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1. The supernova legacy survey: Measurement of ΩM, ΩΛand w from the first year data set

Author

Astier, P, Guy, J, Regnault, N, Pain, R, Aubourg, E, Balam, D, Basa, S, Carlberg, RG, Fabbro, S, Fouchez, D, Hook, IM, Howell, DA, Lafoux, H, Neill, JD, Palanque-Delabrouille, N, Perrett, K, Pritchet, CJ, Rich, J, Sullivan, M, Taillet, R, Aldering, G, Antilogus, P, Arsenijevic, V, Balland, C, Baumont, S, Bronder, J, Courtois, H, Ellis, RS, Filiol, M, Gonçalves, AC, Goobar, A, Guide, D, Hardin, D, Lusset, V, Lidman, C, McMahon, R, Mouchet, M, Mourao, A, Perlmutter, S, Ripoche, P, Tao, C, and Walton, N

Subjects
Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present distance measurements to 71 high redshift type la supernovae discovered during the first year of the 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in four bands, as part of the CFHT Legacy Survey (CFHTLS). Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes to confirm the nature of the supernovae and to measure their redshift. With this data set, we have built a Hubble diagram extending to z = 1, with all distance measurements involving at least two bands. Systematic uncertainties are evaluated making use of the multi-band photometry obtained at CFHT. Cosmological fits to this first year SNLS Hubble diagram give the following results: ΩM = 0.263 ± 0.042 (stat) ± 0.032 (sys) for a flat ACDM model; and w = -1.023 ± 0.090 (stat) ± 0.054 (sys) for a flat cosmology with constant equation of state w when combined with the constraint from the recent Sloan Digital Sky Survey measurement of baryon acoustic oscillations. © ESO 2006.

Published
2006

2. The Supernova Legacy Survey: measurement of Ω , Ω and from the first year data set

Author

Astier, P, Guy, J, Regnault, N, Pain, R, Aubourg, E, Balam, D, Basa, S, Carlberg, RG, Fabbro, S, Fouchez, D, Hook, IM, Howell, DA, Lafoux, H, Neill, JD, Palanque-Delabrouille, N, Perrett, K, Pritchet, CJ, Rich, J, Sullivan, M, Taillet, R, Aldering, G, Antilogus, P, Arsenijevic, V, Balland, C, Baumont, S, Bronder, J, Courtois, H, Ellis, RS, Filiol, M, Gonçalves, AC, Goobar, A, Guide, D, Hardin, D, Lusset, V, Lidman, C, McMahon, R, Mouchet, M, Mourao, A, Perlmutter, S, Ripoche, P, Tao, C, and Walton, N

Published
2006

3. Spectroscopic observations and analysis of the peculiar SN 1999aa

Author

Garavini, G, Folatelli, G, Goobar, A, Nobili, S, Aldering, G, Amadon, A, Amanullah, R, Astier, P, Balland, C, Blanc, G, Burns, MS, Conley, A, Dahlen, T, Deustua, SE, Ellis, R, Fabbro, S, Fan, X, Frye, B, Gates, EL, Gibbons, R, Goldhaber, G, Goldman, B, Groom, DE, Haissinski, J, Hardin, D, Hook, IM, Howell, DA, Kasen, D, Kent, S, Kim, AG, Knop, RA, Lee, BC, Lidman, C, Mendez, J, Miller, GJ, Moniez, M, Mourao, A, Newberg, H, Nugent, PE, Pain, R, Perdereau, O, Perlmutter, S, Prasad, V, Quimby, R, Raux, J, Regnault, N, Rich, J, Richards, GT, Ruiz-Lapuente, P, Sainton, G, Schaefer, BE, Schahmaneche, K, Smith, E, Spadafora, AL, Stanishev, V, Walton, NA, Wang, L, Wood-Vasey, WM, and Project, SC

Subjects
Physics, 010308 nuclear & particles physics, High velocity, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Optical spectra, Spectral line, Supernova, Cosmology supernovae, Time history, Space and Planetary Science, Ionization, 0103 physical sciences, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics
Abstract

