東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Investigating the Wavelength Depende...

Tung, Nathan.

Linked to FindBook

Google Book

Amazon

博客來

Investigating the Wavelength Dependence of Weak Lensing Measurement From a Space Telescope and Estimating the Reduced Shear Signal in the Hubble Space Telescope Frontier Parallel Fields.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Investigating the Wavelength Dependence of Weak Lensing Measurement From a Space Telescope and Estimating the Reduced Shear Signal in the Hubble Space Telescope Frontier Parallel Fields./
Author:	Tung, Nathan.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2019,
Description:	134 p.
Notes:	Source: Dissertations Abstracts International, Volume: 80-12, Section: B.
Contained By:	Dissertations Abstracts International80-12B.
Subject:	Astrophysics. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=13896997
ISBN:	9781392241127

Investigating the Wavelength Dependence of Weak Lensing Measurement From a Space Telescope and Estimating the Reduced Shear Signal in the Hubble Space Telescope Frontier Parallel Fields.
Tung, Nathan.

Investigating the Wavelength Dependence of Weak Lensing Measurement From a Space Telescope and Estimating the Reduced Shear Signal in the Hubble Space Telescope Frontier Parallel Fields. - Ann Arbor : ProQuest Dissertations & Theses, 2019 - 134 p.

Source: Dissertations Abstracts International, Volume: 80-12, Section: B.

Thesis (Ph.D.)--University of California, Los Angeles, 2019.

This item must not be added to any third party search indexes.

Ignoring redshift dependence, the statistical performance of a weak lensing survey is set by two numbers: the effective shape noise of the sources, which includes the intrinsic ellipticity dispersion and the measurement noise, and the density of sources that are useful for weak lensing measurements. We provide some general guidance for weak lensing shear measurements from a "generic" space telescope using the galaxy flux signal-to-noise ratio (S/N), ellipticity measurement variance, and effective galaxy number per square degree as metrics to evaluate weak lensing measurement performance across wavelength. Galaxy data are collected from both the ULTRAVISTA field and the Hubble Space Telescope (HST) Frontier Parallel Fields (FPFs) and fitted to radially symmetric Sersic galaxy light profiles. The Sersic galaxy profiles are then stretched to impose an artificial weak lensing shear, and then convolved with a pure Airy Disk PSF to simulate imaging of weak gravitationally lensed galaxies from a hypothetical diffraction-limited space telescope. Our results consistently show that weak lensing measurements are optimized for the longest wavelengths available in the survey, until thermal background from the telescope or interplanetary dust reduces the sensitivity. We also perform a crude measurement of galaxy ellipticities in the HST FPFs using Source Extractor (SExtractor) software (Bertin & Arnouts, 1996) in order to estimate a reduced shear at the location of the parallel fields. The average ellipticity among a significantly large density of distant galaxy images is directly related to reduced gravitational shear signal, which we approximate with our simplifying assumptions and use to estimate the primary FF galaxy cluster masses to illustrate that shear measurements at long NIR wavelengths are completely reasonable.

ISBN: 9781392241127Subjects--Topical Terms:

535904
Astrophysics.

Investigating the Wavelength Dependence of Weak Lensing Measurement From a Space Telescope and Estimating the Reduced Shear Signal in the Hubble Space Telescope Frontier Parallel Fields.
LDR:03132nmm a2200349 4500 001 2210853
005 20191121124322.5
008 201008s2019 ||||||||||||||||| ||eng d
020 $a 9781392241127
035 $a (MiAaPQ)AAI13896997
035 $a (MiAaPQ)ucla:17820
035 $a AAI13896997
040 $a MiAaPQ $c MiAaPQ
100 1 $a Tung, Nathan. $3 3437995
245 1 0 $a Investigating the Wavelength Dependence of Weak Lensing Measurement From a Space Telescope and Estimating the Reduced Shear Signal in the Hubble Space Telescope Frontier Parallel Fields.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2019
300 $a 134 p.
500 $a Source: Dissertations Abstracts International, Volume: 80-12, Section: B.
500 $a Publisher info.: Dissertation/Thesis.
500 $a Advisor: Wright, Edward L.
502 $a Thesis (Ph.D.)--University of California, Los Angeles, 2019.
506 $a This item must not be added to any third party search indexes.
506 $a This item must not be sold to any third party vendors.
520 $a Ignoring redshift dependence, the statistical performance of a weak lensing survey is set by two numbers: the effective shape noise of the sources, which includes the intrinsic ellipticity dispersion and the measurement noise, and the density of sources that are useful for weak lensing measurements. We provide some general guidance for weak lensing shear measurements from a "generic" space telescope using the galaxy flux signal-to-noise ratio (S/N), ellipticity measurement variance, and effective galaxy number per square degree as metrics to evaluate weak lensing measurement performance across wavelength. Galaxy data are collected from both the ULTRAVISTA field and the Hubble Space Telescope (HST) Frontier Parallel Fields (FPFs) and fitted to radially symmetric Sersic galaxy light profiles. The Sersic galaxy profiles are then stretched to impose an artificial weak lensing shear, and then convolved with a pure Airy Disk PSF to simulate imaging of weak gravitationally lensed galaxies from a hypothetical diffraction-limited space telescope. Our results consistently show that weak lensing measurements are optimized for the longest wavelengths available in the survey, until thermal background from the telescope or interplanetary dust reduces the sensitivity. We also perform a crude measurement of galaxy ellipticities in the HST FPFs using Source Extractor (SExtractor) software (Bertin & Arnouts, 1996) in order to estimate a reduced shear at the location of the parallel fields. The average ellipticity among a significantly large density of distant galaxy images is directly related to reduced gravitational shear signal, which we approximate with our simplifying assumptions and use to estimate the primary FF galaxy cluster masses to illustrate that shear measurements at long NIR wavelengths are completely reasonable.
590 $a School code: 0031.
650 4 $a Astrophysics. $3 535904
650 4 $a Physics. $3 516296
650 4 $a Astronomy. $3 517668
690 $a 0596
690 $a 0605
690 $a 0606
710 2 $a University of California, Los Angeles. $b Physics 0666. $3 3171199
773 0 $t Dissertations Abstracts International $g 80-12B.
790 $a 0031
791 $a Ph.D.
792 $a 2019
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=13896997