from Planck Collaboration XI (2014) is calculated across all valid pixels in each image, which cover approximately 0.6 deg$^2$. For a summary of the data set's general properties, refer to Table 2.</caption><thead><tr><th rowspan="2">ERO fields<br>per project</th><th rowspan="2">RA<br>[deg]</th><th rowspan="2">Dec<br>[deg]</th><th rowspan="2">l<br>[deg]</th><th rowspan="2">b<br>[deg]</th><th rowspan="2">E(B-V)<br>[FoV]</th><th colspan="2">FWHM<br>[arcsec]</th><th colspan="2">Astrometry<br>[mas]</th><th colspan="2">Number of<br>objects</th></tr><tr><th>I<sub>E</sub></th><th>H<sub>E</sub></th><th>I<sub>E</sub></th><th>H<sub>E</sub></th><th>I<sub>E</sub></th><th>H<sub>E</sub></th></tr></thead><tbody><tr><td>Horsehead</td><td>85.150</td><td>-2.613</td><td>207.053</td><td>-16.931</td><td>2.020</td><td>0.158</td><td>0.54</td><td>4.7</td><td>14.2</td><td>157 264</td><td>250 942</td></tr><tr><td>Messier 78</td><td>86.690</td><td>-0.015</td><td>205.414</td><td>-14.356</td><td>1.588</td><td>0.158</td><td>0.56</td><td>3.9</td><td>14.5</td><td>116 373</td><td>238 334</td></tr><tr><td>Taurus</td><td>64.983</td><td>+28.023</td><td>169.257</td><td>-15.552</td><td>0.468</td><td>0.165</td><td>0.53</td><td>3.8</td><td>13.7</td><td>123 726</td><td>223 725</td></tr><tr><td>Barnard 30</td><td>82.880</td><td>+12.316</td><td>192.500</td><td>-11.526</td><td>1.001</td><td>0.158</td><td>0.54</td><td>4.4</td><td>14.4</td><td>163 063</td><td>243 012</td></tr><tr><td>NGC 6254</td><td>254.303</td><td>-4.100</td><td>15.145</td><td>+23.062</td><td>0.227</td><td>0.155</td><td>0.55</td><td>4.5</td><td>16.5</td><td>413 297</td><td>321 363</td></tr><tr><td>NGC 6397</td><td>265.174</td><td>-53.658</td><td>338.178</td><td>-11.951</td><td>0.316</td><td>0.160</td><td>0.54</td><td>2.8</td><td>15.5</td><td>782 612</td><td>493 281</td></tr><tr><td>NGC 6822</td><td>296.236</td><td>-14.788</td><td>25.352</td><td>-18.389</td><td>0.203</td><td>0.156</td><td>0.55</td><td>3.5</td><td>14.5</td><td>1 694 021</td><td>488 601</td></tr><tr><td>Holmberg II</td><td>124.790</td><td>+70.706</td><td>144.291</td><td>+32.697</td><td>0.035</td><td>0.157</td><td>0.60</td><td>5.8</td><td>15.4</td><td>466 276</td><td>245 597</td></tr><tr><td>IC 10</td><td>5.063</td><td>+59.288</td><td>118.952</td><td>-3.342</td><td>0.822</td><td>0.157</td><td>0.55</td><td>3.0</td><td>14.9</td><td>1 403 807</td><td>416 300</td></tr><tr><td>IC 342</td><td>56.730</td><td>+68.084</td><td>138.188</td><td>+10.577</td><td>0.342</td><td>0.156</td><td>0.54</td><td>5.3</td><td>14.6</td><td>2 033 293</td><td>452 034</td></tr><tr><td>NGC 2403</td><td>114.211</td><td>+65.586</td><td>150.587</td><td>+29.184</td><td>0.046</td><td>0.155</td><td>0.54</td><td>6.8</td><td>15.1</td><td>1 152 966</td><td>316 055</td></tr><tr><td>NGC 6744</td><td>287.430</td><td>-63.842</td><td>332.240</td><td>-26.139</td><td>0.059</td><td>0.157</td><td>0.52</td><td>6.2</td><td>14.9</td><td>924 913</td><td>336 109</td></tr><tr><td>Fornax</td><td>54.017</td><td>-35.267</td><td>236.425</td><td>-54.132</td><td>0.018</td><td>0.162</td><td>0.63</td><td>10.3</td><td>14.4</td><td>369 315</td><td>265 091</td></tr><tr><td>Dorado</td><td>64.014</td><td>-55.780</td><td>265.638</td><td>-43.706</td><td>0.018</td><td>0.159</td><td>0.65</td><td>7.2</td><td>15.7</td><td>518 445</td><td>356 621</td></tr><tr><td>Perseus</td><td>49.638</td><td>+41.651</td><td>150.296</td><td>-13.272</td><td>0.156</td><td>0.156</td><td>0.56</td><td>8.2</td><td>15.4</td><td>546 563</td><td>335 340</td></tr><tr><td>Abell 2390</td><td>328.397</td><td>+17.709</td><td>73.967</td><td>-27.799</td><td>0.106</td><td>0.157</td><td>0.56</td><td>5.1</td><td>15.2</td><td>469 056</td><td>310 617</td></tr><tr><td>Abell 2764</td><td>5.713</td><td>-49.249</td><td>315.028</td><td>-67.201</td><td>0.018</td><td>0.158</td><td>0.69</td><td>7.9</td><td>15.8</td><td>542 729</td><td>321 407</td></tr></tbody></table>