We present an extensive new time-series of spectroscopic data of the peculiar SN 1999aa in NGC 2595. Our data set includes 25 optical spectra between -11 and +58 days with respect to B-band maximum light, providing an unusually complete time history. The early spectra resemble those of a SN 1991T-like object but with a relatively strong Ca H&K absorption feature. The first clear sign of Si II 6355, characteristic of Type Ia supernovae, is found at day -7 and its velocity remains constant up to at least the first month after B-band maximum light. The transition to normal-looking spectra is found to occur earlier than in SN 1991T suggesting SN 1999aa as a possible link between SN 1991T-like and Branch-normal supernovae. Comparing the observations with synthetic spectra, doubly ionized Fe, Si and Ni are identified at early epochs. These are characteristic of SN 1991T-like objects. Furthermore, in the day -11 spectrum, evidence is found for an absorption feature which could be identified as high velocity C II 6580 or H-alpha. At the same epoch C III 4648.8 at photospheric velocity is probably responsible for the absorption feature at 4500 A. High velocity Ca is found around maximum light together with Si II and Fe II confined in a narrow velocity window. Implied constraints on supernovae progenitor systems and explosion hydrodynamical models are briefly discussed., 46 pages including 23 figures. Accepted for publication by AJ. For full-resolution figures see http://www.physto.se/~gabri/sn99aa/

