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Start Over Author "M. Cropper" Publisher oxford university press (oup)
5 results on '"M. Cropper"'

1. First XMM-Newton observations of strongly magnetic cataclysmic variables -- II. Timing studies of DP Leo and WW Hor

Author

D. Pandel, F. A. Cordova, R. E. Shirey, G. Ramsay, M. Cropper, K. O. Mason, R. Much, and D. Kilkenny

Subjects
Physics, Orbital elements, Accretion (meteorology), Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, White dwarf, Astronomy, Astronomy and Astrophysics, Astrophysics, Orbital period, Light curve, Intermediate polar, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Optical depth, Eclipse
Abstract

XMM-Newton was used to observe two eclipsing, magnetic cataclysmic variables, DP Leo and WW Hor, continuously for three orbital cycles each. Both systems were in an intermediate state of accretion. For WW Hor we also obtained optical light curves with the XMM-Newton Optical Monitor and from ground-based observations. Our analysis of the X-ray and optical light curves allows us to constrain physical and geometrical parameters of the accretion regions and derive orbital parameters and eclipse ephemerides of the systems. For WW Hor we directly measure horizontal and vertical temperature variations in the accretion column. From comparisons with previous observations we find that changes in the accretion spot longitude are correlated with the accretion rate. For DP Leo the shape of the hard X-ray light curve is not as expected for optically thin emission, showing the importance of optical depth effects in the post-shock region. We find that the spin period of the white dwarf is slightly shorter than the orbital period and that the orbital period is decreasing faster than expected for energy loss by gravitational radiation alone., Accepted for publication in MNRAS, 12 pages, 6 figures

Published
2002
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2. Spectropolarimetry of the magnetic white dwarf PG1015+014: evidence for a 100-MG field

Author

Dayal Wickramasinghe and M. Cropper

Subjects
Physics, symbols.namesake, Nuclear magnetic resonance, Space and Planetary Science, symbols, White dwarf, Balmer series, Astronomy and Astrophysics, Magnetic star, Champ magnetique
Abstract

Presentation de la spectropolarimetrie de la naine blanche magnetique PG1015+014 montrant un spectre riche en composantes Zeeman des raies Hα et de Balmer dans l'etendue de longueur d'onde 4000-7000 A. Les donnees sont utilisees pour modeliser le champ magnetique a la surface de l'etoile

Published
1988
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4. The high-overtone p-mode spectrum of the rapidly oscillating AP star HR 1217 (HD 24712) - results of a frequency analysis of 324 hr of multi-site photometric observations obtained during a 46-d time-span in 1986*

Author

Denis J. Sullivan, H. Schneider, Christiaan Sterken, Werner W. Weiss, J. Christopher Clemens, H. J. Wood, J. Seeman, A. van der Peet, Souza Oliveira Kepler, P. Martinez, Steven D. Kawaler, M. Cropper, D. W. Kurtz, Tobias J. Kreidl, and J. M. Matthews

Subjects
Physics, business.industry, Overtone, Stellar rotation, Astronomy and Astrophysics, Astrophysics, Magnetic field, Photometry (optics), Dipole, Amplitude, Optics, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, business, Rapidly oscillating Ap star, Stellar pulsation
Abstract

The present high-speed photometry for the rapidly oscillating Ap star HR 1217 indicates that the 6-min light variations are amplitude-modulated, in phase with the magnetic variations. Amplitude and magnetic maxima coincide, while the mean light minimum occurs at a perhaps significantly different time. It is established that HR 1217 is an oblique rotator with a centered dipole magnetic field, as well as an oblique pulsator whose pulsation and magnetic axes are aligned. There are six principal frequencies of pulsation; the secondary frequencies indicate that the principal ones are amplitude-modulated on a time-scale of months.

