II/388 Euclid final merged catalog. Q1 data release (Euclid Coll., 2025)
Euclid. I. Overview of the Euclid mission. Q1 data release.
Euclid Collaboration, Mellier Y., Abdurrouf , Acevedo Barroso J.A.,
Achucarro A., Adamek J., Adam R., Addison G.E., Aghanim N., Aguena M. et al.
<Astron. Astrophys. 697, A1 (2025)>
=2025A&A...697A...1E 2025A&A...697A...1E
=2025yCat.2388....0E 2025yCat.2388....0E
ADC_Keywords: Surveys ; Photometry ; Optical ; Infrared
Mission_Name: Euclid
Keywords: instrumentation: detectors - instrumentation: spectrographs -
space vehicles: instruments - telescopes - surveys -
cosmology: observations
Abstract:
The current standard model of cosmology successfully describes a
variety of measurements, but the nature of its main ingredients,
dark matter and dark energy, remains unknown. Euclid is a medium-class
mission in the Cosmic Vision 2015-2025 programme of the European Space
Agency (ESA) that will provide high-resolution optical imaging, as
well as near-infrared imaging and spectroscopy, over about 14000deg2
of extragalactic sky. In addition to accurate weak lensing and
clustering measurements that probe structure formation over half of
the age of the Universe, its primary probes for cosmology, these
exquisite data will enable a wide range of science. This paper
provides a high-level overview of the mission, summarising the survey
characteristics, the various data-processing steps, and data products.
We also highlight the main science objectives and expected
performance.
Description:
Euclid Q1 data were publicly released on March 19, 2025, by the ESA
Euclid science archive as well as the complementary archive at the
NASA/IPAC Infrared Science Archive (IRSA). The main component of the
Q1 data contain Level 2 data of a single visit (at the depth of the
Euclid Wide Survey) over the Euclid Deep Fields (EDFs): 20deg2 of
the EDF North, 10deg2 of EDF Fornax, and 23deg2 of the EDF South.
The deep fields will be visited multiple times during the mission. ESA
memo EUCL-EST-ME-8-018 specifies the scope, content, and data product
definition of Q1, and extends the content of the two previous ESA
memos, EUCL-EST-ME-8-007 and EUCL-EST-ME-8-014.
Final merged catalog with photometric and morphological information.
It contains object positions, total fluxes, colors and some object
characterization parameters. This product is an output from the MER
catalog assembly Processing Element, and is used by the PHZ, SIR, SHE
and LE3 Processing Functions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
mer1.sam 1053 1000 Euclid final merged catalog
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See also:
https://euclid.esac.esa.int/dr/q1/dpdd/ : Euclid Q1 version Home Page
Byte-by-byte Description of file: mer1.sam
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Bytes Format Units Label Explanations
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1- 19 I19 --- ObjectId Euclid unique source identifier
(OBJECT_ID)
21- 35 F15.11 deg RAdeg Source barycenter right ascension
(J2000) (SExtractor ALPHA_J2000)
(RIGHT_ASCENSION)
