Search Publications
Periodic changes in the morphology of the Galactic resonance rings
Melnik, A. M.; Dambis, A. K.; Podzolkova, E. N.
We study the periodic enhancement of either trailing or leading segments of the resonance elliptical rings in the dynamical model of the Galaxy which reproduces distributions of observed velocities derived from Gaia DR3 (EDR3) data along the Galactocentric distance. The model disc forms a nuclear ring, an inner combined ring, and outer resonance r…
The clustering properties of high-redshift passive galaxies
Pentericci, L.; Magliocchetti, M.; Santini, P. +1 more
We investigate the clustering properties of 3 < z < 5 candidate passive galaxies from the Merlin et al. (2019) sample residing in the GOODS-North (35 sources) and GOODS-South (33 sources) fields. Within the large uncertainties due to the paucity of sources we do not detect clustering signal in GOODS-North, while this is present in GOODS-Sout…
Central concentration of asymmetric features in post-starburst galaxies at z 0.8
Kajisawa, Masaru; Himoto, Kazuharu G.
We present morphological analyses of post-starburst galaxies (PSBs) at 0.7 < z < 0.9 in the COSMOS field. We fitted ultraviolet to mid-infrared multiband photometry of objects with i < 24 from COSMOS2020 catalogue with population synthesis models assuming non-parametric, piece-wise constant function of star formation history, and selected…
Hot accretion flows in low-luminosity active galactic nuclei in NGC 4258 and NGC 7213
Szanecki, Michał; Niedźwiecki, Andrzej; Wojaczyński, Rafał
We study the high energy emission of two active galactic nuclei (AGNs), NGC 4258 and NGC 7213. We directly apply the general-relativistic hot flow model, KERRFLOW, to the archival BeppoSAX, NuSTAR, and Suzaku observations of these objects. Most of these data sets indicate that about 10-20 per cent of the accretion power is used for the direct heat…
Application of the binary spectral model to high-resolution spectra. First estimation of the fundamental parameters for HD 20784
Kovalev, Mikhail; Straumit, Ilya
In this paper, we applied previously developed method of binary spectral model fitting to the high-resolution spectra of HD 20784. Simultaneously analysing all three available epochs, we found spectroscopic parameters for both components of the system. These parameters are consistent with stellar evolution model's predictions and analysis of the p…
Preparing for Gaia searches for optical counterparts of gravitational wave events during O4
Jonker, Peter G.; van Leeuwen, M.; Hodgkin, Simon +9 more
The discovery of gravitational wave (GW) events and the detection of electromagnetic counterparts from GW170817 has started the era of multimessenger GW astronomy. The field has been developing rapidly, and in this paper, we discuss the preparation for detecting these events with ESA's Gaia satellite, during the 4th observing run of the LIGO-Virgo…
New atomic data for C I Rydberg states compared with solar UV spectra
Del Zanna, G.; Storey, P. J.; Dufresne, R. P.
We use the Breit-Pauli R-matrix method to calculate accurate energies and radiative data for states in C I up to n = 30 and with l ≤ 3. We provide the full data set of decays to the five 2s2 2p2 ground configuration states 3P0,1,2, 1D2, and 1S0. This is the fir…
MEGASTAR - III. Stellar parameters and data products for DR1 late-type stars
Mollá, M.; Cardiel, N.; Gil de Paz, A. +5 more
MEGARA (Multi Espectrógrafo en Gran Telescopio Canarias de Alta Resolución para Astronomía) is the optical integral-field and multi-object spectrograph at the Gran Telescopio Canarias. We have created MEGASTAR , an empirical library of stellar spectra obtained using MEGARA at high resolution, $R=20\, 000$ (full width at half-maximum), available in…
A joint measurement of galaxy luminosity functions and large-scale field densities during the Epoch of Reionization
Furlanetto, Steven R.; Trapp, A. C.
One of the most exciting advances of the current generation of telescopes has been the detection of galaxies during the epoch of reionization, using deep fields that have pushed these instruments to their limits. It is essential to optimize our analyses of these fields in order to extract as much information as possible from them. In particular, s…
Evolution of the truncation radius in GX 339-4 from XMM-Newton spectral timing
Chainakun, P.; Young, A. J.; O'Mathúna, B. +1 more
We investigate the changing geometry of the accretion disc in the X-ray binary GX 339-4 using a combination of spectral and timing models to fit six XMM-Newton observations taken during the end of the 2015 X-ray outburst. We use progressively more complex models of the X-ray reflection spectra, from simple disc lines to full relativistic reflectio…