Published
1989
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5. Euclid preparation : XXIII. Derivation of galaxy physical properties with deep machine learning using mock fluxes and H-band images

Author

Collaboration, Euclid, Bisigello, L, Conselice, C J, Baes, M, Bolzonella, M, Brescia, M, Cavuoti, S, Cucciati, O, Humphrey, A, Hunt, L K, Maraston, C, Pozzetti, L, Tortora, C, van Mierlo, S E, Aghanim, N, Auricchio, N, Baldi, M, Bender, R, Bodendorf, C, Bonino, D, Branchini, E, Brinchmann, J, Camera, S, Capobianco, V, Carbone, C, Carretero, J, Castander, F J, Castellano, M, Cimatti, A, Congedo, G, Conversi, L, Copin, Y, Corcione, L, Courbin, F, 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, Franzetti, P, Fumana, M, Garilli, B, Gillard, W, Gillis, B, Giocoli, C, Grazian, A, Grupp, F, Guzzo, L, Haugan, S V H, Holmes, W, Hormuth, F, Hornstrup, A, Jahnke, K, Kümmel, M, Kermiche, S, Kiessling, A, Kilbinger, M, Kohley, R, 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, Medinaceli, E, Meneghetti, M, Merlin, E, Meylan, G, Moresco, M, Moscardini, L, Munari, E, Niemi, S M, Padilla, C, Paltani, S, Pasian, F, Pedersen, K, Pettorino, V, Polenta, G, Poncet, M, Popa, L, Raison, F, Renzi, A, Rhodes, J, Riccio, G, Rix, H -W, Romelli, E, Roncarelli, M, Rosset, C, Rossetti, E, Saglia, R, Sapone, D, Sartoris, B, Schneider, P, Scodeggio, M, Secroun, A, Seidel, G, Sirignano, C, Sirri, G, Stanco, L, Tallada-Crespí, P, Tavagnacco, D, Taylor, A N, Tereno, I, Toledo-Moreo, R, Torradeflot, F, Tutusaus, I, Valentijn, E A, Valenziano, L, Vassallo, T, Wang, Y, Zacchei, A, Zamorani, G, Zoubian, J, Andreon, S, Bardelli, S, Boucaud, A, Colodro-Conde, C, Ferdinando, D Di, Graciá-Carpio, J, Lindholm, V, Maino, D, Mei, S, Scottez, V, Sureau, F, Tenti, M, Zucca, E, Borlaff, A S, Ballardini, M, Biviano, A, Bozzo, E, Burigana, C, Cabanac, R, Cappi, A, Carvalho, C S, Casas, S, Castignani, G, Cooray, A, Coupon, J, Courtois, H M, Cuby, J, Davini, S, De Lucia, G, Desprez, G, Dole, H, Escartin, J A, Escoffier, S, Farina, M, Fotopoulou, S, Ganga, K, Garcia-Bellido, J, George, K, Giacomini, F, Gozaliasl, G, Hildebrandt, H, Hook, I, Huertas-Company, M, Kansal, V, Keihanen, E, Kirkpatrick, C C, Loureiro, A, Macías-Pérez, J F, Magliocchetti, M, Mainetti, G, Marcin, S, Martinelli, M, Martinet, N, Metcalf, R B, Monaco, P, Morgante, G, Nadathur, S, Nucita, A A, Patrizii, L, Peel, A, Potter, D, Pourtsidou, A, Pöntinen, M, Reimberg, P, Sánchez, A G, Sakr, Z, Schirmer, M, Sefusatti, E, Sereno, M, Stadel, J, Teyssier, R, Valieri, C, Valiviita, J, Viel, M, Astronomy, Euclid Collaboration, L. Bisigello, C. J. Conselice, M. Bae, M. Bolzonella, M. Brescia, S. Cavuoti, O. Cucciati, A. Humphrey, L. K. Hunt, C. Maraston, L. Pozzetti, C. Tortora, S. E. van Mierlo, N. Aghanim, N. Auricchio, M. Baldi, R. Bender, C. Bodendorf, D. Bonino, E. Branchini, J. Brinchmann, S. Camera, V. Capobianco, C. Carbone, J. Carretero, F. J. Castander, M. Castellano, A. Cimatti, G. Congedo, L. Conversi, Y. Copin, L. Corcione, F. Courbin, M. Cropper, A. Da Silva, H. Degaudenzi, M. Douspi, F. Dubath, C. A. J. Duncan, X. Dupac, S. Dusini, S. Farren, S. Ferriol, M. Fraili, E. Franceschi, P. Franzetti, M. Fumana, B. Garilli, W. Gillard, B. Gilli, C. Giocoli, A. Grazian, F. Grupp, L. Guzzo, S. V. H. Haugan, W. Holme, F. Hormuth, A. Hornstrup, K. Jahnke, M. Kümmel, S. Kermiche, A. Kiessling, M. Kilbinger, R. Kohley, M. Kunz, H. Kurki-Suonio, S. Ligori, P. B. Lilje, I. Lloro, E. Maiorano, O. Mansutti, O. Marggraf, K. Markovic, F. Marulli, R. Massey, S. Maurogordato, E. Medinaceli, M. Meneghetti, E. Merlin, G. Meylan, M. Moresco, L. Moscardini, E. Munari, S. M. Niemi, C. Padilla, S. Paltani, F. Pasian, K. Pedersen, V. Pettorino, G. Polenta, M. Poncet, L. Popa, F. Raison, A. Renzi, J. Rhode, G. Riccio, H. -W. Rix, E. Romelli, M. Roncarelli, C. Rosset, E. Rossetti, R. Saglia, D. Sapone, B. Sartori, P. Schneider, M. Scodeggio, A. Secroun, G. Seidel, C. Sirignano, G. Sirri, L. Stanco, P. Tallada-Crespí, D. Tavagnacco, A. N. Taylor, I. Tereno, R. Toledo-Moreo, F. Torradeflot, I. Tutusau, E. A. Valentijn, L. Valenziano, T. Vassallo, Y. Wang, A. Zacchei, G. Zamorani, J. Zoubian, S. Andreon, S. Bardelli A. Boucaud, C. Colodro-Conde, D. Di