Search Publications

The Nature of Soft Excess in ESO 362-G18 Revealed by XMM-Newton and NuSTAR Spectroscopy
DOI: 10.3847/1538-4357/abf430 Bibcode: 2021ApJ...913...13X

Walton, Dominic J.; García, Javier A.; Harrison, Fiona A. +3 more

We present a detailed spectral analysis of the joint XMM-Newton and NuSTAR observations of the active galactic nuclei (AGNs) in the Seyfert 1.5 Galaxy ESO 362-G18. The broadband (0.3-79 keV) spectrum shows the presence of a power-law continuum with a soft excess below 2 keV, iron Kα emission (∼6.4 keV), and a Compton hump (peaking at ∼20 keV). We …

2021 The Astrophysical Journal
XMM-Newton 29
The Fundamental Plane in the LEGA-C Survey: Unraveling the M/L Ratio Variations of Massive Star-forming and Quiescent Galaxies at z ∼ 0.8
DOI: 10.3847/1538-4357/abf1e7 Bibcode: 2021ApJ...913..103D

Bell, Eric F.; Maseda, Michael V.; D'Eugenio, Francesco +10 more

We explore the connection between the kinematics, structures and stellar populations of massive galaxies at 0.6 < z < 1.0 using the fundamental plane (FP). Combining stellar kinematic data from the Large Early Galaxy Astrophysics Census (LEGA-C) survey with structural parameters measured from deep Hubble Space Telescope imaging, we obtain a …

2021 The Astrophysical Journal
eHST 29
Uniform Forward-modeling Analysis of Ultracool Dwarfs. I. Methodology and Benchmarking
DOI: 10.3847/1538-4357/abf8b2 Bibcode: 2021ApJ...916...53Z

Line, Michael R.; Marley, Mark S.; Liu, Michael C. +2 more

We present a forward-modeling framework using the Bayesian inference tool Starfish and cloudless Sonora-Bobcat model atmospheres to analyze low-resolution (R ≈ 80-250) near-infrared (1.0-2.5 µm) spectra of T dwarfs. Our approach infers effective temperatures, surface gravities, metallicities, radii, and masses, and by accounting for uncertai…

2021 The Astrophysical Journal
Gaia 29
Revealing the Structure and Internal Rotation of the Sagittarius Dwarf Spheroidal Galaxy with Gaia and Machine Learning
DOI: 10.3847/1538-4357/abd5bf Bibcode: 2021ApJ...908..244D

van der Marel, Roeland P.; Fardal, Mark A.; Sohn, Sangmo Tony +3 more

We present a detailed study of the internal structure and kinematics of the core of the Sagittarius dwarf spheroidal galaxy (Sgr). Using machine-learning techniques, we have combined the information provided by 3300 RR Lyrae stars, more than 2000 spectroscopically observed stars, and the Gaia second data release to derive the full phase space, i.e…

2021 The Astrophysical Journal
Gaia eHST 29
Dust-enshrouded AGNs Can Dominate Host-galaxy-scale Cold Dust Emission
DOI: 10.3847/1538-4357/ac185f Bibcode: 2021ApJ...921...55M

Smith, Howard A.; Rosenthal, Lee J.; McKinney, Jed +4 more

It is widely assumed that long-wavelength infrared (IR) emission from cold dust (T ~ 20-40 K) is a reliable tracer of star formation even in the presence of a bright active galactic nucleus (AGN). Based on radiative transfer (RT) models of clumpy AGN tori, hot dust emission from the torus contributes negligibly to the galaxy spectral energy distri…

2021 The Astrophysical Journal
Herschel 29
ALMA and IRIS Observations of the Solar Chromosphere. I. An On-disk Type II Spicule
DOI: 10.3847/1538-4357/abc9b1 Bibcode: 2021ApJ...906...82C

Martínez-Sykora, Juan; De Pontieu, Bart; Chintzoglou, Georgios +7 more

We present observations of the solar chromosphere obtained simultaneously with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph. The observatories targeted a chromospheric plage region of which the spatial distribution (split between strongly and weakly magnetized regions) allowed the study of l…

2021 The Astrophysical Journal
IRIS 29
The Far Ultraviolet M-dwarf Evolution Survey. I. The Rotational Evolution of High-energy Emissions
DOI: 10.3847/1538-4357/abe8d7 Bibcode: 2021ApJ...911..111P

France, Kevin; Youngblood, Allison; Pineda, J. Sebastian

M-dwarf stars are prime targets for exoplanet searches because of their close proximity and favorable properties for both planet detection and characterization. However, the potential habitability and atmospheric characterization of these exoplanetary systems depends critically on the history of high-energy stellar radiation from X-rays to NUV, wh…

2021 The Astrophysical Journal
eHST 29
The Atacama Cosmology Telescope: Microwave Intensity and Polarization Maps of the Galactic Center
DOI: 10.3847/1538-4357/ac133f Bibcode: 2021ApJ...920....6G

Hasselfield, Matthew; Sifón, Cristóbal; Aiola, Simone +30 more

We present arcminute-resolution intensity and polarization maps of the Galactic center made with the Atacama Cosmology Telescope. The maps cover a 32 deg2 field at 98, 150, and 224 GHz with ∣l∣ ≤ 4°, ∣b∣ ≤ 2°. We combine these data with Planck observations at similar frequencies to create coadded maps with increased sensitivity at large…

2021 The Astrophysical Journal
Herschel 29
Mapping the 3D Kinematical Structure of the Gas Disk of HD 169142
DOI: 10.3847/2041-8213/ac283e Bibcode: 2021ApJ...920L..33Y

Öberg, Karin; Bae, Jaehan; Teague, Richard +1 more

The disk around HD 169142 has been suggested to host multiple embedded planets due to the range of structures observed in the dust distributions. We analyze archival Atacama Large (sub-) Millimetre Array observations of 12CO (2-1), 13CO (2-1), and C18O (2-1) to search for large-scale kinematic structures associated…

2021 The Astrophysical Journal
Gaia 29
Measuring Turbulence with Young Stars in the Orion Complex
DOI: 10.3847/2041-8213/abd8c9 Bibcode: 2021ApJ...907L..40H

Kounkel, Marina; Li, Hui; Ha, Trung +2 more

Stars form in molecular clouds in the interstellar medium (ISM) with a turbulent kinematic state. Newborn stars therefore should retain the turbulent kinematics of their natal clouds. Gaia DR2 and APOGEE-2 surveys in combination provide three-dimensional (3D) positions and 3D velocities of young stars in the Orion Molecular Cloud Complex. Using th…

2021 The Astrophysical Journal
Gaia 29