Published
2003

4. Euclid preparation: XIII. Forecasts for galaxy morphology with the Euclid Survey using Deep Generative Models

Author

Euclid Collaboration, Bretonnière, H., Huertas-Company, M., Boucaud, A., Lanusse, F., Jullo, E., MERLIN, Emiliano, Tuccillo, D., CASTELLANO, MARCO, Brinchmann, J., Conselice, C. J., Poncet, M., Popa, L., POZZETTI, Lucia, Raison, F., Rebolo, R., Rhodes, J., Roncarelli, M., Rossetti, E., Saglia, R., Schneider, P., Dole, H., Secroun, A., Seidel, G., Sirignano, C., Sirri, G., Stanco, L., Starck, J. -L., Tallada-Crespí, P., Taylor, A. N., Tereno, I., Toledo-Moreo, R., Cabanac, R., Torradeflot, F., Valentijn, E. A., VALENZIANO, LUCA, Wang, Y., Welikala, N., Weller, J., Zamorani, G., Zoubian, J., Baldi, M., BARDELLI, Sandro, Courtois, H. M., Camera, S., FARINELLI, Ruben, Medinaceli, E., Mei, S., Polenta, G., Romelli, Erik, Tenti, M., Vassallo, T., ZACCHEI, Andrea, ZUCCA, Elena, Castander, F. J., Baccigalupi, C., Balaguera-Antolínez, A., BIVIANO, ANDREA, BORGANI, STEFANO, Bozzo, E., BURIGANA, CARLO, CAPPI, Alberto, Carvalho, C. S., Casas, S., Castignani, G., Duc, P. A., Colodro-Conde, C., Coupon, J., de la Torre, S., Fabricius, M., FARINA, Maria, Ferreira, P. G., Flose-Reimberg, P., Fotopoulou, S., GALEOTTA, Samuele, Ganga, K., Fosalba, P., Garcia-Bellido, J., Gaztanaga, E., Gozaliasl, G., Hook, I. M., Joachimi, B., Kansal, V., Kashlinsky, A., Keihanen, E., Kirkpatrick, C. C., Lindholm, V., Guinet, D., Mainetti, G., Maino, D., Maoli, R., Martinelli, M., Martinet, N., McCracken, H. J., Metcalf, R. B., MORGANTE, GIANLUCA, Morisset, N., Nightingale, J., Kruk, S., Nucita, A., Patrizii, L., Potter, D., Renzi, A., RICCIO, GIUSEPPE, Sánchez, A. G., Sapone, D., Schirmer, M., Schultheis, M., Scottez, V., Kuchner, U., SEFUSATTI, Emiliano, Teyssier, R., Tutusaus, I., Valiviita, J., VIEL, MATTEO, Whittaker, L., Knapen, J. H., Serrano, S., Soubrie, E., Tramacere, A., Wang, L., Amara, A., AURICCHIO, NATALIA, Bender, R., Bodendorf, C., BONINO, Donata, Branchini, Enzo, Brau-Nogue, S., BRESCIA, Massimo, Capobianco, Vito, CARBONE, Carmelita, Carretero, J., CAVUOTI, STEFANO, Cimatti, A., Cledassou, R., Congedo, G., Conversi, L., Copin, Y., CORCIONE, Leonardo, Costille, A., Cropper, M., Da Silva, A., Degaudenzi, H., Douspis, M., Dubath, F., Duncan, C. A. J., Dupac, X., Dusini, S., Farrens, S., Ferriol, S., FRAILIS, Marco, FRANCESCHI, ENRICO, FUMANA, Marco, GARILLI, BIANCA MARIA ROSA, Gillard, W., Gillis, B., GIOCOLI, Carlo, GRAZIAN, Andrea, Grupp, F., Haugan, S. V. H., Holmes, W., Hormuth, F., Hudelot, P., Jahnke, K., Kermiche, S., Kiessling, A., Kilbinger, M., Kitching, T., Kohley, R., Kümmel, M., Kunz, M., Kurki-Suonio, H., LIGORI, Sebastiano, Lilje, P. B., Lloro, I., MAIORANO, Elisabetta, MANSUTTI, Oriana, Marggraf, O., Markovic, K., Marulli, F., Massey, R., Maurogordato, S., Melchior, M., MENEGHETTI, MASSIMO, Meylan, G., Moresco, M., Morin, B., Moscardini, L., Munari, Emiliano, Nakajima, R., Niemi, S. M., Padilla, C., Paltani, S., Pasian, F., Pedersen, K., Pettorino, V., Pires, S., Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Cosmologie et Statistiques (LCS - COSMOSTAT), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Lanusse, Francois, UAM. Departamento de Física Teórica, Bretonniere, H., Huertas-Company, M., Boucaud, A., Lanusse, F., Jullo, E., Merlin, E., Tuccillo, D., Castellano, M., Brinchmann, J., Conselice, C. J., Dole, H., Cabanac, R., Courtois, H. M., Castander, F. J., Duc, P. A., Fosalba, P., Guinet, D., Kruk, S., Kuchner, U., Serrano, S., Soubrie, E., Tramacere, A., Wang, L., Amara, A., Auricchio, N., Bender, R., Bodendorf, C., Bonino, D., Branchini, E., Brau-Nogue, S., Brescia, M., Capobianco, V., Carbone, C., Carretero, J., Cavuoti, S., Cimatti, A., Cledassou, R., Congedo, G., Conversi, L., Copin, Y., Corcione, L., Costille, A., Cropper, M., Da