Showing papers by "Michael W. Werner published in 2020"
Université de Montréal1, California Institute of Technology2, McGill University3, American Museum of Natural History4, York University5, Goddard Space Flight Center6, Max Planck Society7, University of Ottawa8, University of Kansas9, NASA Exoplanet Science Institute10, University of California, Los Angeles11, University of Tokyo12, University of California, Berkeley13, University of Hawaii14
TL;DR: In this paper, the authors presented the results of an extensive 4-year Keck/HIRES radial-velocity (RV) follow-up program of the WASP-107 system and provided a detailed study of the physics governing the accretion of its gas envelope.
Abstract: With a mass in the Neptune regime and a radius of Jupiter, WASP-107b presents a challenge to planet formation theories. Meanwhile, the planet's low surface gravity and the star's brightness also make it one of the most favorable targets for atmospheric characterization. Here, we present the results of an extensive 4-year Keck/HIRES radial-velocity (RV) follow-up program of the WASP-107 system and provide a detailed study of the physics governing the accretion of its gas envelope. We reveal that WASP-107b's mass is only 1.8 Neptune masses ($M_b = 30.5 \pm 1.7$ $M_\oplus$). The resulting extraordinarily low density suggests that WASP-107b has a H/He envelope mass fraction of $> 85$% unless it is substantially inflated. The corresponding core mass of $<4.6$ $M_\oplus$ at 3$\sigma$ is significantly lower than what is traditionally assumed to be necessary to trigger massive gas envelope accretion. We demonstrate that this large gas-to-core mass ratio most plausibly results from the onset of accretion at $\gtrsim 1$ AU onto a low-opacity, dust-free atmosphere and subsequent migration to the present-day $a_b = 0.0566 \pm 0.0017$ AU. Beyond WASP-107b, we also detect a second more massive planet ($M_c \sin i = 0.36 \pm 0.04$ $M_{J}$) on a wide eccentric orbit ($e_c = 0.28 \pm 0.07$) which may have influenced the orbital migration and spin-orbit misalignment of WASP-107b. Overall, our new RV observations and envelope accretion modeling provide crucial insights into the intriguing nature of WASP-107b and the system's formation history. Looking ahead, WASP-107b will be a keystone planet to understand the physics of gas envelope accretion.
28 citations
Ames Research Center1, California Institute of Technology2, University of Minnesota3, University of Chicago4, Northwestern University5, Villanova University6, University of Wyoming7, Lowell Observatory8, University of Illinois at Urbana–Champaign9, Max Planck Society10, NASA Headquarters11, Goddard Space Flight Center12, Johns Hopkins University13, Harvard University14, University of Crete15, Foundation for Research & Technology – Hellas16, University of Central Lancashire17, University of Wisconsin-Madison18
17 citations
University of New Mexico1, University of Kansas2, Université de Montréal3, Massachusetts Institute of Technology4, University of Chile5, University of Maryland, College Park6, Max Planck Society7, Smithsonian Institution8, NASA Exoplanet Science Institute9, University of California, Berkeley10, California Institute of Technology11, University of California, Riverside12, Princeton University13, Ames Research Center14, Goddard Space Flight Center15, Wesleyan University16, University of Bern17, Search for extraterrestrial intelligence18
TL;DR: Alfred P. Sloan Foundation through Caltech/JPL grant and National Science Foundation through TESS Guest Investigator Program (TESS) grant as mentioned in this paper was used by NASA.
Abstract: NASA through Caltech/JPL grant
RSA-1006130
RSA-1610091
NASA through TESS Guest Investigator Program
80NSSC19K1727
National Science Foundation (NSF)
AST-1824644
CONICYT/PFCHA-Doctorado Nacional, Chile
21140646
Heising-Simons Foundation
Hellman Faculty Fund
Alfred P. Sloan Foundation
The David & Lucile Packard Foundation
Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)
CONICYT FONDECYT
1201371
Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)
Basal AFB-170002
NASA's Science Mission directorate
9 citations
13 Dec 2020
TL;DR: SPHEREx, the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and ices Explorer, is a NASA MIDEX mission planned for launch in 2024 as discussed by the authors.
Abstract: SPHEREx, the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and ices Explorer, is a NASA MIDEX mission planned for launch in 2024. SPHEREx will carry out the first all-sky spectral survey at wavelengths between 0.75µm and 5µm with spectral resolving power ~40 between 0.75 and 3.8µm and ~120 between 3.8 and 5µm At the end of its two-year mission, SPHEREx will provide 0.75-to-5µm spectra of each 6.”2x6.”2 pixel on the sky - 14 billion spectra in all. This paper updates an earlier description of SPHEREx presenting changes made during the mission's Preliminary Design Phase, including a discussion of instrument integration and test ow and a summary of the data processing, analysis, and distribution plans.
