TY  - GEN
A1  - Abramowski, Attila
A1  - Aharonian, Felix A.
A1  - Benkhali, Faical Ait
A1  - Akhperjanian, A. G.
A1  - Angüner, Ekrem Oǧuzhan
A1  - Backes, Michael
A1  - Balenderan, Shangkari
A1  - Balzer, Arnim
A1  - Barnacka, Anna
A1  - Becherini, Yvonne
A1  - Tjus, Julia Becker
A1  - Berge, David
A1  - Bernhard, Sabrina
A1  - Bernlöhr, Konrad
A1  - Birsin, E.
A1  - Biteau, Jonathan
A1  - Böttcher, Markus
A1  - Boisson, Catherine
A1  - Bolmont, J.
A1  - Bordas, Pol
A1  - Bregeon, Johan
A1  - Brun, Francois
A1  - Brun, Pierre
A1  - Bryan, Mark
A1  - Bulik, Tomasz
A1  - Carrigan, Svenja
A1  - Casanova, Sabrina
A1  - Chadwick, Paula M.
A1  - Chakraborty, Nachiketa
A1  - Chalme-Calvet, R.
A1  - Chaves, Ryan C. G.
A1  - Chretien, M.
A1  - Colafrancesco, Sergio
A1  - Cologna, Gabriele
A1  - Conrad, Jan
A1  - Couturier, Claire
A1  - Cui, Yudong
A1  - Davids, Isak Delberth
A1  - Degrange, Bernhard
A1  - Deil, Christoph
A1  - deWilt, P.
A1  - Djannati-Ataï, A.
A1  - Domainko, Wilfried
A1  - Donath, Axel
A1  - Dubus, G.
A1  - Dutson, K.
A1  - Dyks, J.
A1  - Dyrda, M.
A1  - Edwards, Tanya
A1  - Egberts, Kathrin
A1  - Eger, Peter
A1  - Espigat, P.
A1  - Farnier, C.
A1  - Fegan, Stephen
A1  - Feinstein, Fabrice
A1  - Fernandes, Milton Virgilio
A1  - Fernandez, Diane
A1  - Fiasson, A.
A1  - Fontaine, Gerard
A1  - Förster, Andreas
A1  - Fuessling, M.
A1  - Gabici, S.
A1  - Gajdus, M.
A1  - Gallant, Yves A.
A1  - Garrigoux, Tania
A1  - Giavitto, G.
A1  - Giebels, Berrie
A1  - Glicenstein, Jean-Francois
A1  - Gottschall, Daniel
A1  - Grondin, M. -H.
A1  - Grudzinska, M.
A1  - Hadasch, Daniela
A1  - Haeffner, S.
A1  - Hahn, Joachim
A1  - Harris, Jonathan
A1  - Heinzelmann, Götz
A1  - Henri, G.
A1  - Hermann, German
A1  - Hervet, O.
A1  - Hillert, Andreas
A1  - Hinton, James Anthony
A1  - Hofmann, Werner
A1  - Hofverberg, Petter
A1  - Holler, Markus
A1  - Horns, Dieter
A1  - Ivascenko, Alex
A1  - Jacholkowska, A.
A1  - Jahn, C.
A1  - Jamrozy, Marek
A1  - Janiak, M.
A1  - Jankowsky, F.
A1  - Jung-Richardt, I.
A1  - Kastendieck, Max Anton
A1  - Katarzynski, K.
A1  - Katz, U.
A1  - Kaufmann, S.
A1  - Khelifi, B.
A1  - Kieffer, Michel
A1  - Klepser, S.
A1  - Klochkov, Dmitry
A1  - Kluzniak, W.
A1  - Kolitzus, David
A1  - Komin, Nu
A1  - Kosack, Karl
A1  - Krakau, Steffen
A1  - Krayzel, F.
A1  - Krueger, Pat P.
A1  - Laffon, H.
A1  - Lamanna, G.
A1  - Lefaucheur, J.
A1  - Lefranc, Valentin
A1  - Lemiere, A.
A1  - Lemoine-Goumard, M.
A1  - Lenain, J. -P.
A1  - Lohse, Thomas
A1  - Lopatin, A.