Silva, A., Degaudenzi, H., Douspis, M., Dubath, F., Duncan, C. A. J., Dupac, X., Dusini, S., Farrens, S., Ferriol, S., Frailis, M., Franceschi, E., Fumana, M., Garilli, B., Gillard, W., Gillis, B., Giocoli, C., Grazian, A., Grupp, F., Haugan, S. V. H., Holmes, W., Hormuth, F., Hudelot, P., Jahnke, K., Kermiche, S., Kiessling, A., Kilbinger, M., Kitching, T., Kohley, R., Kummel, M., Kunz, M., Kurki-Suonio, H., Ligori, S., Lilje, P. B., Lloro, I., Maiorano, E., Mansutti, O., Marggraf, O., Markovic, K., Marulli, F., Massey, R., Maurogordato, S., Melchior, M., Meneghetti, M., Meylan, G., Moresco, M., Morin, B., Moscardini, L., Munari, E., Nakajima, R., Niemi, S. M., Padilla, C., Paltani, S., Pasian, F., Pedersen, K., Pettorino, V., Pires, S., Poncet, M., Popa, L., Pozzetti, L., Raison, F., Rebolo, R., Rhodes, J., Roncarelli, M., Rossetti, E., Saglia, R., Schneider, P., Secroun, A., Seidel, G., Sirignano, C., Sirri, G., Stanco, L., Starck, J. -L., Tallada-Crespi, P., Taylor, A. N., Tereno, I., Toledo-Moreo, R., Torradeflot, F., Valentijn, E. A., Valenziano, L., Wang, Y., Welikala, N., Weller, J., Zamorani, G., Zoubian, J., Baldi, M., Bardelli, S., Camera, S., Farinelli, R., Medinaceli, E., Mei, S., Polenta, G., Romelli, E., Tenti, M., Vassallo, T., Zacchei, A., Zucca, E., Baccigalupi, C., Balaguera-Antolinez, A., Biviano, A., Borgani, S., Bozzo, E., Burigana, C., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Colodro-Conde, C., Coupon, J., De La Torre, S., Fabricius, M., Farina, M., Ferreira, P. G., Flose-Reimberg, P., Fotopoulou, S., Galeotta, S., Ganga, K., Garcia-Bellido, J., Gaztanaga, E., Gozaliasl, G., Hook, I. M., Joachimi, B., Kansal, V., Kashlinsky, A., Keihanen, E., Kirkpatrick, C. C., Lindholm, V., Mainetti, G., Maino, D., Maoli, R., Martinelli, M., Martinet, N., Mccracken, H. J., Metcalf, R. B., Morgante, G., Morisset, N., Nightingale, J., Nucita, A., Patrizii, L., Potter, D., Renzi, A., Riccio, G., Sanchez, A. G., Sapone, D., Schirmer, M., Schultheis, M., Scottez, V., Sefusatti, E., Teyssier, R., Tutusaus, I., Valiviita, J., Viel, M., Whittaker, L., Knapen, J. H., Bretonniere H., Huertas-Company M., Boucaud A., Lanusse F., Jullo E., Merlin E., Tuccillo D., Castellano M., Brinchmann J., Conselice C.J., Dole H., Cabanac R., Courtois H.M., Castander F.J., Duc P.A., Fosalba P., Guinet D., Kruk S., Kuchner U., Serrano S., Soubrie E., Tramacere A., Wang L., Amara A., Auricchio N., Bender R., Bodendorf C., Bonino D., Branchini E., Brau-Nogue S., Brescia M., Capobianco V., Carbone C., Carretero J., Cavuoti S., Cimatti A., Cledassou R., Congedo G., Conversi L., Copin Y., Corcione L., Costille A., Cropper M., Da Silva A., Degaudenzi H., Douspis M., Dubath F., Duncan C.A.J., Dupac X., Dusini S., Farrens S., Ferriol S., Frailis M., Franceschi E., Fumana M., Garilli B., Gillard W., Gillis B., Giocoli C., Grazian A., Grupp F., Haugan S.V.H., Holmes W., Hormuth F., Hudelot P., Jahnke K., Kermiche S., Kiessling A., Kilbinger M., Kitching T., Kohley R., Kummel M., Kunz M., Kurki-Suonio H., Ligori S., Lilje P.B., Lloro I., Maiorano E., Mansutti O., Marggraf O., Markovic K., Marulli F., Massey R., Maurogordato S., Melchior M., Meneghetti M., Meylan G., Moresco M., Morin B., Moscardini L., Munari E., Nakajima R., Niemi S.M., Padilla C., Paltani S., Pasian F., Pedersen K., Pettorino V., Pires S., Poncet M., Popa L., Pozzetti L., Raison F., Rebolo R., Rhodes J., Roncarelli M., Rossetti E., Saglia R., Schneider P., Secroun A., Seidel G., Sirignano C., Sirri G., Stanco L., Starck J.