Calendar

Sep
12
Thu
Colloquium Thesis Proposal: Rachel Marra
Sep 12 @ 1:30 pm – 2:30 pm
Colloquium Thesis Proposal: Rachel Marra @ Jett Hall 210

An Observer’s Examination of the Circumgalactic Medium using Cosmological Simulations

Rachel Marra, NMSU

A significant aspect to understanding galaxy evolution is having an understanding of the intricacies involving the inflow and outflow of baryons onto a galaxy. Gas needs to accrete onto the galaxy in order for star formation to occur, while stellar winds, supernovae, and radiation pressure result in the outflow of gas from the galaxy. The diffuse region around the galaxy that has gas from interstellar medium (ISM) inflows and intergalactic medium (IGM) outflows interacting is the circumgalactic medium (CGM). Studying the CGM will help us learn about the baryon cycle and give us a better understanding of galactic evolution.

The primary method to studying the CGM is through absorption, as the density is too low to detect emission. Studying these absorption features allows us to learn about the physical properties of the gas giving rise to the absorption. Other than through observations, cosmological simulations play a large role in how we learn about the CGM of galaxies. Using MOCKSPEC, the Quasar Absorption Line Analysis Pipeline, to create mock quasar sightlines through the VELA simulation suite of galaxies, we use the absorption features seen in the sightlines to study the CGM in the simulations. While there are many ions that are used to study the CGM, we focus on OVI.

We intend to study how effective our methods are for studying the CGM with both observations and simulations. The covering fraction of OVI for a sample of observed galaxies will be compared with the covering fraction that is found from a selection of LOS that probe simulated, Milky-Way type galaxies. This tells us if the simulations can reproduce the observations, and if they do not, we can gain insights as to why the simulations do not match observed data. We will also investigate if the metallicity calculated from an observed absorption feature reflects the actual metallicity of the probed gas by using mock sightlines through simulations. Additionally, we will do a comparison of different methodologies used to study the CGM in simulations, to determine if using mock quasar sightlines is a more realistic and accurate method to compare to observed data.

Feb
26
Wed
Colloquium Thesis Proposal: Sean Sellers
Feb 26 @ 3:30 pm – 4:30 pm
Colloquium Thesis Proposal: Sean Sellers @ Domenici Hall 006

A Multi-Wavelength Study of the Evolution of Solar Flares

Sean Sellers, NMSU

 

May
8
Fri
Sarah Kovac: Thesis Proposal
May 8 @ 3:00 pm – 4:00 pm
Sarah Kovac: Thesis Proposal @ Remote via Zoom

Enhancing Time-Dependent Solar Wind Models to Constrain Effects on Non-Magnetized Planetary Atmospherese

Sarah Kovac, NMSU

The Sun generates a solar wind of particles which propagate throughout the solar system and can be modeled using magnetohydrodynamics and in situ spacecraft data. This solar wind is known to interact with the ionospheres and upper atmospheres of terrestrial planets, thus contributing to their atmospheric evolution. Atmospheric stripping, the process of ionizing particles such that they escape the atmosphere of a planet, is an essential component in atmospheric evolution. One feature of the solar wind is a stream interaction region (SIR), which is created when multiple solar wind streams are compressed to create regions with higher densities, stronger magnetic fields, and steeper velocity profiles. The effects of high energy solar events, like coronal mass ejections and flares, have been shown to contribute to atmospheric stripping, but lower energy events, such as SIRs, have not been studied in detail. These lower energy events are far more common and present throughout the entire solar cycle. Thus, while less intense, SIRs provide an equally important, but poorly understood, source of planetary atmospheric erosion. Venus and Mars are ideal targets for studying atmospheric erosion via SIRs due to their lack of an intrinsic magnetic field, similar atmospheric compositions, sufficient orbital spacing (0.7 AU and 1.5 AU, respectively), and known auroral emission. Both the auroral emission intensity and altitude are dependent on the energy of the solar wind, meaning it can be used as a tracer for space weather conditions. Most current solar wind models primarily make use of steady-state solutions, which fail to account for evolution in the photosphere, and consequently the corona, over time. As such, the models may be producing solar wind measurements in the vicinity of Venus and Mars that are misleading. This work will utilize a new time-dependent solar wind model to capture solar wind and SIR evolution, providing constraints on the influence of SIRs on terrestrial planet atmospheres. Utilizing in situ data from multiple heliocentric distances, this work will improve the model’s ability to make accurate predictions and help determine conditions where the solar wind may be responsible for atmospheric emission. Hence, this research will improve the understanding of solar wind evolution throughout the inner solar system and allow us to accurately characterize the effects of solar wind variability on terrestrial planet atmospheres.
Jun
12
Fri
Thesis Proposal: Kristen Luchsinger
Jun 12 @ 3:00 pm – 4:00 pm
Thesis Proposal: Kristen Luchsinger @ Remote via Zoom

Title

Kristen Luchsinger, NMSU


Jul
17
Fri
Thesis Proposal: David DeColibus
Jul 17 @ 2:00 pm – 3:00 pm
Thesis Proposal: David DeColibus @ Remote via Zoom

What Processes Control The Surface Composition of Miranda?

David DeColibus, NMSU