A near infrared Tully-Fisher survey behind the Galactic plane
type: CreativeWork
description: This thesis presents a first look at the directly measured peculiar velocity low field within the Southern Zone of Avoidance. Large peculiar velocity surveys are hampered by the low detection rates and poor data quality of galaxies in the Zone of Avoidance (ZoA) where the obscuring effects of dust and stars in the Milky Way prevent the detection of galaxies across 10 - 20% of the sky. Moreover, dynamically significant structures lie hidden behind the Galactic plane. Dedicated surveys have been conducted to unveil the mass distribution within the ZoA. The ZoA peculiar velocity survey presented here makes use of deep systematic Hi survey data, new high resolution Hi observations and new deep near infrared (NIR) observations to provide high fidelity measurements for use with the NIR Tully-Fisher relation. Hi observations reveal galaxies where both optical and NIR surveys fail. The HIZOA deep Hi survey conducted at the 64m Parkes telescope revealed ~ 1 000 galaxies in the southern ZoA (Henning et al. 2005, Donley et al. 2005, Shafi 2008) . Accurate Hi linewidths are required for the measurement of Tully-Fisher distances. The fidelity of the Hi linewidths depends both on the velocity resolution and signal-to-noise ratio of the spectrum. New Hi data were therefore acquired at Parkes for 82 galaxies, providing a mean factor ~ 3:4 improvement in the fractional uncertainties in the 50% linewidth. A deep NIR follow-up survey of HIZOA galaxies within 6000 kms -1 was conducted using the 1:4m IRSF telescope using the SIRIUS camera for simultaneous imaging in the near infrared J, H and Ks bands. These deep, high resolution NIR observations are able to penetrate the dust and deblend foreground stars making it possible to detect the NIR counterparts for the Hi-detected galaxies. The survey images have an exposure time of 10 min resulting in a limiting magnitude approximately 2m deeper than the 2MASS survey and the SIRIUS camera has a 00:045 pix -1 pixel scale and 7:07 _ 7:07 field …
abstract: This thesis presents a first look at the directly measured peculiar velocity low field within the Southern Zone of Avoidance. Large peculiar velocity surveys are hampered by the low detection rates and poor data quality of galaxies in the Zone of Avoidance (ZoA) where the obscuring effects of dust and stars in the Milky Way prevent the detection of galaxies across 10 - 20% of the sky. Moreover, dynamically significant structures lie hidden behind the Galactic plane. Dedicated surveys have been conducted to unveil the mass distribution within the ZoA. The ZoA peculiar velocity survey presented here makes use of deep systematic Hi survey data, new high resolution Hi observations and new deep near infrared (NIR) observations to provide high fidelity measurements for use with the NIR Tully-Fisher relation. Hi observations reveal galaxies where both optical and NIR surveys fail. The HIZOA deep Hi survey conducted at the 64m Parkes telescope revealed ~ 1 000 galaxies in the southern ZoA (Henning et al. 2005, Donley et al. 2005, Shafi 2008) . Accurate Hi linewidths are required for the measurement of Tully-Fisher distances. The fidelity of the Hi linewidths depends both on the velocity resolution and signal-to-noise ratio of the spectrum. New Hi data were therefore acquired at Parkes for 82 galaxies, providing a mean factor ~ 3:4 improvement in the fractional uncertainties in the 50% linewidth. A deep NIR follow-up survey of HIZOA galaxies within 6000 kms -1 was conducted using the 1:4m IRSF telescope using the SIRIUS camera for simultaneous imaging in the near infrared J, H and Ks bands. These deep, high resolution NIR observations are able to penetrate the dust and deblend foreground stars making it possible to detect the NIR counterparts for the Hi-detected galaxies. The survey images have an exposure time of 10 min resulting in a limiting magnitude approximately 2m deeper than the 2MASS survey and the SIRIUS camera has a 00:045 pix -1 pixel scale and 7:07 _ 7:07 field …
author: Williams, Wendy L
language: eng
date published: 2011
date modified: 2026-07-22T22:23:06Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Astronomy

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/13513