-L., Tallada-Crespi P., Taylor A.N., Tereno I., Toledo-Moreo R., Torradeflot F., Valentijn E.A., Valenziano L., Wang Y., Welikala N., Weller J., Zamorani G., Zoubian J., Baldi M., Bardelli S., Camera S., Farinelli R., Medinaceli E., Mei S., Polenta G., Romelli E., Tenti M., Vassallo T., Zacchei A., Zucca E., Baccigalupi C., Balaguera-Antolinez A., Biviano A., Borgani S., Bozzo E., Burigana C., Cappi A., Carvalho C.S., Casas S., Castignani G., Colodro-Conde C., Coupon J., De La Torre S., Fabricius M., Farina M., Ferreira P.G., Flose-Reimberg P., Fotopoulou S., Galeotta S., Ganga K., Garcia-Bellido J., Gaztanaga E., Gozaliasl G., Hook I.M., Joachimi B., Kansal V., Kashlinsky A., Keihanen E., Kirkpatrick C.C., Lindholm V., Mainetti G., Maino D., Maoli R., Martinelli M., Martinet N., McCracken H.J., Metcalf R.B., Morgante G., Morisset N., Nightingale J., Nucita A., Patrizii L., Potter D., Renzi A., Riccio G., Sanchez A.G., Sapone D., Schirmer M., Schultheis M., Scottez V., Sefusatti E., Teyssier R., Tutusaus I., Valiviita J., Viel M., Whittaker L., Knapen J.H., Astronomy, Bretonniere, H, Huertas-Company, M, Boucaud, A, Lanusse, F, Jullo, E, Merlin, E, Tuccillo, D, Castellano, M, Brinchmann, J, Conselice, Cj, Dole, H, Cabanac, R, Courtois, Hm, Castander, Fj, Duc, Pa, Fosalba, P, Guinet, D, Kruk, S, Kuchner, U, Serrano, S, Soubrie, E, Tramacere, A, Wang, L, Amara, A, Auricchio, N, Bender, R, Bodendorf, C, Bonino, D, Branchini, E, Brau-Nogue, S, Brescia, M, Capobianco, V, Carbone, C, Carretero, J, Cavuoti, S, Cimatti, A, Cledassou, R, Congedo, G, Conversi, L, Copin, Y, Corcione, L, Costille, A, Cropper, M, Da Silva, A, Degaudenzi, H, Douspis, M, Dubath, F, Duncan, Caj, Dupac, X, Dusini, S, Farrens, S, Ferriol, S, Frailis, M, Franceschi, E, Fumana, M, Garilli, B, Gillard, W, Gillis, B, Giocoli, C, Grazian, A, Grupp, F, Haugan, Svh, Holmes, W, Hormuth, F, Hudelot, P, Jahnke, K, Kermiche, S, Kiessling, A, Kilbinger, M, Kitching, T, Kohley, R, Kummel, M, Kunz, M, Kurki-Suonio, H, Ligori, S, Lilje, Pb, Lloro, I, Maiorano, E, Mansutti, O, Marggraf, O, Markovic, K, Marulli, F, Massey, R, Maurogordato, S, Melchior, M, Meneghetti, M, Meylan, G, Moresco, M, Morin, B, Moscardini, L, Munari, E, Nakajima, R, Niemi, Sm, Padilla, C, Paltani, S, Pasian, F, Pedersen, K, Pettorino, V, Pires, S, Poncet, M, Popa, L, Pozzetti, L, Raison, F, Rebolo, R, Rhodes, J, Roncarelli, M, Rossetti, E, Saglia, R, Schneider, P, Secroun, A, Seidel, G, Sirignano, C, Sirri, G, Stanco, L, Starck, Jl, Tallada-Crespi, P, Taylor, An, Tereno, I, Toledo-Moreo, R, Torradeflot, F, Valentijn, Ea, Valenziano, L, Wang, Y, Welikala, N, Weller, J, Zamorani, G, Zoubian, J, Baldi, M, Bardelli, S, Camera, S, Farinelli, R, Medinaceli, E, Mei, S, Polenta, G, Romelli, E, Tenti, M, Vassallo, T, Zacchei, A, Zucca, E, Baccigalupi, C, Balaguera-Antolinez, A, Biviano, A, Borgani, S, Bozzo, E, Burigana, C, Cappi, A, Carvalho, C, Casas, S, Castignani, G, Colodro-Conde, C, Coupon, J, de la Torre, S, Fabricius, M, Farina, M, Ferreira, Pg, Flose-Reimberg, P, Fotopoulou, S, Galeotta, S, Ganga, K, Garcia-Bellido, J, Gaztanaga, E, Gozaliasl, G, Hook, Im, Joachimi, B, Kansal, V, Kashlinsky, A, Keihanen, E, Kirkpatrick, Cc, Lindholm, V, Mainetti, G, Maino, D, Maoli, R, Martinelli, M, Martinet, N, Mccracken, Hj, Metcalf, Rb, Morgante, G, Morisset, N, Nightingale, J, Nucita, A, Patrizii, L, Potter, D, Renzi, A, Riccio, G, Sanchez, Ag, Sapone, D, Schirmer, M, Schultheis, M, Scottez, V, Sefusatti, E, Teyssier, R, Tutusaus, I, Valiviita, J, Viel, M, Whittaker, L, Knapen, Jh, Department of Physics, Research Program in Systems Oncology, and Helsinki Institute of Physics

