O
Ortwin Gerhard
Researcher at Max Planck Society
Publications - 463
Citations - 29734
Ortwin Gerhard is an academic researcher from Max Planck Society. The author has contributed to research in topics: Galaxy & Bulge. The author has an hindex of 90, co-authored 450 publications receiving 27269 citations. Previous affiliations of Ortwin Gerhard include University of Basel & ASTRON.
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Journal ArticleDOI
The build-up of the cD halo of M87 - evidence for accretion in the last Gyr
TL;DR: In this article, the authors present kinematic and photometric evidence for an accretion event in the halo of the cD galaxy M87 in the last Gyr using velocities for ~300 planetary nebulas (PNs) in the M87 halo.
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The planetary nebula population in the halo of M87
TL;DR: In this article, the diffuse light in the outer regions of the nearby elliptical galaxy M87 in the Virgo cluster was investigated using planetary nebulas (PNs) as tracers.
Journal ArticleDOI
PLATO as it is: a legacy mission for Galactic archaeology
Andrea Miglio,Cristina Chiappini,B. Mosser,Guy R. Davies,Kenneth C. Freeman,L. Girardi,Paula Jofre,Daisuke Kawata,B. M. Rendle,Marica Valentini,Luca Casagrande,William J. Chaplin,Gerard Gilmore,Keith Hawkins,B. Holl,T. Appourchaux,Kevin Belkacem,Diego Bossini,K. Brogaard,M. J. Goupil,Josefina Montalbán,Arlette Noels,Friedrich Anders,T. S. Rodrigues,Giampaolo Piotto,D. L. Pollacco,Heike Rauer,C. Allende Prieto,P. P. Avelino,C. Babusiaux,Caroline Barban,Beatriz Barbuy,Sarbani Basu,Frédéric Baudin,Othman Benomar,Olivier Bienaymé,James Binney,Joss Bland-Hawthorn,A. Bressan,Carla Cacciari,Tiago L. Campante,Santi Cassisi,Jørgen Christensen-Dalsgaard,Francoise Combes,O. L. Creevey,Margarida S. Cunha,R. S. de Jong,P. de Laverny,Scilla Degl'Innocenti,Sébastien Deheuvels,E. Depagne,J. DeRidder,P. DiMatteo,M. Di Mauro,Marc-Antoine Dupret,P. Eggenberger,Yvonne Elsworth,Benoit Famaey,Sofia Feltzing,Rafael A. García,Ortwin Gerhard,Brad K. Gibson,Laurent Gizon,Misha Haywood,Rasmus Handberg,Ulrike Heiter,Saskia Hekker,Daniel Huber,Rodrigo A. Ibata,D. Katz,Steven D. Kawaler,H. Kjeldsen,D. W. Kurtz,Nadège Lagarde,Yveline Lebreton,Mikkel N. Lund,S. R. Majewski,Paola Marigo,Marie Martig,S. Mathur,Ivan Minchev,Thierry Morel,Sergio Ortolani,Marc H. Pinsonneault,Bertrand Plez,P. G. Prada Moroni,D. Pricopi,Alejandra Recio-Blanco,Céline Reylé,Annie C. Robin,Ian W. Roxburgh,Maurizio Salaris,Basilio X. Santiago,Ricardo P. Schiavon,Aldo Serenelli,Sanjib Sharma,V. Silva Aguirre,Caroline Soubiran,Matthias Steinmetz,Dennis Stello +99 more
TL;DR: In this article, the authors identify five key outstanding questions relating to the formation and evolution of the Milky Way that will need precise and accurate ages for large samples of stars to be addressed, and identify the requirements in terms of number of targets and the precision on the stellar properties that are needed to tackle such questions.
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Mass-to-light ratio gradients in early-type galaxy haloes
Nicola R. Napolitano,M. Capaccioli,Aaron J. Romanowsky,Nigel G. Douglas,Michael R. Merrifield,Konrad Kuijken,Magda Arnaboldi,Ortwin Gerhard,Kenneth C. Freeman +8 more
TL;DR: In this paper, the logarithmic radial gradient of the mass-to-light ratio (dML) was used to characterize the halo masses of early-type galaxies.
Journal ArticleDOI
Planetary Nebula Spectrograph survey of S0 galaxy kinematics - II. Clues to the origins of S0 galaxies
Arianna Cortesi,Arianna Cortesi,Arianna Cortesi,Michael R. Merrifield,Lodovico Coccato,Magda Arnaboldi,Ortwin Gerhard,Steven P. Bamford,Nicola R. Napolitano,Aaron J. Romanowsky,Aaron J. Romanowsky,Nigel G. Douglas,Konrad Kuijken,Massimo Capaccioli,Kenneth C. Freeman,Kanak Saha,Ana L. Chies-Santos +16 more
TL;DR: In this paper, the stellar kinematics of six S0 galaxies derived from observations of planetary nebulae, obtained using the Planetary Nebula Spectrograph, were analyzed using a maximum-likelihood method that combines the discrete kinematic data with a photometric component decomposition.