Investigation of Gaia and GaiaNIR using selection functions on star clusters
(2025) FYSK04 20242Department of Physics
Astrophysics
- Abstract
- Gaia Near InfraRed, or GaiaNIR for short, is a proposed successor to the original Gaia satellite. Its main improvement over the Gaia satellite is the fact that GaiaNIR will observe in the infrared spectrum. This would allow the telescope to see through the heavy extinction of the Milky Way, as the interstellar gas and dust obstructs light mainly in the visible spectrum. A selection function utilizes observations in order to predict what observations will be missed by a telescope. It does this by creating a parent catalog, which is a subset of the observational data, containing attributes relevant to the detection probability, such as brightness and star density. Thus a final plot can be made, showing the completeness, i.e. how many... (More)
- Gaia Near InfraRed, or GaiaNIR for short, is a proposed successor to the original Gaia satellite. Its main improvement over the Gaia satellite is the fact that GaiaNIR will observe in the infrared spectrum. This would allow the telescope to see through the heavy extinction of the Milky Way, as the interstellar gas and dust obstructs light mainly in the visible spectrum. A selection function utilizes observations in order to predict what observations will be missed by a telescope. It does this by creating a parent catalog, which is a subset of the observational data, containing attributes relevant to the detection probability, such as brightness and star density. Thus a final plot can be made, showing the completeness, i.e. how many observations were missed. The main objective of this thesis was to investigate the observational properties of the Gaia satellite using the selection function, and compare the findings to the potential observational power of GaiaNIR. This would create a visualization of the increase in observational power for GaiaNIR, as well as set up a framework for showing the extent of GaiaNIR's scope in the inner regions of the Milky Way. The thesis used Gaia data from DR3, taking the measurement data of eight different star clusters, filtered out as many background and foreground stars as possible using proper motion plots, and applied the selection function to the aforementioned clusters. One of the clusters, Omega Centauri, was also projected at different distances and extinctions in order to compare the Gaia observations to the supposed GaiaNIR observations of similar clusters. This applied selection function showed that the completeness decreased when the line of sight neared the center of the star clusters, as the star density is too high to resolve individual stars. Moreover, the results showed that the Gaia satellite had the hardest time resolving clusters with a high extinction value, as well as clusters very far away. Since GaiaNIR is supposed to be made for observations in high extinction areas well within our galaxy, it will be very well-suited to resolve these extinction-heavy star clusters. This could result in very valuable measurements of the proper motion of these star clusters, as they could shed a light on the inner workings of the star cluster. The discoveries could include finding a black hole at the center of these star clusters, or mapping a dark matter halo around these clusters. (Less)
- Popular Abstract (Swedish)
- Satelliten Gaia har samlat data för ESA sedan den skjöts upp år 2013. Denna data har gett astronomer en ny inblick i hur den galaktiska miljön ser ut i vår närhet. Gaia har varit ett så lyckat projekt att man nu har börjat arbeta med en uppföljare till Gaiasatteliten, GaiaNIR, som står för Gaia Near InfraRed. Planen är att GaiaNIR ska observera i det infraröda spektrumet, något som gör att extinktionen minskar betydligt. Extinktion är den gas och det stoff som finns i yttre rymden och blockerar synligt ljus från att tränga igenom partiklarna. Detta gör att det blir extremt svårt att observera där dessa partiklar finns, vilka återfinns speciellt i mitten av Vintergatan. Därför kommer GaiaNIR att revolutionera vår vetskap om Vintergatans... (More)
