Euclid Quick Data Release (Q1) Ultracool dwarfs in the Euclid Deep Field North

/ Authors

A. Mohandasan, R. Smart, C. Reyl'e, V. Brun, A. P'erez-Garrido, E. Bañados, B. Goldman, S. Casewell, M. Osorio, T. Dupuy

and 490 more authors

M. Rejkuba, E. L. Mart'in, C. Dominguez-Tagle, M. vZerjal, N. Hu'elamo, N. Lodieu, P. Cruz, R. Rebolo, M. Phillips, J.-Y. Zhang, N. Aghanim, B. Altieri, A. Amara, S. Andreon, N. Auricchio, C. Baccigalupi, M. Baldi, A. Balestra, S. Bardelli, P. Battaglia, A. Biviano, A. Bonchi, E. Branchini, M. Brescia, J. Brinchmann, S. Camera, G. Cañas-Herrera, V. Capobianco, C. Carbone, J. Carretero, S. Casas, M. Castellano, G. Castignani, S. Cavuoti, K. Chambers, A. Cimatti, C. Colodro-Conde, G. Congedo, C. Conselice, L. Conversi, Y. Copin, A. Costille, F. Courbin, H. Courtois, M. Cropper, A. Silva, H. Degaudenzi, G. D. Lucia, H. Dole, M. Douspis, F. Dubath, X. Dupac, S. Dusini, S. Escoffier, M. Farina, F. Faustini, S. Ferriol, S. Fotopoulou, M. Frailis, E. Franceschi, S. Galeotta, K. George, W. Gillard, B. Gillis, C. Giocoli, J. Graciá-Carpio, B. Granett, A. Grazian, F. Grupp, S. Haugan, J. Hoar, W. Holmes, I. Hook, F. Hormuth, A. Hornstrup, K. Jahnke, M. Jhabvala, E. Keihanen, S. Kermiche, A. Kiessling, B. Kubik, K. Kuijken, M. Kummel, M. Kunz, H. Kurki-Suonio, Q. L. Boulc'h, A. Brun, D. L. Mignant, S. Ligori, P. Lilje, V. Lindholm, I. Lloro, G. Mainetti, D. Maino, E. Maiorano, O. Mansutti, S. Marcin, O. Marggraf, M. Martinelli, N. Martinet, F. Marulli, R. Massey, E. Medinaceli, S. Mei, Y. Mellier, M. Meneghetti, E. Merlin, G. Meylan, A. Mora, M. Moresco, L. Moscardini, R. Nakajima, C. Neissner, S. Niemi, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, W. Percival, V. Pettorino, S. Pires, G. Polenta, M. Poncet, L. Popa, L. Pozzetti, F. Raison, A. Renzi, J. Rhodes, G. Riccio, E. Romelli, M. Roncarelli, R. Saglia, Z. Sakr, D. Sapone, B. Sartoris, J. Schewtschenko, M. Schirmer, P. Schneider, T. Schrabback, A. Secroun, G. Seidel, S. Serrano, P. Simon, C. Sirignano, G. Sirri, L. Stanco, J. Steinwagner, C. Surace, P. Tallada-Cresp'i, A. Taylor, I. Tereno, R. Toledo-Moreo, F. Torradeflot, A. Tsyganov, I. Tutusaus, L. Valenziano, J. Valiviita, T. Vassallo, G. Kleijn, A. Veropalumbo, D. Vibert, Y. Wang, J. Weller, A. Zacchei, G. Zamorani, F. Zerbi, E. Zucca, J. Mart'in-Fleitas, V. S. U. M. E. L. Pasteur, Cnrs, Observatoire des Sciences de l'Univers Theta Franche-Comte Bourgogne, Institut Utinam, Observatoire de Besanccon, BP 1615, 25010 Besanccon Cedex, France, I. Torino, 20 viaOsservatorio, 1. P. Torinese, Italy, S. O. Physics, Astronomy, Mathematics, U. Hertfordshire, C. Lane, Hatfield AL10 9AB, Uk, A. Universit'e, Cnes, Lam, Marseille, Departamento de F'isica Aplicada, Universidad Polit'ecnica de Cartagena, Campus Muralla del Mar, 30202 Cartagena, Murcia, Spain., M. Astronomie, 17 Konigstuhl, 69117 Heidelberg, Germany, I. University, 1. R. J. Cassini, 67400 Illkirch-Graffenstaden, U. Strasbourg, O. Strasbourg, Umr 7550, 67000 Strasbourg, U. Leicester, University Road, Leicester, LE1 