Ferdinando, J. Graciá-Carpio, V. Lindholm, D. Maino, S. Mei, V. Scottez, F. Sureau, M. Tenti, E. Zucca, A. S. Borlaff, M. Ballardini, A. Biviano, E. Bozzo, C. Burigana, R. Cabanac, A. Cappi, C. S. Carvalho, S. Casa, G. Castignani, A. Cooray, J. Coupon, H. M. Courtoi, J. Cuby, S. Davini, G. De Lucia, G. Desprez, H. Dole, J. A. Escartin, S. Escoffier, M. Farina, S. Fotopoulou, K. Ganga, J. Garcia-Bellido, K. George, F. Giacomini, G. Gozaliasl, H. Hildebrandt, I. Hook, M. Huertas-Company, V. Kansal, E. Keihanen, C. C. Kirkpatrick, A. Loureiro, J. F. Macías-Pérez, M. Magliocchetti, G. Mainetti, S. Marcin, M. Martinelli, N. Martinet, R. B. Metcalf, P. Monaco, G. Morgante, S. Nadathur, A. A. Nucita, L. Patrizii, A. Peel, D. Potter, A. Pourtsidou, M. Pöntinen, P. Reimberg, A. G. Sánchez, Z. Sakr, M. Schirmer, E. Sefusatti, M. Sereno, J. Stadel, R. Teyssier, C. Valieri, J. Valiviita, M. Viel, Bisigello, L., Conselice, C. J., Baes, M., Bolzonella, M., Brescia, M., Cavuoti, S., Cucciati, O., Humphrey, A., Hunt, L. K., Maraston11, C., Pozzetti, L., Tortora, C., van Mierlo, S. E., Aghanim, N., Auricchio, N., Baldi, M., Bender, R., Bodendorf, C., Bonino, D., Branchini, E., Brinchmann, J., Camera, S., Capobianco, V., Carbone, C., Carretero, J., Castander, F. J., Castellano, M., Cimatti, A., Congedo, G., Conversi, L., Copin, Y., Corcione, L., Courbin, F., 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., Franzetti, P., Fumana, M., Garilli, B., Gillard, W., Gillis, B., Giocoli, C., Grazian, A., Grupp, F., Guzzo, L., Haugan, S. V. H., Holmes, W., Hormuth, F., Hornstrup, A., Jahnke, K., Kümmel, M., Kermiche, S., Kiessling, A., Kilbinger, M., Kohley, R., 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., Medinaceli, E., Meneghetti, M., Merlin, E., Meylan, G., Moresco, M., Moscardini, L., Munari, E., Niemi, S. M., Padilla, C., Paltani, S., Pasian, F., Pedersen, K., Pettorino, V., Polenta, G., Poncet, M., Popa, L., Raison, F., Renzi, A., Rhodes, J., Riccio, G., Rix, H. -W., Romelli, E., Roncarelli, M., Rosset, C., Rossetti, E., Saglia, R., Sapone, D., Sartoris, B., Schneider, P., Scodeggio, M., Secroun, A., Seidel, G., Sirignano, C., Sirri, G., Stanco, L., Tallada-Crespí, P., Tavagnacco, D., Taylor, A. N., Tereno, I., Toledo-Moreo, R., Torradeflot, F., Tutusaus, I., Valentijn, E. A., Valenziano, L., Vassallo, T., Wang, Y., Zacchei, A., Zamorani, G., Zoubian, J., Andreon, S., Boucaud, S. Bardelli A., Colodro-Conde, C., Di Ferdinando, D., Graciá-Carpio, J., Lindholm, V., Maino, D., Mei, S., Scottez, V., Sureau, F., Tenti, M., Zucca, E., Borlaff, A. S., Ballardini, M., Biviano, A., Bozzo, E., Burigana, C., Cabanac, R., Cappi, A., Carvalho, C. S., Casas, S., Castignani, G., Cooray, A., Coupon, J., Courtois, H. M., Cuby, J., Davini, S., De Lucia, G., Desprez, G., Dole, H., Escartin, J. A., Escoffier, S., Farina, M., Fotopoulou, S., Ganga, K., Garcia-Bellido, J., George, K., Giacomini, F., Gozaliasl, G., Hildebrandt, H., Hook, I., Huertas-Company, M., Kansal, V., Keihanen, E., Kirkpatrick, C. C., Loureiro, A., Macías-Pérez, J. F., Magliocchetti, M., Mainetti, G., Marcin, S., Martinelli, M., Martinet, N., Metcalf, R. B., Monaco, P., Morgante, G., Nadathur, S., Nucita, A. A., Patrizii, L., Peel, A., Potter, D., Pourtsidou, A., Pöntinen, M., Reimberg, P., Sánchez, A. G., Sakr, Z., Schirmer, M., Sefusatti, E., Sereno, M., Stadel, J., Teyssier, R., Valieri, C., Valiviita111, J., Viel, M., Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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 Paris Cité (UPCité), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Centre de Calcul de l'IN2P3 (CC-IN2P3), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
FOS: Physical sciences, Euclid, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, galaxies: general, galaxies: general, galaxies: photometry, galaxies: star formation, galaxies: evolution, Astrophysics - Astrophysics of Galaxies, Cosmology, galaxies: photometry, Physics and Astronomy, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: star formation, photometry [galaxies], star formation [galaxies], galaxies: evolution, Astrophysics::Galaxy Astrophysics, evolution [galaxies], general [galaxies]
Abstract

