Search Publications
Predicting the Extreme Ultraviolet Radiation Environment of Exoplanets around Low-mass Stars: GJ 832, GJ 176, and GJ 436
Peacock, Sarah; Barman, Travis; Baron, E. +3 more
Correct estimates of stellar extreme ultraviolet (EUV; 100-1170 Å) flux are important for studying the photochemistry and stability of exoplanet atmospheres, as EUV radiation ionizes hydrogen and contributes to the heating, expansion, and potential escape of a planet’s upper atmosphere. Contamination from interstellar hydrogen makes observing EUV …
Resolved Neutral Carbon Emission in Nearby Galaxies: [C I] Lines as Total Molecular Gas Tracers
Tan, Qinghua; Salak, Dragan; Gao, Yu +6 more
We present maps of atomic carbon [C I]({}3{{{P}}}1\to {{}3{{P}}}0) and [C I]({}3{{{P}}}2\to {{}3{{P}}}1) emission (hereafter [C I] (1-0) and [C I] (2-1), respectively) at a linear resolution ∼1 kpc scale for a sample of one H II, six LINER, three Seyfert, and f…
Crossing the Line: Active Galactic Nuclei in the Star-forming Region of the BPT Diagram
Salim, Samir; Agostino, Christopher J.
In this work, we investigate the reliability of the BPT diagram for excluding galaxies that host an active galactic nucleus (AGN). We determine the prevalence of X-ray AGNs in the star-forming region of the BPT diagram and discuss the reasons behind this apparent misclassification, focusing primarily on relatively massive ({log}({M}* )≳…
Type Ibn Supernovae May not all Come from Massive Stars
Zabludoff, Ann I.; French, K. Decker; Berger, Edo +5 more
Because core-collapse supernovae are the explosions of massive stars, which have relatively short lifetimes, they occur almost exclusively in galaxies with active star formation. On the other hand, the Type Ibn supernova PS1-12sk exploded in an environment that is much more typical of thermonuclear (Type Ia) supernovae: on the outskirts of the bri…
Interstellar Neutral Gas Species and Their Pickup Ions inside the Heliospheric Termination Shock. Ionization Rates for H, O, Ne, and He
Tokumaru, Munetoshi; Bzowski, Maciej; Sokół, Justyna M.
Solar ionizing factors are responsible for modulation of interstellar neutral gas and its derivative populations inside the heliosphere. We provide an overview of the current state of knowledge about them for heliospheric particles inside the termination shock. We discuss charge exchange with solar wind particles, photoionization, and electron imp…
Characterization of Ring Substructures in the Protoplanetary Disk of HD 169142 from Multiwavelength Atacama Large Millimeter/submillimeter Array Observations
Flock, Mario; Henning, Thomas; Dent, William R. F. +10 more
We present a detailed multiwavelength characterization of the multi-ring disk of HD 169142. We report new Atacama Large Millimeter/submillimeter Array (ALMA) observations at 3 mm and analyze them together with archival 0.89 and 1.3 mm data. Our observations resolve three out of the four rings in the disk previously seen in high-resolution ALMA dat…
Understanding the Limitations of Gyrochronology for Old Field Stars
Metcalfe, Travis S.; Egeland, Ricky
Nearly half a century has passed since the initial indications that stellar rotation slows while chromospheric activity weakens with a power-law dependence on age, the so-called Skumanich relations. Subsequent characterization of the mass-dependence of this behavior up to the age of the Sun led to the advent of gyrochronology, which uses the rotat…
Multiple Temperature Components of the Hot Circumgalactic Medium of the Milky Way
Nicastro, Fabrizio; Mathur, Smita; Gupta, Anjali +2 more
We present a deep XMM-Newton observation of the Galactic halo emission in the direction of the blazar 1ES 1553+113. In order to extract the Galactic halo component from the diffuse soft X-ray emission spectrum, accurately modeling the foreground components is crucial. Here we present complex modeling of the foregrounds with unprecedented details. …
Multiple Components of the Jhelum Stellar Stream
Conroy, Charlie; Hogg, David W.; Price-Whelan, Adrian M. +1 more
In simple models of the Milky Way, tidally disrupting satellites produce long and thin—nearly one-dimensional—stellar streams. Using astrometric data from the Gaia second data release and photometry from the Dark Energy Survey, we demonstrate that the Jhelum stream, a stellar stream in the inner halo, is a two-dimensional structure. The spatial di…
Star Formation and ISM Properties in the Host Galaxies of Three Far-infrared Luminous Quasars at z ∼ 6
Strauss, Michael A.; Fan, Xiaohui; Jiang, Linhua +11 more
We present Karl G. Jansky Very Large Array observations of the CO (2-1) line emission toward three far-infrared luminous quasars at z ∼ 6: SDSS J231038.88+185519.7 and SDSS J012958.51-003539.7 with ∼0.″6 resolution and SDSS J205406.42-000514.8 with ∼2.″1 resolution. All three sources are detected in the CO (2-1) line emission—one source is margina…