Search Publications
Comparison of proper motions in declination for 387 Gaia DR2 and HIPPARCOS stars from ILS observations over many decades
Taris, F.; Damljanović, G.
Context. The second solution of the Gaia catalog, which has been available since April 2018, plays an important role in the realization of the future Gaia reference frame. Since 1997, the reference frame has been materialized by the optical HIPPARCOS positions of about 120 000 stars. The HIPPARCOS has been compared with and linked to the Internati…
Near- to mid-infrared spectroscopy of the heavily obscured AGN LEDA 1712304 with AKARI/IRC
Oyabu, S.; Toba, Y.; Kaneda, H. +5 more
Context. Although heavily obscured active galactic nuclei (AGNs) have been found by many observational studies, the properties of the surrounding dust are poorly understood. Using AKARI/IRC spectroscopy, we discovered a new heavily obscured AGN in LEDA 1712304 which shows a deep spectral absorption feature due to silicate dust.
Aims: We study…
An XMM-Newton look at the strongly variable radio-weak BL Lac Fermi J1544-0639
Pian, E.; Masetti, N.; Ubertini, P. +6 more
Context. Fermi J1544-0639/ASASSN-17gs/AT2017egv was identified as a gamma-ray/optical transient on May 15, 2017. Subsequent multiwavelength observations suggest that this source may belong to the new class of radio-weak BL Lacs.
Aims: We studied the X-ray spectral properties and short-term variability of Fermi J1544-0639 to constrain the X-ra…
Detection of an excessively strong 3-µm absorption near the lunar highland crater Dufay
Wöhler, C.; Grumpe, A.; Bhatt, M. +3 more
Using the near-infrared spectral reflectance data of the Chandrayaan-1 Moon Mineralogy Mapper (M3) instrument, we report an unusually bright structure of 30 × 60 km2 on the lunar equatorial farside near crater Dufay. At this location, the 3-µm absorption band feature, which is commonly ascribed to hydroxyl (OH) and/or w…
Characterization of the Agilkia region through discrete-element simulation of Philae's rebound
Grieger, Björn; Küppers, Michael; Wu, Xiaoyu +1 more
Context. The cold gas system and anchoring harpoons that were designed to hold Philae down after it landed on the Agilkia region of comet 67P/Churyumov-Gerasimenko (67P) failed. This caused the lander to move on a complex trajectory that comprised multiple impacts and rebounds. The motion of Philae was mainly dominated by the gravitational environ…
The stellar host in star-forming low-mass galaxies: Evidence for two classes
Muñoz-Tuñón, C.; Méndez-Abreu, J.; Lumbreras-Calle, A.
Context. The morphological evolution of star-forming galaxies provides important clues to understand their physical properties, as well as the triggering and quenching mechanisms of star formation.
Aims: We analyze the morphology of galaxies hosting star-forming events at low redshift (z < 0.36). We aim at connecting morphology and star-fo…
The influence of Hinode/SOT NFI instrumental effects on the visibility of simulated prominence fine structures in Hα
Gunár, S.; Ichimoto, K.; Jurčák, J.
Context. Models of entire prominences with their numerous fine structures distributed within the prominence magnetic field use approximate radiative transfer techniques to visualize the simulated prominences. However, to accurately compare synthetic images of prominences obtained in this way with observations and to precisely analyze the visibilit…
Star clusters in the dwarf irregular galaxy Leo A
Vansevičius, V.; Stonkutė, R.; Čeponis, M. +2 more
Context. Leo A is an isolated gas-rich dwarf irregular galaxy of low stellar mass and metallicity residing at the outskirts of the Local Group. Ages of the stellar populations in Leo A range from ∼10 Myr to ∼10 Gyr. So far, only one star cluster has been discovered in this galaxy.
Aims: Our aim is to search for star cluster candidates in the …
Follow-up observations of X-ray emitting hot subdwarf stars: the compact He-poor sdO star Feige 34
Tiengo, A.; Mereghetti, S.; Esposito, P. +1 more
We report on results obtained with the XMM-Newton observation of Feige 34 carried out in April 2018. This is the first spectroscopic X-ray observation of a compact and helium-poor hot subdwarf star. The source was detected at a flux level fX = 3.4 × 10-14 erg cm-2 s-1 in the energy range 0.2-3 keV, which…
Phase-curve analysis of comet 67P/Churyumov-Gerasimenko at small phase angles
Lamy, P. L.; Lara, L. M.; Bertaux, J. -L. +31 more
Aims: The Rosetta-OSIRIS images acquired at small phase angles in three wavelengths during the fly-by of the spacecraft on 9-10 April 2016 provided a unique opportunity to study the opposition effect on the surface of comet 67P/Churyumov-Gerasimenko (67P). Our goal is to study phase curves of the nucleus at small phase angles for a variety of…