7RH, C. D. Astrobiolog'ia, CSIC--INTA, Esac campus, camino bajo del castillo sn, 28692 Villanueva de la Canada, Madrid, Institute for Astronomy, U. Edinburgh, R. Observatory, B. Hill, Edinburgh EH9 3HJ, E. Observatory, Karl-Schwarzschild-Str.2, 85748 Garching, Instituto de Astrof'isica de Canarias, V'ia L'actea, 38205 La Laguna, Tenerife, U. L. Laguna, D. Astrof'isica, 38205 La Laguna, 38200, L. Laguna, Consejo Superior Investigaciones Cientificas, Calle Serrano 117, 28014 Madrid, Universit'e Paris-Saclay, I. D. Spatiale, 91405, Orsay, Esacesa, Camino Bajo de Castillo, Sn, Urb. Villafranca del Castillo, S. O. Mathematics, Physics, U. Surrey, Guildford, Surrey, GU2 7XH, Inaf Brera, 28 ViaBrera, 20133 Milano, I. Bologna, V. G. 933, 40129 Bologna, Ifpu, Institute for Fundamental Physics of the Universe, 2. viaBeirut, 34127 Trieste, Inaf Trieste, 11 ViaG.B.Tiepolo, 34127 Trieste, Infn, Sezione di Trieste, 2. ViaValerio, TS 34127Trieste, Sissa, International School for Advanced Studies, Via Bonomea 265, TS 34136Trieste, D. Astronomia, U. Bologna, V. G. 932, I. Bologna, 62 vialeBertiPichat, 40129 Bologna, Inaf - Padova, 5. Viadell'Osservatorio, 35131 Padova, S. Center, Italian Space Agency, via del Politecnico snc, 00133 Roma, D. Fisica, U. Genova, 33 viaDodecaneso, 16146, Genova, I. Genova, Department of PhysicsE. Pancini, U. Federico, 6. ViaCinthia, 80126, Napoli, I. -. Capodimonte, 16 viaMoiariello, 80131 Napoli, I. D. A. E. C. D. Espacco, U. Porto, Caup, Rua das Estrelas, P. Porto, Portugal, F. Porto, Rua do Campo Alegre, 4169-007 Porto, U. Torino, 1. ViaP.Giuria, 10125 Torino, I. Torino, European Space AgencyESTEC, 1. Keplerlaan, 2. Noordwijk, The Netherlands., Institute Lorentz, Leiden University, 2. NielsBohrweg, 2333 CA Leiden, L. Observatory, 55 Einsteinweg, 2333 CC Leiden, Inaf-Iasf Milano, 12 ViaAlfonsoCorti, 20133 Milano, Centro de Investigaciones Energ'eticas, Medioambientales y Tecnol'ogicas, 40 AvenidaComplutense, 28014 Madrid, Port d'Informaci'o Cient'ifica, Campus Uab, C. Sn, 08193 Bellaterra, I. F. Physics, Cosmology, Rwth Aachen University, 52056 Aachen, Inafiasf Roma, 33 viaFrascati, 00078 Monte Porzio Catone, I. Naples, U. Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, Usa, D. Bologna, J. B. C. F. Astrophysics, D. Physics, U. Manchester, Oxford Road, M13 9PL, European Space AgencyESRIN, 1. LargoGalileoGalilei, 00044 Frascati, Roma, 1. Universit'eClaudeBernardLyon, CNRSIN2p3, I. Lyon, Umr 5822, Villeurbanne, F-69100, Institut de Ci'encies del Cosmos, U. Barcelona, 1. Mart'iiFranques, 08193 Barcelona, I. C. D. R. I. E. Avanccats, 23 PasseigdeLlu'isCompanys, 08193 Barcelona, 1. UCBLyon, Iuf, 4. R. E. Fermi, 69622 Villeurbanne, Mullard Space Science Laboratory, U. London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, Departament de F'isica, F. Ciencias, Universidade Tecnica de Lisboa, C8 Edif'icio, C. Grande, P. Lisboa, 1049-001 Lisboa, D. O. Astronomy, U. Geneva, 16 ch.d'Ecogia, 1290 Versoix, Switzerland., INFN-Padova, 8. viaMarzolo, 35131 Padova, Cppm, I. D. A. E. P. Spaziali, V. Cavaliere, 100, 