Search Publications
Spatially Resolved Stellar, Dust, and Gas Properties of the Post-interacting Whirlpool Galaxy System
Lebouteiller, Vianney; Wilson, Christine D.; Baes, Maarten +15 more
Using infrared imaging from the Herschel Space Observatory, observed as part of the Very Nearby Galaxies Survey, we investigate the spatially resolved dust properties of the interacting Whirlpool galaxy system (NGC 5194 and NGC 5195), on physical scales of ~1 kpc. Spectral energy distribution modeling of the new infrared images in combination with…
Hot Disks and Delayed Bar Formation
Weiner, Benjamin J.; Abraham, Roberto G.; Elmegreen, Bruce G. +4 more
We present observational evidence for the inhibition of bar formation in dispersion-dominated (dynamically hot) galaxies by studying the relationship between galactic structure and host galaxy kinematics in a sample of 257 galaxies between 0.1 < z <= 0.84 from the All-Wavelength Extended Groth Strip International Survey and the Deep Extragal…
The Submillimeter and Millimeter Excess of the Small Magellanic Cloud: Magnetic Dipole Emission from Magnetic Nanoparticles?
Hensley, Brandon; Draine, B. T.
The Small Magellanic Cloud (SMC) has surprisingly strong submillimeter- and millimeter-wavelength emission that is inconsistent with standard dust models, including those with emission from spinning dust. Here, we show that the emission from the SMC may be understood if the interstellar dust mixture includes magnetic nanoparticles, emitting magnet…
Black Hole Powered Nebulae and a Case Study of the Ultraluminous X-Ray Source IC 342 X-1
Feng, Hua; Grisé, Fabien; Kaaret, Philip +6 more
We present new radio, optical, and X-ray observations of three ultraluminous X-ray sources (ULXs) that are associated with large-scale nebulae. We report the discovery of a radio nebula associated with the ULX IC 342 X-1 using the Very Large Array (VLA). Complementary VLA observations of the nebula around Holmberg II X-1, and high-frequency Austra…
Interstellar H I and H2 in the Magellanic Clouds: An Expanded Sample Based on Ultraviolet Absorption-line Data
Welty, Daniel E.; Wong, Tony; Xue, Rui
We have determined column densities of H I and/or H2 for sight lines in the Magellanic Clouds from archival Hubble Space Telescope and Far-Ultraviolet Spectroscopic Explorer spectra of H I Lyα and H2 Lyman-band absorption. Together with some similar data from the literature, we now have absorption-based N(H I) and/or N(H…
Two Extrasolar Asteroids with Low Volatile-element Mass Fractions
Koester, D.; Zuckerman, B.; Xu, S. +2 more
Using ultraviolet spectra obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope, we extend our previous ground-based optical determinations of the composition of the extrasolar asteroids accreted onto two white dwarfs, GD 40 and G241-6. Combining optical and ultraviolet spectra of these stars with He-dominated atmospheres, 13…
Dynamics of the Solar Magnetic Bright Points Derived from Their Horizontal Motions
Chitta, L. P.; Kariyappa, R.; van Ballegooijen, A. A. +2 more
The subarcsecond bright points (BPs) associated with the small-scale magnetic fields in the lower solar atmosphere are advected by the evolution of the photospheric granules. We measure various quantities related to the horizontal motions of the BPs observed in two wavelengths, including the velocity autocorrelation function. A 1 hr time sequence …
LoCuSS: A Dynamical Analysis of X-Ray Active Galactic Nuclei in Local Clusters
Finoguenov, A.; Smith, G. P.; Okabe, N. +7 more
We present a study of the distribution of X-ray active galactic nuclei (AGNs) in a representative sample of 26 massive clusters at 0.15 < z < 0.30, combining Chandra observations sensitive to X-ray point sources of luminosity LX ~ 1042 erg s-1 at the cluster redshift with extensive and highly complete spectro…
Three-dimensional Evolution of Solar Wind during Solar Cycles 22-24
Manoharan, P. K.
This paper presents an analysis of three-dimensional evolution of solar wind density turbulence and speed at various levels of solar activity between solar cycles 22 and 24. The solar wind data used in this study have been obtained from the interplanetary scintillation (IPS) measurements made at the Ooty Radio Telescope, operating at 327 MHz. Resu…
Spitzer Observations of Young Red Quasars
Lacy, Mark; Schulz, Bernhard; Urrutia, Tanya +3 more
We present mid-infrared spectra and photometry of 13 redshift 0.4 < z < 1 dust reddened quasars obtained with Spitzer IRS and MIPS. We compare properties derived from their infrared spectral energy distributions (intrinsic active galactic nucleus (AGN) luminosity and far-infrared luminosity from star formation) to the host luminosities and m…