Search Publications
First detection of NHD and ND2 in the interstellar medium. Amidogen deuteration in IRAS 16293-2422
Caselli, P.; Sipilä, O.; Bizzocchi, L. +7 more
Context. Deuterium fractionation processes in the interstellar medium (ISM) have been shown to be highly efficient in the family of nitrogen hydrides. To date, observations have been limited to ammonia (NH2D, NHD2, ND3) and imidogen radical (ND) isotopologues.
Aims: We want to explore the high-frequency window…
Systematics and accuracy of VLBI astrometry: A comparison with Gaia Data Release 2
Liu, N.; Zhu, Z.; Liu, J. -C. +1 more
Context. The third generation of the ICRF - ICRF3 - was published in 2018. This new fundamental catalog provides radio source positions measured independently at three bands: S/X, K, and X/Ka, representing three independent radio celestial frames which altogether constitute a multi-frequency ICRF.
Aims: We aim to investigate the overall prope…
Role of the impact parameter in exoplanet transmission spectroscopy
Strassmeier, K. G.; Mallonn, M.; von Essen, C. +3 more
Context. Transmission spectroscopy is a promising tool for the atmospheric characterization of transiting exoplanets. Because the planetary signal is faint, discrepancies have been reported regarding individual targets.
Aims: We investigate the dependence of the estimated transmission spectrum on deviations of the orbital parameters of the st…
Li-rich K giants, dust excess, and binarity
Jorissen, A.; Pourbaix, D.; Escorza, A. +3 more
The origin of the Li-rich K giants is still highly debated. Here, we investigate the incidence of binarity among this family from a nine-year radial-velocity monitoring of a sample of 11 Li-rich K giants using the HERMES spectrograph attached to the 1.2 m Mercator Telescope. A sample of 13 non-Li-rich giants (8 of them being surrounded by dust acc…
Analysis of the TiO isotopologues in stellar optical spectra
Yurchenko, Sergei N.; Pavlenko, Ya. V.; Tennyson, Jonathan +1 more
Context. We used the new ExoMol TiO rovibronic line lists to identify and model TiO isotopologue features in spectra of M dwarfs.
Aims: We investigate problems involving the computation of electronic bands for different isotopologues of TiO by modelling optical spectra of late-type stars. Based on this, we determine their Ti isotopic abundanc…
High-resolution X-ray spectroscopy of the stellar wind in Vela X-1 during a flare
Bianchi, S.; Guainazzi, M.; Grinberg, V. +8 more
Context. We present a ~130 ks observation of the prototypical wind-accreting, high-mass X-ray binary Vela X-1 collected with XMM-Newton at orbital phases between 0.12 and 0.28. A strong flare took place during the observation that allows us to investigate the reaction of the clumpy stellar wind to the increased X-ray irradiation.
Aims: To exa…
Reflection component in the Bright Atoll Source GX 9+9
Sanna, A.; Di Salvo, T.; Burderi, L. +5 more
Context. GX 9+9 (4U 1728-16) is a low mass X-ray binary source harboring a neutron star. Although it belongs to the subclass of the bright Atoll sources together with GX 9+1, GX 3+1, and GX 13+1, its broadband spectrum is poorly studied and apparently does not show reflection features in the spectrum.
Aims: To constrain the continuum well and…
X-ray absorption in INTEGRAL active galactic nuclei. Host galaxy inclination
Ubertini, P.; Malizia, A.; Bassani, L. +2 more
In this work the INTEGRAL hard X-ray selected sample of active galactic nuclei (AGN) has been used to investigate the possible contribution of absorbing material distributed within the host galaxies to the total amount of NH measured in the X-ray band. We collected all the available axial ratio measurements of the galaxies hosting our A…
Expected performances of the Characterising Exoplanet Satellite (CHEOPS). II. The CHEOPS simulator
Queloz, D.; Benz, W.; Deline, A. +14 more
Context. The CHaracterising ExOPlanet Satellite (CHEOPS) is a mission dedicated to the search for exoplanetary transits through high precision photometry of bright stars already known to host planets. The telescope will provide the unique capability of determining accurate radii for planets whose masses have already been measured from ground-based…
Multi-wavelength campaign on NGC 7469. VI. Photoionisation modelling of the emission line regions and the warm absorber
Kriss, G. A.; Arav, N.; Bianchi, S. +16 more
Aims: We aim to investigate and characterise the photoionised X-ray emission line regions within the Seyfert 1 galaxy NGC 7469.
Methods: We applied the photoionisation model, PION, within the spectral fitting code SPEX to analyse the 640 ks reflection grating spectrometer spectrum of NGC 7469 gathered during an XMM-Newton observing campa…