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Exploring The Distant Universe With Cross-correlation Statistics

Matthews, Daniel J. (2014) Exploring The Distant Universe With Cross-correlation Statistics. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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Future cosmological surveys will require distance information for an extremely large number of galaxies in order to gain insight into the structure and history of our Universe. Current methods of obtaining accurate distance information such as measuring the redshifts of galaxies via spectroscopy are not feasible for such enormous datasets, mainly due to the long exposure times required. Photometric redshifts, where the redshift is measured using broadband imaging through only a few filters, are a promising avenue of study, although there are inherent limitations to this method making them less understood than spectroscopic redshifts. Understanding these limitations and improving the calibration of photometric redshifts will be very important for future cosmological measurements. This thesis presents tests of a new technique for calibrating photometric redshifts that exploits the clustering of galaxies due to gravitational interaction. This cross-correlation technique uses the measured spatial clustering on the sky of a photometric sample that has only imaging information, with a spectroscopic sample that has secure and accurate redshifts. These tests shows that measurements of this clustering as a function of redshift can be used to accurately reconstruct the true redshift distribution of the photometric sample. In addition, this thesis shows how similar clustering measurements can be used to constrain the contamination of a high redshift candidate sample by low redshift interlopers. Finally it describes a new catalog that combines spectroscopic redshifts and deep photometry that can be used as a testbed for future photo-$z$ studies.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Matthews, Daniel J.djm70@pitt.eduDJM70
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairNewman, Jeffrey A.janewman@pitt.eduJANEWMAN
Committee MemberZentner, Andrew R.zentner@pitt.eduZENTNER
Committee MemberWood-Vasey, W. Michaelwmwv@pitt.eduWMWV
Committee MemberFreitas, Ayresafreitas@pitt.eduAFREITAS
Committee MemberCroft, Rupert
Date: 29 May 2014
Date Type: Publication
Defense Date: 14 January 2014
Approval Date: 29 May 2014
Submission Date: 4 April 2014
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Number of Pages: 124
Institution: University of Pittsburgh
Schools and Programs: Dietrich School of Arts and Sciences > Physics
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Cosmology, astronomy, galaxies
Date Deposited: 29 May 2014 21:04
Last Modified: 15 Nov 2016 14:18


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