Search Publications
Probing the circumnuclear absorbing medium of the buried AGN in NGC 1068 through NuSTAR observations
Bauer, F. E.; Brandt, W. N.; Bianchi, S. +9 more
We present the results of the latest NuSTAR monitoring campaign of the Compton-thick Seyfert 2 galaxy NGC 1068, composed of four ∼50 ks observations performed between 2017 July and 2018 February to search for flux and spectral variability on time-scales from 1 to 6 months. We detect one unveiling and one eclipsing event with time-scales less than …
The M Supergiant High-mass X-Ray Binary 4U 1954+31
Habel, Nolan; Fekel, Francis C.; Hinkle, Kenneth H. +5 more
The X-ray binary 4U 1954+31 has been classified as a low-mass X-ray binary containing an M giant and a neutron star (NS). It has also been included in the rare class of X-ray symbiotic binaries. The Gaia parallax, infrared colors, spectral type, abundances, and orbital properties of the M star demonstrate that the cool star in this system is not a…
Loose Ends for the Exomoon Candidate Host Kepler-1625b
Angus, Ruth; Howard, Andrew W.; Kipping, David +2 more
The claim of an exomoon candidate in the Kepler-1625b system has generated substantial discussion regarding possible alternative explanations for the purported signal. In this work, we examine these possibilities in detail. First, the effect of more flexible trend models is explored, and we show that sufficiently flexible models are capable of att…
The distribution of relative proper motions of wide binaries in Gaia DR2: MOND or multiplicity?
Clarke, C. J.
We examine the distribution of on-sky relative velocities for wide binaries previously assembled from theGaia DR2 data and focus on the origin of the high-velocity tail of apparently unbound systems, which may be interpreted as evidence for non-Newtonian gravity in the weak field limit. We argue that this tail is instead explicable in terms of a p…
Do Statistical Models Capture the Dynamics of the Magnetopause During Sudden Magnetospheric Compressions?
Wild, J. A.; Milan, S. E.; Imber, S. M. +9 more
Under periods of strong solar wind driving, the magnetopause can become compressed, playing a significant role in draining electrons from the outer radiation belt. Also termed "magnetopause shadowing," this loss process has traditionally been attributed to a combination of magnetospheric compression and outward radial diffusion of electrons. Howev…
Elemental abundances of M dwarfs based on high-resolution near-infrared spectra: Verification by binary systems
Kuzuhara, Masayuki; Omiya, Masashi; Reiners, Ansgar +4 more
M dwarfs are prominent targets of planet search projects, and their chemical composition is crucial to understanding the formation process or interior of orbiting exoplanets. However, measurements of elemental abundances of M dwarfs have been limited due to difficulties in the analysis of their optical spectra. We conducted a detailed chemical ana…
Cataclysmic Variables in the First Year of the Zwicky Transient Facility
Riddle, Reed; Szkody, Paula; Bellm, Eric C. +25 more
Using selection criteria based on amplitude, time, and color, we have identified 329 objects as known or candidate cataclysmic variables (CVs) during the first year of testing and operation of the Zwicky Transient Facility. Of these, 90 are previously confirmed CVs, 218 are strong candidates based on the shape and color of their light curves obtai…
The MASSIVE Survey. XV. A Stellar Dynamical Mass Measurement of the Supermassive Black Hole in Massive Elliptical Galaxy NGC 1453
Ma, Chung-Pei; Greene, Jenny E.; Blakeslee, John P. +4 more
We present a new stellar dynamical mass measurement (M_{BH}) of the supermassive black hole (SMBH) in NGC 1453, a fast-rotating massive elliptical galaxy in the MASSIVE survey. We measure stellar kinematics in 135 spatial bins in the central 1.5 kpc × 2 kpc region of the galaxy using high signal-to-noise ratio (S/N ∼ 130) spectra from the Gemini-N…
Returning Samples from Enceladus for Life Detection
MacKenzie, Shannon M.; Davila, Alfonso F.; Neveu, Marc +7 more
Evidence suggests that Saturn's icy moon Enceladus has a subsurface ocean that sources plumes of water vapor and ice vented to space from its south pole. In situ analyses of this material by the Cassini spacecraft have shown that the ocean contains key ingredients for life (elements H, C, N, O and possibly S; simple and complex organic compounds; …
Transmission Spectroscopy of WASP-79b from 0.6 to 5.0 µm
Jayaraman, Rahul; Nikolov, Nikolay; Sing, David K. +18 more
As part of the Panchromatic Exoplanet Treasury program, we have conducted a spectroscopic study of WASP-79b, an inflated hot Jupiter orbiting an F-type star in Eridanus with a period of 3.66 days. Building on the original WASP and TRAPPIST photometry of Smalley et al., we examine Hubble Space Telescope (HST)/Wide Field Camera 3 (WFC3) (1.125-1.650…