activity
20102026
most citedFirst results of Herschel/PACS observations of Neptune

76 citations · 220 across the 24 of their papers we have counts for

collaborators

25 papers

astro-ph.EP2026

A Sulfur-Rich Atmosphere for the Young Jupiter Analog AF Lep b Reveals Significant Solid Accretion

Jerry W. Xuan, William O. Balmer, Yayaati Chachan +25

AF Lep b is one of the closest analogs to Jupiter in terms of mass () and semi-major axis ( AU) amenable to spectroscopic characterization. We present JWST/NIR…

astro-ph.EP2026

Atmospheric characterization of six ultra-hot Jupiters from -band high-resolution spectroscopy

Luke Finnerty, Michael P. Fitzgerald, Yinzi Xin +27

We present new Keck/KPIC high-resolution spectroscopic detections of three ultra-hot Jupiters (UHJs) in the band: WASP-189b (), MASCARA-1b (), and…

astro-ph.EP2026★ 12 cited

The compositions of the HR 8799 planets reflect accretion of both solids and metal-enriched gas

Jerry W. Xuan, Jean-Baptiste Ruffio, Yayaati Chachan +24

With four giant planets (, $T_\rm{eff}\sim900-1200$ K) orbiting between 15-70 au, HR 8799 provides an unparalleled testbed for studying giant planet formatio…

astro-ph.EP2026

Possible stratospheric emission in the warm Neptune GJ 436 b from high-resolution spectroscopy

Luke Finnerty, Michael P Fitzgerald, Jerry W Xuan +26

We present high spectral resolution band (2.91--3.85 m) observations of the warm Neptune GJ 436 b from Keck II/KPIC. KPIC's single-mode fiber feed reduces the band sky b…

astro-ph.EP2026★ 4 cited

Distinct Rotational Evolution of Giant Planets and Brown Dwarf Companions

Chih-Chun Hsu, Jason J. Wang, Jerry W. Xuan +27

We present a rotational velocity (vsini) survey of 32 stellar/substellar objects and giant planets using Keck/KPIC high-resolution spectroscopy, including 6 giant planets (2-7 M$_\…

astro-ph.EP2025

Chemical and Isotopic Homogeneity Between the L Dwarf CD-35 2722 B and its Early M Host Star

Gavin Wang, Jerry Xuan, Darío Picos +29

CD-35 2722 B is an L dwarf companion to the nearby, Myr old M1 dwarf CD-35 2722 A. We present a detailed analysis of both objects using high-resolution ($R \sim 35,00…

astro-ph.EP2025

The watery atmosphere of HD~209458~b revealed by joint - and -band high-resolution spectroscopy

Luke Finnerty, Julie Inglis, Michael P. Fitzgerald +26

We present a joint analysis of high-resolution - and -band observations of the benchmark hot Jupiter \hdb\ from the Keck Planet Imager and Characterizer (KPIC). One half nigh…

astro-ph.EP2025

Water dissociation and rotational broadening in the atmosphere of KELT-20 b from high-resolution spectroscopy

Luke Finnerty, Yinzi Xin, Jerry W. Xuan +29

We present atmospheric retrievals from Keck/KPIC phase II observations of the ultra-hot Jupiter KELT-20/MASCARA-2~b. Previous free retrievals of molecular abundances for ultra-hot…

astro-ph.EP2025

HD 206893 B at High Spectral Resolution with the Keck Planet Imager and Characterizer (KPIC)

Ben Sappey, Quinn Konopacky, Clarissa R. Do O +38

We present an atmospheric characterization and orbital analysis of HD 206893 B, an exceptionally red, L/T-transition substellar companion in a multiplanetary system, via Keck Plane…

astro-ph.EP2024★ 8 cited

PDS 70b Shows Stellar-like Carbon-to-oxygen Ratio

Chih-Chun Hsu, Jason J. Wang, Geoffrey A. Blake +27

The 5 Myr PDS 70 is the only known system with protoplanets residing in the cavity of the circumstellar disk from which they formed, ideal for studying exoplanet formation an…

astro-ph.EP2024

True mass and atmospheric composition of the non-transiting hot Jupiter HD 143105 b

Luke Finnerty, Yinzi Xin, Jerry W. Xuan +28

We present Keck/KPIC phase II -band observations of the non-transiting hot Jupiter HD 143105 b. Using a cross-correlation approach, we make the first detection of the planetary…

astro-ph.EP2024

RV measurements of directly imaged brown dwarf GQ Lup B to search for exo-satellites

