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Articles 1 - 7 of 7
Full-Text Articles in Other Astrophysics and Astronomy
A Spectroscopic Survey Of Atmospheres Of Super-Earths, Luke Brust
A Spectroscopic Survey Of Atmospheres Of Super-Earths, Luke Brust
Honors Theses
Recent research has made it possible to use spectroscopy to analyze the composition of the atmospheres of exoplanets, planets that orbit other stars. Most projects thus far have focused on the atmospheres of gas giants, as it is less challenging to observe them with available equipment. This project studies the atmospheres of four Super- Earths, planets that have a mass greater than the Earth but smaller than Neptune. This is accomplished by processing the raw spectroscopic data from the Hubble Space Telescope and modeling the atmosphere using the program š-Rex3. This survey found clear results from two of the selected ā¦
Effects Of The Gravity Gradient On The Path Of 1i/āOumuamua, Hannah R. Richardson
Effects Of The Gravity Gradient On The Path Of 1i/āOumuamua, Hannah R. Richardson
Honors Theses
In October 2017, the asteroid 1I/āOumuamua first passed into viewing range [1]. The asteroid is notable for being the first interstellar object to enter the solar system. 1I/āOumuamua was also unusual in its geometry; it is thought to have an aspect ratio of 6:1 and a length of approximately 400 m [2] [3]. The asteroid was observed to experience a non-Keplerian acceleration estimated to be on the order of 1ā„10ā6 m s2 . Several theories have been proposed for the cause of this acceleration, all of which are non-gravitational in nature: volatile outgassing, photon pressure, and solar winds [1][4]. However, ā¦
Theoretical Spectroscopic Predictions Of Electronically Excited States, Noah R. Garrett
Theoretical Spectroscopic Predictions Of Electronically Excited States, Noah R. Garrett
Honors Theses
The quest for faster computation of anharmonic vibrational frequencies of both ground and excited electronic states has led to combining coupled cluster theory harmonic force constants with density functional theory (DFT) cubic and quartic force constants for defining a quartic force field (QFF) utilized in conjunction with vibrational perturbation theory at second order (VPT2). This work shows that explicitly correlated coupled cluster theory at the singles, doubles, and perturbative triples level [CCSD(T)-F12] provides accurate anharmonic vibrational frequencies and rotational constants when conjoined with any of B3LYP, CAM-B3LYP, BHandHLYP, PBE0, and ĻB97XD for roughly one-quarter of the computational time of the ā¦
Constraining H0 Via Extragalactic Parallax, Nicholas Ferree
Constraining H0 Via Extragalactic Parallax, Nicholas Ferree
Honors Theses
We examine the prospects for measurement of the Hubble parameter š»0 via observation of the secular parallax of other galaxies due to our own motion relative to the cosmic microwave background rest frame. Peculiar velocities make distance measurements to individual galaxies highly uncertain, but a survey sampling many galaxies can still yield a precise š»0 measurement. We use both a Fisher information formalism and simulations to forecast errors in š»0 from such surveys, marginalizing over the unknown peculiar velocities. The optimum survey observes ā¼ 102 galaxies within a redshift š»0max = 0.06. The required errors ā¦
Optimal Method For Reconstructing Polychromatic Maps From Broadband Observations With An Aysmmetric Antenna Pattern, Brianna Cantrall, Emory F. Bunn, Solomon Quinn
Optimal Method For Reconstructing Polychromatic Maps From Broadband Observations With An Aysmmetric Antenna Pattern, Brianna Cantrall, Emory F. Bunn, Solomon Quinn
Honors Theses
Broadband time-ordered data obtained from telescopes with a wavelength-dependent, asymmetric beam pattern can be used to extract maps at multiple wavelengths from a single scan. This technique is especially useful when collecting data on cosmic phenomena such as the Cosmic Microwave Background (CMB) radiation, as it provides the ability to separate the CMB signal from foreground contaminants. We develop a method to determine the optimal linear combinations of wavelengths (ācolorsā) that can be reconstructed for a given telescope design and the number of colors that are measurable with high signal-to-noise ratio. The optimal colors are found as eigenvectors of a ā¦
Spectroscopic Analysis Of Potential Astromolecules Via Quantum Chemical Quartic Force Fields, Mason Gardner
Spectroscopic Analysis Of Potential Astromolecules Via Quantum Chemical Quartic Force Fields, Mason Gardner
Honors Theses
Astrochemistry has been substantially aided by computational techniques, particularly through the use of Quartic Force Field (QFF) analysis. Several methods have proven useful at correlating computed spectroscopic data with experimental observations. The F12-TZ QFF correlated well with experimental data for silicon oxide compounds, particularly those potentially involved in development from rocky bodies to planetary masses [27]. Compared to argon matrix experimental data, the vibrational frequencies for the molecules SiO2, SiO3, Si2O3, and Si2O4 become less accurate as the complexity of the molecules increases but should still be predictive of infrared characteristics of silicon oxides as they form clusters in space ā¦
Finding Obscure Black Hole Growth Via Spectral Energy Distribution Modeling, Randall K. Chan
Finding Obscure Black Hole Growth Via Spectral Energy Distribution Modeling, Randall K. Chan
Honors Theses
An active galactic nucleus (AGN) occurs when the supermassive black hole at the center of the galaxy starts to grow. We still currently do not know what triggers AGN. Theories suggest that galaxy mergers could trigger AGNs, but past research has not been able to find a correlation between x-ray detected AGNs and disturbed galaxies. The present research looks specifically at AGN not detected in the x-ray, or obscured AGN. Using a newly updated IDL code, FAST, we were able to identify potential obscured AGN through spectral energy distribution (SED) modeling. We found a total of 526 obscured AGN in ā¦