<table><caption>**Table B.2.** Sky coverage and depth properties for the 17 ERO fields, pertaining to both compact sources (galaxies and point sources) and extended emission, are detailed below. The limiting magnitude for extended emission (LSB limit) is expressed in terms of the $1\sigma$ asinh AB magnitude, utilising the $10'' \times 10''$ scale metric. For further information on the depth metrics, refer to Sects. 8 and 9.</caption><thead><tr><th rowspan="2">ERO fields<br>per project</th><th rowspan="2">Area<br>[deg<sup>2</sup>]</th><th colspan="4">Galaxies, 10 σ [AB mag]</th><th colspan="4">Point sources, 5 σ [AB mag]</th><th colspan="4">LSB limit [AB mag arcsec<sup>-2</sup>]</th></tr><tr><th>I<sub>E</sub></th><th>Y<sub>E</sub></th><th>J<sub>E</sub></th><th>H<sub>E</sub></th><th>I<sub>E</sub></th><th>Y<sub>E</sub></th><th>J<sub>E</sub></th><th>H<sub>E</sub></th><th>I<sub>E</sub></th><th>Y<sub>E</sub></th><th>J<sub>E</sub></th><th>H<sub>E</sub></th></tr></thead><tbody><tr><td>Horsehead</td><td>0.58</td><td>24.83</td><td>22.63</td><td>22.80</td><td>22.77</td><td>27.05</td><td>24.32</td><td>24.46</td><td>24.34</td><td>29.53</td><td>28.04</td><td>28.25</td><td>28.22</td></tr><tr><td>Messier 78</td><td>0.60</td><td>24.90</td><td>22.61</td><td>22.71</td><td>22.82</td><td>27.10</td><td>24.34</td><td>24.47</td><td>24.41</td><td>29.66</td><td>28.08</td><td>28.24</td><td>28.26</td></tr><tr><td>Taurus</td><td>0.61</td><td>24.93</td><td>22.77</td><td>23.01</td><td>23.05</td><td>27.09</td><td>24.34</td><td>24.49</td><td>24.45</td><td>29.58</td><td>28.06</td><td>28.24</td><td>28.28</td></tr><tr><td>Barnard 30</td><td>0.60</td><td>24.91</td><td>22.70</td><td>22.86</td><td>22.99</td><td>27.12</td><td>24.31</td><td>24.44</td><td>24.38</td><td>29.54</td><td>28.01</td><td>28.18</td><td>28.18</td></tr><tr><td>NGC 6254</td><td>0.60</td><td>25.11</td><td>22.97</td><td>23.22</td><td>23.26</td><td>27.23</td><td>24.37</td><td>24.51</td><td>24.46</td><td>29.66</td><td>28.05</td><td>28.22</td><td>28.26</td></tr><tr><td>NGC 6397</td><td>0.61</td><td>25.16</td><td>22.93</td><td>23.11</td><td>23.15</td><td>27.11</td><td>24.21</td><td>24.31</td><td>24.22</td><td>29.51</td><td>27.70</td><td>27.74</td><td>27.75</td></tr><tr><td>NGC 6822</td><td>0.60</td><td>25.19</td><td>22.81</td><td>23.08</td><td>23.11</td><td>26.79</td><td>24.20</td><td>24.34</td><td>24.27</td><td>29.53</td><td>27.83</td><td>27.98</td><td>27.99</td></tr><tr><td>Holmberg II</td><td>0.60</td><td>25.54</td><td>23.20</td><td>23.44</td><td>23.47</td><td>27.45</td><td>24.69</td><td>24.85</td><td>24.78</td><td>29.97</td><td>28.43</td><td>28.60</td><td>28.61</td></tr><tr><td>IC 10</td><td>0.62</td><td>26.12</td><td>23.43</td><td>23.63</td><td>23.65</td><td>27.43</td><td>24.80</td><td>24.89</td><td>24.74</td><td>30.23</td><td>28.09</td><td>28.23</td><td>28.20</td></tr><tr><td>IC 342</td><td>0.59</td><td>25.41</td><td>22.87</td><td>23.23</td><td>23.31</td><td>26.70</td><td>24.45</td><td>24.60</td><td>24.52</td><td>29.81</td><td>28.04</td><td>28.18</td><td>28.18</td></tr><tr><td>NGC 2403</td><td>0.60</td><td>25.51</td><td>23.15</td><td>23.38</td><td>23.43</td><td>27.22</td><td>24.62</td><td>24.79</td><td>24.71</td><td>29.98</td><td>28.21</td><td>28.38</td><td>28.39</td></tr><tr><td>NGC 6744</td><td>0.60</td><td>25.29</td><td>22.97</td><td>23.21</td><td>23.31</td><td>27.09</td><td>24.50</td><td>24.64</td><td>24.58</td><td>29.81</td><td>28.05</td><td>28.20</td><td>28.21</td></tr><tr><td>Fornax</td><td>0.57</td><td>25.07</td><td>22.97</td><td>23.38</td><td>23.37</td><td>26.89</td><td>24.56</td><td>24.87</td><td>24.81</td><td>29.66</td><td>28.29</td><td>28.56</td><td>28.56</td></tr><tr><td>Dorado</td><td>0.60</td><td>25.52</td><td>23.15</td><td>23.37</td><td>23.37</td><td>27.40</td><td>24.68</td><td>24.84</td><td>24.76</td><td>30.05</td><td>28.41</td><td>28.58</td><td>28.60</td></tr><tr><td>Perseus</td><td>0.70</td><td>26.12</td><td>23.77</td><td>24.04</td><td>24.08</td><td>28.03</td><td>25.20</td><td>25.38</td><td>25.32</td><td>30.57</td><td>28.77</td><td>28.95</td><td>28.94</td></tr><tr><td>Abell 2390</td><td>0.75</td><td>25.88</td><td>23.60</td><td>23.85</td><td>23.87</td><td>27.83</td><td>25.08</td><td>25.23</td><td>25.17</td><td>30.42</td><td>28.70</td><td>28.86</td><td>28.88</td></tr><tr><td>Abell 2764</td><td>0.75</td><td>26.06</td><td>23.71</td><td>23.94</td><td>23.96</td><td>27.83</td><td>25.19</td><td>25.34</td><td>25.27</td><td>30.56</td><td>28.78</td><td>28.96</td><td>28.98</td></tr></tbody></table>
<figure><img src="image_33.png" /><figcaption>**Fig. B.1.** The 17 ERO fields (approximately 0.6 deg² each, *I*<sub>E</sub> preview). The blue frame encompasses the entirety of the FITS image for each science stack, guaranteeing that no quality *Euclid* data are omitted during projection into the equatorial coordinate system. Pixels identified as valid are those shared by both the VIS and NISP instruments. A dithering pattern impacted three fields – Taurus, NGC 6254, and IC 10 – resulting in incomplete sky coverage. The Fornax field is limited by having only two VIS exposures, leading to prominent gaps. Holmberg II, Fornax, and Dorado suffer from issues related to stray light, which will be addressed in the upcoming ERO data release. Any observed variations in the background of the remaining images stem from the LSB detection of Galactic nebulae (top row) or the presence of faint Galactic cirrus, illustrating the *Euclid*'s capability to easily capture these subtle astronomical features.</figcaption></figure>
<figure><img src="image_34.png" /><figcaption>**Fig. B.2.** Released on 7 November 2023, the first set of five colour images unveiled *Euclid*'s capabilities to the global community. The images (cropped FoV= 0.5 deg²), starting from the top left, feature the Perseus cluster, IC 342, NGC 6822, NGC 6397, and the Horsehead nebula, along with a cutout on the lower right (10' × 10') that highlights the image resolution and depth achieved by *Euclid*. The pipeline detailed in this paper produced each of the three channels that contributed to the initial RGB images. These images were subsequently refined using external tools. The chosen colour palette assigns assigns the *I*<sub>E</sub>, *Y*<sub>E</sub>, and *H*<sub>E</sub> bands to the blue, green, and red channels respectively, displaying the full sensitivity range of the observatory and offering a new perspective on these astronomical subjects. Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi.</figcaption></figure>
## Appendix C: Selection of relevant stars along a given line of sight