37- 51 F15.11 deg DEdeg Source barycenter declination (J2000)
(SExtractor DELTA_J2000)
(DECLINATION)
53- 67 I15 --- SegMapId Source ID in the associated
segmentation map
(SEGMENTATIONMAPID)
69 I1 --- VisDet [0/1] Flag to indicate if the source
is detected in the VIS mosaic (1) or
is only detected in the NIR mosaic
(0) (VIS_DET)
71- 82 E12.6 uJy FluxVis1 ? VIS band source aperture photometry
flux (1 FWHM diameter) on
PSF-matched images
(FLUXVIS1FWHM_APER)
84- 95 E12.6 uJy FluxVis2 ? VIS band source aperture photometry
flux (2 FWHM diameter) on
PSF-matched images
(FLUXVIS2FWHM_APER)
97- 108 E12.6 uJy FluxVis3 ? VIS band source aperture photometry
flux (3 FWHM diameter) on
PSF-matched images
(FLUXVIS3FWHM_APER)
110- 121 E12.6 uJy FluxVis4 ? VIS band source aperture photometry
flux (4 FWHM diameter) on
PSF-matched images
(FLUXVIS4FWHM_APER)
123- 134 E12.6 uJy FluxY1 ? NIR Y band source aperture
photometry flux (1 FWHM diameter) on
PSF-matched images
(FLUXY1FWHM_APER)
136- 147 E12.6 uJy FluxY2 ? NIR Y band source aperture
photometry flux (2 FWHM diameter) on
PSF-matched images
(FLUXY2FWHM_APER)
149- 160 E12.6 uJy FluxY3 ? NIR Y band source aperture
photometry flux (3 FWHM diameter) on
PSF-matched images
(FLUXY3FWHM_APER)
162- 173 E12.6 uJy FluxY4 ? NIR Y band source aperture
photometry flux (4 FWHM diameter) on
PSF-matched images
(FLUXY4FWHM_APER)
175- 187 E13.6 uJy FluxJ1 ? NIR J band source aperture
photometry flux (1 FWHM diameter) on
PSF-matched images
(FLUXJ1FWHM_APER)
189- 200 E12.6 uJy FluxJ2 ? NIR J band source aperture
photometry flux (2 FWHM diameter) on
PSF-matched images
(FLUXJ2FWHM_APER)
202- 213 E12.6 uJy FluxJ3 ? NIR J band source aperture
photometry flux (3 FWHM diameter) on
PSF-matched images
(FLUXJ3FWHM_APER)
215- 226 E12.6 uJy FluxJ4 ? NIR J band source aperture
photometry flux (4 FWHM diameter) on
PSF-matched images
(FLUXJ4FWHM_APER)
228- 239 E12.6 uJy FluxH1 ? NIR H band source aperture
photometry flux (1 FWHM diameter) on
PSF-matched images
(FLUXH1FWHM_APER)
241- 252 E12.6 uJy FluxH2 ? NIR H band source aperture
photometry flux (2 FWHM diameter) on
PSF-matched images
(FLUXH2FWHM_APER)
254- 265 E12.6 uJy FluxH3 ? NIR H band source aperture
photometry flux (3 FWHM diameter) on
PSF-matched images
(FLUXH3FWHM_APER)
267- 278 E12.6 uJy FluxH4 ? NIR H band source aperture
photometry flux (4 FWHM diameter) on
PSF-matched images
(FLUXH4FWHM_APER)
280- 291 E12.6 uJy FluxNIR1 ? NIR stack band source aperture
photometry flux (1 FWHM diameter) on
PSF-matched images
(FLUXNIRSTACK1FWHMAPER)
293- 304 E12.6 uJy FluxNIR2 ? NIR stack band source aperture
photometry flux (2 FWHM diameter) on
PSF-matched images
(FLUXNIRSTACK2FWHMAPER)
306- 317 E12.6 uJy FluxNIR3 ? NIR stack band source aperture
photometry flux (3 FWHM diameter) on
PSF-matched images
(FLUXNIRSTACK3FWHMAPER)
319- 330 E12.6 uJy FluxNIR4 ? NIR stack band source aperture
photometry flux (4 FWHM diameter) on
PSF-matched images
(FLUXNIRSTACK4FWHMAPER)
332- 343 E12.6 uJy e_FluxVis1 ? VIS band source aperture photometry
flux (1 FWHM diameter) on
PSF-matched images error
