Search Publications
The Radio Spectral Energy Distribution and Star-formation Rate Calibration in Galaxies
Boquien, M.; De Looze, I.; Murphy, E. J. +17 more
We study the spectral energy distribution (SED) of the radio continuum (RC) emission from the Key Insight in Nearby Galaxies Emitting in Radio (KINGFISHER) sample of nearby galaxies to understand the energetics and origin of this emission. Effelsberg multi-wavelength observations at 1.4, 4.8, 8.4, and 10.5 GHz combined with archive data allow us, …
Trends in Atmospheric Properties of Neptune-size Exoplanets
Crossfield, Ian J. M.; Kreidberg, Laura
Precise atmospheric observations have been made for a growing sample of warm Neptunes. Here, we investigate the correlations between these observations and a large number of system parameters to show that, at 95% confidence, the amplitude of a warm Neptune's spectral features in transmission correlates with either its equilibrium temperature (T
No Evidence for Extensions to the Standard Cosmological Model
Sellentin, Elena; Heavens, Alan; Hosenie, Zafiirah +4 more
We compute the Bayesian evidence for models considered in the main analysis of Planck cosmic microwave background data. By utilizing carefully defined nearest-neighbor distances in parameter space, we reuse the Monte Carlo Markov chains already produced for parameter inference to compute Bayes factors B for many different model-data set combinatio…
Clouds, Streams and Bridges. Redrawing the blueprint of the Magellanic System with Gaia DR1
Erkal, Denis; Belokurov, Vasily; Mackey, Dougal +5 more
We present the discovery of stellar tidal tails around the Large and the Small Magellanic Clouds (LMC and SMC, respectively) in the Gaia DR1 data. In between the Clouds, their tidal arms are stretched towards each other to form an almost continuous stellar bridge. Our analysis relies on the exquisite quality of the Gaia's photometric catalogue to …
Origins of the Ambient Solar Wind: Implications for Space Weather
Cranmer, Steven R.; Riley, Pete; Gibson, Sarah E.
The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its abilit…
Massive Warm/Hot Galaxy Coronae as Probed by UV/X-Ray Oxygen Absorption and Emission. I. Basic Model
Faerman, Yakov; Sternberg, Amiel; McKee, Christopher F.
We construct an analytic phenomenological model for extended warm/hot gaseous coronae of L* galaxies. We consider UV O VI Cosmic Origins Spectrograph (COS)-Halos absorption line data in combination with Milky Way (MW) X-ray O vii and O viii absorption and emission. We fit these data with a single model representing the COS-Halos galaxie…
Quasars as standard candles. I. The physical relation between disc and coronal emission
Lusso, E.; Risaliti, G.
Context. A tight non-linear relation exists between the X-ray and UV emission in quasars (I.e. LX ∝LUVγ), with a dispersion of 0.2 dex over approximately three orders of magnitude in luminosity. Such observational evidence has two relevant consequences: (1) an ubiquitous physical mechanism must regulate the energy transfer fr…
A New Stellar Atmosphere Grid and Comparisons with HST/STIS CALSPEC Flux Distributions
Koekemoer, Anton M.; Gordon, Karl D.; Bohlin, Ralph C. +3 more
The Space Telescope Imaging Spectrograph has measured the spectral energy distributions for several stars of types O, B, A, F, and G. These absolute fluxes from the CALSPEC database are fit with a new spectral grid computed from the ATLAS-APOGEE ATLAS9 model atmosphere database using a chi-square minimization technique in four parameters. The qual…
Electron holes in phase space: What they are and why they matter
Hutchinson, I. H.
This is a tutorial and selective review explaining the fundamental concepts and some currently open questions concerning the plasma phenomenon of the electron hole. The widespread occurrence of electron holes in numerical simulations, space-craft observations, and laboratory experiments is illustrated. The elementary underlying theory is developed…
Active Cryovolcanism on Europa?
Spencer, J. R.; Sparks, W. B.; Hand, K. P. +4 more
Evidence for plumes of water on Europa has previously been found using the Hubble Space Telescope using two different observing techniques. Roth et al. found line emission from the dissociation products of water. Sparks et al. found evidence for off-limb continuum absorption as Europa transited Jupiter. Here, we present a new transit observation o…