Search Publications
Variability survey of brightest stars in selected OB associations
Tuvikene, Taavi; Eenmäe, Tõnis; Kolka, Indrek +2 more
Context. The stellar evolution theory of massive stars remains uncalibrated with high-precision photometric observational data mainly due to a small number of luminous stars that are monitored from space. Automated all-sky surveys have revealed numerous variable stars but most of the luminous stars are often overexposed. Targeted campaigns can imp…
Semi-empirical seismic relations of A-F stars from COROT and Kepler legacy data
Moya, A.; Suárez, J. C.; García Hernández, A. +1 more
Asteroseismology is witnessing a revolution, thanks to high-precise asteroseismic space data (MOST, COROT, Kepler, BRITE) and their large ground-based follow-up programs. Those instruments have provided an unprecedented large amount of information, which allows us to scrutinize its statistical properties in the quest for hidden relations among pul…
The structure of Andromeda II dwarf spheroidal galaxy
del Pino, Andrés; Hidalgo, Sebastian L.; Łokas, Ewa L. +1 more
We analyse in detail the spatial distribution and kinematic properties of two different stellar populations in Andromeda II dwarf spheroidal galaxy. We obtained their detailed surface density maps together with their radial density profiles. The two populations differ not only in age and metallicity, but also in their spatial distribution and kine…
An XMM-Newton and NuSTAR Study of IGR J18214-1318: A Non-pulsating High-mass X-Ray Binary with a Neutron Star
Fürst, Felix; Pottschmidt, Katja; Wilms, Jörn +5 more
IGR J18214-1318, a Galactic source discovered by the International Gamma-Ray Astrophysics Laboratory, is a high-mass X-ray binary (HMXB) with a supergiant O-type stellar donor. We report on the XMM-Newton and NuSTAR observations that were undertaken to determine the nature of the compact object in this system. This source exhibits high levels of a…
Orion revisited. III. The Orion Belt population
Bouy, H.; Burkert, A.; Sarro, L. M. +11 more
Aims: This paper continues our study of the foreground population to the Orion molecular clouds. The goal is to characterize the foreground population north of NGC 1981 and to investigate the star formation history in the large Orion star-forming region. We focus on a region covering about 25 square degrees, centered on the ɛ Orionis supergia…
Temporal and spatial variations of the absolute reflectivity of Jupiter and Saturn from 0.38 to 1.7 µm with PlanetCam-UPV/EHU
Hueso, R.; Sánchez-Lavega, A.; Rojas, J. F. +3 more
Aims: We provide measurements of the absolute reflectivity of Jupiter and Saturn along their central meridians in filters covering a wide range of visible and near-infrared wavelengths (from 0.38 to 1.7 µm) that are not often presented in the literature. We also give measurements of the geometric albedo of both planets and discuss the l…
The Relativistic Jet-accretion Flow-Wind Connection in Mrk 231
O'Dea, Christopher P.; Miniutti, Giovanni; Punsly, Brian +2 more
Long-term radio monitoring of the broad absorption line (BAL) quasar Mrk 231 at 17.6 GHz detected a strong flare in 2015. This triggered four epochs of Very Long Baseline Array (VLBA) observations from 8.4 to 43 GHz as well as three epochs of X-ray observations with NuSTAR and two with XMM over a 15 week period. Two ejected components were detecte…
Exploring the progenitors of brightest cluster galaxies at z ∼ 2
Conselice, Christopher J.; Zhao, Dongyao; Aragón-Salamanca, Alfonso +5 more
We present a new method for tracing the evolution of brightest cluster galaxies (BCGs) from z ∼ 2 to z ∼ 0. We conclude on the basis of semi-analytical models that the best method to select BCG progenitors at z ∼ 2 is a hybrid environmental density and stellar mass ranking approach. Ultimately, we are able to retrieve 45 per cent of BCG progenitor…
Resolving the X-ray emission from the Lyman-continuum emitting galaxy Tol 1247-232
Kaaret, P.; Prestwich, A. H.; Brorby, M. +1 more
Chandra observations of the nearby, Lyman-continuum (LyC) emitting galaxy Tol 1247-232 resolve the X-ray emission and show that it is dominated by a point-like source with a hard spectrum (Γ = 1.6 ± 0.5) and a high luminosity [(9 ± 2) × 1040 erg s- 1]. Comparison with an earlier XMM-Newton observation shows flux variation of …
Calculating travel times and arrival speeds of CMEs to Earth: An analytic tool for space weather forecasting
Aguilar-Rodriguez, E.; Corona-Romero, P.; Gonzalez-Esparza, J. A. +3 more
Coronal mass ejections (CME) are one of the most important phenomena derived from solar activity that potentially perturb space weather of Earth. In this work we present a semiempirical arrival forecasting tool for Earth-directed halo CMEs. This tool combines the piston shock model and an empirical relationship to estimate in situ arrivals of halo…