Katelyn Horstman, Jean-Baptiste Ruffio, Konstantin Batygin +35

GQ Lup B is one of the few substellar companions with a detected cicumplanetary disk, or CPD. Observations of the CPD suggest the presence of a cavity, possibly formed by an exo-sa…

astro-ph.EP2024★ 6 cited

Fringing analysis and forward modeling of Keck Planet Imager and Characterizer (KPIC) spectra

Katelyn A. Horstman, Jean-Baptiste Ruffio, Jason J. Wang +27

The Keck Planet Imager and Characterizer (KPIC) combines high contrast imaging with high resolution spectroscopy (R~35,000 in K band) to study directly imaged exoplanets and brown…

astro-ph.EP2024★ 15 cited

Atmospheric characterization of the super-Jupiter HIP 99770 b with KPIC

Yapeng Zhang, Jerry W. Xuan, Dimitri Mawet +28

Young, self-luminous super-Jovian companions discovered by direct imaging provide a challenging test of planet formation and evolution theories. By spectroscopically characterizing…

astro-ph.IM2024

The high-contrast performance of the Keck Planet Imager and Characterizer

Jason J. Wang, Dimitri Mawet, Jerry W. Xuan +25

The Keck Planet Imager and Characterizer (KPIC), a series of upgrades to the Keck II Adaptive Optics System and Instrument Suite, aims to demonstrate high-resolution spectroscopy o…

astro-ph.SR2024★ 18 cited

Rotation and Abundances of the Benchmark Brown Dwarf HD 33632 Ab from Keck/KPIC High-resolution Spectroscopy

Chih-Chun Hsu, Jason J. Wang, Jerry W. Xuan +24

We present the projected rotational velocity and molecular abundances for HD 33632 Ab obtained via Keck Planet Imager and Characterizer high-resolution spectroscopy. HD 33632 Ab is…

astro-ph.EP2024★ 2 cited

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…

astro-ph.SR2024★ 17 cited

Fresh view of the hot brown dwarf HD 984 B through high-resolution spectroscopy

J. C. Costes, J. W. Xuan, A. Vigan +26

Context. High-resolution spectroscopy has the potential to drive a better understanding of the atmospheric composition, physics, and dynamics of young exoplanets and brown dwarfs,…

astro-ph.SR2024

Orbital and Atmospheric Characterization of the 1RXS J034231.8+121622 System Using High-Resolution Spectroscopy Confirms That The Companion is a Low-Mass Star

Clarissa R. Do Ó, Ben Sappey, Quinn M. Konopacky +33

The 1RXS J034231.8+121622 system consists of an M dwarf primary and a directly imaged low-mass stellar companion. We use high resolution spectroscopic data from Keck/KPIC to estima…

astro-ph.SR2023★ 3 cited

Validation of elemental and isotopic abundances in late-M spectral types with the benchmark HIP 55507 AB system

Jerry W. Xuan, Jason J. Wang, Luke Finnerty +48

M dwarfs are common host stars to exoplanets but often lack atmospheric abundance measurements. Late-M dwarfs are also good analogs to the youngest substellar companions, which sha…

astro-ph.EP2023★ 1 cited

Atmospheric metallicity and C/O of HD 189733 b from high-resolution spectroscopy

Luke Finnerty, Jerry W. Xuan, Yinzi Xin +27

We present high-resolution -band emission spectra of the quintessential hot Jupiter HD 189733 b from the Keck Planet Imager and Characterizer (KPIC). Using a Bayesian retrieval…

astro-ph.GA2021★ 10 cited

Mapping physical parameters in Orion KL at high spatial resolution

Olivia H. Wilkins, P. Brandon Carroll, Geoffrey A. Blake

The Orion Kleinmann-Low nebula (Orion KL) is notoriously complex and exhibits a range of physical and chemical components. We conducted high angular resolution (sub-arcsecond) obse…

astro-ph.GA2013★ 38 cited

A Search for l-C3H+ and l-C3H in Sgr B2(N), Sgr B2(OH), and the Dark Cloud TMC-1

Brett A. McGuire, P. Brandon Carroll, Ryan A. Loomis +5

Pety et al. (2012) recently reported the detection of several transitions of an unknown carrier in the Horsehead PDR and attribute them to l-C3H+. Here, we have tested the predicti…

astro-ph.EP2010★ 76 cited

First results of Herschel/PACS observations of Neptune

E. Lellouch, P. Hartogh, H. Feuchtgruber +51

We report on the initial analysis of a Herschel/PACS full range spectrum of Neptune, covering the 51-220 micrometer range with a mean resolving power of ~ 3000, and complemented by…