J/A+A/708/A63 Euclid Perseus ETG photometry (Martocchia+, 2026)
Euclid: Early Release Observations. The star-formation history of massive
early-type galaxies in the Perseus cluster.
Martocchia S., Boselli A., Cuillandre J.-C., Mondelin M., Bolzonella M.,
Tortora C., Fossati M., Maraston C., Amram P., Baes M., Boissier S.,
Boquien M., Bouy H., Durret F., Gutierrez C.M., Kluge M., Roehlly Y.,
Saifollahi T., Taylor M.A., Thomas D., Woods T.E., Zamorani G., Altieri B.,
Andreon S., Auricchio N., Baccigalupi C., Baldi M., Bardelli S.,
Battaglia P., Bender R., Biviano A., Branchini E., Brescia M., Camera S.,
Canas-Herrera G., Capobianco V., Carbone C., Carretero J., Castellano M.,
Castignani G., Cavuoti S., Chambers K.C., Cimatti A., Colodro-Conde C.,
Congedo G., Conselice C.J., Conversi L., Copin Y., Costille A., Courbin F.,
Courtois H.M., Degaudenzi H., De Lucia G., Dubath F., Dupac X.,
Escoffier S., Fabricius M., Farina M., Farinelli R., Faustini F.,
Ferriol S., Finelli F., Frailis M., Franceschi E., Franzetti P., Fumana M.,
Galeotta S., George K., Gillis B., Giocoli C., Gomez-Alvarez P.,
Gracia-Carpio J., Grazian A., Grupp F., Haugan S.V.H., Holmes W.,
Hook I.M., Hormuth F., Hornstrup A., Jahnke K., Jhabvala M., Joachimi B.,
Kermiche S., Kiessling A., Kubik B., Kummel M., Kurki-Suonio H.,
Le Brun A.M.C., Le Mignant D., Ligori S., Lilje P.B., Lindholm V.,
Lloro I., Mainetti G., Maino D., Mansutti O., Marggraf O., Martinelli M.,
Martinet N., Marulli F., Massey R.J., Medinaceli E., Mellier Y.,
Meneghetti M., Merlin E., Meylan G., Mora A., Moscardini L., Neissner C.,
Niemi S.-M., Padilla C., Paltani S., Pasian F., Pedersen K., Percival W.J.,
Pettorino V., Pires S., Polenta G., Poncet M., Popa L.A., Pozzetti L.,
Renzi A., Rhodes J., Riccio G., Romelli E., Roncarelli M., Saglia R.,
Sakr Z., Sanchez A.G., Sapone D., Sartoris B., Schneider P., Secroun A.,
Seidel G., Serrano S., Sihvola E., Simon P., Sirignano C., Sirri G.,
Steinwagner J., Tallada-Crespi P., Taylor A.N., Tereno I., Tessore N.,
Toft S., Toledo-Moreo R., Torradeflot F., Tutusaus I., Valenziano L.,
Valiviita J., Vassallo T., Veropalumbo A., Wang Y., Weller J.,
Zinchenko I.A., Zucca E., Garcia-Bellido J., Martin-Fleitas J., Maturi M.,
Scottez V.
