J/A+A/711/A24ivo://CDS.VizieR/J/A+A/711/A24CDSEuclid CollaborationBisigello L.Rodighiero G.Fotopoulou S.,Ricci F.Jahnke K.Feltre A.Allevato V.Shankar F.Cassata P.,Dalla Bonta E.Gandolfi G.Girardi G.Giulietti M.Grazian A.,Lovell C.Maiolino R.Matamoro Zatarain T.Mezcua M.Prandoni I.,Roberts D.Roster W.Salvato M.Siudek M.Tarsitano F.Toba Y.,Vietri A.Wang L.Zamorani G.Baes M.Belladitta S.Nersesian A.,Spinoglio L.Lopez Lopez X.Aghanim N.Altieri B.Amara A.,Andreon S.Auricchio N.Aussel H.Baccigalupi C.Baldi M.,Balestra A.Bardelli S.Basset A.Battaglia P.Bender R.Biviano A.,Bonchi A.Branchini E.Brescia M.Brinchmann J.Camera S.,Canas-Herrera G.Capobianco V.Carbone C.Carretero J.Casas S.,Castellano M.Castignani G.Cavuoti S.Chambers K.C.Cimatti A.,Colodro-Conde C.Congedo G.Conselice C.J.Conversi L.Copin Y.,Courbin F.Courtois H.M.Cropper M.Da Silva A.Degaudenzi H.,De Lucia G.Di Giorgio A.M.Dolding C.Dole H.Dubath F.,Duncan C.A.J.Dupac X.Dusini S.Ealet A.Escoffier S.Farina M.,Farinelli R.Faustini F.Ferriol S.Finelli F.Frailis M.,Franceschi E.Galeotta S.George K.Gillard W.Gillis B.Giocoli C.,Gomez-Alvarez P.Gracia-Carpio J.Granett B.R.Grupp F.Gwyn S.,Haugan S.V.H.Hoekstra H.Holmes W.Hook I.M.Hormuth F.,Hornstrup A.Hudelot P.Jhabvala M.Keihaenen E.Kermiche S.,Kiessling A.Kubik B.Kuemmel M.Kunz M.Kurki-Suonio H.,Le Boulc'h Q.Le Brun A.M.C.Le Mignant D.Liebing P.Ligori S.,Lilje P.B.Lindholm V.Lloro I.Mainetti G.Maino D.Maiorano E.,Mansutti O.Marcin S.Marggraf O.Martinelli M.Martinet N.,Marulli F.Massey R.Maurogordato S.Medinaceli E.Mei S.,Melchior M.Mellier Y.Meneghetti M.Merlin E.Meylan G.Mora A.,Moresco M.Moscardini L.Nakajima R.Neissner C.Niemi S.-M.,Nightingale J.W.Padilla C.Paltani S.Pasian F.Pedersen K.,Percival W.J.Pettorino V.Pires S.Polenta G.Poncet M.Popa L.A.,Pozzetti L.Raison F.Rebolo R.Renzi A.Rhodes J.Riccio G.,Romelli E.Roncarelli M.Rossetti E.Rottgering H.J.A.Rusholme B.,Saglia R.Sakr Z.Sapone D.Sartoris B.Schewtschenko J.A.,Schirmer M.Schneider P.Schrabback T.Scodeggio M.Secroun A.,Seidel G.Serrano S.Simon P.Sirignano C.Sirri G.Stanco L.,Steinwagner J.Tallada-Crespi P.Taylor A.N.Teplitz H.I.Tereno I.,Toft S.Toledo-Moreo R.Torradeflot F.Tutusaus I.Valenziano L.,Valiviita J.Vassallo T.Verdoes Kleijn G.Veropalumbo A.Wang Y.,Weller J.Zacchei A.Zerbi F.M.Zinchenko I.A.Zucca E.,Ballardini M.Bolzonella M.Bozzo E.Burigana C.Cabanac R.Cappi A.,Di Ferdinando D.Escartin Vigo J.A.Gabarra L.Huertas-Company M.,Martin-Fleitas J.Matthew S.Maturi M.Mauri N.Pezzotta A.,Poentinen M.Porciani C.Risso I.Scottez V.Sereno M.Tenti M.,Viel M.Wiesmann M.Akrami Y.Andika I.T.Anselmi S.Archidiacono M.,Atrio-Barandela F.Benoist C.Benson K.Bertacca D.Bethermin M.,Blanchard A.Blot L.Brown M.L.Bruton S.Calabro A.Caro F.,Carvalho C.S.Castro T.Charles Y.Cogato F.Contini T.Cooray A.R.,Cucciati O.Davini S.De Paolis F.Desprez G.Diaz-Sanchez A.,Diaz J.Di Domizio S.Diego J.M.Enia A.Fang Y.Ferrari A.G.,Ferreira P.G.Finoguenov A.Fontana A.Fontanot F.Franco A.,Ganga K.Garcia-Bellido J.Gasparetto T.Gautard V.Gaztanaga E.,Giacomini F.Gianotti F.Gozaliasl G.Guidi M.Gutierrez C.M.,Hall A.Hartley W.G.Hemmati S.Hernandez-Monteagudo C.,Hildebrandt H.Hjorth J.Kajava J.E.Kang Y.Kansal V.,Karagiannis D.Kiiveri K.Kirkpatrick C.Kruk S.Le Graet J.,Legrand L.Lembo M.Lepori F.Leroy G.Lesci G.F.Lesgourgues J.,Leuzzi L.Liaudat T.I.Loureiro A.Macias-Perez J.Maggio G.,Magliocchetti M.Magnier E.A.Mancini C.Mannucci F.Maoli R.,Martins C.J.A.P.Maurin L.Miluzio M.Monaco P.Moretti C.,Morgante G.Nadathur S.Naidoo K.Navarro-Alsina A.Nesseris S.,Passalacqua F.Paterson K.Patrizii L.Pisani A.Potter D.Quai S.,Radovich M.Rocci P.-F.Sacquegna S.Sahlen M.Sanders D.B.Sarpa E.,Scarlata C.Schaye J.Schneider A.Sciotti D.Sellentin E.,Shulevski A.Smith L.C.Tanidis K.Tao C.Testera G.Teyssier R.,Tosi S.Troja A.Tucci M.Valieri C.Venhola A.Vergani D.Verza G.,Vielzeuf P.Viitanen A.Walton N.A.Weaver J.R.Soubrie E.Scott D.2026-06-30T15:40:32Z2026-06-30T16:40:13ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.fractive-galactic-nucleiredshiftedultraviolet-astronomyRecent observations with the James Webb Space Telescope (JWST) have revealed an interesting population of sources with a compact morphology and a characteristic v-shaped continuum, namely blue at a rest frame {lambda}<4000{AA} and red at longer wavelengths. The