Subjects
INFORMATION, structure [Galaxies], FOS: Physical sciences, Techniques: image processing, Morphology (biology), observation [Cosmology], Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Surveys, Cosmology: observation, 01 natural sciences, Settore FIS/05 - Astronomia e Astrofisica, DEPENDENCE, Galaxies: structure, galaxies, evolution, 0103 physical sciences, image processing [Techniques], structure, Survey, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, COSMOS, Physics, 010308 nuclear & particles physics, galaxie, Cosmology: observations, [PHYS.ASTR.GA] Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Galaxies: evolution, Física, Astronomy and Astrophysics, technique, 115 Astronomy, Space science, evolution [Galaxies], Astrophysics - Astrophysics of Galaxies, techniques, image processing, surveys, cosmology, observations, Galaxy, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), SIMULATION, Generative grammar
Abstract

Artículo escrito por un elevado número de autores, sólo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiere., We present a machine learning framework to simulate realistic galaxies for the Euclid Survey, producing more complex and realistic galaxies than the analytical simulations currently used in Euclid. The proposed method combines a control on galaxy shape parameters offered by analytic models with realistic surface brightness distributions learned from real Hubble Space Telescope observations by deep generative models. We simulate a galaxy field of 0.4 deg2 as it will be seen by the Euclid visible imager VIS, and we show that galaxy structural parameters are recovered to an accuracy similar to that for pure analytic Sérsic profiles. Based on these simulations, we estimate that the Euclid Wide Survey (EWS) will be able to resolve the internal morphological structure of galaxies down to a surface brightness of 22.5 mag arcsec-2, and the Euclid Deep Survey (EDS) down to 24.9 mag arcsec-2. This corresponds to approximately 250 million galaxies at the end of the mission and a 50% complete sample for stellar masses above 1010.6 M (resp. 109.6 M) at a redshift z ∼ 0.5 for the EWS (resp. EDS). The approach presented in this work can contribute to improving the preparation of future high-precision cosmological imaging surveys by allowing simulations to incorporate more realistic galaxies