<Astron. Astrophys. 708, A63 (2026)>
=2026A&A...708A..63M 2026A&A...708A..63M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Photometry, infrared
Keywords: galaxies: clusters: general -
galaxies: ellipticals and lenticulars, cD - galaxies: evolution -
galaxies: interactions - galaxies: clusters: individual: Perseus -
galaxies: stellar content
Abstract:
The Euclid Early Release Observations (ERO) programme targeted the
Perseus galaxy cluster in its central region over 0.7deg2. We
combined the exceptional image quality and depth of the ERO Perseus
with FUV and NUV observations from GALEX and AstroSat/UVIT, as well as
with ugrizHa data from MegaCam at the CFHT, to deliver FUV-to-NIR
magnitudes of the 87 brightest galaxies within the Perseus cluster. We
reconstructed the star-formation history (SFH) of 59 early-type
galaxies (ETGs) within the sample, through the spectral energy
distribution (SED) fitting code CIGALE and state-of-the-art stellar
population (SP) models to reproduce the galactic UV emission from hot,
old, low-mass stars (i.e. the UV upturn). In addition, for the six
most massive ETGs in Perseus [stellar masses
log(Mstellar/M☉)≥10.3], we analysed their spatially resolved SP
and SFH through a radial SED fitting. In agreement with our previous
work on Virgo ETGs, we found that (i) the majority of the analysed
galaxies needs the presence of an UV upturn component to explain their
FUV emission, with average temperatures <TUV≳33800K; (ii) the ETGs
of Perseus have grown their stellar masses quickly, with star-
formation timescales tau≲1500Myr. We found that all ETGs in the
sample have formed more than about 30% of their stellar masses at z∼5,
up to extreme fractions of ∼100%. At z∼5, the stellar masses of the
most massive nearby ETGs, which have present-day stellar masses
log(M*/M☉)>10.8, are then found to be comparable to those
of the red quiescent galaxies observed by JWST at similar redshifts
(z>4.6). This study can be extended to ETGs in the 14000 deg2
extragalactic sky that will soon be observed by Euclid, in combination
with those from other major upcoming surveys (e.g. Rubin/LSST), and
other UV observations, to ultimately assess whether the massive ETGs
that we observe today represent the progeny of the massive high-z JWST
red quiescent galaxies.
Description:
Aperture photometry from FUV images (both GALEX and AstroSat/UVIT) are
provided for the brightest galaxies in the Perseus cluster in the
Euclid ERO field. FUV, NUV magnitudes from both GALEX and
Astrosat/UVIT, ugriz magnitudes from CFHT/MegaCam and Euclid IYJH
magnitudes are provided along with their 1sigma errors and aperture
radii in arcsec. Photometric apertures are circular, except for
PGC012358 and UGC02665 which have elliptical apertures. In these two
cases, R_G and R_U refers to semi-major axes, while the semi- minor
axis (SMin) is = 8.812 arcsec for GALEX and = 6.604 for UVIT, with
position angle PA=120deg for PGC012358. For UHC02665,
SMinGALEX=16.5-arcsec, SMinUVIT=17.3-arcsec, PA=33.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 126 87 GALEX and AstroSat/UVIT photometry of galaxies
in the Perseus cluster
tableb2.dat 129 87 CFHT/MegaCam and Euclid ugrizIYJH photometry of
galaxies in the Perseus cluster in the GALEX
apertures
tableb3.dat 128 28 CFHT/MegaCam and Euclid ugrizIYJH photometry of
galaxies in the Perseus cluster in the
AstroSat/UVIT apertures
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/192] Galaxy ID number
5- 29 A25 --- Galaxy Galaxy name from Cuillandre+2025
31- 40 F10.7 deg RAdeg [49.26/50.27] Right ascension (J2000)
42- 51 F10.7 deg DEdeg [41.23/42.02] Declination (J2000)
