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About Me

Who Am I?

Hi I'm Cicero X. Lu. I am a PhD candidate in astronomy at Johns Hopkins University, currently supported as a NASA FINESST fellow. My main research interest is in planet formation and exoplanets.

My Ph.D. thesis advisor is Dr. Christine Chen. In our recent [paper], we studied the properties of dust grains in the β Pictoris disk as a function of stellocentric distance. We find that as stellocentric distance increases, (1) small silicate grains become more crystalline (less amorphous), (2) more irregular in shape, and (3) more Fe-poor. Applying these trends to beta Pic's planetary architecture, we find that the dust population interior and exterior to the orbits of beta Pic b differs substantially in crystallinity and shape. As grains are continuously generated by planetesimal collisions in the disk, their property can elucidate their parent bodies' composition. This implies that the surfaces of large planetesimals are more Fe-rich and collisionally-processed closer to the star but more Fe-poor and primordial farther from the star. I will present this [paper] at AAS 240.

My academic advisor is Professor Kevin Schlaufman. We have investigated the small-planet occurrence as a function of metallicity for late-type dwarf stars in the Kepler Field to constraint planet formation models. Our paper is here. You can view the presentation slides of this work presented at the Chesapeake Bay Area Exoplanet Meeting (CHEXO) on Dec. 11th, 2020.

During my undergraduate at University of California, Los Angeles, I studied stellar dynamics of hierarchical triple system under the guidance of Professor Smadar Naoz. We have a paper together here.

Kepler Mission

Planet Formation

Big Data

Machine Learning

Research

Projects

Sequencing Dusty Disk Spectra: A Non-Parametric, Systematic Analysis Revealing the Relationships Between Disks and their Host Stars 2021-Current

Debris disks provide exciting opportunities to study planet formation throughout the disk. In exoplanetary debris disks, little is known about whether differentiated (crust and mantle) planetesimals are common in regions close to a star. If a debris disk contains crustal materials, indicating the existence of differentiated planetesimals, then we can understand its planetary evolution stage. The processes in which a star affects its debris disks are also largely unknown. A fundamental question is whether the stello-centric distance to the edge of icy belts, such as the Kuiper belt, is affected by its host star luminosity. The most comprehensive, homogeneous debris disk catalog to-date, the Spitzer IRS debris disk catalog, provides unique laboratories for studying these questions. I will identify the crust-like and mantle-like dust contents in the extrasolar debris disks in the Spitzer IRS debris disk catalog, and investigate the dust properties as a function of the stellar properties, using a non-parametric, systematic tool called Sequencer. The identification and characterization of the mineralogy of the debris disks will provide well-motivated candidates for future JWST studies on planetary evolutions.

Trends in Silicates in the β Pictoris Debris Disk 2019-2021

Main Results: We re-analyze the Spitzer Infrared Spectrograph (IRS) β Pictoris debris disk data and identify a new 18 micron forsterite emission band. We also recover a 23 micron forsterite emission band with a substantially larger line-to-continuum ratio than previously reported. We discover three trends about sub-micron-sized grains in β Pic: as stellocentric distance increases, (1) small silicate grains become more crystalline (less amorphous), (2) they become more irregular in shape, and (3) for crystalline silicate grains, the Fe/Mg ratio decreases. Applying these trends to β pic's planetary architecture, we find that the dust population exterior to the orbits of β pic b and c differs substantially in crystallinity and shape.

[Slides]

SNe in Hierarchical Triple System 2014-2018

Main Results: Proof-of-concept simulations found that black hole and low-mass X-ray binary system with a tertiary companion on wide orbit when inner close binary undergoes supernova(SN), will emit gravitational waves in extremely short timescale before coalescence. A new possible channel to detect GW emissions of this type of systems can be forecasted by the electromagnetic observations for next generation space observatory LISA.

[Paper] [Poster]

Get in Touch

Contact

cicerolu@jhu.edu

Bloomberg 115
3400 N. Charles Street
Baltimore MD 21218