A1  - Lu, Chia-Chun
A1  - Marandon, Vincent
A1  - Marcowith, Alexandre
A1  - Marx, Ramin
A1  - Maurin, G.
A1  - Maxted, Nigel
A1  - Mayer, Michael
A1  - McComb, T. J. Lowry
A1  - Mehault, J.
A1  - Meintjes, P. J.
A1  - Menzler, Ulf
A1  - Meyer, M.
A1  - Mitchell, Alison M. W.
A1  - Moderski, R.
A1  - Mohamed, M.
A1  - Mora, K.
A1  - Moulin, Emmanuel
A1  - Murach, Thomas
A1  - de Naurois, Mathieu
A1  - Niemiec, J.
A1  - Nolan, Sam J.
A1  - Oakes, Louise
A1  - Odaka, Hirokazu
A1  - Ohm, S.
A1  - Optiz, Björn
A1  - Ostrowski, Michal
A1  - Oya, I.
A1  - Panter, Michael
A1  - Parsons, R. Daniel
A1  - Arribas, M. Paz
A1  - Pekeur, Nikki W.
A1  - Pelletier, G.
A1  - Petrucci, P. -O.
A1  - Peyaud, B.
A1  - Pita, S.
A1  - Poon, Helen
A1  - Pühlhofer, Gerd
A1  - Punch, M.
A1  - Quirrenbach, A.
A1  - Raab, S.
A1  - Reichardt, I.
A1  - Reimer, Anita
A1  - Reimer, Olaf
A1  - Renaud, Metz
A1  - de los Reyes, Raquel
A1  - Rieger, Frank
A1  - Romoli, C.
A1  - Rosier-Lees, S.
A1  - Rowell, G.
A1  - Rudak, B.
A1  - Rulten, C. B.
A1  - Sahakian, Vardan
A1  - Salek, D.
A1  - Sanchez, David M.
A1  - Santangelo, Andrea
A1  - Schlickeiser, Reinhard
A1  - Schuessler, F.
A1  - Schulz, A.
A1  - Schwanke, Ullrich
A1  - Schwarzburg, S.
A1  - Schwemmer, S.
A1  - Sol, H.
A1  - Spanier, Felix
A1  - Spengler, G.
A1  - Spies, Franziska
A1  - Stawarz, Lukasz
A1  - Steenkamp, Riaan
A1  - Stegmann, Christian
A1  - Stinzing, F.
A1  - Stycz, K.
A1  - Sushch, Iurii
A1  - Tavernet, J. -P.
A1  - Tavernier, T.
A1  - Taylor, A. M.
A1  - Terrier, R.
A1  - Tluczykont, Martin
A1  - Trichard, C.
A1  - Valerius, K.
A1  - van Eldik, C.
A1  - van Soelen, B.
A1  - Vasileiadis, Georges
A1  - Veh, J.
A1  - Venter, Christo
A1  - Viana, Aion
A1  - Vincent, P.
A1  - Vink, Jacco
A1  - Völk, Heinrich J.
A1  - Volpe, Francesca
A1  - Vorster, Martine
A1  - Vuillaume, T.
A1  - Wagner, S. J.
A1  - Wagner, P.
A1  - Wagner, R. M.
A1  - Ward, Martin
A1  - Weidinger, Matthias
A1  - Weitzel, Quirin
A1  - White, R.
A1  - Wierzcholska, A.
A1  - Willmann, P.
A1  - Woernlein, A.
A1  - Wouters, D.
A1  - Yang, Ruizhi
A1  - Zabalza, Victor
A1  - Zaborov, Dmitry
A1  - Zacharias, M.
A1  - Zdziarski, A. A.
A1  - Zech, Alraune
A1  - Zechlin, Hannes -S.
T1  - H.E.S.S. detection of TeV emission from the interaction region between the supernova remnant G349.7+0.2 and a molecular cloud (vol 574, A100, 2015)
T2  - Astronomy and astrophysics : an international weekly journal
KW  - gamma rays: general
KW  - ISM: supernova remnants
KW  - ISM: clouds
KW  - errata, addenda
Y1  - 2015
U6  - https://doi.org/10.1051/0004-6361/201425070e
SN  - 1432-0746
VL  - 580
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Horikoshi, Momoko
A1  - Yaghootkar, Hanieh
A1  - Mook-Kanamori, Dennis O.