00133 Roma, H. P. Laboratory, U. Bristol, Tyndall Avenue, Bristol, BS8 1TL, Universitatssternwarte Munchen, F. Physik, Ludwig-Maximilians-Universitat Munchen, 1. Scheinerstrasse, 8. Munchen, M. F. P. Physics, 1. Giessenbachstr., I. Astrophysics, U. Oslo, P. O. B. 1. Blindern, 0315 Oslo, Norway., Jet propulsion Laboratory, C. I. O. Technology., 4800 Oak Grove Drive, Pasadena, Ca, 91109, L. University, Lancaster, LA1 4YB, Felix Hormuth Engineering, 17 Goethestr., 69181 Leimen, T. Denmark, Elektrovej 327, 2800 Kgs. Lyngby, Denmark., Cosmic Dawn Center, Nasa Goddard Space Flight Center, Greenbelt, MD 20771, H. I. O. Physics, 2. GustafHallstrominkatu, 0. Helsinki, Finland., U. Geneve, D'epartement de Physique Th'eorique, Centre for Theoretical Physics, 24 quai Ernest-Ansermet, 4. CH-1211Geneve, 64 P.O.Box, U. Helsinki, Helsinki, Centre de Calcul de l'IN2P3CNRS, 21 avenue Pierre de Coubertin F-69627 Villeurbanne Cedex, Laboratoire d'etude de l'Univers et des phenomenes eXtremes, Observatoire de Paris, Universit'e Psl, Sorbonne Universit'e, 92190 Meudon, Ska Observatory, J. Bank, Lower Withington, Macclesfield, Cheshire SK11 9FT, Dipartimento di FisicaAldo Pontremoli, U. Milano, 16 viaCeloria, I. Milano, U. Sciences, A. Switzerland, School of Materials Science, 5210 Windisch, U. Bonn, Argelander Institut fur Astronomie, 71 AufdemHugel, 53121 Bonn, I. Roma, P. A. Moro, 2. -. C. D. D. Fisica, Edificio G. Marconi, 00133 Roma, V. G. 932, Institute for Computational Cosmology, D. University, South Road, Durham, DH1 3LE, Universit'e de Paris Cit'e, Astroparticule et Cosmologie, 7. Paris, C. Laboratory, Centre Pierre Binetruy, IRL2007

/ Abstract

Ultracool dwarfs (UCDs) encompass the lowest mass stars and brown dwarfs, defining the stellar substellar boundary. They have significant potential for advancing the understanding of substellar physics; however, these objects are challenging to detect due to their low luminosity. The wide coverage and deep sensitivity of the Euclid survey will increase the number of confirmed and well characterised UCDs by several orders of magnitude. In this study, we take advantage of the Euclid Quick Data Release (Q1) and in particular we look in detail at the known and new UCDs in the Euclid Deep Field North (22.9 deg2 down to JE = 24.5 mag), to understand the advantages of using the slitless Euclid spectroscopy. We compile a comparison sample of known UCDs and use their spectra to demonstrate the capability of Euclid to derive spectral types using a template matching method. This method is then applied to the spectra of the newly identified candidates. We confirm that 33 of these candidates are new UCDs, with spectral types ranging from M7 to T1 and JE = 17 to 21 mag. We look at their locus in colour colour diagrams and compare them with the expected colours of QSOs. A machine readable catalogue is provided for further study, containing both the comparison sample and the newly identified UCDs, along with their spectral classifications where the Q1 spectra quality allows for confident determination