Publications (29)
A Supergiants
N. Przybilla, F. Bresolin, K. Butler +3
A-type supergiants are primary targets for quantitative spectroscopy of individual stars in nearby galaxies because of their intrinsic brightness. An overview is given on the non-L…
Improved helium line formation for EHe stars
N. Przybilla, K. Butler, U. Heber +1
Quantitative analyses of extreme helium stars to date face the difficulty that theory fails to reproduce the observed helium lines in their entirety, wings and line cores. Here, we…
Quantitative spectroscopy of B-type supergiants
D. WeÃmayer, N. Przybilla, K. Butler
Context. B-type supergiants are versatile tools to address various astrophysical topics, ranging from stellar atmospheres over stellar and galactic evolution to the cosmic distance…
z-GAL -- A NOEMA spectroscopic redshift survey of bright Herschel galaxies: [I] Overview
P. Cox, R. Neri, S. Berta +35
(Abridged) Using the IRAM NOEMA interferometer, we measures the redshifts of 126 bright galaxies detected in the Herschel H-ATLAS, HeLMS, and HerS surveys. We report reliable spect…
The present-day cosmic phosphorus abundance
P. Aschenbrenner, K. Butler, N. Przybilla
The present-day phosphorus abundance in the solar neighbourhood is determined from a sample of OB-type stars. This is in order to constrain the endpoint of the galactochemical evol…
Observations of the extreme runaway HD271791: nucleosynthesis in a core-collapse supernova
V. Schaffenroth, N. Przybilla, K. Butler +2
Some young, massive stars can be found in the Galactic halo. As star formation is unlikely to occur in the halo, they must have been formed in the disk and been ejected shortly aft…
The Infrared Light Curve of SN 2011fe in M101 and the Distance to M101
T. Matheson, R. R. Joyce, L. E. Allen +42
We present near infra-red light curves of supernova (SN) 2011fe in M101, including 34 epochs in H band starting fourteen days before maximum brightness in the B-band. The light cur…
Abundance analysis of prime B-type targets for asteroseismology I. Nitrogen excess in slowly-rotating beta Cephei stars
T. Morel, K. Butler, C. Aerts +2
We present the results of a detailed NLTE abundance study of nine beta Cephei stars, all of them being prime targets for theoretical modelling: gamma Peg, delta Cet, nu Eri, beta C…
B field in OB stars (BOB): The outstandingly strong magnetic field in the evolved He-strong star CPD-62 2124
N. Castro, L. Fossati, S. Hubrig +12
The origin and evolution of magnetism in OB stars is far from being well understood. With approximately 70 magnetic OB stars known, any new object with unusual characteristics may…
The blue supergiant Sher 25 revisited in the Gaia era
D. WeÃmayer, N. Przybilla, A. Ebenbichler +2
Aims. The evolutionary status of the blue supergiant Sher 25 and its membership to the massive cluster NGC 3603 are investigated. Methods. A hybrid non-LTE (local thermodynamic equ…
Chemical composition of Galactic OB stars I. CNO abundances in O9 stars
M. R. Villamariz, A. Herrero, S. R. Becker +1
We present NLTE abundances of CNO for a sample of four O9 stars in the Galaxy, together with new determinations of their stellar parameters, , , (He) and m…
Identification of Near-Infrared [Se III] and [Kr VI] Emission Lines in Planetary Nebulae
N. C. Sterling, S. Madonna, K. Butler +5
We identify [Se III] 1.0994 micron in the planetary nebula (PN) NGC 5315 and [Kr VI] 1.2330 micron in three PNe, from spectra obtained with the FIRE spectrometer on the 6.5-m Baade…
Observations and predictions at CesrTA, and outlook for ILC
G. Dugan, M. Billing, K. Butler +19
In this paper, we will describe some of the recent experimental measurements [1, 2, 3] performed at CESRTA [4], and the supporting simulations, which probe the interaction of the e…
The Quintuplet Cluster II. Analysis of the WN stars
A. Liermann, W. -R. Hamann, L. M. Oskinova +2
Based on -band integral-field spectroscopy, we analyze four Wolf-Rayet stars of the nitrogen sequence (WN) found in the inner part of the Quintuplet cluster. All WN stars (WR102…
z-GAL -- A NOEMA spectroscopic redshift survey of bright Herschel galaxies: [II] Dust properties
D. Ismail, A. Beelen, V. Buat +34
(Abridged) We present the dust properties of 125 bright Herschel galaxies selected from the z-GAL survey. The large instantaneous bandwidth of NOEMA provides an exquisite sampling…