A1  - Sovio, Ulla
A1  - Taal, H. Rob
A1  - Hennig, Branwen J.
A1  - Bradfield, Jonathan P.
A1  - St Pourcain, Beate
A1  - Evans, David M.
A1  - Charoen, Pimphen
A1  - Kaakinen, Marika
A1  - Cousminer, Diana L.
A1  - Lehtimaki, Terho
A1  - Kreiner-Moller, Eskil
A1  - Warrington, Nicole M.
A1  - Bustamante, Mariona
A1  - Feenstra, Bjarke
A1  - Berry, Diane J.
A1  - Thiering, Elisabeth
A1  - Pfab, Thiemo
A1  - Barton, Sheila J.
A1  - Shields, Beverley M.
A1  - Kerkhof, Marjan
A1  - van Leeuwen, Elisabeth M.
A1  - Fulford, Anthony J.
A1  - Kutalik, Zoltan
A1  - Zhao, Jing Hua
A1  - den Hoed, Marcel
A1  - Mahajan, Anubha
A1  - Lindi, Virpi
A1  - Goh, Liang-Kee
A1  - Hottenga, Jouke-Jan
A1  - Wu, Ying
A1  - Raitakari, Olli T.
A1  - Harder, Marie N.
A1  - Meirhaeghe, Aline
A1  - Ntalla, Ioanna
A1  - Salem, Rany M.
A1  - Jameson, Karen A.
A1  - Zhou, Kaixin
A1  - Monies, Dorota M.
A1  - Lagou, Vasiliki
A1  - Kirin, Mirna
A1  - Heikkinen, Jani
A1  - Adair, Linda S.
A1  - Alkuraya, Fowzan S.
A1  - Al-Odaib, Ali
A1  - Amouyel, Philippe
A1  - Andersson, Ehm Astrid
A1  - Bennett, Amanda J.
A1  - Blakemore, Alexandra I. F.
A1  - Buxton, Jessica L.
A1  - Dallongeville, Jean
A1  - Das, Shikta
A1  - de Geus, Eco J. C.
A1  - Estivill, Xavier
A1  - Flexeder, Claudia
A1  - Froguel, Philippe
A1  - Geller, Frank
A1  - Godfrey, Keith M.
A1  - Gottrand, Frederic
A1  - Groves, Christopher J.
A1  - Hansen, Torben
A1  - Hirschhorn, Joel N.
A1  - Hofman, Albert
A1  - Hollegaard, Mads V.
A1  - Hougaard, David M.
A1  - Hyppoenen, Elina
A1  - Inskip, Hazel M.
A1  - Isaacs, Aaron
A1  - Jorgensen, Torben
A1  - Kanaka-Gantenbein, Christina
A1  - Kemp, John P.
A1  - Kiess, Wieland
A1  - Kilpelainen, Tuomas O.
A1  - Klopp, Norman
A1  - Knight, Bridget A.
A1  - Kuzawa, Christopher W.
A1  - McMahon, George
A1  - Newnham, John P.
A1  - Niinikoski, Harri
A1  - Oostra, Ben A.
A1  - Pedersen, Louise
A1  - Postma, Dirkje S.
A1  - Ring, Susan M.
A1  - Rivadeneira, Fernando
A1  - Robertson, Neil R.
A1  - Sebert, Sylvain
A1  - Simell, Olli
A1  - Slowinski, Torsten
A1  - Tiesler, Carla M. T.
A1  - Toenjes, Anke
A1  - Vaag, Allan
A1  - Viikari, Jorma S.
A1  - Vink, Jacqueline M.
A1  - Vissing, Nadja Hawwa
A1  - Wareham, Nicholas J.
A1  - Willemsen, Gonneke
A1  - Witte, Daniel R.
A1  - Zhang, Haitao
A1  - Zhao, Jianhua
A1  - Wilson, James F.
A1  - Stumvoll, Michael
A1  - Prentice, Andrew M.
A1  - Meyer, Brian F.