Colour transformations for comparing *Euclid* photometry with existing literature are based on synthetic photometry of prevalent stars in the observation region, demonstrated through the Dorado and Perseus cases. Figure C.1 depicts outcomes from querying the Besançon model of the Galaxy (Robin et al. 2003; Czekaj 2012; Lagarde et al. 2021) for a 1 deg² area towards NGC 1553, illustrating the process of deriving these transformations for accurate photometric comparisons. Both the Besançon model and the Planck 2013 dust map indicate an $A_V \approx 0.04$ in the direction of NGC 1553, suggesting that extinction effects are minimal and unlikely to be discernible in the figure. The right panels of the figure illustrate the models employed, with the SSED models represented by black open squares and the TSED models by black dots. It is important to note that [α/Fe] is explicitly considered only in the selection process for TSED models. Figure C.2 showcases the stellar populations expected along the line of sight towards Perseus, traversing extensive regions of the Galaxy’s thin and thick discs.

<figure><img src="image_35.png" /></figure>

**Fig. C.1.** Relevant stars along the line of sight towards the Dorado field. This example showcases the selection process conducted prior to deriving colour transformations. The coloured dots depict the simulated stellar population along the line of sight, as provided by the Besançon model of the Galaxy. In the two left panels, the colour coding represents metallicity [M/H]. In the two right panels, the colour coding corresponds to [α/Fe], with black symbols marking the models available within the data-containing range of the simulation. Grey lines delineate the approximate boundaries we established for this selection process, ensuring that the subsequent colour transformations accurately reflect the characteristics of the stellar population along the observed line of sight.

