Search Publications
Constraining the Lyα Escape Fraction with Far-infrared Observations of Lyα Emitters
Ivison, R. J.; Wang, L.; Bock, J. +22 more
We study the far-infrared properties of 498 Lyα emitters (LAEs) at z = 2.8, 3.1, and 4.5 in the Extended Chandra Deep Field-South, using 250, 350, and 500 µm data from the Herschel Multi-tiered Extragalactic Survey and 870 µm data from the LABOCA ECDFS Submillimeter Survey. None of the 126, 280, or 92 LAEs at z = 2.8, 3.1, and 4.5, res…
The Variable Sky of Deep Synoptic Surveys
Matheson, Thomas; Howell, Steve B.; Mighell, Kenneth J. +2 more
The discovery of variable and transient sources is an essential product of synoptic surveys. The alert stream will require filtering for personalized criteria—a process managed by a functionality commonly described as a Broker. In order to understand quantitatively the magnitude of the alert generation and Broker tasks, we have undertaken an analy…
Multi-spacecraft Observations of Linear Modes and Sideband Waves in Ion-scale Solar Wind Turbulence
Motschmann, Uwe; Glassmeier, Karl-Heinz; Narita, Yasuhito +1 more
In the scenario of weak turbulence, energy is believed to be cascaded from smaller to larger wave numbers and frequencies due to weak wave-wave interactions. Based on its perturbative treatment one may regard plasma turbulence as a superposition of linear modes (or normal modes) and sideband waves (or nonlinear modes). In this study, we use magnet…
Discovery of X-Ray Emission from the First Be/Black Hole System
Iwasawa, K.; Casares, J.; Paredes, J. M. +3 more
MWC 656 (=HD 215227) was recently discovered to be the first binary system composed of a Be star and a black hole (BH). We observed it with XMM-Newton, and detected a faint X-ray source compatible with the position of the optical star, thus proving it to be the first Be/BH X-ray binary. The spectrum analysis requires a model fit with two component…
Exploratory X-Ray Monitoring of Luminous Radio-quiet Quasars at High Redshift: Initial Results
Brandt, W. N.; Kaspi, Shai; Schneider, Donald P. +6 more
We present initial results from an exploratory X-ray monitoring project of two groups of comparably luminous radio-quiet quasars (RQQs). The first consists of four sources at 4.10 <= z <= 4.35, monitored by Chandra, and the second is a comparison sample of three sources at 1.33 <= z <= 2.74, monitored by Swift. Together with archival X…
Fomalhaut b as A Cloud of Dust: Testing Aspects of Planet Formation Theory
Currie, Thayne; Kenyon, Scott J.; Bromley, Benjamin C.
We consider the ability of three models—impacts, captures, and collisional cascades—to account for a bright cloud of dust in Fomalhaut b. Our analysis is based on a novel approach to the power-law size distribution of solid particles central to each model. When impacts produce debris with (1) little material in the largest remnant and (2) a steep …
An XMM-Newton Study of the Mixed-morphology Supernova Remnant W28 (G6.4-0.1)
Safi-Harb, Samar; Zhou, Ping; Chen, Yang +3 more
We have performed an XMM-Newton imaging and spectroscopic study of supernova remnant (SNR) W28, a prototype mixed-morphology or thermal composite SNR believed to be interacting with a molecular cloud. The observed hot X-ray emitting plasma is characterized by low metal abundances, showing no evidence of ejecta. The X-rays arising from the deformed…
CLASH-VLT: Constraints on the Dark Matter Equation of State from Accurate Measurements of Galaxy Cluster Mass Profiles
Donahue, Megan; Broadhurst, Tom; Kuchner, Ulrike +39 more
A pressureless scenario for the dark matter (DM) fluid is a widely adopted hypothesis, despite the absence of direct observational evidence. According to general relativity, the total mass-energy content of a system shapes the gravitational potential well, but different test particles perceive this potential in different ways depending on their pr…
Coronal Inflows during the Interval 1996-2014
Sheeley, N. R., Jr.; Wang, Y. -M.
We extend our previous counts of coronal inflows from the 5 yr interval 1996-2001 to the 18 yr interval 1996-2014. By comparing stackplots of these counts with similar stackplots of the source-surface magnetic field and its longitudinal gradient, we find that the inflows occur in long-lived streams with counting rates in excess of 18 inflows per d…
The UV Continuum of z > 1 Star-forming Galaxies in the Hubble Ultraviolet UltraDeep Field
Finkelstein, Steven L.; Grogin, Norman A.; Koekemoer, Anton M. +11 more
We estimate the UV continuum slope, β, for 923 galaxies in the range 1 < z < 8 in the Hubble Ultradeep Field (HUDF). These data include 460 galaxies at 1 < z < 2 down to an absolute magnitude M_UV= -14(∼ 0.006 L^*z=1; 0.02 L^*z=0), comparable to dwarf galaxies in the local universe. We combine deep HST/UVIS photom…