TY  - JOUR
A1  - Todt, Helge Tobias
A1  - Sander, Angelika
A1  - Hainich, Rainer
A1  - Hamann, Wolf-Rainer
A1  - Quade, Markus
A1  - Shenar, Tomer
T1  - Potsdam Wolf-Rayet model atmosphere grids for WN stars
T2  - Astronomy and astrophysics : an international weekly journal
N2  - We present new grids of Potsdam Wolf-Rayet (PoWR) model atmospheres for Wolf-Rayet stars of the nitrogen sequence (WN stars). The models have been calculated with the latest version of the PoWR stellar atmosphere code for spherical stellar winds. The WN model atmospheres include the non-LTE solutions of the statistical equations for complex model atoms, as well as the radiative transfer equation in the co-moving frame. Iron-line blanketing is treated with the help of the superlevel approach, while wind inhomogeneities are taken into account via optically thin clumps. Three of our model grids are appropriate for Galactic metallicity. The hydrogen mass fraction of these grids is 50%, 20%, and 0%, thus also covering the hydrogen-rich late-type WR stars that have been discovered in recent years. Three grids are adequate for LMC WN stars and have hydrogen fractions of 40%, 20%, and 0%. Recently, additional grids with SMC metallicity and with 60%, 40%, 20%, and 0% hydrogen have been added. We provide contour plots of the equivalent widths of spectral lines that are usually used for classification and diagnostics.
KW  - stars: evolution
KW  - stars: mass-loss
KW  - stars: winds, outflows
KW  - stars: Wolf-Rayet
KW  - stars: atmospheres
KW  - stars: massive
Y1  - 2015
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/38782
SN  - 0004-6361
SN  - 1432-0746
VL  - 579
PB  - EDP Sciences
CY  - Les Ulis
ER  -