<figure><img src="image_36.png" /></figure>

**Fig. C.2.** Relevant stars along the line of sight towards the Perseus field. The layout is as in Fig. C.1
# Appendix D: Optical model of the telescope

To accurately correlate the flux observed at large radii with the energy concentrated in the core of the PSF, a model of the *Euclid* PSF was developed. This modelling encompassed the broadband *Euclid* PSF across five distinct wavelengths, each representing the $I_E$, $Y_E$, $J_E$, and $H_E$ bands. The approach involved calculating the modulus squared of the Fourier transform of the pupil function, adhering to the Fraunhofer far-field diffraction approximation (Born & Wolf 1999). The pupil function represents the complex amplitude of light within the pupil, assuming ideal optical conditions without any phase term. Consequently, the pupil function equates to the real transmission of the pupil, designated as 1 inside the pupil's boundary and 0 outside. The *Euclid* pupil was simulated on a substantial grid (16 384 × 16 384) using an outer diameter of 1.21 m for the primary mirror M1, a central obstruction of 0.395 m by the secondary mirror M2, and the width of 12 mm for the three spider arms. The spiders are connected tangentially to the structure supporting M2 (see e.g. Racca et al. 2016).

## Appendix D.1: Model of the encompassed energy of the Euclid PSF

To precisely determine the radial profile of the PSF by examining the cumulative flux fraction as a function of radius, we implemented a sampling strategy for our model PSF to achieve a resolution finer than 0.′01. This necessitates oversampling by a factor of 5 relative to the Nyquist rate, resulting in a simulated field size of 2.5 × 2.5 on our 16 384 × 16 384 grid. Subsequently, we calculated the four *Euclid* broadband PSFs, adjusting the pupil sampling to ensure a consistent pixel scale across all wavelengths. This enabled us to calculate the proportion of total flux within a circular aperture of incrementally increasing radius, aligning these values with measurements extracted from the ERO data set.

For context, if we consider a perfect Airy disc for *Euclid*, the FWHM in radians is determined by the formula $1.025 \times \lambda/D$ (M1), which yields the following FWHM values at the central wavelength for each of the four broadband filters: $I_E = 0.′136$, $Y_E = 0.′179$, $J_E = 0.′213$, and $H_E = 0.′298$. This theoretical calculation aligns with the natural FWHM observed in VIS non-resampled data at the finer 0.′1 pixel$^{-1}$ sampling rate. However, the coarser 0.′3 pixel$^{-1}$ sampling rate of NISP degrades the observed FWHM, averaging approximately 0.′41 across its three bands.

## Appendix D.2: Energy in the diffraction spikes

Both VIS and NISP images display six pronounced diffraction spikes around bright stars, a result of the structure created by the three supporting spiders. In the case of a nearly 5th magnitude star, such as that seen in one of our ERO fields (Fig. 23), each spike stretches from 12' in VIS to as much as 20' in NISP for the $H_E$-band. The extent of these spikes is influenced by the wavelength, with longer wavelengths exhibiting stronger effects and allowing for detection at greater distances. This phenomenon underscores two crucial points: first, the extended PSF is likely to have minimal power at large radii, evidenced by our ability to trace the spikes over substantial distances; second, there is a need to specifically model and measure the energy contained within the diffraction spikes for each *Euclid* band to affirm the methodology employed in determining the extended PSF.

A preliminary estimate of the total flux present in the diffraction pattern can be derived geometrically by calculating the area ratio of the spiders to the transmissive area, resulting in a value of 1.89%. However, due to the blinding effect of a 5th magnitude star on the ERO images, it is not feasible to directly measure this total quantity within a radius of 5" from our images. Instead, the proportion of energy situated beyond a specific radius, which is quantifiable based on the ERO data, must initially be predicted through simulations. To simulate the fraction of flux from the central object located within the six diffraction spikes, we created the largest feasible field for our simulation grid, realised when the PSF is critically (Nyquist) sampled. In this scenario, the pupil diameter is halved in comparison to our grid size, rendering one pupil pixel equivalent to the diameter of M1 divided by our grid size: 148 microns on the primary mirror. This adjusted simulation extends to a radius of 7', with analyses of the ERO data suggesting that a significant portion of the energy within the spikes is contained within this radius. By creating identical pupil models both with and without the presence of spiders, we computed the corresponding PSFs, subtracted one from the other, and subsequently quantified the fraction of flux attributable to the spiders. In this way we ascertain the total fraction of flux from the central star located within all six diffraction spikes beyond a radius of 10", yielding the following percentages for each band: $I_E = 0.22\%$, $Y_E = 0.41\%$, $J_E = 0.60\%$, and $H_E = 0.80\%$.