Published
2021

5. A kilonova as the electromagnetic counterpart to a gravitational-wave source.

Author

Smartt SJ, Chen TW, Jerkstrand A, Coughlin M, Kankare E, Sim SA, Fraser M, Inserra C, Maguire K, Chambers KC, Huber ME, Krühler T, Leloudas G, Magee M, Shingles LJ, Smith KW, Young DR, Tonry J, Kotak R, Gal-Yam A, Lyman JD, Homan DS, Agliozzo C, Anderson JP, Angus CR, Ashall C, Barbarino C, Bauer FE, Berton M, Botticella MT, Bulla M, Bulger J, Cannizzaro G, Cano Z, Cartier R, Cikota A, Clark P, De Cia A, Della Valle M, Denneau L, Dennefeld M, Dessart L, Dimitriadis G, Elias-Rosa N, Firth RE, Flewelling H, Flörs A, Franckowiak A, Frohmaier C, Galbany L, González-Gaitán S, Greiner J, Gromadzki M, Guelbenzu AN, Gutiérrez CP, Hamanowicz A, Hanlon L, Harmanen J, Heintz KE, Heinze A, Hernandez MS, Hodgkin ST, Hook IM, Izzo L, James PA, Jonker PG, Kerzendorf WE, Klose S, Kostrzewa-Rutkowska Z, Kowalski M, Kromer M, Kuncarayakti H, Lawrence A, Lowe TB, Magnier EA, Manulis I, Martin-Carrillo A, Mattila S, McBrien O, Müller A, Nordin J, O'Neill D, Onori F, Palmerio JT, Pastorello A, Patat F, Pignata G, Podsiadlowski P, Pumo ML, Prentice SJ, Rau A, Razza A, Rest A, Reynolds T, Roy R, Ruiter AJ, Rybicki KA, Salmon L, Schady P, Schultz ASB, Schweyer T, Seitenzahl IR, Smith M, Sollerman J, Stalder B, Stubbs CW, Sullivan M, Szegedi H, Taddia F, Taubenberger S, Terreran G, van Soelen B, Vos J, Wainscoat RJ, Walton NA, Waters C, Weiland H, Willman M, Wiseman P, Wright DE, Wyrzykowski Ł, and Yaron O

Abstract

Gravitational waves were discovered with the detection of binary black-hole mergers and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate. Here we report observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817 and with a weak, short γ-ray burst. The transient has physical parameters that broadly match the theoretical predictions of blue kilonovae from neutron-star mergers. The emitted electromagnetic radiation can be explained with an ejected mass of 0.04 ± 0.01 solar masses, with an opacity of less than 0.5 square centimetres per gram, at a velocity of 0.2 ± 0.1 times light speed. The power source is constrained to have a power-law slope of -1.2 ± 0.3, consistent with radioactive powering from r-process nuclides. (The r-process is a series of neutron capture reactions that synthesise many of the elements heavier than iron.) We identify line features in the spectra that are consistent with light r-process elements (atomic masses of 90-140). As it fades, the transient rapidly becomes red, and a higher-opacity, lanthanide-rich ejecta component may contribute to the emission. This indicates that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.

Published
2017
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6. Supernovae and cosmology with future European facilities.

Author

Hook IM

Abstract

Prospects for future supernova surveys are discussed, focusing on the European Space Agency's Euclid mission and the European Extremely Large Telescope (E-ELT), both expected to be in operation around the turn of the decade. Euclid is a 1.2 m space survey telescope that will operate at visible and near-infrared wavelengths, and has the potential to find and obtain multi-band lightcurves for thousands of distant supernovae. The E-ELT is a planned, general-purpose ground-based, 40-m-class optical-infrared telescope with adaptive optics built in, which will be capable of obtaining spectra of type Ia supernovae to redshifts of at least four. The contribution to supernova cosmology with these facilities will be discussed in the context of other future supernova programmes such as those proposed for DES, JWST, LSST and WFIRST.

Published
2013
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7. PTF 11kx: a type Ia supernova with a symbiotic nova progenitor.