nature of these sources, which are called little red dots (LRDs), is still highly debated because it is unclear whether they host active galactic nuclei (AGNs) and their number seems to drop drastically at z<4. We took advantage of the 63deg^2^ covered by the quick Euclid Quick Data Release (Q1) to extend the search for LRDs to brighter magnitudes and lower redshifts than what was possible with JWST. This is fundamental for a broader view of the evolution of this peculiar galaxy population. The selection was performed by fitting the available photometric data (Euclid, the Spitzer Infrared Array Camera (IRAC), and ground-based griz data) with two power laws to retrieve the rest-frame optical and UV slopes consistently over a wide redshift range (i.e. z<7.6). We then excluded extended objects and possible line emitters and inspected the data visually to remove any imaging artefacts. The final selection included 3341 LRD candidates from z=0.33 to z=3.6, 29 of which were also detected in IRAC. The resulting rest-frame UV luminosity function, in contrast with previous JWST studies, shows that the number density of LRD candidates increases from high redshift to z=1.5-2.5 and decreases at even lower redshifts. The subsample of more robust LRD candidates that are also detected with IRAC show a weaker evolution, however, which is affected by low statistics and limited by the IRAC resolution. The comparison with previous quasar UV luminosity functions shows that LRDs are not the dominant AGN population at z<4 and M_UV_<-21. Follow-up studies of these LRD candidates are pivotal to confirm their nature, probe their physical properties, and determine whether they are compatible with JWST sources because the different spatial resolution and wavelength coverage of Euclid and JWST might select different samples of compact sources.2026A&A...711A..24Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/711/A24CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/711/A10 : Euclid (Q1). Census of dwarf galaxies (Euclid Coll., 2026)J/A+A/711/A16 : X-ray point-like sources of Euclid (Q1) (Euclid Coll.+, 2026)J/A+A/711/A37 : Ultracool dwarfs in Euclid Deep Fields (Zerjal+, 2026)J/A+A/711/A38 : Euclid Q1. Photometric studies of known transientsJ/A+A/711/A39 : Euclid Q1. Secondary nuclei in ET galaxies (Fabricius+, 2026)J/A+A/711/A20 : Galaxies of Euclid (Q1) (Euclid Coll.+, 2026)J/A+A/711/A24 : Euclid Q1. Little red dots properties (Euclid Coll., 2026)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/711/A24https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/711/A24http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/711/A24https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/711/A24https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/711/A24http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/711/A24GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/711/A24/tabled1 (Little red dots (LRDs)properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/711/A24/tabled1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/711/A24/tabled1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/711/A24/tabled1?GETtext/xml+votable180.050000true50.81155389-27.901950.0055555555555555564/2145 5/2557 2559 2901 2903 3839 4010-4011 8506 8579 8592 8982-8983 8989 9032 6/10235 11601 11603 11609 11611 15351 15353-15355 16034-16035 16038 16056 33979 33982-33983 34028 34030 34307 34309-34311 34313 34315 34337 34339-34342 34352-34353 34372 34374 34376-34377 35926-35927 35953 35955 35964 36098 36104 36106-36107https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/711/A24?format=asciiUVdefaultJ/A+A/711/A24/tabled1Little red dots (LRDs)propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification numbermeta.id;meta.mainRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainzRedshiftsrc.redshiftfloate_zError on the redshiftstat.error;src.redshiftfloatUVMAGRest-frame UV magnitudemagphys.magAbsfloate_UVMAGError on the rest-frame UV magnitudemagstat.errorfloatbetaUVRest-frame UV slope (f_lambda_{prop.to}lambda^beta^)meta.crypticfloate_betaUVError on the rest-frame UV slopestat.errorfloatbetaoptRest-frame optical slope (f_lambda_{prop.to}lambda^beta^)meta.crypticfloate_betaoptError on the rest-frame optical slopestat.errorfloat