<figure><img src="image_37.png" /><figcaption>**Fig. D.1.** Main panels from left to right: The full 13′×13′ field simulated PSF in the $I_E$, $Y_E$, $J_E$, and $H_E$ bands, in log scale, the core of the PSF in the inset (6″×6″), and the pupil function in the top-left corner of the left panel. The pure diffraction halo grows larger towards the NIR.</figcaption></figure>
Appendix E: ERO catalogue parameters by SourceExtractor

<table><caption>**Table E.1.** Input parameters for the SourceExtractor run producing the ERO science validation catalogues are outlined below. Some parameters generate multiple columns in the output catalogue, as exemplified by MAG_APER, which covers 10 different apertures as described in Sect. 8. This is indicated by the jump in column numbers in this table. In total, the ERO catalogues feature 364 columns. The parameter descriptions are from SourceExtractor.</caption><thead><tr><th>Column</th><th>Parameter</th><th>Description</th><th>Unit</th></tr></thead><tbody><tr><td>1</td><td>NUMBER</td><td>Running object number</td><td></td></tr><tr><td>2</td><td>X_IMAGE</td><td>Object position along x</td><td>[pixel]</td></tr><tr><td>3</td><td>Y_IMAGE</td><td>Object position along y</td><td>[pixel]</td></tr><tr><td>4</td><td>ID_PARENT</td><td>Parent ID (before deblending)</td><td></td></tr><tr><td>5</td><td>EXT_NUMBER</td><td>FITS extension number</td><td></td></tr><tr><td>6</td><td>FLUX_ISO</td><td>Isophotal flux</td><td>[ADU]</td></tr><tr><td>7</td><td>FLUXERR_ISO</td><td>RMS error for isophotal flux</td><td>[ADU]</td></tr><tr><td>8</td><td>MAG_ISO</td><td>Isophotal magnitude</td><td>[mag]</td></tr><tr><td>9</td><td>MAGERR_ISO</td><td>RMS error for isophotal magnitude</td><td>[mag]</td></tr><tr><td>10</td><td>FLUX_ISOCOR</td><td>Corrected isophotal flux</td><td>[ADU]</td></tr><tr><td>11</td><td>FLUXERR_ISOCOR</td><td>RMS error for corrected isophotal flux</td><td>[ADU]</td></tr><tr><td>12</td><td>MAG_ISOCOR</td><td>Corrected isophotal magnitude</td><td>[mag]</td></tr><tr><td>13</td><td>MAGERR_ISOCOR</td><td>RMS error for corrected isophotal magnitude</td><td>[mag]</td></tr><tr><td>14</td><td>FLUX_APER</td><td>Flux vector within fixed circular aperture(s)</td><td>[ADU]</td></tr><tr><td>24</td><td>FLUXERR_APER</td><td>RMS error vector for aperture flux(es)</td><td>[ADU]</td></tr><tr><td>34</td><td>MAG_APER</td><td>Fixed aperture magnitude vector</td><td>[mag]</td></tr><tr><td>44</td><td>MAGERR_APER</td><td>RMS error vector for fixed aperture mag.</td><td>[mag]</td></tr><tr><td>54</td><td>FLUX_AUTO</td><td>Flux within a Kron-like elliptical aperture</td><td>[ADU]</td></tr><tr><td>55</td><td>FLUXERR_AUTO</td><td>RMS error for AUTO flux</td><td>[ADU]</td></tr><tr><td>56</td><td>MAG_AUTO</td><td>Kron-like elliptical aperture magnitude</td><td>[mag]</td></tr><tr><td>57</td><td>MAGERR_AUTO</td><td>RMS error for AUTO magnitude</td><td>[mag]</td></tr><tr><td>58</td><td>KRON-radius</td><td>Kron apertures in units of A or B</td><td></td></tr><tr><td>59</td><td>FLUX_PETRO</td><td>Flux within a Petrosian-like elliptical aperture</td><td>[ADU]</td></tr><tr><td>60</td><td>FLUXERR_PETRO</td><td>RMS error for Petrosian flux</td><td>[ADU]</td></tr><tr><td>61</td><td>MAG_PETRO</td><td>Petrosian-like elliptical aperture magnitude</td><td>[mag]</td></tr><tr><td>62</td><td>MAGERR_PETRO</td><td>RMS error for Petrosian magnitude</td><td>[mag]</td></tr><tr><td>63</td><td>PETRO-radius</td><td>Petrosian apertures in units of A or B</td><td></td></tr><tr><td>64</td><td>FLUX_GROWTH</td><td>Cumulated growth-curve</td><td>[ADU]</td></tr><tr><td>65</td><td>FLUX_GROWTHSTEP</td><td>Step for growth-curves</td><td>[pixel]</td></tr><tr><td>66</td><td>MAG_GROWTH</td><td>Cumulated magnitude growth-curve</td><td>[mag]</td></tr><tr><td>67</td><td>MAG_GROWTHSTEP</td><td>Step for growth-curves</td><td>[pixel]</td></tr><tr><td>68</td><td>FLUX-radius</td><td>Fraction-of-light radii</td><td>[pixel]</td></tr><tr><td>69</td><td>BACKGROUND</td><td>Background at centroid position</td><td>[ADU]</td></tr><tr><td>70</td><td>MU_MAX</td><td>Peak surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>71</td><td>X_FOCAL</td><td>Barycenter position along focal-plane x axis</td><td></td></tr><tr><td>72</td><td>Y_FOCAL</td><td>Barycenter position along focal-plane y axis</td><td></td></tr><tr><td>73</td><td>X_WORLD</td><td>Barycenter position along world x axis</td><td>[deg]</td></tr><tr><td>74</td><td>Y_WORLD</td><td>Barycenter