- Satelliten Gaia har samlat data för ESA sedan den skjöts upp år 2013. Denna data har gett astronomer en ny inblick i hur den galaktiska miljön ser ut i vår närhet. Gaia har varit ett så lyckat projekt att man nu har börjat arbeta med en uppföljare till Gaiasatteliten, GaiaNIR, som står för Gaia Near InfraRed. Planen är att GaiaNIR ska observera i det infraröda spektrumet, något som gör att extinktionen minskar betydligt. Extinktion är den gas och det stoff som finns i yttre rymden och blockerar synligt ljus från att tränga igenom partiklarna. Detta gör att det blir extremt svårt att observera där dessa partiklar finns, vilka återfinns speciellt i mitten av Vintergatan. Därför kommer GaiaNIR att revolutionera vår vetskap om Vintergatans inre. Men för att kunna skjuta upp GaiaNIR måste flera tester göras. Bland annat måste det finnas någon slags vetskap om hur mycket bättre GaiaNIR kommer att se. Detta arbete ämnar att göra en analys av Gaiadatan med hjälp av en slags urvalsfunktion. Denna funktion visar hur bra en viss observation är, genom att med matematiska formler värdera en mätning baserat på hur många objekt - av de som finns med - som går att uppfattas. Detta är väldigt relevant för stjärnhopar, där många stjärnor i hopen kan vara diffusa, och vara svåra att uppfatta då de befinner sig bakom andra stjärnor, från vår synpunkt sett. Genom att titta på Gaiadatan utifrån urvalsfunktionen för dessa stjärnhopar skapas flera betydelsefulla resultat. I arbetet dras slutsatser utifrån resultaten som visar i vilka situationer GaiaNIR kommer att vara en stor förbättring i förhållande till Gaia, hur detta skulle påverka resultaten samt vilka forskningsmöjligheter som skulle kunna uppkomma som ett resultat av GaiaNIRs förbättrade observationer. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9185705
- author
- Hulthin, Emil LU
- supervisor
-
- David Hobbs LU
- organization
- course
- FYSK04 20242
- year
- 2025
- type
- M2 - Bachelor Degree
- subject
- report number
- 2025–EXA239
- language
- English
- id
- 9185705
- date added to LUP
- 2025-03-03 08:54:04
- date last changed
- 2025-03-03 08:54:04
@misc{9185705,
abstract = {{Gaia Near InfraRed, or GaiaNIR for short, is a proposed successor to the original Gaia satellite. Its main improvement over the Gaia satellite is the fact that GaiaNIR will observe in the infrared spectrum. This would allow the telescope to see through the heavy extinction of the Milky Way, as the interstellar gas and dust obstructs light mainly in the visible spectrum. A selection function utilizes observations in order to predict what observations will be missed by a telescope. It does this by creating a parent catalog, which is a subset of the observational data, containing attributes relevant to the detection probability, such as brightness and star density. Thus a final plot can be made, showing the completeness, i.e. how many observations were missed. The main objective of this thesis was to investigate the observational properties of the Gaia satellite using the selection function, and compare the findings to the potential observational power of GaiaNIR. This would create a visualization of the increase in observational power for GaiaNIR, as well as set up a framework for showing the extent of GaiaNIR's scope in the inner regions of the Milky Way. The thesis used Gaia data from DR3, taking the measurement data of eight different star clusters, filtered out as many background and foreground stars as possible using proper motion plots, and applied the selection function to the aforementioned clusters. One of the clusters, Omega Centauri, was also projected at different distances and extinctions in order to compare the Gaia observations to the supposed GaiaNIR observations of similar clusters. This applied selection function showed that the completeness decreased when the line of sight neared the center of the star clusters, as the star density is too high to resolve individual stars. Moreover, the results showed that the Gaia satellite had the hardest time resolving clusters with a high extinction value, as well as clusters very far away. Since GaiaNIR is supposed to be made for observations in high extinction areas well within our galaxy, it will be very well-suited to resolve these extinction-heavy star clusters. This could result in very valuable measurements of the proper motion of these star clusters, as they could shed a light on the inner workings of the star cluster. The discoveries could include finding a black hole at the center of these star clusters, or mapping a dark matter halo around these clusters.}},
author = {{Hulthin, Emil}},
language = {{eng}},
note = {{Student Paper}},
title = {{Investigation of Gaia and GaiaNIR using selection functions on star clusters}},
year = {{2025}},
}