Extragalactic Stellar Astronomy with Blue Supergiants
N. Przybilla, F. Bresolin, K. Butler +3
The present generation of large telescopes facilitates spectroscopy of blue supergiants in galaxies out to distances beyond the Local Group. Recent developments in NLTE spectrum sy…
B fields in OB stars (BOB): Detection of a magnetic field in the He-strong star CPD-57° 3509
N. Przybilla, L. Fossati, S. Hubrig +12
We report the detection of a magnetic field in the helium-strong star CPD-57 3509 (B2 IV), a member of the Galactic open cluster NGC3293, and characterise the star's atmospheric an…
Non-LTE Abundances of Magnesium, Aluminum and Sulfur in OB Stars Near the Solar Circle
S. Daflon, K. Cunha, V. V. Smith +1
Non-LTE abundances of magnesium, aluminum and sulfur are derived for a sample of 23 low-v \sin i stars belonging to six northern OB associations of the Galactic disk within 1 kpc o…
Quantitative Spectroscopy of BA-type Supergiants
N. Przybilla, K. Butler, S. R. Becker +1
Luminous BA-SGs allow topics ranging from NLTE physics and the evolution of massive stars to the chemical evolution of galaxies and cosmology to be addressed. A hybrid NLTE techniq…
Extreme helium stars: non-LTE matters Helium and hydrogen spectra of the unique objects V652 Her and HD144941
N. Przybilla, K. Butler, U. Heber +1
Quantitative analyses of low-mass hydrogen-deficient (super-)giant stars - so-called extreme helium stars - to date face two major difficulties. First, theory fails to reproduce th…
B fields in OB stars (BOB): The magnetic triple stellar system HD 164492C in the Trifid nebula
J. F. Gonzalez, S. Hubrig, N. Przybilla +15
HD 164492C is a spectroscopic triple stellar system that has been recently detected to possess a strong magnetic field. We have obtained high-resolution spectroscopic and spectropo…
CRIRES high-resolution near-infrared spectroscopy of diffuse interstellar band profiles. Detection of 12 new DIBs in the YJ band and the introduction of a combined ISM sight line and stellar analysis approach
A. Ebenbichler, A. Postel, N. Przybilla +7
A high spectral resolution investigation of diffuse interstellar bands (DIBs) in the near-infrared ( band) is conducted to test new methods, to confirm and improve existing par…
Up-dated opacities from the Opacity Project
N. R. Badnell, M. A. Bautista, K. Butler +5
Using the code AUTOSTRUCTURE, extensive calculations of inner-shell atomic data have been made for the chemical elements He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and…
Runaway BN supergiant star HD 93840: Progenitor of an imminent core-collapse supernova above the Galactic plane
D. WeÃmayer, M. A. Urbaneja, K. Butler +1
We present a quantitative spectral analysis of the extreme nitrogen-enhanced supergiant HD 93840 (BN1 Ib) at an intermediate galactic latitude. Based on an optical high-resolution…
A versatile dual-species Zeeman slower for caesium and ytterbium
S. A. Hopkins, K. Butler, R. Freytag +5
We describe the design, construction and operation of a versatile dual-species Zeeman slower for both Cs and Yb, which is easily adaptable for use with other alkali metals and alka…
Statistical equilibrium of silicon in the solar atmosphere
J. R. Shi, T. Gehren, K. Butler +2
The statistical equilibrium of neutral and ionised silicon in the solar photosphere is investigated. Line formation is discussed and the solar silicon abundance determined. High-re…
The neon content of nearby B-type stars and its implications for the solar model problem
T. Morel, K. Butler
The recent downward revision of the solar photospheric abundances now leads to severe inconsistencies between the theoretical predictions for the internal structure of the Sun and…
HVS7: a chemically peculiar hyper-velocity star
N. Przybilla, M. F. Nieva, A. Tillich +3
Context: Hyper-velocity stars are suggested to originate from the dynamical interaction of binary stars with the supermassive black hole in the Galactic centre (GC), which accelera…
LMC origin of the hyper-velocity star HE 0437-5439. Beyond the supermassive black hole paradigm
N. Przybilla, M. F. Nieva, U. Heber +4
Context: Hyper-velocity stars move so fast that only a supermassive black hole (SMBH) seems to be capable to accelerate them. Hence the Galactic centre (GC) is their only suggested…