Search Publications
Stellar laboratories. X. New Cu IV-VII oscillator strengths and the first detection of copper and indium in hot white dwarfs
Rauch, T.; Werner, K.; Kruk, J. W. +4 more
Context. Accurate atomic data is an essential ingredient for the calculation of reliable non-local thermodynamic equilibrium (NLTE) model atmospheres that are mandatory for the spectral analysis of hot stars.
Aims: We aim to search for and identify for the first time spectral lines of copper (atomic number Z = 29) and indium (Z = 49) in hot w…
Connecting the Wilson depression to the magnetic field of sunspots
Solanki, S. K.; Lagg, A.; Löptien, B. +1 more
Context. In sunspots, the geometric height of continuum optical depth unity is depressed compared to the quiet Sun. This so-called Wilson depression is caused by the Lorentz force of the strong magnetic field inside the spots. However, it is not understood in detail yet how the Wilson depression is related to the strength and geometry of the magne…
An elliptic expansion of the potential field source surface model
Wimmer-Schweingruber, R. F.; Kruse, M.; Heidrich-Meisner, V. +1 more
Context. The potential field source surface model is frequently used as a basis for further scientific investigations where a comprehensive coronal magnetic field is of importance. Its parameters, especially the position and shape of the source surface, are crucial for the interpretation of the state of the interplanetary medium. Improvements have…
Is NGC 300 a pure exponential disk galaxy?
Bell, Eric F.; Holwerda, Benne W.; Monachesi, Antonela +6 more
NGC 300 is a low-mass disk galaxy in the Sculptor group. In the literature, it has been identified as a pure exponential disk galaxy, as its luminosity profile can be well fit with a single exponential law over many disk scale lengths (Type I). We investigate the stellar luminosity distribution of NGC 300 using Hubble Space Telescope archive data,…
Wide binaries in planetary nebulae with Gaia DR2
Dafonte, C.; González-Santamaría, I.; Manteiga, M. +3 more
Context. The Gaia Data Release 2 (DR2) was used to select a sample of 211 central stars of planetary nebulae (CSPNe) with good-quality astrometric measurements, which we refer to as Golden Astrometry Planetary Nebulae (GAPN). Gaia astrometric and photometric measurements allowed us to derive accurate distances and radii and to calculate luminositi…
Fragmentation and isomerization of polycyclic aromatic hydrocarbons in the interstellar medium: Coronene as a case study
Chen, Tao; Li, Aigen; Luo, Yi
Aims: Due to the limitations of current computational technology, the fragmentation and isomerization products of vibrationally-excited polycyclic aromatic hydrocarbon (PAH) molecules and their derivatives have been poorly studied. In this work, we investigate the intermediate products of PAHs and their derivatives as well as the gas-phase re…
Optical spectroscopy of type 2 LINERs
Hermosa Muñoz, L.; Márquez, I.; Masegosa, J. +1 more
Context. Type 2 Low-ionization Nuclear Emission-line Regions (LINERs) have been optically classified with the Palomar data as not presenting a broad component in the Balmer emission lines that are associated with the broad-line region (BLR) of the active galactic nuclei (AGN).
Aims: We aim to unveil the presence of different kinematic compone…
Panchromatic calibration of Ca II triplet luminosity dependence
Dias, B.; Parisi, M. C.
Context. The line strength of the near-infrared Ca II triplet (CaT) lines are a proxy for measuring metallicity from integrated and individual stellar spectra of bright red giant stars. In the latter case it is a mandatory step to remove the magnitude (proxy for gravity, temperature, and luminosity) dependence from the equivalent width (EW) of the…
Molecular gas in distant brightest cluster galaxies
Castignani, G.; Combes, F.; Salomé, P. +1 more
The mechanisms governing the stellar mass assembly and star formation history of brightest cluster galaxies (BCGs) are still being debated. By means of new and archival molecular gas observations we investigate the role of dense megaparsec-scale environments in regulating the fueling of star formation in distant BCGs, through cosmic time. We obser…
A new study of the spectroscopic binary 7 Vul with a Be star primary
Harmanec, P.; Labadie-Bartz, J.; Yang, S. +5 more
We confirmed the binary nature of the Be star 7 Vul, derived a more accurate spectroscopic orbit with an orbital period of 69.d4212±0.d0034, and improved the knowledge of the basic physical elements of the system. Analyzing available photometry and the strength of the Hα emission, we also document the lo…