(FLUXERRVIS1FWHM_APER)
345- 356 E12.6 uJy e_FluxVis2 ? VIS band source aperture photometry
flux (2 FWHM diameter) on
PSF-matched images error
(FLUXERRVIS2FWHM_APER)
358- 369 E12.6 uJy e_FluxVis3 ? VIS band source aperture photometry
flux (3 FWHM diameter) on
PSF-matched images error
(FLUXERRVIS3FWHM_APER)
371- 382 E12.6 uJy e_FluxVis4 ? VIS band source aperture photometry
flux (4 FWHM diameter) on
PSF-matched images error
(FLUXERRVIS4FWHM_APER)
384- 395 E12.6 uJy e_FluxY1 ? NIR Y band source aperture
photometry flux (1 FWHM diameter) on
PSF-matched images error
(FLUXERRY1FWHM_APER)
397- 408 E12.6 uJy e_FluxY2 ? NIR Y band source aperture
photometry flux (2 FWHM diameter) on
PSF-matched images error
(FLUXERRY2FWHM_APER)
410- 421 E12.6 uJy e_FluxY3 ? NIR Y band source aperture
photometry flux (3 FWHM diameter) on
PSF-matched images error
(FLUXERRY3FWHM_APER)
423- 434 E12.6 uJy e_FluxY4 ? NIR Y band source aperture
photometry flux (4 FWHM diameter) on
PSF-matched images error
(FLUXERRY4FWHM_APER)
436- 447 E12.6 uJy e_FluxJ1 ? NIR J band source aperture
photometry flux (1 FWHM diameter) on
PSF-matched images error
(FLUXERRJ1FWHM_APER)
449- 460 E12.6 uJy e_FluxJ2 ? NIR J band source aperture
photometry flux (2 FWHM diameter) on
PSF-matched images error
(FLUXERRJ2FWHM_APER)
462- 473 E12.6 uJy e_FluxJ3 ? NIR J band source aperture
photometry flux (3 FWHM diameter) on
PSF-matched images error
(FLUXERRJ3FWHM_APER)
475- 486 E12.6 uJy e_FluxJ4 ? NIR J band source aperture
photometry flux (4 FWHM diameter) on
PSF-matched images error
(FLUXERRJ4FWHM_APER)
488- 499 E12.6 uJy e_FluxH1 ? NIR H band source aperture
photometry flux (1 FWHM diameter) on
PSF-matched images error
(FLUXERRH1FWHM_APER)
501- 512 E12.6 uJy e_FluxH2 ? NIR H band source aperture
photometry flux (2 FWHM diameter) on
PSF-matched images error
(FLUXERRH2FWHM_APER)
514- 525 E12.6 uJy e_FluxH3 ? NIR H band source aperture
photometry flux (3 FWHM diameter) on
PSF-matched images error
(FLUXERRH3FWHM_APER)
527- 538 E12.6 uJy e_FluxH4 ? NIR H band source aperture
photometry flux (4 FWHM diameter) on
PSF-matched images error
(FLUXERRH4FWHM_APER)
540- 551 E12.6 uJy e_FluxNIR1 ? NIR stack band source aperture
photometry flux (1 FWHM diameter) on
PSF-matched images error
(FLUXERRNIRSTACK1FWHMAPER)
553- 564 E12.6 uJy e_FluxNIR2 ? NIR stack band source aperture
photometry flux (2 FWHM diameter) on
PSF-matched images error
(FLUXERRNIRSTACK2FWHMAPER)
566- 577 E12.6 uJy e_FluxNIR3 ? NIR stack band source aperture
photometry flux (3 FWHM diameter) on
PSF-matched images error
(FLUXERRNIRSTACK3FWHMAPER)
579- 590 E12.6 uJy e_FluxNIR4 ? NIR stack band source aperture
photometry flux (4 FWHM diameter) on
PSF-matched images error
(FLUXERRNIRSTACK4FWHMAPER)
592- 604 E13.6 uJy FluxYTemp ? NIR Y band source template fitting
flux (TPHOT measurement)
(FLUXYTEMPLFIT)
606- 618 E13.6 uJy FluxJTemp ? NIR J band source template fitting
flux (TPHOT measurement)
(FLUXJTEMPLFIT)
620- 632 E13.6 uJy FluxHTemp ? NIR H band source template fitting
flux (TPHOT measurement)
(FLUXHTEMPLFIT)
