Prakash, Abhishek
(2017)
PROBING THE LARGE SCALE STRUCTURE OF THE UNIVERSE THROUGH LUMINOUS RED GALAXIES.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
This is the latest version of this item.
Abstract
The study of Baryon Acoustic Oscillations (BAO) has become a key tool for exploring the nature of Dark Energy. BAO refers to periodic fluctuations in the density of baryonic matter in the universe that were caused by acoustic oscillations created by radiation pressure differences. Luminous Red Galaxies (LRGs) have played a vital role in the detection of BAO. These are the most massive galaxies in the z∼1 universe, showing a characteristic 4000 ̊A break in their spectral energy distributions (SEDs). This thesis establishes a new algorithm for selecting high redshift LRGs for spectroscopic surveys like SDSS-IV/eBOSS and DESI, which aim to precisely measure the BAO signal at high redshifts. We further adapt these methods for assembling the next generation eBOSS LRG sample and explain these methods in detail. These methods have been used by other international teams to assemble high redshift LRG sample for various investigations.
Large-scale clustering measurements are prone to systematic uncertainties associated with imaging surveys. This thesis establishes modern statistical techniques to overcome these challenges. A multivariate regression analysis, primarily applied on the eBOSS LRG and quasar samples, is presented for a better understanding of the systematic uncertainties and their effects on the clustering measurements. Another key aspect of this work is the development of a machine learning algorithm for estimating photometric redshifts. Applying this machinery yields accurate estimates of the distances of galaxies using their photometric properties alone, i.e., their colors and magnitudes. This work culminates with new cluster- ing measurements that use these photometric redshifts in an attempt to detect BAO in the
eBOSS LRG sample. We also presented initial results from an ongoing effort to measure the clustering of LRGs around quasars using the first two years of spectroscopic data from eBOSS.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
28 September 2017 |
| Date Type: |
Publication |
| Defense Date: |
18 July 2017 |
| Approval Date: |
28 September 2017 |
| Submission Date: |
29 July 2017 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
177 |
| 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, galaxies, spectroscopy, redshifts |
| Date Deposited: |
28 Sep 2017 23:06 |
| Last Modified: |
28 Sep 2017 23:06 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/33010 |
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PROBING THE LARGE SCALE STRUCTURE OF THE UNIVERSE THROUGH LUMINOUS RED GALAXIES. (deposited 28 Sep 2017 23:06)
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