Search Publications
A Population of Bona Fide Intermediate-mass Black Holes Identified as Low-luminosity Active Galactic Nuclei
Boutsia, Konstantina; Chilingarian, Igor V.; Zolotukhin, Ivan Yu. +4 more
Nearly every massive galaxy harbors a supermassive black hole (SMBH) in its nucleus. SMBH masses are millions to billions of solar mass, and they correlate with properties of spheroids of their host galaxies. While the SMBH growth channels, mergers, and gas accretion are well established, their origin remains uncertain: they could have emerged eit…
The Chemical Homogeneity of Sun-like Stars in the Solar Neighborhood
Dreizler, Stefan; Bedell, Megan; Casagrande, Luca +9 more
The compositions of stars are a critical diagnostic tool for many topics in astronomy such as the evolution of our Galaxy, the formation of planets, and the uniqueness of the Sun. Previous spectroscopic measurements indicate a large intrinsic variation in the elemental abundance patterns of stars with similar overall metal content. However, system…
CO and Dust Properties in the TW Hya Disk from High-resolution ALMA Observations
Hughes, A. Meredith; Wilner, David J.; Cleeves, L. Ilsedore +10 more
We analyze high angular resolution ALMA observations of the TW Hya disk to place constraints on the CO and dust properties. We present new, sensitive observations of the 12CO J = 3 - 2 line at a spatial resolution of 8 au (0.″14). The CO emission exhibits a bright inner core, a shoulder at r ≈ 70 au, and a prominent break in slope at r …
“Super-deblended” Dust Emission in Galaxies. II. Far-IR to (Sub)millimeter Photometry and High-redshift Galaxy Candidates in the Full COSMOS Field
Calabrò, Antonello; Dickinson, Mark; Daddi, Emanuele +17 more
We present a “super-deblended” far-infrared (FIR) to (sub)millimeter photometric catalog in the Cosmic Evolution Survey (COSMOS), prepared with the method recently developed by Liu et al., with key adaptations. We obtain point-spread function fitting photometry at fixed prior positions including 88,008 galaxies detected in VLA 1.4, 3 GHz, and/or M…
The Eccentric Cavity, Triple Rings, Two-armed Spirals, and Double Clumps of the MWC 758 Disk
Dong, Ruobing; Tamura, Motohide; Wisniewski, John +15 more
Spatially resolved structures in protoplanetary disks hint at unseen planets. Previous imaging observations of the transitional disk around MWC 758 revealed an inner cavity, a ring-like outer disk, emission clumps, and spiral arms, all possibly generated by companions. We present ALMA dust continuum observations of MWC 758 at 0.87 mm wavelength wi…
Sun-to-Earth MHD Simulation of the 2000 July 14 “Bastille Day” Eruption
Downs, Cooper; Riley, Pete; Linker, Jon A. +6 more
Solar eruptions are the main driver of space-weather disturbances at Earth. Extreme events are of particular interest, not only because of the scientific challenges they pose, but also because of their possible societal consequences. Here we present a magnetohydrodynamic (MHD) simulation of the 2000 July 14 “Bastille Day” eruption, which produced …
Size-Luminosity Relations and UV Luminosity Functions at z = 6-9 Simultaneously Derived from the Complete Hubble Frontier Fields Data
Ouchi, Masami; Shimasaku, Kazuhiro; Oguri, Masamune +3 more
We construct z ∼ 6-7, 8, and 9 faint Lyman break galaxy samples (334, 61, and 37 galaxies, respectively) with accurate size measurements with the software glafic from the complete Hubble Frontier Fields (HFF) cluster and parallel fields data. These are the largest samples hitherto and reach down to the faint ends of recently obtained deep luminosi…
The Large-scale Structure of the Halo of the Andromeda Galaxy. II. Hierarchical Structure in the Pan-Andromeda Archaeological Survey
Lewis, Geraint F.; Dotter, Aaron; Babul, Arif +29 more
The Pan-Andromeda Archaeological Survey is a survey of >400 square degrees centered on the Andromeda (M31) and Triangulum (M33) galaxies that has provided the most extensive panorama of an L ⋆ galaxy group to large projected galactocentric radii. Here, we collate and summarize the current status of our knowledge of the substructures …
The Disk Substructures at High Angular Resolution Project (DSHARP). III. Spiral Structures in the Millimeter Continuum of the Elias 27, IM Lup, and WaOph 6 Disks
Hughes, A. Meredith; Wilner, David J.; Andrews, Sean M. +13 more
We present an analysis of Atacama Large Millimeter/submillimeter Array 1.25 mm continuum observations of spiral structures in three protoplanetary disks from the Disk Substructures at High Angular Resolution Project. The disks around Elias 27, IM Lup, and WaOph 6 were observed at a resolution of ∼40-60 mas (∼6-7 au). All three disks feature m = 2 …
One Large Blob and Many Streams Frosting the nearby Stellar Halo in Gaia DR2
Helmi, Amina; Veljanoski, Jovan; Koppelman, Helmer
We explore the phase-space structure of nearby halo stars identified kinematically from the Gaia second data release (DR2). We focus on their distribution in velocity and in “integrals of motion” space, as well as on their photometric properties. Our sample of stars selected to be moving at a relative velocity of at least 210 km s-1, wi…