Project Description: Quasars are powered by material accreting onto supermassive black holes (SMBH) in episodic events. With new spectra from the James Webb Space Telescope (JWST), we can now test the hypothesis that SMBH in the early universe were less massive and accreting more vigorously than their counterparts radiating the same power at later cosmic times.
SMBH masses are determined by measuring the velocity spread of emitting gas in close orbits around the SMBH. The emission lines of Hydrogen and other elements are broadened by that motion. The best calibrator is a H line in the blue-green; the earliest quasars have that line redshifted into the infrared, well recorded in JWST spectra.
The intern's task will be to fit the continuum and multiple components to the relevant emission lines in both the JWST spectra and a matched comparison sample from the Sloan Digital Sky Survey. The calibrated SMBH masses and accretion rates will then be compared to test for evolution.
NASA Relevance: NASA's Science Mission Directorate vision includes addressing the question: How does the Universe work? We will use data from its flagship mission, the James Webb Space Telescope, to increase our understanding of the growth of supermassive black holes in the early Universe.
Work Description:
- Learn queries and data retrieval for relevant samples of quasar spectra from NASA archives.
- Study articles from the astronomical literature for tested techniques of spectrum analysis of quasars, as well as reviews about SMBH masses.
- Master python scripts for line profile and continuum fitting on archival 1-dimensional spectra.
- Learn techniques for extracting 1-D spectra from 2-D JWST spectral data cubes.
- Apply line and continuum fitting techniques to extracted JWST spectra.
- Learn statistical methods to compare high-redshift and medium-redshift samples.
- Co- or lead author on published paper.
Open or Reserved Project: 1 position reserved, but will consider new student if requested student not awarded.