Search Publications
The Very Low Albedo of WASP-12b from Spectral Eclipse Observations with Hubble
Nikolov, Nikolay; Gibson, Neale P.; Sing, David K. +11 more
We present an optical eclipse observation of the hot Jupiter WASP-12b using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. These spectra allow us to place an upper limit of {A}g< 0.064 (97.5% confidence level) on the planet’s white light geometric albedo across 290-570 nm. Using six wavelength bins acro…
Detection of the Ultraviolet Spectrum of the Hot Subdwarf Companion of 60 Cygni (B1 Ve) from a Survey of IUE Spectra of Be Stars
Gies, Douglas R.; Wang, Luqian; Peters, Geraldine J.
We used archival International Ultraviolet Explorer (IUE) high-dispersion, short wavelength spectra data to search for evidence of the spectra of hot subdwarf companions of six rapidly rotating Be stars in binary systems. We searched for the signature of a hot companion through an analysis of the cross-correlation functions (CCFs) of observed and …
Fermi Non-detections of Four X-Ray Jet Sources and Implications for the IC/CMB Mechanism
Georganopoulos, Markos; Breiding, Peter; Meyer, Eileen T. +3 more
Since its launch in 1999, the Chandra X-ray observatory has discovered several dozen X-ray jets associated with powerful quasars. In many cases, the X-ray spectrum is hard and appears to come from a second spectral component. The most popular explanation for the kpc-scale X-ray emission in these cases has been inverse-Compton (IC) scattering of Co…
Properties of Turbulence in the Reconnection Exhaust: Numerical Simulations Compared with Observations
Sorriso-Valvo, L.; Goldman, M. V.; Newman, D. L. +6 more
The properties of the turbulence that develops in the outflows of magnetic reconnection have been investigated using self-consistent plasma simulations, in three dimensions. As commonly observed in space plasmas, magnetic reconnection is characterized by the presence of turbulence. Here we provide a direct comparison of our simulations with report…
Observational Evidence for the Associated Formation of Blobs and Raining Inflows in the Solar Corona
Davies, J. A.; Lavraud, B.; Kilpua, E. +6 more
The origin of the slow solar wind is still a topic of much debate. The continual emergence of small transient structures from helmet streamers is thought to constitute one of the main sources of the slow wind. Determining the height at which these transients are released is an important factor in determining the conditions under which the slow sol…
H2CO Distribution and Formation in the TW HYA Disk
Wilner, David J.; Cleeves, L. Ilsedore; Andrews, Sean M. +8 more
H2CO is one of the most readily detected organic molecules in protoplanetary disks. Yet its distribution and dominant formation pathway(s) remain largely unconstrained. To address these issues, we present ALMA observations of two H2CO lines ({3}12{--}{2}11 and {5}15{--}{4}14) at 0.″…
On the Relation between the In Situ Properties and the Coronal Sources of the Solar Wind
Lepri, S. T.; Zhao, L.; Zurbuchen, T. H. +4 more
We categorize the types of solar wind using a new classification scheme based on the location of the wind’s coronal source regions in the solar atmosphere and near-solar heliosphere. We first trace the solar wind measured by ACE/SWEPAM and SWICS from 1998 to 2011 at 1 au back to a 2.5{R}{{s}} solar surface using ballistic mapping at con…
Dense CO in Mrk 71-A: Superwind Suppressed in a Young Super Star Cluster
James, Bethan L.; Oey, M. S.; Reiter, Megan +4 more
We report the detection of CO(J=2-1) coincident with the super star cluster (SSC) Mrk 71-A in the nearby Green Pea analog galaxy, NGC 2366. Our observations with the Northern Extended Millimeter Array reveal a compact, ∼7 pc, molecular cloud whose mass ({10}5 {M}⊙ ) is similar to that of the SSC, consistent with a high star f…
Powerful H2 Line Cooling in Stephan’s Quintet. II. Group-wide Gas and Shock Modeling of the Warm H2 and a Comparison with [C II] 157.7 µm Emission and Kinematics
Boulanger, F.; Appleton, P. N.; Xu, C. K. +7 more
We map for the first time the two-dimensional H2 excitation of warm intergalactic gas in Stephan's Quintet on group-wide (50 × 35 kpc2) scales to quantify the temperature, mass, and warm H2 mass fraction as a function of position using Spitzer. Molecular gas temperatures are seen to rise (to T > 700 K) and the s…
A Probabilistic Approach to Fitting Period-luminosity Relations and Validating Gaia Parallaxes
Rix, Hans-Walter; Fouesneau, Morgan; Price-Whelan, Adrian M. +3 more
Pulsating stars, such as Cepheids, Miras, and RR Lyrae stars, are important distance indicators and calibrators of the “cosmic distance ladder,” and yet their period-luminosity-metallicity (PLZ) relations are still constrained using simple statistical methods that cannot take full advantage of available data. To enable optimal usage of data provid…