position along world y axis</td><td>[deg]</td></tr><tr><td>75</td><td>ALPHA SKY</td><td>Right ascension of barycenter (native)</td><td>[deg]</td></tr><tr><td>76</td><td>DELTA SKY</td><td>Declination of barycenter (native)</td><td>[deg]</td></tr><tr><td>77</td><td>ALPHA_J2000</td><td>Right ascension of barycenter (J2000)</td><td>[deg]</td></tr><tr><td>78</td><td>DELTA_J2000</td><td>Declination of barycenter (J2000)</td><td>[deg]</td></tr><tr><td>79</td><td>ALPHA_B1950</td><td>Right ascension of barycenter (B1950)</td><td>[deg]</td></tr><tr><td>80</td><td>DELTA_B1950</td><td>Declination of barycenter (B1950)</td><td>[deg]</td></tr><tr><td>81</td><td>ERRX2_IMAGE</td><td>Variance of position along x</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>82</td><td>ERRY2_IMAGE</td><td>Variance of position along y</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>83</td><td>ERRXY_IMAGE</td><td>Covariance of position between x and y</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>84</td><td>ERRA_IMAGE</td><td>RMS position error along major axis</td><td>[pixel]</td></tr><tr><td>85</td><td>ERRB_IMAGE</td><td>RMS position error along minor axis</td><td>[pixel]</td></tr><tr><td>86</td><td>ERRTHETA_IMAGE</td><td>Error ellipse position angle (CCW/x)</td><td>[deg]</td></tr><tr><td>87</td><td>ERRCXX_IMAGE</td><td>Cxx error ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>88</td><td>ERRCYY_IMAGE</td><td>Cyy error ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>89</td><td>ERRCXY_IMAGE</td><td>Cxy error ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>90</td><td>XPEAK_IMAGE</td><td>x-coordinate of the brightest pixel</td><td>[pixel]</td></tr><tr><td>91</td><td>YPEAK_IMAGE</td><td>y-coordinate of the brightest pixel</td><td>[pixel]</td></tr><tr><td>92</td><td>XPEAK_FOCAL</td><td>Focal-plane x coordinate of the brightest pixel</td><td></td></tr><tr><td>93</td><td>YPEAK_FOCAL</td><td>Focal-plane y coordinate of the brightest pixel</td><td></td></tr><tr><td>94</td><td>XPEAK_WORLD</td><td>World-x coordinate of the brightest pixel</td><td>[deg]</td></tr><tr><td>95</td><td>YPEAK_WORLD</td><td>World-y coordinate of the brightest pixel</td><td>[deg]</td></tr></tbody></table>
<table><thead><tr><th>Column</th><th>Parameter</th><th>Description</th><th>Unit</th></tr></thead><tbody><tr><td>96</td><td>ALPHAPEAK SKY</td><td>Right ascension of brightest pix (native)</td><td>[deg]</td></tr><tr><td>97</td><td>DELTAPEAK SKY</td><td>Declination of brightest pix (native)</td><td>[deg]</td></tr><tr><td>98</td><td>ALPHAPEAK J2000</td><td>Right ascension of brightest pix (J2000)</td><td>[deg]</td></tr><tr><td>99</td><td>DELTAPEAK J2000</td><td>Declination of brightest pix (J2000)</td><td>[deg]</td></tr><tr><td>100</td><td>ALPHAPEAK B1950</td><td>Right ascension of brightest pix (B1950)</td><td>[deg]</td></tr><tr><td>101</td><td>DELTAPEAK B1950</td><td>Declination of brightest pix (B1950)</td><td>[deg]</td></tr><tr><td>102</td><td>XMIN_IMAGE</td><td>Minimum x-coordinate among detected pixels</td><td>[pixel]</td></tr><tr><td>103</td><td>YMIN_IMAGE</td><td>Minimum y-coordinate among detected pixels</td><td>[pixel]</td></tr><tr><td>104</td><td>XMAX_IMAGE</td><td>Maximum x-coordinate among detected pixels</td><td>[pixel]</td></tr><tr><td>105</td><td>YMAX_IMAGE</td><td>Maximum y-coordinate among detected pixels</td><td>[pixel]</td></tr><tr><td>106</td><td>XWIN_IMAGE</td><td>Windowed position estimate along x</td><td>[pixel]</td></tr><tr><td>107</td><td>YWIN_IMAGE</td><td>Windowed position estimate along y</td><td>[pixel]</td></tr><tr><td>108</td><td>ERRX2WIN_IMAGE</td><td>Variance of windowed position along x</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>109</td><td>ERRY2WIN_IMAGE</td><td>Variance of windowed position along y</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>110</td><td>ERRXYWIN_IMAGE</td><td>Covariance of windowed position between x and y</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>111</td><td>ERRAWIN_IMAGE</td><td>RMS windowed position error along major axis</td><td>[pixel]</td></tr><tr><td>112</td><td>ERRBWWIN_IMAGE</td><td>RMS windowed position error along minor axis</td><td>[pixel]</td></tr><tr><td>113</td><td>ERRTHETAWIN_IMAGE</td><td>Windowed error ellipse position angle (CCW/x)</td><td>[deg]</td></tr><tr><td>114</td><td>ERRCXXWIN_IMAGE</td><td>Cxx windowed error ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>115</td><td>ERRCYYWIN_IMAGE</td><td>Cyy