Next generation telescopes, like Euclid, Rubin/LSST, and Roman, will open new windows on the Universe, allowing us to infer physical properties for tens of millions of galaxies. Machine learning methods are increasingly becoming the most efficient tools to handle this enormous amount of data, because they are often faster and more accurate than traditional methods. We investigate how well redshifts, stellar masses, and star-formation rates (SFR) can be measured with deep learning algorithms for observed galaxies within data mimicking the Euclid and Rubin/LSST surveys. We find that Deep Learning Neural Networks and Convolutional Neutral Networks (CNN), which are dependent on the parameter space of the training sample, perform well in measuring the properties of these galaxies and have a better accuracy than methods based on spectral energy distribution fitting. CNNs allow the processing of multi-band magnitudes together with $H_{\scriptscriptstyle\rm E}$-band images. We find that the estimates of stellar masses improve with the use of an image, but those of redshift and SFR do not. Our best results are deriving i) the redshift within a normalised error of less than 0.15 for 99.9$\%$ of the galaxies with S/N>3 in the $H_{\scriptscriptstyle\rm E}$-band; ii) the stellar mass within a factor of two ($\sim0.3 \rm dex$) for 99.5$\%$ of the considered galaxies; iii) the SFR within a factor of two ($\sim0.3 \rm dex$) for $\sim$70$\%$ of the sample. We discuss the implications of our work for application to surveys as well as how measurements of these galaxy parameters can be improved with deep learning., accepted for publication in MNRAS, 21 pages, 22 figures, 6 tables

Published
2023
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