Search Publications
Threads, Ribbons, and Rings in the Radio Galaxy IC 4296
Camilo, F.; White, S. V.; Condon, J. J. +5 more
The nearby elliptical galaxy IC 4296 has produced a large (510 kpc) low-luminosity radio source with typical FR I core/jet/lobe morphology. The unprecedented combination of brightness sensitivity, dynamic range, and angular resolution of a new 1.28 GHz MeerKAT continuum image reveals striking new morphological features, which we call threads, ribb…
Radial Migration from the Metallicity Gradient of Open Clusters and Outliers
Zhao, Gang; Chen, Yuqin; Zhang, Haopeng
Radial migration is an important process in the evolution of the Galactic disk. The metallicity gradient of open clusters and its outliers provide an effective way to examine this process. In this work, we compile metallicity, age, and kinematic parameters for 225 open clusters and carry out a quantitative analysis of radial migration via the calc…
An Exploration of Model Degeneracies with a Unified Phase Curve Retrieval Analysis: The Light and Dark Sides of WASP-43 b
Waldmann, I. P.; Tinetti, G.; Edwards, B. +2 more
The analysis of exoplanetary atmospheres often relies upon the observation of transit or eclipse events. While very powerful, these snapshots provide mainly one-dimensional information on the planet structure and do not easily allow precise latitude-longitude characterizations. The phase curve technique, which consists of measuring the planet emis…
Uniform Forward-modeling Analysis of Ultracool Dwarfs. II. Atmospheric Properties of 55 Late-T Dwarfs
Line, Michael R.; Marley, Mark S.; Liu, Michael C. +2 more
We present a large uniform forward-modeling analysis for 55 late-T (T7-T9) dwarfs, using low-resolution (R ≈ 50-250) near-infrared (1.0-2.5 µm) spectra and cloudless Sonora-Bobcat model atmospheres. We derive the objects' effective temperatures, surface gravities, metallicities, radii, masses, and bolometric luminosities using our newly deve…
Revisiting the Distance to Radio Loops I and IV Using Gaia and Radio/Optical Polarization Data
Dickinson, C.; Pearson, T. J.; Panopoulou, G. V. +2 more
Galactic synchrotron emission exhibits large angular scale features known as radio spurs and loops. Determining the physical size of these structures is important for understanding the local interstellar structure and for modeling the Galactic magnetic field. However, the distance to these structures is either under debate or entirely unknown. We …
Simultaneous Multiwavelength Flare Observations of EV Lacertae
Hamaguchi, Kenji; Barclay, Thomas; Davenport, James R. A. +17 more
We present the first results of our ongoing project conducting simultaneous multiwavelength observations of flares on nearby active M dwarfs. We acquired data of the nearby dM3.5e star EV Lac using five different observatories: NASA's Transiting Exoplanet Survey Satellite (TESS), NASA's Neil Gehrels Swift Observatory (Swift), NASA's Neutron Interi…
The Atacama Cosmology Telescope: Detection of Millimeter-wave Transient Sources
Hilton, Matt; Choi, Steve K.; Dünner, Rolando +29 more
We report on the serendipitous discovery of three transient millimeter-wave sources using data from the Atacama Cosmology Telescope. The first, detected at R.A. = 273.8138, decl. = -49.4628 at ~50σ total, brightened from less than 5 mJy to at least 1100 mJy at 150 GHz with an unknown rise time shorter than 13 days, during which the increase from 2…
The Gravity Collective: A Search for the Electromagnetic Counterpart to the Neutron Star-Black Hole Merger GW190814
Conselice, Christopher J.; Filippenko, Alexei V.; Kilpatrick, Charles D. +80 more
We present optical follow-up imaging obtained with the Katzman Automatic Imaging Telescope, Las Cumbres Observatory Global Telescope Network, Nickel Telescope, Swope Telescope, and Thacher Telescope of the LIGO/Virgo gravitational wave (GW) signal from the neutron star-black hole (NSBH) merger GW190814. We searched the GW190814 localization region…
Anisotropies in Compressible MHD Turbulence: Probing Magnetic Fields and Measuring Magnetization
Lazarian, A.; Hu, Yue; Xu, Siyao
Probing magnetic fields in the interstellar medium (ISM) is notoriously challenging. Motivated by the modern theories of magnetohydrodynamic (MHD) turbulence and turbulence anisotropy, we introduce the Structure Function Analysis (SFA) as a new approach to measure the magnetic-field orientation and estimate the magnetization. We analyze the statis…
Looking for Obscured Young Star Clusters in NGC 1313
Smith, Linda J.; Calzetti, Daniela; Lin, Zesen +7 more
Using recently acquired Hubble Space Telescope NIR observations (J, Paβ, and H bands) of the nearby galaxy NGC 1313, we investigate the timescales required by a young star cluster to emerge from its natal cloud. We search for extincted star clusters, potentially embedded in their natal cloud as either (1) compact sources in regions with high Hα/Pa…