windowed error ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>116</td><td>ERRCXYWIN_IMAGE</td><td>Cxy windowed error ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>117</td><td>X2_IMAGE</td><td>Variance along x</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>118</td><td>Y2_IMAGE</td><td>Variance along y</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>119</td><td>XY_IMAGE</td><td>Covariance between x and y</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>120</td><td>A_IMAGE</td><td>Profile RMS along major axis</td><td>[pixel]</td></tr><tr><td>121</td><td>B_IMAGE</td><td>Profile RMS along minor axis</td><td>[pixel]</td></tr><tr><td>122</td><td>THETA_IMAGE</td><td>Position angle (CCW/x)</td><td>[deg]</td></tr><tr><td>123</td><td>ELONGATION</td><td>A_IMAGE/B_IMAGE</td><td></td></tr><tr><td>124</td><td>ELLIPTICITY</td><td>1 - B_IMAGE/A_IMAGE</td><td></td></tr><tr><td>125</td><td>CXX_IMAGE</td><td>Cxx object ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>126</td><td>CYY_IMAGE</td><td>Cyy object ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>127</td><td>CXY_IMAGE</td><td>Cxy object ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>128</td><td>ISOAREAF_IMAGE</td><td>Isophotal area (filtered) above Detection threshold</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>129</td><td>ISOAREA_IMAGE</td><td>Isophotal area above analysis threshold</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>130</td><td>X2WIN_IMAGE</td><td>Windowed variance along x</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>131</td><td>Y2WIN_IMAGE</td><td>Windowed variance along y</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>132</td><td>XYWIN_IMAGE</td><td>Windowed covariance between x and y</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>133</td><td>CXXWIN_IMAGE</td><td>Windowed Cxx object ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>134</td><td>CYYWIN_IMAGE</td><td>Windowed Cyy object ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>135</td><td>CXYWIN_IMAGE</td><td>Windowed Cxy object ellipse parameter</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>136</td><td>AWIN_IMAGE</td><td>Windowed profile RMS along major axis</td><td>[pixel]</td></tr><tr><td>137</td><td>BWIN_IMAGE</td><td>Windowed profile RMS along minor axis</td><td>[pixel]</td></tr><tr><td>138</td><td>THETAWIN_IMAGE</td><td>Windowed position angle (CCW/x)</td><td>[deg]</td></tr><tr><td>139</td><td>CLASS_STAR</td><td>S/G classifier output</td><td></td></tr><tr><td>140</td><td>FWHM_IMAGE</td><td>FWHM assuming a gaussian core</td><td>[pixel]</td></tr><tr><td>141</td><td>XPSF_IMAGE</td><td>X coordinate from PSF-fitting</td><td>[pixel]</td></tr><tr><td>142</td><td>YPSF_IMAGE</td><td>Y coordinate from PSF-fitting</td><td>[pixel]</td></tr><tr><td>143</td><td>ALPHAPSF J2000</td><td>Right ascension of the fitted PSF (J2000)</td><td>[deg]</td></tr><tr><td>144</td><td>DELTAPSF J2000</td><td>Declination of the fitted PSF (J2000)</td><td>[deg]</td></tr><tr><td>145</td><td>FLUX_PSF</td><td>Flux from PSF-fitting</td><td>[ADU]</td></tr><tr><td>146</td><td>FLUXERR_PSF</td><td>RMS flux error for PSF-fitting</td><td>[ADU]</td></tr><tr><td>147</td><td>MAG_PSF</td><td>Magnitude from PSF-fitting</td><td>[mag]</td></tr><tr><td>148</td><td>MAGERR_PSF</td><td>RMS magnitude error from PSF-fitting</td><td>[mag]</td></tr><tr><td>149</td><td>FLUXPOINTSOURCE</td><td>Point source flux from fitting</td><td>[ADU]</td></tr><tr><td>150</td><td>FLUXERR POINTSOURCE</td><td>RMS error on fitted point source total flux</td><td>[ADU]</td></tr><tr><td>151</td><td>MAG POINTSOURCE</td><td>Point source total magnitude from fitting</td><td>[mag]</td></tr><tr><td>152</td><td>MAGERR POINTSOURCE</td><td>RMS error on fitted point source total magnitude</td><td>[mag]</td></tr><tr><td>153</td><td>FLUX_DISK</td><td>Disk total flux from fitting</td><td>[ADU]</td></tr><tr><td>154</td><td>FLUXERR_DISK</td><td>RMS error on fitted disk total flux</td><td>[ADU]</td></tr><tr><td>155</td><td>MAG_DISK</td><td>Disk total magnitude from fitting</td><td>[mag]</td></tr><tr><td>156</td><td>MAGERR_DISK</td><td>RMS error on fitted disk total magnitude</td><td>[mag]</td></tr><tr><td>157</td><td>MU_MAX_DISK</td><td>Peak disk surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>158</td><td>MU_EFF_DISK</td><td>Effective disk surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>159</td><td>MU_MEAN_DISK</td><td>Mean effective disk surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>160</td><td>FLUX_SPHEROID</td><td>Spheroid total flux from fitting</td><td>[ADU]</td></tr><tr><td>161</td><td>FLUXERR_SPHEROID</td><td>RMS error on fitted spheroid total flux</td><td>[ADU]</td></tr></tbody></table>
