Abstract: I study the effects of climate-related shocks on emigration within the US. I develop a theoretical framework under which a Bayesian hypothetical migrant will update their expectation about the number of events they will experience in a given location and will choose to emigrate as a function of these changes. I empirically show that, in a destination ambivalent setting, there is a statistically significant and positive relationship between the number of emigrant households and the number of climate shocks, of any type, in the origin county. In a dyadic setting I find that a similar statistically significant and positive relationship exists between the number of households emigrating to a given destination and the number of climate shocks to the origin county. Curiously, I also find a positive, increasing and statistically significant relationship between the number of destination county climate shocks, prior to emigration, and the number of emigrant households. I subsequently utilize migration as an instrument by which climate shocks to the origin county can influence mean annual wages in the destination county, in the year post emigration, and find that the results are inconclusive. The inclusion of origin-destination fixed effects eliminating any statistically significant relationship while the omission of such fixed effects lead the relationship to be statistically significant and positive.
I received the Econometrics Award at UC San Diego's School of Global Policy and Strategy in May 2024 for the work in this paper
link to paper (on request)
Abstract: The high sensitivity of the Small Aperture Telescopes' (SAT) detectors and readout systems motivate stringent shielding requirements within the SAT instrument to ensure wayward signals at the Simons Observatory (SO) observing site do not contaminate observational measurements. We present an overview of the design of the radio frequency and magnetic shielding within the SAT instrument as well as results from the in-lab tests conducted to assess the shielding performance of the first Simons Observatory Small Aperture Telescope, SAT-MF1.
link to paper
Context: Classical novae are among the most frequent transient events in the Milky Way, and key agents of ongoing nucleosynthesis. Despite their large numbers, they have never been observed in soft ɣ-ray emission from which insights on both, explosion mechanism as well as nucleosynthesis products could be gathered.}
Aims: Our goal is to constrain the ejecta masses of 7Be and 22Na from classical novae through their ɣ-ray line emissions at 478 and 1275,keV.
Methods: We extract posterior distributions on the line fluxes from archival data of the INTEGRAL/SPI spectrometer telescope. We then use a Bayesian hierarchical model to link individual objects and diffuse emission and infer ejecta masses from the whole population of classical novae in the Galaxy.
Results: Individual novae are too dim to be detectable, and the upper bounds on their uncertainties cover several orders of magnitude. Within the framework our hierarchical model, we can nevertheless infer tight upper bounds on the 22Na ejecta masses, given all uncertainties from individual objects as well as diffuse emission, of $<2.1 \times 10^{-7}\,\mrm{M_{\odot}}$ (99.85th percentile).
Conclusions: In the context of ONe nucleosynthesis, the 22Na bounds are consistent with theoretical expectations, and exclude that most ONe novae happen on white dwarfs with masses around $1.35\,\mrm{M_{\odot}}$. The upper bounds from 7Be are uninformative. From the combined ejecta mass estimate of 22Na and its 𝛽⁺ -decay, we infer a positron production rate of $<5.4 \times 10^{42}\,\mrm{e^+\,s^{-1}}$, which would make at most 10% of the total annihilation rate in the Milky Way.
link to paper