Pulsed thermal emission from the accreting pulsar XMMU J054134.7-682550 (2009)
Manousakis, A., Walter, R., Audard, M., Lanz, T.
Aims. Soft X-ray excesses have been detected in several Be/X-ray binaries and interpreted as the signature of hard X-ray reprocessing in the inner accretion disk. The system XMMU J054134.7-682550,...
Analysis of Galactic late-type O dwarfs: more constraints on the weak wind problem (2009)
Marcolino, W. L. F., Martins, F., Hillier, D. J., Lanz, T., Escolano, C.
We have investigated the stellar and wind properties of a sample of five late-type O dwarfs in order to address the weak wind problem. A grid of TLUSTY models was used to obtain the stellar...
K. Rousselet-perraut, C. Stehlé, T. Lanz, T. Boudoyen, M. Kilbinger, ...
Abstract. By means of numerical simulations, we investigate the ability of optical interferometry, via the fringe phase observable, to address stellar activity and magnetism. To derive abundance maps...
The Gaia satellite: a tool for Emission Line Stars and Hot Stars (2008)
Martayan, C, Frémat, Y, Blomme, R, Jonckheere, A, Borges, M, De Batz, B, ...
The Gaia satellite will be launched at the end of 2011. It will observe at least 1 billion stars, and among them several million emission line stars and hot stars. Gaia will provide parallaxes for...
Zsargo, J., Hillier, D. J., Lanz, T., Leutenegger, M. A., Cohen, D.
We have studied superionization and X-ray line formation in the spectra of Zeta Pup using our new stellar atmosphere code (XCMFGEN) that can be used to simultaneously analyze optical, UV, and X-ray...
flasher vs. helium enrichment ⋆ (2008)
S. Moehler, S. Dreizler, T. Lanz, G. Bono, A. V. Sweigart, A. Calamida, ...
The hottest horizontal-branch stars in ω Centauri. Late hot
The weak magnetic field of the O9.7 supergiant zeta Orionis A (2008)
Martins, F., Escolano, C., Marcolino, W., Lanz, T., ...
We report here the detection of a weak magnetic field of 50 - 100 G on the O9.7 supergiant zeta Ori A, using spectropolarimetric observations obtained with NARVAL at the 2m Telescope Bernard Lyot...
M. A. Barstow, I. Hubeny, T. Lanz
Since the first soft X-ray and EUV studies of hot DA white dwarfs it has been apparent that the fluxes of white dwarfs in these wavelength ranges
Moehler, S., Dreizler, S., Lanz, T., Bono, G., Sweigart, A. V., Calamida, A., ...
UV observations of some massive globular clusters uncovered a significant population of very hot stars below the hot end of the horizontal branch (HB), the so-called blue hook stars. This feature...
Audard, M., Skinner, S., Guedel, M., Lanz, T., Paerels, F., Arce, H.
We report on initial results of our Spitzer Cycle 2 program to observe the young massive star R Mon and its associated HH 39 Herbig-Haro object in the mid-infrared. Our program used all instruments...
Clumping in O-type Supergiants (2007)
Lanz, T., Hillier, D. J., Foellmi, C.
We have analyzed the spectra of seven Galactic O4 supergiants, with the NLTE wind code CMFGEN. For all stars, we have found that clumped wind models match well lines from different species spanning a...
Clumping in O-type Supergiants (2007)
Lanz, T., Hillier, D. J., Foellmi, C.
We have analyzed the spectra of seven Galactic O4 supergiants, with the NLTE wind code CMFGEN. For all stars, we have found that clumped wind models match well lines from different species spanning a...
Hunter, I., Dufton, P. L., Smartt, S. J., Ryans, R. S. I., Evans, C. J., Lennon, D. J., ...
We present an analysis of high-resolution FLAMES spectra of approximately 50 early B-type stars in three young clusters at different metallicities, NGC6611 in the Galaxy, N11 in the Large Magellanic...
On the sensitivity of HeI singlet lines to the FeIV model atom in O stars (2006)
Najarro, F., Hillier, D. J., Puls, J., Lanz, T., Martins, F.
Recent calculations and analyses of O star spectra have revealed discrepancies between theory and observations, and between different theoretical calculations, for the strength of optical HeI singlet...
On the sensitivity of He I singlet lines to the Fe IV model atom in O stars (2006)
Najarro, F., Hillier, D. J., Puls, J., Lanz, T., Martins, F.
High Resolution Fe Lyman and Balmer Band Spectroscopy of the Bursts in EXO 0748-676 (2006)
Cottam, J., Paerels, F., Telis, G., Audard, M., Méndez, R.M., Boirin, L., ...
We present the results of high resolution spectroscopy of the x-ray bursts in the LMXB EXO 0748-676. Early observations with XMM/RGS showed evidence for gravitationally redshifted absorption lines,...
A non-LTE analysis of the spectra of two narrow lined main sequence stars in the SMC (2005)
Hunter, I., Dufton, P. L., Ryans, R. S. I., Lennon, D. J., Rolleston, W. R. J., Hubeny, I., ...
An analysis of high-resolution VLT/UVES spectra of two B-type main sequence stars, NGC 346-11 and AV 304, in the Small Magellanic Cloud (SMC), has been undertaken, using the non-LTE TLUSTY model...