A1  - Pearson, Ewan R.
A1  - Boreham, Colin A. G.
A1  - Cooper, Cyrus
A1  - Gillman, Matthew W.
A1  - Dedoussis, George V.
A1  - Moreno, Luis A.
A1  - Pedersen, Oluf
A1  - Saarinen, Maiju
A1  - Mohlke, Karen L.
A1  - Boomsma, Dorret I.
A1  - Saw, Seang-Mei
A1  - Lakka, Timo A.
A1  - Koerner, Antje
A1  - Loos, Ruth J. F.
A1  - Ong, Ken K.
A1  - Vollenweider, Peter
A1  - van Duijn, Cornelia M.
A1  - Koppelman, Gerard H.
A1  - Hattersley, Andrew T.
A1  - Holloway, John W.
A1  - Hocher, Berthold
A1  - Heinrich, Joachim
A1  - Power, Chris
A1  - Melbye, Mads
A1  - Guxens, Monica
A1  - Pennell, Craig E.
A1  - Bonnelykke, Klaus
A1  - Bisgaard, Hans
A1  - Eriksson, Johan G.
A1  - Widen, Elisabeth
A1  - Hakonarson, Hakon
A1  - Uitterlinden, Andre G.
A1  - Pouta, Anneli
A1  - Lawlor, Debbie A.
A1  - Smith, George Davey
A1  - Frayling, Timothy M.
A1  - McCarthy, Mark I.
A1  - Grant, Struan F. A.
A1  - Jaddoe, Vincent W. V.
A1  - Jarvelin, Marjo-Riitta
A1  - Timpson, Nicholas J.
A1  - Prokopenko, Inga
A1  - Freathy, Rachel M.
T1  - New loci associated with birth weight identify genetic links between intrauterine growth and adult height and metabolism
JF  - Nature genetics
N2  - Birth weight within the normal range is associated with a variety of adult-onset diseases, but the mechanisms behind these associations are poorly understood(1). Previous genome-wide association studies of birth weight identified a variant in the ADCY5 gene associated both with birth weight and type 2 diabetes and a second variant, near CCNL1, with no obvious link to adult traits(2). In an expanded genome-wide association metaanalysis and follow-up study of birth weight (of up to 69,308 individuals of European descent from 43 studies), we have now extended the number of loci associated at genome-wide significance to 7, accounting for a similar proportion of variance as maternal smoking. Five of the loci are known to be associated with other phenotypes: ADCY5 and CDKAL1 with type 2 diabetes, ADRB1 with adult blood pressure and HMGA2 and LCORL with adult height. Our findings highlight genetic links between fetal growth and postnatal growth and metabolism.
Y1  - 2013
U6  - https://doi.org/10.1038/ng.2477
SN  - 1061-4036
VL  - 45
IS  - 1
SP  - 76
EP  - U115
PB  - Nature Publ. Group
CY  - New York
ER  - 
TY  - JOUR
A1  - Almeida, Leonardo A.
A1  - Sana, H.
A1  - Taylor, W.
A1  - Barbá, Rodolfo
A1  - Bonanos, Alceste Z.
A1  - Crowther, Paul
A1  - Damineli, Augusto
A1  - de Koter, A.
A1  - de Mink, Selma E.
A1  - Evans, C. J.
A1  - Gieles, Mark
A1  - Grin, Nathan J.
A1  - Hénault-Brunet, V.
A1  - Langer, Norbert
A1  - Lennon, D.
A1  - Lockwood, Sean
A1  - Maíz Apellániz, Jesús
A1  - Moffat, A. F. J.
A1  - Neijssel, C.
A1  - Norman, C.
A1  - Ramírez-Agudelo, O. H.
A1  - Richardson, N. D.
A1  - Schootemeijer, Abel
A1  - Shenar, Tomer
A1  - Soszyński, Igor
A1  - Tramper, Frank
A1  - Vink, J. S.
T1  - The tarantula massive binary monitoring
BT  - I. Observational campaign and OB-type spectroscopic binaries
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Context:
Massive binaries play a crucial role in the Universe. Knowing the distributions of their orbital parameters is important for a wide range of topics from stellar feedback to binary evolution channels and from the distribution of supernova types to gravitational wave progenitors, yet no direct measurements exist outside the Milky Way.