634- 645 E12.6 uJy e_FluxYTemp ? NIR Y band source template fitting
flux error (TPHOT measurement)
(FLUXERRYTEMPLFIT)
647- 658 E12.6 uJy e_FluxJTemp ? NIR J band source template fitting
flux error (TPHOT measurement)
(FLUXERRJTEMPLFIT)
660- 671 E12.6 uJy e_FluxHTemp ? NIR H band source template fitting
flux error (TPHOT measurement)
(FLUXERRHTEMPLFIT)
673- 684 E12.6 uJy FluxVispsf ? VIS band source PSF-fitting
photometry flux (TPHOT measurement)
(FLUXVISPSF)
686- 697 E12.6 uJy e_FluxVispsf ? VIS band source PSF-fitting
photometry flux error (TPHOT
measurement) (FLUXERRVISPSF)
699- 710 E12.6 uJy FluxSeg VIS or NIR stack band source
segmented area flux
(FLUX_SEGMENTATION)
712- 723 E12.6 uJy e_FluxSeg VIS or NIR stack band source total
flux (Kron aperture)
(FLUXERR_SEGMENTATION)
725- 736 E12.6 uJy FluxDetTot ? VIS or NIR stack band source total
flux error (Kron aperture)
(FLUXDETECTIONTOTAL)
738- 749 E12.6 uJy e_FluxDetTot ? VIS or NIR stack band source
segmented area flux
(FLUXERRDETECTIONTOTAL)
751- 762 E12.6 uJy FluxVisSer ? VIS band source flux from the
Sersic fit (FLUXVISSERSIC)
764- 775 E12.6 uJy FluxYSer ? NIR Y band source flux from the
Sersic fit (FLUXYSERSIC)
777- 788 E12.6 uJy FluxJSer ? NIR J band source flux from the
Sersic fit (FLUXJSERSIC)
790- 801 E12.6 uJy FluxHSer ? NIR H band source flux from the
Sersic fit (FLUXHSERSIC)
803- 814 E12.6 uJy e_FluxVisSer ? VIS band source flux error from
the Sersic fit (FLUXERRVISSERSIC)
816- 827 E12.6 uJy e_FluxYSer ? NIR Y band source flux error from
the Sersic fit (FLUXERRYSERSIC)
829- 840 E12.6 uJy e_FluxJSer ? NIR J band source flux error from
the Sersic fit (FLUXERRJSERSIC)
842- 853 E12.6 uJy e_FluxHSer ? NIR H band source flux error from
the Sersic fit (FLUXERRHSERSIC)
855- 856 I2 --- FlagVis [0/10] Objects flag keeping track of
the flagged pixels in the
VIS flag image (FLAG_VIS)
858- 859 I2 --- FlagY [0/10] Objects flag keeping track of
the flagged pixels in the
NIR Y flag image (FLAG_Y)
861- 862 I2 --- FlagJ [0/10] Objects flag keeping track of
the flagged pixels in the
NIR J flag image (FLAG_J)
864- 865 I2 --- FlagH [0/10] Objects flag keeping track of
the flagged pixels in the
NIR H flag image (FLAG_H)
867- 868 I2 --- FlagNIR [0/10] Objects flag keeping track of
the flagged pixels in the NIR stack
flag image (FLAGNIRSTACK)
870 I1 --- FlagDeblend [0/1] Flag marking if the object was
originally blended with another one
(DEBLENDED_FLAG)
872- 876 I5 --- ParentID ID of the parent sources of a
deblended object (PARENT_ID)
878- 881 I4 --- ParentVisNIR ID of the parent sources of a
deblended object (PARENT_VISNIR)
883 I1 --- FlagPL [1]? Point-like flag
(POINTLIKEFLAG) (1)
885- 892 F8.6 --- PPL ? Probability between 0 and 1 that
the source is point-like
(POINTLIKEPROB) (2)
894 I1 --- FlagSpur [0/1] Spurious source flag
(SPURIOUS_FLAG)
896- 906 E11.6 --- PSpur Probability between 0 and 1 that the
source is spurious (SPURIOUS_PROB)
908- 916 F9.6 mag magSG ? Magnitude used to compute
POINTLIKEPROB (MAGSTARGALSEP)
918- 921 I4 --- FQualDet Detection step flags that could
