The impact of angular momentum on the stellar mass and stellar density of galaxies
(2024) FYSK04 20241Department of Physics
Astrophysics
- Abstract
- The current work aims to investigate the impact of angular momentum in galaxy formation especially in the coevolution of the stellar central density (Σ⋆,1.2kpc) and total stellar mass (M⋆). This is achieved by tracing the histories of three simulated halos where the specific angular momentum is altered by modifying the initial conditions of the Lagrangian patch of baryons. The analysis consists of data from a reference galaxy and two cases with increased or decreased angular momentum values for z = 5 to z = 1.95. The evolutionary trajectories of the given simulations in Σ⋆,1.2kpc - M⋆ plot are created. The results show that some hints exist about the emergence of a possible pattern between the slopes of the galactic path close to z = 2. To... (More)
- The current work aims to investigate the impact of angular momentum in galaxy formation especially in the coevolution of the stellar central density (Σ⋆,1.2kpc) and total stellar mass (M⋆). This is achieved by tracing the histories of three simulated halos where the specific angular momentum is altered by modifying the initial conditions of the Lagrangian patch of baryons. The analysis consists of data from a reference galaxy and two cases with increased or decreased angular momentum values for z = 5 to z = 1.95. The evolutionary trajectories of the given simulations in Σ⋆,1.2kpc - M⋆ plot are created. The results show that some hints exist about the emergence of a possible pattern between the slopes of the galactic path close to z = 2. To detect a clear pattern and thus confirm that angular momentum is the reason that drives this trend, the size of the simulation needs to be expanded to lower redshift values. Additionally, the surface density profile for the three halos at z = 1.95 illustrated an indistinguishable behaviour between the corresponding curves, a result that is also reflected in the Σ⋆,1.2kpc - M⋆ plane. This outcome suggests that despite the notable alternations in the galactic evolution, the central region responds in a similar way until z = 1.95. (Less)
- Popular Abstract
- Galactic Carousel: Does the spin count?
When looking at galaxies through powerful telescopes, one can wonder about their peculiar rotational movements. Do the stars inside galaxies move together like a large carousel? Cosmology attempts to answer this question. Particularly, the structural evolution of galaxies is a significant field of study providing information not only for the current condition of galactic systems but also for their overall evolutionary processes. Recent studies suggest that a potential factor that may affect the formation of galaxies is the angular momentum.
More specifically, the cosmological interpretation of the angular momentum is that of a quantity that provides information about the rotational motion of a... (More) - Galactic Carousel: Does the spin count?
When looking at galaxies through powerful telescopes, one can wonder about their peculiar rotational movements. Do the stars inside galaxies move together like a large carousel? Cosmology attempts to answer this question. Particularly, the structural evolution of galaxies is a significant field of study providing information not only for the current condition of galactic systems but also for their overall evolutionary processes. Recent studies suggest that a potential factor that may affect the formation of galaxies is the angular momentum.
More specifically, the cosmological interpretation of the angular momentum is that of a quantity that provides information about the rotational motion of a celestial object. To visualize the significance of this concept, one can imagine that in the early Universe, the galaxies that we observe now were nothing more than large-scale clouds of gas. If nothing had disturbed the balance of that system these primordial gas clouds would have remained unchanged. However, various events contributed to the change of the Universe’s initial conditions, and hence under the influence of the gravitational field, these clouds collapsed inwards. This phenomenon resulted in the cloud being rotated while simultaneously shrinking in size and eventually forming galaxies. Thus the angular momentum enters the equation.
In general, cosmology is a rather challenging field of study as the existing observational instrumentation gives a picture of the present universe at a specific time, making it hard to determine its evolutionary mechanisms. Astronomers use simulations to modify the initial conditions of the early Universe. By analysing the extracted data, hypothetical scenarios can be formed that may lead to potential deductions. A useful tool to create such theories regarding the evolutionary development of galaxies is plotting the total stellar mass against the central stellar density. The method that will be followed in this project to inspect the impact of angular momentum is the creation of such graphs from different values of angular momenta. In doing so, patterns or strong indications of trends showing the impact the angular momentum has on the formation of galaxies will be revealed. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9163460
- author
- Kokkinaki, Evdokia Georgia LU
- supervisor
-
- Corentin Cadiou LU
- Oscar Agertz LU
- organization
- course
- FYSK04 20241
- year
- 2024
- type
- M2 - Bachelor Degree
- subject
- keywords
- cosmology, astrophysics, angular momentum, galaxy formation, stellar mass, stellar central density, initial conditions, galaxy evolution
- report number
- 2024–EXA227
- language
- English
- id
- 9163460
- date added to LUP
- 2024-07-01 13:11:07
- date last changed
- 2024-07-01 13:11:07
@misc{9163460,
abstract = {{The current work aims to investigate the impact of angular momentum in galaxy formation especially in the coevolution of the stellar central density (Σ⋆,1.2kpc) and total stellar mass (M⋆). This is achieved by tracing the histories of three simulated halos where the specific angular momentum is altered by modifying the initial conditions of the Lagrangian patch of baryons. The analysis consists of data from a reference galaxy and two cases with increased or decreased angular momentum values for z = 5 to z = 1.95. The evolutionary trajectories of the given simulations in Σ⋆,1.2kpc - M⋆ plot are created. The results show that some hints exist about the emergence of a possible pattern between the slopes of the galactic path close to z = 2. To detect a clear pattern and thus confirm that angular momentum is the reason that drives this trend, the size of the simulation needs to be expanded to lower redshift values. Additionally, the surface density profile for the three halos at z = 1.95 illustrated an indistinguishable behaviour between the corresponding curves, a result that is also reflected in the Σ⋆,1.2kpc - M⋆ plane. This outcome suggests that despite the notable alternations in the galactic evolution, the central region responds in a similar way until z = 1.95.}},
author = {{Kokkinaki, Evdokia Georgia}},
language = {{eng}},
note = {{Student Paper}},
title = {{The impact of angular momentum on the stellar mass and stellar density of galaxies}},
year = {{2024}},
}