Search Publications
Redshift identification of X-ray-selected active galactic nuclei in the J1030 field: searching for large-scale structures and high-redshift sources
Prandoni, I.; Bolzonella, M.; Vignali, C. +23 more
We publicly release the spectroscopic and photometric redshift catalog of the sources detected with Chandra in the field of the z = 6.3 quasar SDSS J1030+0525. This is currently the fifth-deepest extragalactic X-ray field, and reaches a 0.5-2 keV flux limit of f0.5 − 2 = 6 × 10−17 erg s−1 cm−2. Using two…
Multi-band observations of Swift J0840.7−3516: A new transient ultra-compact X-ray binary candidate
Campana, S.; Rea, N.; Esposito, P. +5 more
We report on multi-band observations of the transient source Swift J0840.7−3516, which was detected in outburst in 2020 February by the Neil Gehrels Swift Observatory. The outburst episode lasted just ∼5 days, during which the X-ray luminosity quickly decreased from LX ≈ 3 × 1037 d102 erg s−1 …
The thermal emission of Saturn's icy moons. Effects of topography and regolith properties
Lucas, A.; Ferrari, C.; Jacquemoud, S.
Context. The effects of space weathering and other alteration processes on the upper surface of Saturn's icy moons are yet to be explored.
Aims: We present a thermophysical model parametrised by way of regolith properties such as porosity, grain size, and composition, as well as the local topography. The modelled surface temperature and appar…
Collisional effects in the blue wing of Lyman-α
Kielkopf, J. F.; Allard, N. F.; Spiegelman, F.
Spectral observations below Lyman-α are now obtained with the Cosmic Origin Spectrograph (COS) on the Hubble Space Telescope. It is therefore necessary to provide an accurate treatment of the blue wing of the Lyman-α line that enables correct calculations of radiative transport in DA and DBA white dwarf stars. On the theoretical front, we very rec…
Effects of anisotropy on absorption cross-section spectra of medium-sized spheroidal corundum particles
Mutschke, H.; Höfer, S.; Mayerhöfer, Th. G.
Context. It has been widely accepted that corundum particles condense in the atmospheres of oxygen-rich asymptotic giant branch stars and effectively produce an infrared emission feature at 13 µm. Laboratory experiments have predicted that these particles have the shape of oblate spheroids.
Aims: We investigate the influence of the mate…
The ionization fraction in OMC-2 and OMC-3
Menten, K. M.; Tielens, A. G. G. M.; Wyrowski, F. +4 more
Context. The electron density (ne−) plays an important role in setting the chemistry and physics of the interstellar medium. However, measurements of ne− in neutral clouds have been directly obtained only toward a few lines of sight or they rely on indirect determinations.
Aims: We use carbon radio …
Stereoscopic measurements of coronal Doppler velocities
Barczynski, K.; Mierla, M.; Berghmans, D. +8 more
Context. The Solar Orbiter mission, with an orbit outside the Sun-Earth line and leaving the ecliptic plane, opens up opportunities for the combined analysis of measurements obtained by solar imagers and spectrometers. For the first time different space spectrometers will be located at wide angles to each other, allowing three-dimensional (3D) spe…
An XMM-Newton catalogue of BL Lacs
Racero, E.; Álvarez Crespo, N.; de la Calle Pérez, I. +1 more
Aims: We present an XMM-Newton catalogue of BL Lac X-ray, optical, and UV properties based on cross-correlation with the 1151 BL Lacs listed in the fifth edition of the Roma-BZCAT.
Methods: We searched for the X-ray counterparts to these objects in the field of view of all pointed observations in the XMM-Newton archive over nearly 20 yea…
Goodness-of-fit test for isochrone fitting in the Gaia era. Statistical assessment of the error distribution
Valle, G.; Dell'Omodarme, M.; Tognelli, E.
Context. The increasing precision in observational data made available by recent surveys means that the reliability of stellar models can be tested. For this purpose, a firm theoretical basis is crucial for evaluating the agreement of the data and theoretical predictions. Aims This paper presents a rigorous derivation of a goodness-of-fit statisti…
Bright single-mode RR Lyrae stars: Matching Gaia EDR3 with pulsation and evolutionary models
Kovacs, Geza; Karamiqucham, Behrooz
We combine observed metallicity, optical, and infrared magnitudes with evolutionary and pulsation models to derive average luminosities for 156 single-mode RR Lyrae stars. These luminosities are compared with those obtained from the Gaia EDR3 parallaxes and are found to be in excellent agreement with the high accuracy subsample (62 stars, with rel…