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Papers by Tetyana Nykytyuk

Research paper thumbnail of The Thin and Thick Disks of the Galaxy: Differences in Evolution

Astrophysics and Space Science Proceedings

The chemical evolution of the Galactic disk was investigated in framework of the opened two-zone ... more The chemical evolution of the Galactic disk was investigated in framework of the opened two-zone model with gas inflow. We suppose that the Galactic disk is divided in two zones — the thin and thick disks, which separate chemically and spatially and have different evolution timescales. The Galactic evolution of magnesium was investigated for the thin and thick disks. The obtained results show that the star formation history of the thin disk is more smooth and quiet than the star formation history of the thick disk of our Galaxy. Gas infall plays an important role in creating relative abundance differences between the thin and thick disk — the inflow rate is more intense for the thick disk.

Research paper thumbnail of Chemical evolution of the thick and thin disks of our galaxy

Astronomische Nachrichten - ASTRON NACHR, 2005

Research paper thumbnail of The Galactic thick and thin disks: differences in evolution

Astronomy and Astrophysics, 2006

Context. Recent observations demonstrate that the thin and thick disks of the Galaxy have differe... more Context. Recent observations demonstrate that the thin and thick disks of the Galaxy have different chemical abundance trends and evolution timescales. Aims. The relative abundances of α-elements in the thick Galactic disk are increased relative to the thin disk. Our goal is to investigate the cause of such differences in thick and thin disk abundances. Methods. We investigate the chemical evolution of the Galactic disk in the framework of the open two-zone model with gas inflow. Results. The Galactic abundance trends for α-elements (Mg, Si, O) and Fe are predicted for the thin and thick Galactic disks. Conclusions. The star formation histories of the thin and thick disks must have been different and the gas infall must have been more intense during the thick disk evolution that the thin disk evolution.

Research paper thumbnail of On the metal enrichment of Lalpha> clouds

Research paper thumbnail of Formation of the Halo Stellar Population in Spiral and Elliptical Galaxies

Lecture Notes in Physics, 2003

... k=1 mbk [Qi(τj,k) − Qi(τj−1,k)] (6) ms(tbj ) = ms(tbj−1 ) + mbj−1 − j−1 ∑ k=1 mbk [Qm(τj,k) −... more ... k=1 mbk [Qi(τj,k) − Qi(τj−1,k)] (6) ms(tbj ) = ms(tbj−1 ) + mbj−1 − j−1 ∑ k=1 mbk [Qm(τj,k) − Qm(τj−1,k)] (7) where τj,k = tbj − tbk τj−1,k = tbj−1 − tbk , ... In order to test the validity of thebuilding-up numerical model we carried out a comparison of numerical results with analytical. ...

Research paper thumbnail of The chemical evolution of the halo of the M33 galaxy

Research paper thumbnail of The Local Dwarf Galaxies:Building Blocks Ofmassive Ones? I.THE Fornax Dwarf Galaxy

Odessa Astronomical Publications, 2008

A chemical evolution of the Local Group dwarf galaxy Fornax is considered in the framework of the... more A chemical evolution of the Local Group dwarf galaxy Fornax is considered in the framework of the merger scenario. We suppose a galactic stellar halo to be formed as separate fragments which then merge; thus, we can calculate the set of such the fragments to reproduce the observed metallicity distribution function of a galaxy. Accordingly, if dwarf galaxies were such the systems, which, once merged, have formed massive galaxies, we need to obtain only one fragment to reproduce the observed metallicity distribution function of a dwarf galaxy. To test this assumption, the stellar metallicity distribution functions of Fornax was calculated in the framework of the merger scenario. The more than one fragment was obtained for galaxy under consideration; thus, it is unlikely the systems similar to Fornax to be building blocks of massive galaxies.

