The dynamical effects of the bar on the Galactic thin and thick disks

Giacomo Monari

The dynamical effects of the bar on the Galactic thin and thick disks

Vertaalde titel van de bijdrage: De dynamische effecten van de bar op de Galactische dunne en dikke schijven.

Giacomo Monari

Sterrenkunde

Onderzoeksoutput

1074 Downloads (Pure)

Samenvatting

De Melkweg is ons sterrenstelsel, het thuis van de Aarde en de Zon. Het merendeel van de sterren in de Melkweg bewegen zich voort op banen die bijna cirkelvormig zijn en die geconcentreerd zijn in een smalle laag, de zogenaamde “dunne schijf”. Een kleinere fractie van de sterren in de Galactische schijf hebben andere banen, meer langwerpige en strekken zich uit in een brede laag genaamd de “dikke schijf”. De sterren in de dunne en dikke schijf bewegen zich ook met verschillende snelheden. Als de meeste sterrenstelsels, de Melkweg heeft in het centrum een balk en spiraalarmen gevormd door sterren, gas en stof. De balk en de spiraalarmen hebben invloed op de snelheden van de sterren in de Melkweg. We vinden dat de balk veroorzaakt met name het ontstaan van twee groepen van sterren in de buurt van de Zon: één die naar binnen beweegt, en een andere die naar buiten beweegt in de Melkweg. Deze groepen bestaan in beide schijven. We classificeren de banen van de sterren met een techniek die de tijd berekent die ze nodig hebben om een omwenteling rond het centrum te maken. Voornamelijk voorspellen we vergelijkbare fracties van de sterren in de dunne en dikke schijven die het meest beïnvloed zijn door de balk. Recente metingen laten zien hoe de sterren van de schijf die zich dichter bij het centrum van de Melkweg bevinden meestal sneller bewegen dan die op een grotere afstand. Onze voorspellingen over het effect van de balk op de sterren van de dunne en dikke schijven zijn eens met deze metingen.

Vertaalde titel van de bijdrage	De dynamische effecten van de bar op de Galactische dunne en dikke schijven.
Originele taal-2	English
Kwalificatie	Doctor of Philosophy
Toekennende instantie	Rijksuniversiteit Groningen
Begeleider(s)/adviseur	Helmi, Amina, Supervisor Antoja Castelltort, Maria, Co-supervisor
Datum van toekenning	19-sep.-2014
Plaats van publicatie	[S.l.]
Uitgever	[S.n.]
Gedrukte ISBN's	978-90-367-7170-2
Elektronische ISBN's	978-90-367-7169-6
Status	Published - 2014

Toegang tot document

Title and contentFinal publisher's version, 420 KB
Chapter 1Final publisher's version, 5,2 MB
Chapter 2Final publisher's version, 4,11 MB
Chapter 3Final publisher's version, 4,05 MB
Chapter 4Final publisher's version, 10,3 MB
Complete dissertationFinal publisher's version, 21,8 MB
PropositionsFinal publisher's version, 98,3 KB

Handle.net

Permanente koppeling

Citeer dit

@phdthesis{f885b3bf5ef14f4388db91ad997441e8,

title = "The dynamical effects of the bar on the Galactic thin and thick disks",

abstract = "The Milky Way is our Galaxy, the home to the Earth and the Sun. Most of the stars in the Milky Way move on trajectories that are almost circular and are organized in a flattened structure called “thin disk”. A smaller fraction of stars have different trajectories, more elongated orbits and extend in a wide stratum called “thick disk”. The stars in the thin and thick disks travel also at different speeds. As many galaxies, the Milky Way has a stellar bar in its center and spiral arms formed by stars, gas and dust. The bar and the spiral arms influence the velocity of the stars in the Milky Way. In particular, we find that the effect of the bar is to induce the appearance of two groups of stars near the Sun: one moves inwards and another one moves outwards in the Milky Way. These groups exist for both disks. We classify the stars{\textquoteright} orbits with a technique that calculates the times they need to rotate in the Milky Way. In particular, we expect a similar fraction of the stars in the thin and thick disks that have an orbit strongly modified by the bar. Recent observations show how those stars that are closer to the Milky Way center tend to move outwards faster than those located at larger distances. Our predictions on the effect of the bar on the stars of the thin and thick disks agree with these observations.",

author = "Giacomo Monari",

year = "2014",

language = "English",

isbn = "978-90-367-7170-2",

publisher = "[S.n.]",

school = "University of Groningen",

}

TY - BOOK

T1 - The dynamical effects of the bar on the Galactic thin and thick disks

AU - Monari, Giacomo

PY - 2014

Y1 - 2014

N2 - The Milky Way is our Galaxy, the home to the Earth and the Sun. Most of the stars in the Milky Way move on trajectories that are almost circular and are organized in a flattened structure called “thin disk”. A smaller fraction of stars have different trajectories, more elongated orbits and extend in a wide stratum called “thick disk”. The stars in the thin and thick disks travel also at different speeds. As many galaxies, the Milky Way has a stellar bar in its center and spiral arms formed by stars, gas and dust. The bar and the spiral arms influence the velocity of the stars in the Milky Way. In particular, we find that the effect of the bar is to induce the appearance of two groups of stars near the Sun: one moves inwards and another one moves outwards in the Milky Way. These groups exist for both disks. We classify the stars’ orbits with a technique that calculates the times they need to rotate in the Milky Way. In particular, we expect a similar fraction of the stars in the thin and thick disks that have an orbit strongly modified by the bar. Recent observations show how those stars that are closer to the Milky Way center tend to move outwards faster than those located at larger distances. Our predictions on the effect of the bar on the stars of the thin and thick disks agree with these observations.

AB - The Milky Way is our Galaxy, the home to the Earth and the Sun. Most of the stars in the Milky Way move on trajectories that are almost circular and are organized in a flattened structure called “thin disk”. A smaller fraction of stars have different trajectories, more elongated orbits and extend in a wide stratum called “thick disk”. The stars in the thin and thick disks travel also at different speeds. As many galaxies, the Milky Way has a stellar bar in its center and spiral arms formed by stars, gas and dust. The bar and the spiral arms influence the velocity of the stars in the Milky Way. In particular, we find that the effect of the bar is to induce the appearance of two groups of stars near the Sun: one moves inwards and another one moves outwards in the Milky Way. These groups exist for both disks. We classify the stars’ orbits with a technique that calculates the times they need to rotate in the Milky Way. In particular, we expect a similar fraction of the stars in the thin and thick disks that have an orbit strongly modified by the bar. Recent observations show how those stars that are closer to the Milky Way center tend to move outwards faster than those located at larger distances. Our predictions on the effect of the bar on the stars of the thin and thick disks agree with these observations.

M3 - Thesis fully internal (DIV)

SN - 978-90-367-7170-2

PB - [S.n.]

CY - [S.l.]

ER -

The dynamical effects of the bar on the Galactic thin and thick disks

Samenvatting

Toegang tot document

Handle.net

Vingerafdruk

Citeer dit