4 citations · 8 across the 4 of their papers we have counts for
10 papers
Standardizing reverberation-measured Mg II time-lag quasars, by using the radius-luminosity relation, and constraining cosmological model parameters
Narayan Khadka, Zhefu Yu, Michal Zajaček +3
We use 78 reverberation-measured Mg II time-lag quasars (QSOs) in the redshift range to constrain cosmological parameters in six different cosmological mo…
Perturbing the accretion flow onto a supermassive black hole by a passing star
Petra Suková, Michal Zajaček, Vojtěch Witzany +1
The close neighbourhood of a supermassive black hole contains not only accreting gas and dust, but also stellar-sized objects like stars, stellar-mass black holes, neutron stars, a…
Missing bright red giants in the Galactic center: A fingerprint of its once active state?
Michal Zajaček, Anabella Araudo, Vladimír Karas +5
In the Galactic center nuclear star cluster, bright late-type stars exhibit a flat or even a decreasing surface-density profile, while fainter late-type stars maintain a cusp-like…
Dark energy constraints from quasar observations
B. Czerny, M. L. Martínez-Aldama, G. Wojtkowska +9
Recent measurements of the parameters of the Concordance Cosmology Model (CDM) done in the low-redshift Universe with Supernovae Ia/Cepheids, and in the distant Universe done wi…
Distribution of Radio Spectral Slopes of Galaxies in Optical Diagnostic Diagrams
Michal Zajaček, Andreas Eckart, Silke Britzen +1
For about 500 intermediate-redshift sources (), whose radio flux densities at are larger than 10 mJy, we performed additional observations at 4.85 GHz…
Quasars from LSST as dark energy tracers: first steps
Mary Loli Martínez-Aldama, Swayamtrupta Panda, Bożena Czerny +1
In the near future, new surveys promise a significant increase in the number of quasars (QSO) at large redshifts. This will help to constrain the dark energy models using quasars.…