Author

Dilday B, Howell DA, Cenko SB, Silverman JM, Nugent PE, Sullivan M, Ben-Ami S, Bildsten L, Bolte M, Endl M, Filippenko AV, Gnat O, Horesh A, Hsiao E, Kasliwal MM, Kirkman D, Maguire K, Marcy GW, Moore K, Pan Y, Parrent JT, Podsiadlowski P, Quimby RM, Sternberg A, Suzuki N, Tytler DR, Xu D, Bloom JS, Gal-Yam A, Hook IM, Kulkarni SR, Law NM, Ofek EO, Polishook D, and Poznanski D

Abstract

There is a consensus that type Ia supernovae (SNe Ia) arise from the thermonuclear explosion of white dwarf stars that accrete matter from a binary companion. However, direct observation of SN Ia progenitors is lacking, and the precise nature of the binary companion remains uncertain. A temporal series of high-resolution optical spectra of the SN Ia PTF 11kx reveals a complex circumstellar environment that provides an unprecedentedly detailed view of the progenitor system. Multiple shells of circumstellar material are detected, and the SN ejecta are seen to interact with circumstellar material starting 59 days after the explosion. These features are best described by a symbiotic nova progenitor, similar to RS Ophiuchi.

Published
2012
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8. Supernova SN 2011fe from an exploding carbon-oxygen white dwarf star.

Author

Nugent PE, Sullivan M, Cenko SB, Thomas RC, Kasen D, Howell DA, Bersier D, Bloom JS, Kulkarni SR, Kandrashoff MT, Filippenko AV, Silverman JM, Marcy GW, Howard AW, Isaacson HT, Maguire K, Suzuki N, Tarlton JE, Pan YC, Bildsten L, Fulton BJ, Parrent JT, Sand D, Podsiadlowski P, Bianco FB, Dilday B, Graham ML, Lyman J, James P, Kasliwal MM, Law NM, Quimby RM, Hook IM, Walker ES, Mazzali P, Pian E, Ofek EO, Gal-Yam A, and Poznanski D

Abstract

Type Ia supernovae have been used empirically as 'standard candles' to demonstrate the acceleration of the expansion of the Universe even though fundamental details, such as the nature of their progenitor systems and how the stars explode, remain a mystery. There is consensus that a white dwarf star explodes after accreting matter in a binary system, but the secondary body could be anything from a main-sequence star to a red giant, or even another white dwarf. This uncertainty stems from the fact that no recent type Ia supernova has been discovered close enough to Earth to detect the stars before explosion. Here we report early observations of supernova SN 2011fe in the galaxy M101 at a distance from Earth of 6.4 megaparsecs. We find that the exploding star was probably a carbon-oxygen white dwarf, and from the lack of an early shock we conclude that the companion was probably a main-sequence star. Early spectroscopy shows high-velocity oxygen that slows rapidly, on a timescale of hours, and extensive mixing of newly synthesized intermediate-mass elements in the outermost layers of the supernova. A companion paper uses pre-explosion images to rule out luminous red giants and most helium stars as companions to the progenitor.

Published
2011
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9. The type Ia supernova SNLS-03D3bb from a super-Chandrasekhar-mass white dwarf star.

Author

Howell DA, Sullivan M, Nugent PE, Ellis RS, Conley AJ, Le Borgne D, Carlberg RG, Guy J, Balam D, Basa S, Fouchez D, Hook IM, Hsiao EY, Neill JD, Pain R, Perrett KM, and Pritchet CJ

Abstract

The accelerating expansion of the Universe, and the need for dark energy, were inferred from observations of type Ia supernovae. There is a consensus that type Ia supernovae are thermonuclear explosions that destroy carbon-oxygen white dwarf stars that have accreted matter from a companion star, although the nature of this companion remains uncertain. These supernovae are thought to be reliable distance indicators because they have a standard amount of fuel and a uniform trigger: they are predicted to explode when the mass of the white dwarf nears the Chandrasekhar mass of 1.4 solar masses (M(o)). Here we show that the high-redshift supernova SNLS-03D3bb has an exceptionally high luminosity and low kinetic energy that both imply a super-Chandrasekhar-mass progenitor. Super-Chandrasekhar-mass supernovae should occur preferentially in a young stellar population, so this may provide an explanation for the observed trend that overluminous type Ia supernovae occur only in 'young' environments. As this supernova does not obey the relations that allow type Ia supernovae to be calibrated as standard candles, and as no counterparts have been found at low redshift, future cosmology studies will have to consider possible contamination from such events.

Published
2006
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