9 citations
University of Minnesota1, California Institute of Technology2, University of California, Los Angeles3, Northwestern University4, University of Chicago5, Villanova University6, University of Wyoming7, Queen's University8, Lowell Observatory9, Max Planck Society10, University of Wisconsin-Madison11, University of Illinois at Urbana–Champaign12, Cornell University13, Johns Hopkins University14, Goddard Space Flight Center15, Harvard University16, Foundation for Research & Technology – Hellas17, University of Crete18, Universities Space Research Association19, Massachusetts Institute of Technology20, University of Central Lancashire21
TL;DR: In this paper, Far Infrared (FIR) polarimetry was used for the face-on galaxy M51 and the edgeon galaxy NGC 891, and it was shown that the FIR polarimeters are strongly correlated with the position angles and fractional polarizations, but the polarized intensities are uncorrelated.
Abstract: SOFIA HAWC+ polarimetry at $154~\micron$ is reported for the face-on galaxy M51 and the edge-on galaxy NGC 891. For M51, the polarization vectors generally follow the spiral pattern defined by the molecular gas distribution, the far-infrared (FIR) intensity contours, and other tracers of star formation. The fractional polarization is much lower in the FIR-bright central regions than in the outer regions, and we rule out loss of grain alignment and variations in magnetic field strength as causes. When compared with existing synchrotron observations, which sample different regions with different weighting, we find the net position angles are strongly correlated, the fractional polarizations are moderately correlated, but the polarized intensities are uncorrelated. We argue that the low fractional polarization in the central regions must be due to significant numbers of highly turbulent segments across the beam and along lines of sight in the beam in the central 3 kpc of M51. For NGC 891, the FIR polarization vectors within an intensity contour of 1500 $\rm{MJy~sr^{-1}}$ are oriented very close to the plane of the galaxy. The FIR polarimetry is probably sampling the magnetic field geometry in NGC 891 much deeper into the disk than is possible with NIR polarimetry and radio synchrotron measurements. In some locations in NGC 891 the FIR polarization is very low, suggesting we are preferentially viewing the magnetic field mostly along the line of sight, down the length of embedded spiral arms. There is tentative evidence for a vertical field in the polarized emission off the plane of the disk.
6 citations
University of Minnesota1, California Institute of Technology2, University of California, Los Angeles3, University of Chicago4, Northwestern University5, Villanova University6, University of Wyoming7, Queen's University8, Lowell Observatory9, Max Planck Society10, University of Wisconsin-Madison11, University of Illinois at Urbana–Champaign12, Cornell University13, Goddard Space Flight Center14, Johns Hopkins University15, Harvard University16, Foundation for Research & Technology – Hellas17, University of Crete18, Universities Space Research Association19, Massachusetts Institute of Technology20, University of Central Lancashire21
TL;DR: In this article, high-resolution Airborne Wideband Camera Plus polarimetry at 154 μm is reported for the face-on galaxy M51 and the edgeon galaxy NGC 891, and the FIR polarization vectors within an intensity contour of 1500 are oriented very close to the plane of the galaxy.
Abstract: Stratospheric Observatory for Infrared Astronomy High-resolution Airborne Wideband Camera Plus polarimetry at 154 μm is reported for the face-on galaxy M51 and the edge-on galaxy NGC 891. For M51, the polarization vectors generally follow the spiral pattern defined by the molecular gas distribution, the far-infrared (FIR) intensity contours, and other tracers of star formation. The fractional polarization is much lower in the FIR-bright central regions than in the outer regions, and we rule out loss of grain alignment and variations in magnetic field strength as causes. When compared with existing synchrotron observations, which sample different regions with different weighting, we find the net position angles are strongly correlated, the fractional polarizations are moderately correlated, but the polarized intensities are uncorrelated. We argue that the low fractional polarization in the central regions must be due to significant numbers of highly turbulent segments across the beam and along lines of sight in the beam in the central 3 kpc of M51. For NGC 891, the FIR polarization vectors within an intensity contour of 1500 are oriented very close to the plane of the galaxy. The FIR polarimetry is probably sampling the magnetic field geometry in NGC 891 much deeper into the disk than is possible with NIR polarimetry and radio synchrotron measurements. In some locations in NGC 891, the FIR polarization is very low, suggesting we are preferentially viewing the magnetic field mostly along the line of sight, down the length of embedded spiral arms. There is tentative evidence for a vertical field in the polarized emission off the plane of the disk.
4 citations