53- 58 F6.3 arcsec RG [2.8/86.22] Aperture radius on GALEX FUV images
60- 65 F6.3 mag FUVG [14.72/23.2] GALEX FUV AB magnitude
67- 72 F6.4 mag e_FUVG [0.05/0.36] GALEX FUV 1sigma error
74- 79 F6.3 mag NUVG [14.2/22.19] GALEX NUV AB magnitude
81- 86 F6.4 mag e_NUVG [0.05/0.37] GALEX NUV 1sigma error
88- 94 F7.3 arcsec RU [1.95/79.74]? Aperture radius on UVIT FUV images
96-102 F7.3 mag FUVU [14.44/22.27]? Astrosat/UVIT FUV AB magnitude
104-110 F7.4 mag e_FUVU [0.05/0.35]? Astrosat/UVIT FUV 1sigma error
112-118 F7.3 mag NUVU [13.92/21.53]? Astrosat/UVIT NUV AB magnitude
120-126 F7.4 mag e_NUVU [0.01/0.18]? Astrosat/UVIT NUV 1sigma error
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/192] Galaxy ID number
5- 10 F6.3 mag umagG [12.82/19.8] CFHT/MegaCam u AB magnitude for
GALEX apertures
12- 17 F6.4 mag e_umagG [0.0/0.41] CFHT/MegaCam u 1sigma error
19- 24 F6.3 mag gmagG [11.63/18.46] CFHT/MegaCam g AB magnitude for
GALEX apertures
26- 31 F6.4 mag e_gmagG [0.0/0.31] CFHT/MegaCam g 1sigma error
33- 38 F6.3 mag rmagG [10.77/17.51] CFHT/MegaCam r AB magnitude for
GALEX apertures
40- 45 F6.4 mag e_rmagG [0.0/0.35] CFHT/MegaCam r 1sigma error
47- 52 F6.3 mag imagG [10.58/17.23] CFHT/MegaCam i AB magnitude for
GALEX apertures
54- 59 F6.4 mag e_imagG [0.0/0.27] CFHT/MegaCam i 1sigma error
61- 66 F6.3 mag zmagG [10.52/17.11] CFHT/MegaCam z AB magnitude for
GALEX apertures
68- 73 F6.4 mag e_zmagG [0.0/0.34] CFHT/MegaCam z 1sigma error
75- 80 F6.3 mag IemagG [10.78/17.51] Euclid I AB magnitude for GALEX
apertures
82- 87 F6.4 mag e_IemagG [0.0/0.26] Euclid I 1sigma error
89- 94 F6.3 mag YemagG [10.17/17.03] Euclid Y AB magnitude for GALEX
apertures
96-101 F6.4 mag e_YemagG [0.0/0.35] Euclid Y 1sigma error
103-108 F6.3 mag JemagG [10.06/17.02] Euclid J AB magnitude for GALEX
apertures
110-115 F6.4 mag e_JemagG [0.0/0.24] Euclid J 1sigma error
117-122 F6.3 mag HemagG [9.91/16.94] Euclid H AB magnitude for GALEX
apertures
124-129 F6.4 mag e_HemagG [0.0/0.24] Euclid H 1sigma error
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Byte-by-byte Description of file: tableb3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- ID [1/99] Galaxy ID number
4- 9 F6.3 mag umagU [12.85/18.04] CFHT/MegaCam u AB magnitude for
UVIT apertures
11- 16 F6.4 mag e_umagU [0.0/0.29] CFHT/MegaCam u 1sigma error
18- 23 F6.3 mag gmagU [11.56/16.19] CFHT/MegaCam g AB magnitude for
UVIT apertures
25- 30 F6.4 mag e_gmagU [0.0/0.18] CFHT/MegaCam g 1sigma error
32- 37 F6.3 mag rmagU [10.85/15.21] CFHT/MegaCam r AB magnitude for
UVIT apertures
39- 44 F6.4 mag e_rmagU [0.0/0.2] CFHT/MegaCam r 1sigma error
46- 51 F6.3 mag imagU [10.84/15.06] CFHT/MegaCam i AB magnitude for
UVIT apertures
53- 58 F6.4 mag e_imagU [0.0/0.25] CFHT/MegaCam i 1sigma error
60- 65 F6.3 mag zmagU [10.67/14.72] CFHT/MegaCam z AB magnitude for
UVIT apertures
67- 72 F6.4 mag e_zmagU [0.0/0.35] CFHT/MegaCam z 1sigma error
74- 79 F6.3 mag IemagU [10.83/15.17] Euclid I AB magnitude for UVIT
apertures
81- 86 F6.4 mag e_IemagU [0.0/0.26] Euclid I 1sigma error
88- 93 F6.3 mag YemagU [10.23/14.52] Euclid Y AB magnitude for UVIT
apertures
95-100 F6.4 mag e_YemagU [0.0/0.34] Euclid Y 1sigma error
102-107 F6.3 mag JemagU [10.12/14.53] Euclid J AB magnitude for UVIT
apertures
109-114 F6.4 mag e_JemagU [0.0/0.31] Euclid J 1sigma error
116-121 F6.3 mag HemagU [9.96/14.48] Euclid H AB magnitude for UVIT
apertures
123-128 F6.4 mag e_HemagU [0.0/0.28] Euclid H 1sigma error
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Acknowledgements:
Silvia Martocchia, silvia.martocchia(at)lam.fr
(End) Patricia Vannier [CDS] 28-Jan-2026