Search Publications
Spectrophotometric calibration of low-resolution spectra
Jordi, C.; Fabricius, C.; Carrasco, J. M. +1 more
Context. Low-resolution spectroscopy is a frequently used technique. Aperture prism spectroscopy in particular is an important tool for large-scale survey observations. The ongoing ESA space mission Gaia is the currently most relevant example.
Aims: In this work we analyse the fundamental limitations of the calibration of low-resolution spect…
New insights on the massive interacting binary UU Cassiopeiae
Hadrava, P.; Jurkovic, M. I.; Mennickent, R. E. +7 more
We present the results of our study of the close binary UU Cassiopeiae based on previously published multiwavelength photometric and spectroscopic data. Based on eclipse timings from the last 117 years, we find an improved orbital period of Po = 8.d519296(8). In addition, we find a long cycle of length T ∼ 270 d in…
Kinematics of disk galaxies in (proto-)clusters at z = 1.5
Böhm, A.; Koyama, Y.; Kodama, T. +5 more
Aims: While many aspects of the impact of dense environments on late-type galaxies at redshifts below unity have been scrutinized in the past few decades, observational studies of the interplay between environment and disk galaxy evolution at z > 1 are still scarce. We observed star-forming galaxies at z ≈ 1.5 selected from the HyperSuprim…
Accretion and jets in a low-luminosity AGN: the nucleus of NGC 1052
Larsson, J.; Falocco, S.; Nandi, S.
Aims: We aim to determine the properties of the central region of NGC 1052 using X-ray and radio data. NGC 1052 (z = 0.005) has been investigated for decades in different energy bands and shows radio lobes and a low-luminosity active galactic nucleus.
Methods: We used X-ray images from Chandra and radio images from Very Large Array to ex…
An extremely hot white dwarf with a rapidly rotating K-type subgiant companion: UCAC2 46706450
Rebassa-Mansergas, Alberto; Pelisoli, Ingrid; Irawati, Puji +5 more
The subgiant UCAC2 46706450 is a late-type star with an ultraviolet (UV) excess. It was considered as a candidate to establish a sample of stars of spectral type F, G, and K with white dwarf (WD) companions that could be used to test binary evolution models. To verify the WD nature of the companion, UV spectroscopy has previously been performed by…
OB stars and YSO populations in the region of NGC 6334-NGC 6357 as seen with Gaia DR2
Adami, C.; Zavagno, A.; Russeil, D. +3 more
Aims: Our goal is to better understand the origin and the star-formation history of regions NGC 6334 and NGC 6357. We focus our study on the kinematics of young stars (young stellar objects and OB stars) in both regions mainly on the basis of the Gaia DR2 data.
Methods: For both regions, we compiled catalogs of OB stars and young stellar…
Bipolar molecular outflow of the very low-mass star Par-Lup3-4. Evidence for scaled-down low-mass star formation
de Gregorio-Monsalvo, I.; Huélamo, N.; Testi, L. +7 more
Context. Very low-mass stars are known to have jets and outflows, which is indicative of a scaled-down version of low-mass star formation. However, only very few outflows in very low-mass sources are well characterized.
Aims: We characterize the bipolar molecular outflow of the very low-mass star Par-Lup3-4, a 0.12 M⊙ object known …
BRITE photometry and STELLA spectroscopy of bright stars in Auriga: Rotation, pulsation, orbits, and eclipses⋆
Strassmeier, K. G.; Weber, M.; Granzer, T. +7 more
Context. Knowing rotational and pulsational periods across the Hertzsprung-Russell diagram is of top priority for understanding stellar activity as a function of time.
Aims: We aim to determine periods for bright stars in the Auriga field that are otherwise not easily accessible for ground-based photometry.
Methods: Continuous photometry…
Statistics of solar wind electron breakpoint energies using machine learning techniques
Walsh, A. P.; Rae, I. J.; Smith, A. W. +4 more
Solar wind electron velocity distributions at 1 au consist of a thermal "core" population and two suprathermal populations: "halo" and "strahl". The core and halo are quasi-isotropic, whereas the strahl typically travels radially outwards along the parallel or anti-parallel direction with respect to the interplanetary magnetic field. Using Cluster…
Spectroscopic detection of coronal plasma flows in loops undergoing thermal non-equilibrium cycles
Auchère, Frédéric; Parenti, Susanna; Pelouze, Gabriel +3 more
Context. Long-period intensity pulsations were recently detected in the EUV emission of coronal loops and attributed to cycles of plasma evaporation and condensation driven by thermal non-equilibrium (TNE). Numerical simulations that reproduce this phenomenon also predict the formation of periodic flows of plasma at coronal temperatures along some…