Search Publications
Broadband X-Ray Observation of Broad-line Radio Galaxy 3C 109
Fabian, Andrew C.; Kara, Erin; Lohfink, Anne M. +1 more
We present a study of the central engine in the broad-line radio galaxy 3C 109. To investigate the immediate surrounding of this accreting, supermassive black hole, we perform a multiepoch broadband spectral analysis of a joint NuSTAR/XMM observation (2017), an archival XMM observation (2005) and the 105 month averaged Swift-BAT data. We are able …
The K supergiant runaway star HD 137071
Comerón, F.; Figueras, F.
Context. Extensive work exists on runaway massive stars with peculiar motions that are much higher than those typical of the extreme Population I to which they belong. Work on runaways has focused almost exclusively on O and B stars, most of which undergo a red supergiant phase before ending their lives as supernovae. Very few examples are known o…
Detection and characterization of stellar magnetic activity with Gaia
Lanzafame, Alessandro; Distefano, Elisa
The Gaia Data Release 2 (DR2) supplied a catalog of 147,644 late-type stars for which the analysis of the G-band photometric time series allowed the detection of the rotation period and an estimate of the magnetic activity level. The Gaia DR3 will be based on photometric time series spanning a longer time interval and will allow the detection and …
The near-infrared polarization of the pre-planetary nebula Frosty Leo
Luna, A.; Sabin, L.; Mayya, Y. D. +3 more
We present a near-infrared imaging polarimetric study of the pre-planetary nebula: Frosty Leo. The observations were carried out in J, H, and K' bands using the new polarimeter POLICAN mounted on the 2.1-m telescope of the Guillermo Haro Astrophysical Observatory, Sonora, Mexico. The most prominent result observed in the polarization maps is a lar…
EUV Wave Detection and Characterization Using Deep Learning
Liu, Sixuan; Xu, Long; Yan, Yihua +1 more
Coronal Mass Ejections (CMEs) are the most violent solar bursts. They cause severe disturbances in the solar-terrestrial space and affect human activities in many aspects, especially causing damage to high-tech infrastructure. It usually takes few hours for a CME to arrive at the Earth after eruption. Therefore, many efforts have been devoted to C…
Measuring the mass of the supermassive black hole of the lenticular galaxy NGC 4546
Ricci, T. V.; Steiner, J. E.
Most galaxies with a well-structured bulge host a supermassive black hole (SMBH) in their centre. Stellar kinematics models applied to adaptive optics (AO) assisted integral field unit observations are well-suited to measure the SMBH mass (MBH) and also the total mass-to-light ratio [(M/L)TOT] and possible anisotropies in the…
Signatures of the Galactic bar in high-order moments of proper motions measured by Gaia
Allende Prieto, Carlos; Palicio, Pedro A.; Martinez-Valpuesta, Inma +1 more
Our location in the Milky Way provides an exceptional opportunity to gain insight on the galactic evolution processes, and complement the information inferred from observations of external galaxies. Since the Milky Way is a barred galaxy, the study of motions of individual stars in the bulge and disc is useful to understand the role of the bar. Th…
Current Sheets with Multicomponent Plasma in Magnetospheres of Planets of the Solar System
Popov, V. Yu.; Petrukovich, A. A.; Grigorenko, E. E. +2 more
A self-consistent hybrid model of a thin current sheet (TCS) with a thickness of the order of several ion gyroradii is proposed that takes into account the multicomponent nature of collisionless space plasma. Several plasma components can be present in the tails of the magnetospheres of terrestrial planets (for example, the Earth, Mercury, Mars, a…
Long-term Periodicities in Kepler Photometry of Open Cluster NGC 6811
Saar, S. H.; Velloso, E. N.; do Nascimento, J. -D., Jr.
Long-term photometric variability can sometimes be related to the emergence of starspots in the photosphere following a quasi-periodic magnetic activity cycle. In order to investigate the existence and properties of magnetic cycles in a narrow range of fundamental parameters, we focused on solar-type stars in the intermediate-age open cluster NGC …
Spectral properties of the surface reflectance of the northern polar region of Mercury
Diep, Pham Ngoc; Ngoc, Nguyen Bich; Bott, Nicolas
We analyze MESSENGER reflectance measurements covering the northern polar region of Mercury, the least studied region of the northern mercurian hemisphere. We use observations from the Mercury Dual Imaging System Wide-Angle Camera (MDIS/WAC) and the Mercury Atmospheric and Surface Composition Spectrometer (MASCS/VIRS) to study the spectral depende…