Search Publications
Automatic catalog of RR Lyrae from ∼14 million VVV light curves: How far can we go with traditional machine-learning?
Gurovich, S.; Cabral, J. B.; Granitto, P. M. +1 more
Context. The creation of a 3D map of the bulge using RR Lyrae (RRL) is one of the main goals of the VISTA Variables in the Via Lactea Survey (VVV) and VVV(X) surveys. The overwhelming number of sources undergoing analysis undoubtedly requires the use of automatic procedures. In this context, previous studies have introduced the use of machine lear…
Hot gas heating via magnetic arms in spiral galaxies. The case of M 83
Ehle, M.; Weżgowiec, M.; Soida, M. +3 more
Context. Reconnection heating has been considered as a potential source of the heating of the interstellar medium. In some galaxies, significant polarised radio emission has been found between the spiral arms. This emission has a form of "magnetic arms" that resembles the spiral structure of the galaxy. Reconnection effects could convert some of t…
Spectroscopic classification of a complete sample of astrometrically-selected quasar candidates using Gaia DR2
Milvang-Jensen, B.; Fynbo, J. P. U.; Steinhardt, C. L. +20 more
Here we explore the efficiency and fidelity of a purely astrometric selection of quasars as point sources with zero proper motions in the Gaia data release 2 (DR2). We have built a complete candidate sample including 104 Gaia-DR2 point sources, which are brighter than 20th magnitude in the Gaia G-band within one degree of the north Galactic pole (…
Disk of 2MASS 15491331-3539118 = GQ Lup C as seen by HST and WISE
Alcalá, J. M.; Manara, C. F.; Frasca, A. +7 more
Aims: Very recently, a second companion on a wider orbit has been discovered around GQ Lup. This is a low-mass accreting star that is partially obscured by a disk seen at high inclination. If detected, this disk may be compared to the known disk around the primary.
Methods: We detected this disk on archive HST and WISE data.
Results…
The Solar Orbiter mission
Forveille, Thierry; Shore, Steve
Shapes of stellar activity cycles
Hackman, T.; Käpylä, M. J.; Olspert, N. +4 more
Context. Magnetic activity cycles are an important phenomenon both in the Sun and other stars. The shape of the solar cycle is commonly characterised by a fast rise and a slower decline, but not much attention has been paid to the shape of cycles in other stars.
Aims: Our aim is to study whether the asymmetric shape of the solar cycle is comm…
Forward modeling of galaxy kinematics in slitless spectroscopy
Copin, Y.; Outini, M.
Context. Slitless spectroscopy has long been considered a complicated and confused technique. Nonetheless, with the advent of Hubble Space Telescope (HST) instruments, characterized by a low sky background level and a high spatial resolution (most notably WFC3), slitless spectroscopy has become an adopted survey tool to study galaxy evolution from…
Transit least-squares survey. III. A 1.9 R⊕ transit candidate in the habitable zone of Kepler-160 and a nontransiting planet characterized by transit-timing variations
Batalha, Natalie M.; Bryson, Steve; Heller, René +3 more
The Sun-like star Kepler-160 (KOI-456) has been known to host two transiting planets, Kepler-160 b and c, of which planet c shows substantial transit-timing variations (TTVs). We studied the transit photometry and the TTVs of this system in our search for a suspected third planet. We used the archival Kepler photometry of Kepler-160 to search for …
GJ 357 b. A super-Earth orbiting an extremely inactive host star
Güdel, M.; Sanz-Forcada, J.; Maldonado, J. +5 more
Aims: In this paper we present a deep X-ray observation of the nearby M dwarf GJ 357 and use it to put constraints on the atmospheric evolution of its planet, GJ 357 b. We also analyse the systematic errors in the stellar parameters of GJ 357 in order to see how they affect the perceived planetary properties.
Methods: By comparing the ob…
A distinct magnetic property of the inner penumbral boundary. III. Analysis of simulated sunspots
Rempel, Matthias; Jurčák, Jan; Schmassmann, Markus +2 more
Context. Analyses of sunspot observations revealed a fundamental magnetic property of the umbral boundary: the invariance of the vertical component of the magnetic field.
Aims: We analyse the magnetic properties of the umbra-penumbra boundary in simulated sunspots and thus assess their similarity to observed sunspots. We also aim to investiga…