6 papers
Abundance Measurements of the Metal-poor M subdwarf LHS 174 Using High-resolution Optical Spectroscopy
Neda Hejazi, Sebastien Lepine, Thomas Nordlander +3
Metal-poor M subdwarfs are among the oldest stellar populations and carry valuable information about the chemical enrichment history of the Milky Way. The measurements of chemical…
Chemical Links between a Young M-type T Tauri Star and its Substellar Companion: Spectral Analysis and C/O Measurement of DH Tau A
Neda Hejazi, Jerry W. Xuan, David R. Coria +5
The chemical abundance measurements of host stars and their substellar companions provide a powerful tool to trace the formation mechanism of the planetary systems. We present a de…
The Wanderer: Charting WASP-77A b's Formation and Migration Using a System-Wide Inventory of Carbon and Oxygen Abundances
David R. Coria, Neda Hejazi, Ian J. M. Crossfield +1
The elemental and isotopic abundances of volatiles like carbon, oxygen, and nitrogen may trace a planet's formation location relative to HO, CO, CO, NH, and N "snow…
High-resolution Elemental Abundance Measurements of Cool JWST Planet Hosts Using AutoSpecFit: An Application to the Sub-Neptune K2-18b's Host M dwarf
Neda Hejazi, Ian J. M. Crossfield, Diogo Souto +9
We present an in-depth, high-resolution spectroscopic analysis of the M dwarf K2-18 that hosts a sub-Neptune exoplanet in its habitable zone. We show our technique to accurately no…
Stellar Characterization and Chemical Abundances of Exoplanet Hosting M dwarfs from APOGEE Spectra: Future JWST Targets
Edypo Melo, Diogo Souto, Katia Cunha +11
Exoplanets hosting M dwarfs are the best targets to characterize Earth-like or super-Earth planetary atmospheres with the James Webb Space Telescope (JWST). We determine detailed s…
Are these planets or brown dwarfs? Broadly solar compositions from high-resolution atmospheric retrievals of ~10-30 companions
Jerry W. Xuan, Chih-Chun Hsu, Luke Finnerty +32
Using Keck Planet Imager and Characterizer (KPIC) high-resolution (~35000) spectroscopy from 2.29-2.49 m, we present uniform atmospheric retrievals for eight young substella…