Search Publications
Fundamental parameters of the Ap-stars GO And, 84 UMa, and κ Psc
Sitnova, T. M.; Romanovskaya, A. M.; Ryabchikova, T. A. +1 more
Aims: The aim of this work is to determine fundamental parameters of three Ap stars, GO And (HD 4778), κ Psc (HD 220825), and 84 UMa (HD 120198), using spectroscopic techniques. By analysing these stars, we complete the sample of Ap stars for which fundamental parameters have additionally been derived by means of interferometry. This enables …
A nonlinear solar magnetic field calibration method for the filter-based magnetograph by the residual network
Ji, Kaifan; Su, Jiangtao; Deng, Yuanyong +6 more
Context. The method of solar magnetic field calibration for the filter-based magnetograph is normally the linear calibration method under weak-field approximation that cannot generate the strong magnetic field region well due to the magnetic saturation effect.
Aims: We try to provide a new method to carry out the nonlinear magnetic calibratio…
Infrared photometry and CaT spectroscopy of globular cluster M 28 (NGC 6626)
Minniti, D.; Zoccali, M.; Contreras Ramos, R. +12 more
Context. Recent studies show that the inner Galactic regions host genuine bulge globular clusters, but also halo intruders, complex remnants of primordial building blocks, and objects likely accreted during major merging events.
Aims: In this study we focus on the properties of M 28, a very old and massive cluster currently located in the Gal…
Investigation on the spatiotemporal structures of supra-arcade spikes
Wang, Yuming; Liu, Rui
Context. The vertical current sheet (VCS) trailing coronal mass ejections (CMEs) is the key place at which the flare energy release and the CME buildup take place through magnetic reconnection. The VCS is often studied from the edge-on perspective for the morphological similarity with the two-dimensional "standard" picture, but its three-dimension…
First black hole mass estimation for the quadruple lensed system WGD2038-4008
Assef, R. J.; Godoy, N.; Mediavilla, E. +6 more
Context. The quadruple lensed system WGD2038-4008 (zs = 0.777 ± 0.001) has recently been discovered with the help of new techniques and observations. Black hole masses have been estimated for lensed quasars, but they have mostly been calculated for one broad emission line of one image. However, the images could be affected by microlensi…
Detection of photometric variability in the very low-mass binary VHS J1256-1257AB using TESS and Spitzer
Miles-Páez, P. A.
Aims: We investigate the photometric properties of the M7.5 equal-mass binary VHS J1256-1257AB, which, combined with the late-L dwarf VHS J1256-1257 b, forms one of the few young triple systems of ultra-cool dwarfs currently known.
Methods: We analyzed two-minute TESS and two-second Spitzer archival data with total durations of about 25 …
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XXII. Relative ages of multiple populations in five globular clusters
Piotto, G.; Nardiello, D.; Lucertini, F.
Aims: We present a new technique to estimate the relative ages of multiple stellar populations hosted by the following five globular clusters: NGC 104 (47 Tuc), NGC 6121 (M 4), NGC 6352, NGC 6362, and NGC 6723.
Methods: We used the catalogs of the database HST UV Globular Cluster Survey to create color-magnitude and two-color diagrams of…
Gas and stellar dynamics in Stephan's Quintet. Mapping the kinematics in a closely interacting compact galaxy group
Eckart, A.; Sánchez-Monge, Á.; Yttergren, M. +4 more
In nearby compact galaxy groups we can study the complex processes of galaxy interactions at high resolution and obtain a window into a time in the history of the Universe when the galaxies were closely spaced and the intergalactic medium was awash with gas. Stephan's Quintet is a nearby compact galaxy group and a perfect laboratory for studying t…
Electric field measurements at the plasma frequency around comet 67P by RPC-MIP on board Rosetta
Palmerio, E.; Nilsson, H.; Henri, P. +7 more
Context. The Mutual Impedance Probe (RPC-MIP) carried by the Rosetta spacecraft monitored both the plasma density and the electric field in the close environment of comet 67P/Churyumov-Gerasimenko (67P), as the instrument was operating alternatively in two main modes: active and passive. The active mode is used primarily to perform plasma density …
Gas terminal velocity from MIRO/Rosetta data using neural network approach
Hartogh, P.; Crovisier, J.; Ip, W. H. +8 more
Context. The Microwave Instrument on the Rosetta Orbiter (MIRO) on board the Rosetta spacecraft was designed to investigate the surface and gas activity of the comet 67P/Churyumov-Gerasimenko. The MIRO spectroscopic measurements carry information about the velocity of gas emanating from the nucleus surface. Knowledge of the terminal velocity of th…