97 citations · 184 across the 13 of their papers we have counts for
13 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 substellar…
Elemental Abundances of the Super-Neptune WASP-107b's Host Star Using High-resolution, Near-infrared Spectroscopy
Neda Hejazi, Ian Crossfield, Thomas Nordlander +8
We present the first elemental abundance measurements of the K dwarf (K7V) exoplanet-host star WASP-107 using high-resolution (R = 45,000), near-infrared (H- and K-band) spectra ta…
M Subdwarf Research III. Spectroscopic Diagnostics for Breaking Parameter Degeneracy
Shuo Zhang, Hua-Wei Zhang, Georges Comte +5
To understand the parameter degeneracy of M subdwarf spectra at low resolution, we assemble a large number of spectral features in the wavelength range of 0.6-2.5 μm with band stre…
Chemical Properties of the Local Disk and Halo. II. Abundances of 3745 M dwarfs and Subdwarfs from Improved Model Fitting of Low-Resolution Spectra
Neda Hejazi, Sebastien Lepine, Thomas Nordlander
We present a model-fit pipeline to determine the stellar parameters of M-type dwarfs, which is an improvement upon our previous work described in Hejazi et al. 2020. We apply this…
linemake: An Atomic and Molecular Line List Generator
Vinicius M. Placco, Christopher Sneden, Ian U. Roederer +5
In this research note, we present linemake, an open-source atomic and molecular line list generator. Rather than a replacement for a number of well-established atomic and molecular…
Chemical Properties of the Local Galactic Disk and Halo. I. Fundamental Properties of 1,544 Nearby, High Proper-Motion M dwarfs and subdwarfs
Neda Hejazi, Sebastien Lepine, Derek Homeier +2
Large numbers of low-to-medium resolution spectra of M-type dwarf stars from both the local Galactic disk and halo are available from various surveys. In order to fully exploit the…
Optical - Near Infrared Photometric Calibration of M-dwarf Metallicity and Its Application
Neda Hejazi, Michael M. De Robertis, Peter C. Dawson
Based on a carefully constructed sample of dwarf stars, a new optical-near infrared photometric calibration to estimate the metallicity of late-type K and early-to-mid-type M dwarf…
Touchstone Stars: Highlights from the Cool Stars 18 Splinter Session
Andrew W. Mann, Adam Kraus, Tabetha Boyajian +11
We present a summary of the splinter session on "touchstone stars" -- stars with directly measured parameters -- that was organized as part of the Cool Stars 18 conference. We disc…