Aims:
The Tarantula Massive Binary Monitoring project was designed to help fill this gap by obtaining multi-epoch radial velocity (RV) monitoring of 102 massive binaries in the 30 Doradus region.
Methods: 
In this paper we analyze 32 FLAMES/GIRAFFE observations of 93 O- and 7 B-type binaries. We performed a Fourier analysis and obtained orbital solutions for 82 systems: 51 single-lined (SB1) and 31 double-lined (SB2) spectroscopic binaries.
Results: 
Overall, the binary fraction and orbital properties across the 30 Doradus region are found to be similar to existing Galactic samples. This indicates that within these domains environmental effects are of second order in shaping the properties of massive binary systems. A small difference is found in the distribution of orbital periods, which is slightly flatter (in log space) in 30 Doradus than in the Galaxy, although this may be compatible within error estimates and differences in the fitting methodology. Also, orbital periods in 30 Doradus can be as short as 1.1 d, somewhat shorter than seen in Galactic samples. Equal mass binaries (q> 0.95) in 30 Doradus are all found outside NGC 2070, the central association that surrounds R136a, the very young and massive cluster at 30 Doradus’s core. Most of the differences, albeit small, are compatible with expectations from binary evolution. One outstanding exception, however, is the fact that earlier spectral types (O2–O7) tend to have shorter orbital periods than later spectral types (O9.2–O9.7).
Conclusions: 
Our results point to a relative universality of the incidence rate of massive binaries and their orbital properties in the metallicity range from solar (Z⊙) to about half solar. This provides the first direct constraints on massive binary properties in massive star-forming galaxies at the Universe’s peak of star formation at redshifts z ~ 1 to 2 which are estimated to have Z ~ 0.5 Z⊙.
KW  - stars: early-type
KW  - stars: massive
KW  - binaries: spectroscopic
KW  - binaries: close
Y1  - 2017
U6  - https://doi.org/10.1051/0004-6361/201629844
SN  - 1432-0746
VL  - 598
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Shenar, Tomer
A1  - Richardson, N. D.
A1  - Sablowski, Daniel P.
A1  - Hainich, Rainer
A1  - Sana, H.
A1  - Moffat, A. F. J.
A1  - Todt, Helge Tobias
A1  - Hamann, Wolf-Rainer
A1  - Oskinova, Lida
A1  - Sander, Andreas Alexander Christoph
A1  - Tramper, Frank
A1  - Langer, Norbert
A1  - Bonanos, Alceste Z.
A1  - de Mink, Selma E.
A1  - Gräfener, G.
A1  - Crowther, Paul
A1  - Vink, J. S.
A1  - Almeida, Leonardo A.
A1  - de Koter, A.
A1  - Barbá, Rodolfo
A1  - Herrero, A.
A1  - Ulaczyk, Krzysztof
T1  - The tarantula massive binary monitoring
BT  - II. First SB2 orbital and spectroscopic analysis for the Wolf-Rayet binary R145
JF  - Astronomy and astrophysics : an international weekly journal
N2  - We present the first SB2 orbital solution and disentanglement of the massive Wolf-Rayet binary R145 (P = 159 d) located in the Large Magellanic Cloud. The primary was claimed to have a stellar mass greater than 300 M-circle dot, making it a candidate for being the most massive star known to date. While the primary is a known late-type, H-rich Wolf-Rayet star (WN6h), the secondary has so far not been unambiguously detected. Using moderate-resolution spectra, we are able to derive accurate radial velocities for both components. By performing simultaneous orbital and polarimetric analyses, we derive the complete set of orbital parameters, including the inclination. The spectra are disentangled and spectroscopically analyzed, and an analysis of the wind-wind collision zone is conducted. The disentangled spectra and our models are consistent with a WN6h type for the primary and suggest that the secondary is an O3.5 If*/WN7 type star. We derive a high eccentricity of e = 0 : 78 and minimum masses of M-1 sin(3) i approximate to M-2 sin(3) i = 13 +/- 2 M-circle dot, with q = M-2/M-1 = 1.01 +/- 0.07. An analysis of emission excess stemming from a wind-wind collision yields an inclination similar to that obtained from polarimetry (i = 39 +/- 6 degrees). Our analysis thus implies M-1 = 53(-20)(+40) and M2 = 54(-20)(+40) M-circle dot, excluding M-1 > 300 M-circle dot. A detailed comparison with evolution tracks calculated for single and binary stars together with the high eccentricity suggests that the components of the system underwent quasi-homogeneous evolution and avoided mass-transfer. This scenario would suggest current masses of approximate to 80 M-circle dot and initial masses of M-i,M-1 approximate to 10(5) and M-i,M-2 approximate to 90 M-circle dot, consistent with the upper limits of our derived orbital masses, and would imply an age of approximate to 2.2 Myr.