B-type Supergiants in the SMC: Chemical compositions and (2005)
P. L. Dufton, C. Trundle, D. J. Lennon, I. Hubeny, T. Lanz, ...
(DOI: will be inserted by hand later)
Dufton, P. L., Ryans, R. S. I., Trundle, C., Lennon, D. J., Hubeny, I., Lanz, T., ...
High-resolution UCLES/AAT spectra are presented for nine B-type supergiants in the SMC, chosen on the basis that they may show varying amounts of nuclear-synthetically processed material mixed to...
We have analyzed the far-UV spectrum of two Galactic O4 stars, the O4If+ supergiant HD190429A and the O4V((f)) dwarf HD96715, using archival FUSE and IUE data. We have conducted a quantitative...
NGC 1535: UV Observations and Models (2004)
Koesterke, L., Werner, K., Kruk, J. W., Lanz, T.
We reinvestigate the UV spectrum of NGC1535 by means of recently developed fully line-blanketed non-LTE models. These new models account for the wind in spherical geometry while handling the atomic...
Chandra High Resolution Spectroscopy of the Burst Spectrum of EXO 0748-67 (2004)
Telis, G., Paerels, F., Audard, M., Lanz, T., Cottam, J., Mendez, R.M., ...
We have observed EXO0748-67 for approximately 300 ksec with the High Energy Transmission Grating Spectrometer on Chandra. A total of 35 Type I X-ray bursts occurred during our observation, and from...
Prieto, C. Allende, Lambert, D. L., Hubeny, I., Lanz, T.
With the goal of producing a reliable set of model atoms and singly-ionized ions for use in building NLTE model atmospheres, we have combined measured energy levels, critically-compiled line...
Quantitative Spectroscopy of O Stars at Low Metallicity. O Dwarfs in NGC 346 (2003)
Lanz, T., Hillier, D. J., Heap, S. R., Hubeny, I., Lennon, D. J., ...
We present the results of a detailed UV and optical spectral analysis of the properties of 6 dwarf O-type stars in the SMC H II region NGC 346. Stellar parameters, chemical abundances, and wind...
Modelling of Stellar Atmospheres (2002)
Iau Symposium Vol, N. E. Piskunov, W. W. Weiss, D. F. Gray, C. Allende Prieto, I. Hubeny, ...
We briey describe an on-going project to calculate detailed NLTE fully-blanketed model atmospheres for late-type dwarfs. Present computers and state-of-the-art codes make possible to calculate...
On The Age Estimation of LBDS 53W091 (1999)
YI, Sukyoung, Brown, T. M., Heap, S., Hubeny, I., Landsman, W., Lanz, T., ...
The recent spectral analysis of LBDS 53W091 by Spinrad and his collaborators has suggested that this red galaxy at z=1.55 is at least 3.5 Gyr old. This imposes an important constraint on cosmology,...
Fe II emission lines in the UV spectrum of Sirius-A and Vega (1998)
Van Noort, M., Lanz, T., Kurucz, R. L., Ferlet, R., Hebrard, G., ...
We present high-quality HST/GHRS spectra in the Hydrogen L alpha spectral region of Vega and Sirius-A. Thanks to the signal-to-noise ratio achieved in these observations and to the similarity of the...
UV Spectral Dating of Stars and Galaxies (1997)
Heap, S. R., Brown, T. M., Hubeny, I., Landsman, W., Yi, S., Fanelli, M., ...
An echelle spectrogram (R = 30,000) of the 2300-3100 A region in the ultraviolet spectrum of the F8V star 9 Comae is presented. The observation is used to calibrate features in the mid-ultraviolet...
A CRITICAL COMPILATION OF ATOMIC OSCILLATOR STRENGTHS FOR CARBON, NITROGEN AND OXYGEN IONS (1991)
Allard, N., Lanz, T., Le Dourneuf, M.
We have undertaken a compilation of the oscillator strengths of observed lines for carbon, nitrogen and oxygen ions. It has been achieved for the Be-like spectra, C III, N IV and O V. The theoretical...
A CRITICAL COMPILATION OF ATOMIC OSCILLATOR STRENGTHS FOR CARBON, NITROGEN AND OXYGEN IONS (1991)
Allard, N., Lanz, T., Le Dourneuf, M.
We have undertaken a compilation of the oscillator strengths of observed lines for carbon, nitrogen and oxygen ions. It has been achieved for the Be-like spectra, C III, N IV and O V. The theoretical...
A CRITICAL COMPILATION OF ATOMIC OSCILLATOR STRENGTHS FOR CARBON, NITROGEN AND OXYGEN IONS (1991)
Allard, N., Lanz, T., Le Dourneuf, M.
We have undertaken a compilation of the oscillator strengths of observed lines for carbon, nitrogen and oxygen ions. It has been achieved for the Be-like spectra, C III, N IV and O V. The theoretical...
Reiser, C O, Lanz, T, Hofmann, F, Hofer, G, Rupprecht, H D, Goppelt-Struebe, M
During inflammatory processes of the kidney, lesions of the glomerulus lead to aggregation of thrombocytes and infiltration of macrophages, which can release bioactive mediators. One of these...
Reiser, C O, Lanz, T, Hofmann, F, Hofer, G, Rupprecht, H D, Goppelt-Struebe, M
During inflammatory processes of the kidney, lesions of the glomerulus lead to aggregation of thrombocytes and infiltration of macrophages, which can release bioactive mediators. One of these...