Research paper thumbnail of A Chemical Evolution of Local Dwarf Galaxies: Draco Galaxy

Astrophysics and Space Science Proceedings, 2011

Research paper thumbnail of The Thin and Thick Disks of the Galaxy: Differences in Evolution

Astrophysics and Space Science Proceedings

The chemical evolution of the Galactic disk was investigated in framework of the opened two-zone ... more The chemical evolution of the Galactic disk was investigated in framework of the opened two-zone model with gas inflow. We suppose that the Galactic disk is divided in two zones — the thin and thick disks, which separate chemically and spatially and have different evolution timescales. The Galactic evolution of magnesium was investigated for the thin and thick disks. The obtained results show that the star formation history of the thin disk is more smooth and quiet than the star formation history of the thick disk of our Galaxy. Gas infall plays an important role in creating relative abundance differences between the thin and thick disk — the inflow rate is more intense for the thick disk.

Research paper thumbnail of Chemical evolution of the thick and thin disks of our galaxy

Astronomische Nachrichten - ASTRON NACHR, 2005

Research paper thumbnail of The Galactic thick and thin disks: differences in evolution

Astronomy and Astrophysics, 2006

Context. Recent observations demonstrate that the thin and thick disks of the Galaxy have differe... more Context. Recent observations demonstrate that the thin and thick disks of the Galaxy have different chemical abundance trends and evolution timescales. Aims. The relative abundances of α-elements in the thick Galactic disk are increased relative to the thin disk. Our goal is to investigate the cause of such differences in thick and thin disk abundances. Methods. We investigate the chemical evolution of the Galactic disk in the framework of the open two-zone model with gas inflow. Results. The Galactic abundance trends for α-elements (Mg, Si, O) and Fe are predicted for the thin and thick Galactic disks. Conclusions. The star formation histories of the thin and thick disks must have been different and the gas infall must have been more intense during the thick disk evolution that the thin disk evolution.

Research paper thumbnail of On the metal enrichment of Lalpha> clouds

Research paper thumbnail of Formation of the Halo Stellar Population in Spiral and Elliptical Galaxies

Lecture Notes in Physics, 2003

... k=1 mbk [Qi(τj,k) − Qi(τj−1,k)] (6) ms(tbj ) = ms(tbj−1 ) + mbj−1 − j−1 ∑ k=1 mbk [Qm(τj,k) −... more ... k=1 mbk [Qi(τj,k) − Qi(τj−1,k)] (6) ms(tbj ) = ms(tbj−1 ) + mbj−1 − j−1 ∑ k=1 mbk [Qm(τj,k) − Qm(τj−1,k)] (7) where τj,k = tbj − tbk τj−1,k = tbj−1 − tbk , ... In order to test the validity of thebuilding-up numerical model we carried out a comparison of numerical results with analytical. ...

Research paper thumbnail of The chemical evolution of the halo of the M33 galaxy

Research paper thumbnail of The Local Dwarf Galaxies:Building Blocks Ofmassive Ones? I.THE Fornax Dwarf Galaxy

Odessa Astronomical Publications, 2008

A chemical evolution of the Local Group dwarf galaxy Fornax is considered in the framework of the... more A chemical evolution of the Local Group dwarf galaxy Fornax is considered in the framework of the merger scenario. We suppose a galactic stellar halo to be formed as separate fragments which then merge; thus, we can calculate the set of such the fragments to reproduce the observed metallicity distribution function of a galaxy. Accordingly, if dwarf galaxies were such the systems, which, once merged, have formed massive galaxies, we need to obtain only one fragment to reproduce the observed metallicity distribution function of a dwarf galaxy. To test this assumption, the stellar metallicity distribution functions of Fornax was calculated in the framework of the merger scenario. The more than one fragment was obtained for galaxy under consideration; thus, it is unlikely the systems similar to Fornax to be building blocks of massive galaxies.

Research paper thumbnail of A Chemical Evolution of Local Dwarf Galaxies: Draco Galaxy

Astrophysics and Space Science Proceedings, 2011