J-PLUS Early Data Release (EDR) comprises 18 J-PLUS fields observed with 12 optical bands amounting to 36deg2 (31.7deg2 after masking), with 150k stars and 101k galaxies at r < 21.
The main characteristics of the J-PLUS filter system, EDR limiting magnitudes and median zero points are summarized in the following table:
| # Filter |
Filter name |
CW (Å) |
FWHM (Å) |
m_lim EDR |
ZP |
| 1 |
u |
3485 |
508 |
21.6 |
21.1 |
| 2 |
J0378 |
3785 |
168 |
21.5 |
20.5 |
| 3 |
J0395 |
3950 |
100 |
21.4 |
20.3 |
| 4 |
J0410 |
4100 |
200 |
21.5 |
21.3 |
| 5 |
J0430 |
4300 |
200 |
21.5 |
21.4 |
| 6 |
g |
4803 |
1409 |
22.2 |
23.6 |
| 7 |
J0515 |
5150 |
200 |
21.4 |
21.5 |
| 8 |
r |
6254 |
1388 |
21.9 |
23.6 |
| 9 |
J0660 |
6600 |
145 |
21.3 |
21.0 |
| 10 |
i |
7668 |
1535 |
20.8 |
23.3 |
| 11 |
J0861 |
8610 |
400 |
20.8 |
21.5 |
| 12 |
z |
9114 |
1409 |
20.5 |
22.6 |
Scope
| Total area covered |
36deg2 (31.7deg2 after masking) |
| Image field size |
9500x9500 pixels (2 square degrees) |
| Image pixel scale |
0.555 arcsec |
| Number total of fields |
18 |
| Number of objects in dual catalogue |
413.869 |
| Number of objects in single catalogue |
3.072.287 |
Science Pieces
A colour image of the J-PLUS field 01488 is presented in figure 1. A great variety of astronomical sources are placed in the 2 deg2 FoV of T80Cam@JAST80: main sequence stars, white dwarfs (WD), galaxies, distant QSOs, minor bodies (MB) of the Solar System, etc. In figure 2 a collection of J-PLUS photo-spectra with 12 bands is presented, including the spectroscopic counterpart from SDSS.
Figure 1. Colour image of the J-PLUS field 01488.
Figure 2. J-PLUS photo-spectra with 12 bands of the sources marked in figure 1
Data summary
The sky coverage of the J-PLUS EDR is shown as black in figure 3. Bright stars are masked (white areas) to ensure high quality photometry, with 31.7 deg2 and 251k sources at r < 21.
Figure 3. Sky coverage of the J-PLUS EDR
The EDR limiting magnitude distribution is presented in figure 4, where we indicate the target J-PLUS limits by means of a vertical line, the general distribution of the gathered J-PLUS data (grey histogram) and the distribution of the J-PLUS EDR (coloured histograms). We can appreciate that, with the exception of the i filter, the EDR is fairly close to the target J-PLUS magnitudes.
Figure 4. EDR limiting magnitude distribution
The FWHM and ellipticity distributions of the J-PLUS EDR are shown bellow in figure 5. The values are consistent with those of the parent J-PLUS data, and show FWHM <1.5''. The completeness for stars (point-like sources) and galaxies (extended sources) was computed by comparing with the SDSS dataset in the common areas. The median 50% completeness in J-PLUS EDR tiles is r=21.51 for stars and r=21.10 for galaxies. For reference, the median 95% completeness is reached at r=20.88 for stars and r=20.12 for galaxies.
Figure 5. EDR limiting magnitude distribution
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