indicate the possible corruption of
the MAGSTARGALSEP values
(DETQUALITYFLAG)
923- 931 F9.6 mag/arcsec2 muMax ? Peak surface brightness above the
background in the detection band
(directly from SExtractor) (MU_MAX)
933- 942 F10.6 mag/arcsec2 Diffmu ? The difference between MU_MAX and
MAGSTARGALSEP; valid even for
NIR-only sources (MUMAXMINUSMAG)
944- 951 I8 pix SegArea Isophotal area of the source above
the analysis threshold (SExtractor
ISOAREA_IMAGE) (SEGMENTATION_AREA)
953- 963 E11.6 pix amaj Semi-major axis of the source
(from Asterism) (SEMIMAJOR_AXIS)
965- 970 F6.2 deg PA [-90/90] Position angle (CCW/x) of
the source (SExtractor THETA_IMAGE)
(POSITION_ANGLE)
972- 982 E11.6 --- Ell A parametrization of how stretched an
object is in the detection band
(ELLIPTICITY) (3)
984- 993 E10.6 pix RadKron ? Major semi-axis (in pixels) of the
elliptical aperture used for total
(Kron) aperture photometry on the
detection image (KRON_RADIUS)
995-1003 F9.6 arcsec FWHM FWHM (in arcsec) used in a-phot to
compute colors (FWHM) (4)
1005-1012 F8.6 mag E(B-V) Estimated galactic E(B-V) at the
source centroid according to the
reference Planck map (GAL_EBV)
1014-1021 F8.6 mag e_E(B-V) Error on galactic E(B-V) according to
the reference Planck map
(GALEBVERR)
1023-1041 I19 --- Gaia The associated GAIA source id
(GAIA_ID)
1043-1053 E11.6 --- QualGaia ? The quality of the GAIA match
(GAIAMATCHQUALITY)
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Note (1): flag set to 1 for VIS detections with (DETQUALITYFLAG≡0) AND
(POINTLIKEPROBA≥threshold); otherwise set to NaN
Note (2): (the estimation uses a "star probability cube" defined in the MDB).
Value is set to NaN for NIR-only objects (use MUMAXMINUSMAG for
NIR-only objcts)
Note (3): computed from the minor and major axes of the object itself (directly
from SExtractor)
Note (4): A-phot fluxes are computed within apertures that are multiples
(1; 2; 3; 4 times) of this FWHM.
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History:
From
https://euclid.esac.esa.int/dr/q1/dpdd/merdpd/dpcards/mer_finalcatalog.html
References:
Euclid Collaboration, Paper I 2025A&A...697A...1E 2025A&A...697A...1E
Euclid Collaboration, Paper II 2025A&A...697A...2E 2025A&A...697A...2E
Euclid Collaboration, Paper III 2025A&A...697A...3E 2025A&A...697A...3E
Euclid Collaboration, Paper IV 2025A&A...697A...4E 2025A&A...697A...4E
Euclid Collaboration, Paper V 2025A&A...697A...5E 2025A&A...697A...5E
Cuillandre et al., Paper VI 2025A&A...697A...6C 2025A&A...697A...6C
Martin et al., Paper VII 2025A&A...697A...7M 2025A&A...697A...7M
Massari et al., Paper VIII 2025A&A...697A...8M 2025A&A...697A...8M
Hunt et al., Paper IX 2025A&A...697A...9H 2025A&A...697A...9H
Saifoliahi et al., Paper X 2025A&A...697A..10S 2025A&A...697A..10S
Cuillandre et al., Paper XI 2025A&A...697A..11C 2025A&A...697A..11C
Marleau et al., Paper XII 2025A&A...697A..12M 2025A&A...697A..12M
Kluge et al., Paper XIII 2025A&A...697A..13K 2025A&A...697A..13K
Acevedo Barroso et al., Paper XIV 2025A&A...697A..14A 2025A&A...697A..14A
(End) Patricia Vannier [CDS] 30-Apr-2025