Research

Star formation is an integral part of the life cycle of stars in the universe and thus it is important to understand what conditions and factors affect the formation of stars. Stars form when interstellar gas and dust collapse under their own gravity. Magnetic fields are believed to inhibit star formation by countering the collapse of gas or help produce star-forming structures like filaments by funnel material into clouds. By studying the nearby Orion Molecular cloud, we hope to understand the relationship between the magnetic field orientation and the orientation of linear-filamentary structures, and in turn the importance of magnetic fields on star formation. The Orion Molecular Cloud (OMC) is one of the closest active star-forming regions, located at 400 parsecs away from the Earth. The Cloud is home to a variety of environments, at varying molecular gas densities, and a home for both high- and low-mass young stellar objects.

Starting in August 2021, I started working with Dr. Hector Arce, at Yale, to study magnetic fields in the Orion A cloud. I was funded by the competitive Yale STARS II Academic Fellowship to study the magnetic field in the dense region of OMC-1 using thermal dust emission. I am studying the alignment of the magnetic field in combination with gas structure maps from the CARMA-NRO Survey.

For my Senior Thesis, I am studying the magnetic fields and their alignment to the filamentary structure in less dense regions south of the main molecular cloud, such as OMC-4, OMC-5, L1641-N, and NGC1999. I am collecting starlight polarization using the WIRC+Pol instrument at Palomar to get magnetic field measurements in more diffuse regions of Orion A.

Project: Quick Presentation, Poster, Manuscript in Progress

12CO(1–0) Map of Orion A Source: CARMA-NRO Survey

Above: Remote Observing At Palomar to measure Magnetic Fields in Orion

Below: Presenting my Senior Thesis at Protostars and Planets VII in Kyoto, Japan 

Stars form from the collapse and fragmentation of gas and dust in molecular clouds. These molecular clouds have enough material to produce anywhere from tens to hundreds to tens of thousands of stars, often resulting in dense stellar systems, known as star clusters. Large molecular clouds with active star formation can help inform the processes and conditions required to begin the formation of stars from interstellar material. Before a star begins hydrogen burning and nuclear fusion within its core, it goes through a series of formation accretion and contraction processes after which it reaches equilibrium. During this early stage of a star’s evolution, the object is denoted as a Young Stellar Object (YSO). One defining property of YSOs is their spectroscopic and photometric variability.

The Monoceros R2 Molecular Cloud is one of the closest active star-forming regions from the sun, with a central young embedded star cluster, often referred to as just “Mon R2”. The young embedded cluster provides a perfect laboratory to study both star formation and early-stage stellar evolution. Using photometric measurements of the large sample of young, bright, and active stars in these clusters, we can better understand the surrounding environment and the physical processes occurring at this cluster and better create a model of star formation and early-stage stellar evolution.

During the Summer of 2022, I worked under Dr. Lynne A. Hillenbrand at Caltech with the Caltech WAVE program, studying the young stellar population of the Mon R2 Star Cluster. I studied the membership of the cluster stars and found new candidate stars using data from the new Gaia Data Release 3. We used the embedded cluster to study processes occurring in young stellar objects by looking at the optical variability of the stars using ZTF. I have published two works related to this project: RNAAS article, AJ article. 

Images of Mon R2 in Visible and Infrared bands; Source: ESO/J. Emerson/VISTA/Digitized Sky Survey 2, Cambridge Astronomical Survey Unit

Above: Presenting at AAS 241th Meeting in Seattle, WA

Below: Presenting at PhysCon 2022 in Washington D.C.

The Galactic magnetic field affects many processes in the interstellar medium (ISM), such as star formation and the flow of interstellar gas. We can try to study the plane of the sky component of the magnetic field by using various tracers. One goal is to use neutral hydrogen (HI) orientation as a complementary tracer alongside starlight polarization and dust thermal emission. One thing we want to study is whether different line of sight dust polarization leads to varying measurements of HI Orientation and the magnetic field orientation. We investigate whether there is evidence for a physical loss of alignment between HI orientation and the magnetic field in select regions.

During the Summer of 2021, I worked at Stanford University (remotely) under the Leadership Alliance Summer Research Early Identification Program (SR-EIP) with Dr. Susan E. Clark. I studied the structure of the nearby Interstellar Medium and traced the Galactic magnetic field using starlight polarization and atomic hydrogen (HI) emission. I studied when these two tracers were aligned or misaligned as functions of the location around the Galaxy (latitude and distance) and through line-of-sight dust polarization. I presented my work at Virtual Leadership Alliance National Symposium (VLAN) and Stanford Humanities and Science Symposium.

Project: Poster, Presentation, Abstract

Early radial velocity instruments assisted in the detection of many Hot Jupiters, exoplanets named for their large mass and high temperatures due to their proximity to their host star. This was due to the large reflex motion these large planets induced on their parent star, making them very easy to detect with instruments. However, as instruments have gotten more precise, it has allowed for the discovery of smaller exoplanets, near Earth-size. One of these instruments is the Yale Exoplanet Lab’s EXPRES (EXtreme PREcision Spectrometer), currently reaching the highest precision in the world (Jurgenson, 2016), with radial velocity measurements of around 1 m/s to 0.1 m/s (Holzer et al, 2020). This precision is being applied to the “Search for 100 Earths,” a project to find Earth-like rocky planets that are likely to harbor liquid water. The detection of many Earth-like planets will give a sample for the further study of astrobiology, the study of the nature of life in the universe, as well as assist in developing and refining models for planetary system formation.

Due to the indirect nature at which they are found, radial velocity detected exoplanets heavily depends on the information obtained about the parent star. Parameters like a planet’s mass are derived from observations and measurements of the parent star’s reflex motion. However, radial velocity measurements include not only planetary orbital velocities but also velocities from the surface of the star. These activities on the star’s surface include events like starspots, stellar oscillations, “stellar earthquakes”, or the magnetic cycles. As a result of these additional velocities, it can be harder to detect smaller planets as well as properly get parameters for the planet. Earth itself gives off a reflex motion of around 9 cm/s around the sun, which is extremely hard to detect without precise instruments (Holzer et al, 2020). While working with larger radial velocity planets, stellar noise can be negligible. However, when trying to find small planets, precision of around 5 to 10 cm is needed, which requires every measurement to be accounted for. Different stellar events can also have varying effects on instruments for different amounts of time.

During my first summer at Yale, I worked under Dr. Debra A. Fischer studying exoplanet systems of interest for the EXPRES instrument at Lowell Observatory. I investigated the stellar spectra intensities using CaII H and K lines and calculated activity indicators (S_HK and R’HK values) to estimate noise caused by stellar magnetic activity. By doing so, we can better understand which exoplanet system has false radial velocity not originating from the planet, which can affect the estimations of planetary parameters.