The distance to the Norma cluster and its relation to the great attractor region

 

Show simple item record

dc.contributor.advisor Blyth, Sarah-Louise en_ZA
dc.contributor.advisor Woudt, Patrick A en_ZA
dc.contributor.author Mutabazi, Tom en_ZA
dc.date.accessioned 2015-12-09T14:46:47Z
dc.date.available 2015-12-09T14:46:47Z
dc.date.issued 2015 en_ZA
dc.identifier.citation Mutabazi, T. 2015. The distance to the Norma cluster and its relation to the great attractor region. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/15742
dc.description.abstract The Local Group's peculiar motion with respect to the cosmic microwave background has been measured with high precision and found to be ~627±22 km s-1, but the source of this motion is not clear. Studies to constrain the fractional contribution of the local mass overdensity, particularly in the Great Attractor region and the more distant Shapley Supercluster, remain contradictory. This work is an attempt to disentangle these contributions by measuring a redshift-independent distance to the Norma cluster, which lies at, or close to, the core of the Great Attractor, in order to determine its peculiar velocity. A reliable measurement of the distance and peculiar velocity of Norma will help clarify the velocity flows in the Great Attractor region. The challenge is with observing in the Zone of Avoidance since star crowding and Galactic extinction effects are severe at such low Galactic latitudes. High quality near-infrared images have been used in the photometric analysis for the Norma cluster sample so as to minimise the effect of Galactic extinction. In addition, the imaging cameras used have a small pixel scale resulting in well resolved images for reliable foreground star-subtraction hence accurate photometry. In order to determine the redshift-independent distance, I applied two independent, complemen- tary methods: the Fundamental Plane and the Tully-Fisher relations. The redshift-independent distance and the peculiar velocity of the Norma cluster were measured using 1) the Ks-band Fundamental Plane analysis for 31 galaxies using the 3.6m New Technology Telescope (NTT) at the European Southern Observatory (ESO) 2) the J- and Ks-band Fundamental Plane analysis for 31 galaxies using the Japanese 1.4 m InfraRed Survey Facility (IRSF) at the South African Astronomical Observatory (SAAO) 3) the combined NTT and IRSF Ks-band Fundamental Plane analysis for 41 galaxies 4) the Ks-band Tully-Fisher analysis for 12 galaxies using near-infrared images from the IRSF and HI profiles obtained from the 64-m Parkes radio telescope. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Astronomy en_ZA
dc.title The distance to the Norma cluster and its relation to the great attractor region en_ZA
dc.type Doctoral Thesis
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Astronomy en_ZA
dc.type.qualificationlevel Doctoral
dc.type.qualificationname PhD en_ZA
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Mutabazi, T. (2015). <i>The distance to the Norma cluster and its relation to the great attractor region</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Astronomy. Retrieved from http://hdl.handle.net/11427/15742 en_ZA
dc.identifier.chicagocitation Mutabazi, Tom. <i>"The distance to the Norma cluster and its relation to the great attractor region."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Astronomy, 2015. http://hdl.handle.net/11427/15742 en_ZA
dc.identifier.vancouvercitation Mutabazi T. The distance to the Norma cluster and its relation to the great attractor region. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Astronomy, 2015 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/15742 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Mutabazi, Tom AB - The Local Group's peculiar motion with respect to the cosmic microwave background has been measured with high precision and found to be ~627±22 km s-1, but the source of this motion is not clear. Studies to constrain the fractional contribution of the local mass overdensity, particularly in the Great Attractor region and the more distant Shapley Supercluster, remain contradictory. This work is an attempt to disentangle these contributions by measuring a redshift-independent distance to the Norma cluster, which lies at, or close to, the core of the Great Attractor, in order to determine its peculiar velocity. A reliable measurement of the distance and peculiar velocity of Norma will help clarify the velocity flows in the Great Attractor region. The challenge is with observing in the Zone of Avoidance since star crowding and Galactic extinction effects are severe at such low Galactic latitudes. High quality near-infrared images have been used in the photometric analysis for the Norma cluster sample so as to minimise the effect of Galactic extinction. In addition, the imaging cameras used have a small pixel scale resulting in well resolved images for reliable foreground star-subtraction hence accurate photometry. In order to determine the redshift-independent distance, I applied two independent, complemen- tary methods: the Fundamental Plane and the Tully-Fisher relations. The redshift-independent distance and the peculiar velocity of the Norma cluster were measured using 1) the Ks-band Fundamental Plane analysis for 31 galaxies using the 3.6m New Technology Telescope (NTT) at the European Southern Observatory (ESO) 2) the J- and Ks-band Fundamental Plane analysis for 31 galaxies using the Japanese 1.4 m InfraRed Survey Facility (IRSF) at the South African Astronomical Observatory (SAAO) 3) the combined NTT and IRSF Ks-band Fundamental Plane analysis for 41 galaxies 4) the Ks-band Tully-Fisher analysis for 12 galaxies using near-infrared images from the IRSF and HI profiles obtained from the 64-m Parkes radio telescope. DA - 2015 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2015 T1 - The distance to the Norma cluster and its relation to the great attractor region TI - The distance to the Norma cluster and its relation to the great attractor region UR - http://hdl.handle.net/11427/15742 ER - en_ZA


Files in this item

This item appears in the following Collection(s)

Show simple item record