Search Publications
Mid-infrared Studies of HD 113766 and HD 172555: Assessing Variability in the Terrestrial Zone of Young Exoplanetary Systems
Rieke, George H.; Gáspár, András; Meng, Huan Y. A. +4 more
We present multiepoch infrared photometry and spectroscopy obtained with warm Spitzer, Subaru, and the Stratospheric Observatory for Infrared Astronomy to assess variability for the young (∼20 Myr) and dusty debris systems around HD 172555 and HD 113766A. No variations (within 0.5%) were found for the former at either 3.6 or 4.5 µm, while si…
A Wide Planetary-mass Companion to a Young Low-mass Brown Dwarf in Ophiuchus
Albert, Loïc; Liu, Michael C.; Zhang, Zhoujian +6 more
We present the discovery of a planetary-mass companion to CFHTWIR-Oph 98, a low-mass brown dwarf member of the young Ophiuchus star-forming region, with a wide 200 au separation (1"46). The companion was identified using Hubble Space Telescope images, and confirmed to share common proper motion with the primary using archival and new ground-based …
Multiwavelength Absolute Magnitudes and Colors of Red Clump Stars in the Gaia Era
Bilir, Selçuk; Plevne, Olcay; Seabroke, George M. +1 more
This study presents the multiwavelength investigation of the absolute magnitudes and colors of the red clump (RC) stars selected from APOGEE and GALAH DR2 combined catalog which is complemented with Gaia DR2 astrometric data and multiwavelength photometric data of GALEX GR6/7, SDSS DR7, Gaia DR2, 2MASS, and WISE sky surveys. The analyses are cente…
Kinematics of the Magellanic Stream and Implications for Its Ionization
Richter, Philipp; Bland-Hawthorn, Joss; Fox, Andrew J. +3 more
The Magellanic Stream and the Leading Arm form a massive, filamentary system of gas clouds surrounding the Large and Small Magellanic Clouds. Here we present a new component-level analysis of their ultraviolet (UV) kinematic properties using a sample of 31 sightlines through the Magellanic System observed with the Hubble Space Telescope/Cosmic Ori…
An Accreting, Anomalously Low-mass Black Hole at the Center of Low-mass Galaxy IC 750
Gelfand, Joseph D.; Chen, Yan-Ping; Greenhill, Lincoln J. +5 more
We present a multiwavelength study of the active galactic nucleus in the nearby (D = 14.1 Mpc) low-mass galaxy IC 750, which has circumnuclear 22 GHz water maser emission. The masers trace a nearly edge-on, warped disk ∼0.2 pc in diameter, coincident with the compact nuclear X-ray source that lies at the base of the ∼kiloparsec-scale extended X-ra…
X-Ray Spectroscopy in the Microcalorimeter Era. II. A New Diagnostic on Column Density from the Case A to B Transition in H- and He-like Iron
Ferland, G. J.; Su, Y.; Chakraborty, P. +2 more
The Soft X-ray Spectrometer on board Hitomi, with the unprecedented resolving power of R ∼ 1250, allowed the detection of members of the Fe XXV Kα complex emission spectra from the center of the Perseus Cluster. In this paper, we introduce a novel method of measuring the column density using the optically thin (Case A) to optically thick (Case B) …
Constraining the Mass of the Emerging Galaxy Cluster SpARCS1049+56 at z = 1.71 with Infrared Weak Lensing
Muzzin, Adam; Perlmutter, Saul; Wilson, Gillian +4 more
In the hierarchical structure formation model of the universe, galaxy clusters are assembled through a series of mergers. Accordingly, it is expected that galaxy clusters in the early universe are actively forming and dynamically young. Located at a high redshift of z = 1.71, SpARCS1049+56 offers a unique look into the galaxy cluster formation pro…
A Fully Kinetic Perspective of Electron Acceleration around a Weakly Outgassing Comet
Henri, Pierre; Lapenta, Giovanni; Divin, Andrey +4 more
The cometary mission Rosetta has shown the presence of higher-than-expected suprathermal electron fluxes. In this study, using 3D fully kinetic electromagnetic simulations of the interaction of the solar wind with a comet, we constrain the kinetic mechanism that is responsible for the bulk electron energization that creates the suprathermal distri…
The Origin of a Distributed Stellar Population in the Star-forming Region W4
Lim, Beomdu; Lee, Jeong-Eun; Yun, Hyeong-Sik +5 more
Stellar kinematics provides the key to understanding the formation process and dynamical evolution of stellar systems. Here, we present a kinematic study of the massive star-forming region (SFR) W4 in the Cassiopeia OB6 association using the Gaia Data Release 2 and high-resolution optical spectra. This SFR is composed of a core cluster (IC 1805) a…
2003-2019 Monitoring of the Crab Emission through INTEGRAL SPI, or Vice Versa
Jourdain, E.; Roques, J. P.
The Crab Nebula is used by many instruments as a calibration source, in particular at high energy, where it is one of the brightest celestial objects. The spectrometer INTEGRAL SPI (20 keV-8 MeV), in operation since 2002 October, offers a large data set dedicated to this source, with regular campaigns planned twice per year. We have analyzed the a…