KW  - binaries: spectroscopic
KW  - stars: Wolf-Rayet
KW  - stars: massive
KW  - Magellanic Clouds
KW  - stars: individual: R 145
KW  - stars: atmospheres
Y1  - 2017
U6  - https://doi.org/10.1051/0004-6361/201629621
SN  - 1432-0746
VL  - 598
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - GEN
A1  - Vink, Jorick Sandor
A1  - Heger, Alexander
A1  - Krumholz, Mark R.
A1  - Puls, Joachim
A1  - Banerjee, Shiladitya
A1  - Castro, Norberto
A1  - Chen, K.-J.
A1  - Chenè, A.-N.
A1  - Crowther, P. A.
A1  - Daminelli, A.
A1  - Gräfener, G.
A1  - Groh, J. H.
A1  - Hamann, Wolf-Rainer
A1  - Heap, S.
A1  - Herrero, A.
A1  - Kaper, L.
A1  - Najarro, F.
A1  - Oskinova, Lida
A1  - Roman-Lopes, A.
A1  - Rosen, A.
A1  - Sander, A.
A1  - Shirazi, M.
A1  - Sugawara, Y.
A1  - Tramper, F.
A1  - Vanbeveren, D.
A1  - Voss, R.
A1  - Wofford, A.
A1  - Zhang, Y.
T1  - Very massive stars in the local universe
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Recent studies have claimed the existence of very massive stars (VMS) up to 300 M⊙ in the local Universe. As this finding may represent a paradigm shift for the canonical stellar upper-mass limit of 150 M⊙, it is timely to discuss the status of the data, as well as the far-reaching implications of such objects. We held a Joint Discussion at the General Assembly in Beijing to discuss (i) the determination of the current masses of the most massive stars, (ii) the formation of VMS, (iii) their mass loss, and (iv) their evolution and final fate. The prime aim was to reach broad consensus between observers and theorists on how to identify and quantify the dominant physical processes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 601 
KW  - stars: massive stars
KW  - stars: mass-loss
KW  - stars: stellar evolution
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-415220
SN  - 1866-8372
IS  - 601
ER  - 
TY  - CHAP
A1  - Vink, J. S.
A1  - Benaglia, P.
A1  - Davies, B.
A1  - de Koter, A.
A1  - Oudmaijer, R. D.
T1  - Advances in mass-loss predictions
N2  - We present the results of Monte Carlo mass-loss predictions for massive stars covering a wide range of stellar parameters. We critically test our predictions against a range of observed massloss rates – in light of the recent discussions on wind clumping. We also present a model to compute the clumping-induced polarimetric variability of hot stars and we compare this with observations of Luminous Blue Variables, for which polarimetric variability is larger than for O and Wolf-Rayet stars. Luminous Blue Variables comprise an ideal testbed for studies of wind clumping and wind geometry, as well as for wind strength calculations, and we propose they may be direct supernova progenitors.
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17948
ER  - 
TY  - CHAP
A1  - de Koter, A.
A1  - Vink, J. S.
A1  - Muijres, L.