<table><thead><tr><th>Column</th><th>Parameter</th><th>Description</th><th>Unit</th></tr></thead><tbody><tr><td>162</td><td>MAG_SPHEROID</td><td>Spheroid total magnitude from fitting</td><td>[mag]</td></tr><tr><td>163</td><td>MAGERR_SPHEROID</td><td>RMS error on fitted spheroid total magnitude</td><td>[mag]</td></tr><tr><td>164</td><td>MU_MAX_SPHEROID</td><td>Peak spheroid surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>165</td><td>MU_EFF_SPHEROID</td><td>Effective spheroid surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>166</td><td>MU_MEAN_SPHEROID</td><td>Mean effective spheroid surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>167</td><td>DISK_INCLINATION</td><td>Disk inclination from fitting</td><td>[deg]</td></tr><tr><td>168</td><td>DISK_INCLINATIONERROR</td><td>RMS error on disk inclination from fitting</td><td>[deg]</td></tr><tr><td>169</td><td>DISK_THETA_IMAGE</td><td>Disk position angle (CCW/x) from fitting</td><td>[deg]</td></tr><tr><td>170</td><td>DISK_THETAERROR_IMAGE</td><td>RMS error on fitted disk position angle</td><td>[deg]</td></tr><tr><td>171</td><td>SPHEROID_SERSICN</td><td>Spheroid Sersic index from fitting</td><td></td></tr><tr><td>172</td><td>SPHEROID_SERSICNERROR</td><td>RMS error on fitted spheroid Sersic index</td><td></td></tr><tr><td>173</td><td>SPHEROID_THETA_IMAGE</td><td>Spheroid position angle (CCW/x) from fitting</td><td>[deg]</td></tr><tr><td>174</td><td>SPHEROID_THETAERROR_IMAGE</td><td>RMS error on spheroid position angle</td><td>[deg]</td></tr><tr><td>175</td><td>SPHEROID_REFF_IMAGE</td><td>Spheroid effective radius from fitting</td><td>[pixel]</td></tr><tr><td>176</td><td>SPHEROID_REFFERROR_IMAGE</td><td>RMS error on fitted spheroid effective radius</td><td>[pixel]</td></tr><tr><td>177</td><td>FLUX MODEL</td><td>Flux from model-fitting</td><td>[ADU]</td></tr><tr><td>178</td><td>FLUXERROR MODEL</td><td>RMS error on model-fitting flux</td><td>[ADU]</td></tr><tr><td>179</td><td>MAG MODEL</td><td>Magnitude from model-fitting</td><td>[mag]</td></tr><tr><td>180</td><td>MAGERR MODEL</td><td>RMS error on model-fitting magnitude</td><td>[mag]</td></tr><tr><td>181</td><td>MU_MAX MODEL</td><td>Peak model surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>182</td><td>FLUX_MAX MODEL</td><td>Peak model flux above background</td><td>[ADU]</td></tr><tr><td>183</td><td>FLUX_EFF MODEL</td><td>Effective model flux above background</td><td>[ADU]</td></tr><tr><td>184</td><td>FLUX_MEAN MODEL</td><td>Mean effective model flux above background</td><td>[ADU]</td></tr><tr><td>185</td><td>MU_EFF MODEL</td><td>Effective model surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>186</td><td>MU_MEAN MODEL</td><td>Mean effective model surface brightness above background</td><td>[mag arcsec<sup>-2</sup>]</td></tr><tr><td>187</td><td>XMODEL_IMAGE</td><td>X coordinate from model-fitting</td><td>[pixel]</td></tr><tr><td>188</td><td>YMODEL_IMAGE</td><td>Y coordinate from model-fitting</td><td>[pixel]</td></tr><tr><td>189</td><td>CXXMODEL_IMAGE</td><td>Cxx ellipse parameter from model-fitting</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>190</td><td>CYYMODEL_IMAGE</td><td>Cyy ellipse parameter from model-fitting</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>191</td><td>CXYMODEL_IMAGE</td><td>Cxy ellipse parameter from model-fitting</td><td>[pixel<sup>-2</sup>]</td></tr><tr><td>192</td><td>SPREAD MODEL</td><td>Spread parameter from model-fitting</td><td></td></tr><tr><td>193</td><td>SPREADERROR MODEL</td><td>Spread parameter error from model-fitting</td><td></td></tr><tr><td>194</td><td>NOISEAREA MODEL</td><td>Equivalent noise area of the fitted model</td><td>[pixel<sup>2</sup>]</td></tr><tr><td>195</td><td>NITER MODEL</td><td>Number of iterations for model-fitting</td><td></td></tr><tr><td>196</td><td>VECTOR MODEL</td><td>Model-fitting coefficients</td><td></td></tr><tr><td>208</td><td>VECTOR MODELERROR</td><td>Model-fitting coefficient uncertainties</td><td></td></tr><tr><td>220</td><td>MATRIX MODELERROR</td><td>Model-fitting covariance matrix</td><td></td></tr><tr><td>364</td><td>CHI2 MODEL</td><td>Reduced Chi2 of the fit</td><td></td></tr></tbody></table>