T1  - Constraints on wind clumping from the empirical mass-loss vs. metallicity relation for early-type stars
N2  - We present the latest results on the observational dependence of the mass-loss rate in stellar winds of O and early-B stars on the metal content of their atmospheres, and compare these with predictions. Absolute empirical rates for the mass loss of stars brighter than 10$^{5.2} L_{\odot}$, based on H$\alpha$ and ultraviolet (UV) wind lines, are found to be about a factor of two higher than predictions. If this difference is attributed to inhomogeneities in the wind this would imply that luminous O and early-B stars have clumping factors in their H$\alpha$ and UV line forming regime of about a factor of 3--5. The investigated stars cover a metallicity range $Z$ from 0.2 to 1 $Z_{\odot}$. We find a hint towards smaller clumping factors for lower $Z$. The derived clumping factors, however, presuppose that clumping does not impact the predictions of the mass-loss rate. We discuss this assumption and explain how we intend to investigate its validity in more detail.
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17736
ER  - 
TY  - CHAP
A1  - Vink, J. S.
T1  - Discussion: Hydrodynamic modeling
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-18046
ER  - 
TY  - CHAP
A1  - Davies, B.
A1  - Vink, J. S.
A1  - Oudmaijer, R. D.
T1  - Modelling the polarimetric variability of hot stars
N2  - Many hot stars exhibit stochastic polarimetric variability, thought to arise from clumping low in the wind. Here we investigate the wind properties required to reproduce this variability using analytic models, with particular emphasis on Luminous Blue Variables. We find that the winds must be highly structured, consisting of a large number of optically-thin clumps; while we find that the overall level of polarization should scale with mass-loss rate – consistent with observations of LBVs. The models also predict variability on very short timescales, which is supported by the results of a recent polarimetric monitoring campaign.
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-17939
ER  - 
TY  - JOUR
A1  - Tramper, F.
A1  - Straal, S. M.
A1  - Sanyal, D.
A1  - Sana, Hugues
A1  - de Koter, A.
A1  - Gräfener, G.
A1  - Langer, N.
A1  - Vink, J. S.
A1  - de Mink, S. E.
A1  - Kaper, L.
T1  - Massive Wolf-Rayet stars on the verge to explode
BT  - the properties of the WO stars
JF  - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015
N2  - The enigmatic oxygen-sequence Wolf-Rayet stars represent a rare stage in the evolution of massive stars. Their properties can provide unique constraints on the pre-supernova evolution of massive stars. This work presents the results of a quantitative spectroscopic analysis of the known single WO stars, with the aim to obtain the key stellar parameters and deduce their evolutionary state.X-Shooter spectra of the WO stars are modeled using the line-blanketed non-local thermal equilibrium atmosphere code cmfgen. The obtained stellar parameters show that the WO stars are very hot, with temperatures ranging from 150 kK to 210 kK. Their chemical composition is dominated by carbon (>50%), while the helium mass fraction is very low (down to 14%). Oxygen mass fractions reach as high as 25%. These properties can be reproduced with dedicated evolutionary models for helium stars, which show that the stars are post core-helium burning and very close to their eventual supernova explosion. The helium-star masses indicate initial masses or approximately 40 - 60M⊙.Thus, WO stars represent the final evolutionary stage of stars with estimated initial masses of 40 - 60M⊙. They are post core-helium burning and may explode as type Ic supernovae within a few thousand years.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-87786
SP  - 109
EP  - 112
ER  - 
TY  - JOUR
A1  - Vink, J. S.
T1  - The True origin of Wolf-Rayet stars
JF  - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015
N2  - The Wolf-Rayet (WR) phenomenon is widespread in astronomy. It involves classical WRs, very massive stars (VMS), WR central stars of planetary nebula CSPN [WRs], and supernovae (SNe). But what is the root cause for a certain type of object to turn into an emission-line star? In this contribution, I discuss the basic aspects of radiation-driven winds that might reveal the ultimate difference between WR stars and canonical O-type stars. I discuss the aspects of (i) self-enrichment via CNO elements, (ii) high effective temperatures (Tₑff), (iii) an increase in the helium abundance (Y ), and finally (iv) the Eddington factor Γₑ. Over the last couple of years, we have made a breakthrough in our understanding of Γₑ -dependent mass loss, which will have far-reaching consequences for the evolution and fate of the most massive stars in the Universe. Finally, I discuss the prospects for studies of the WR phenomenon in the highest redshift Lyα and He ii emitting galaxies.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-87848
SP  - 133
EP  - 138
ER  -