Search Publications
Direct observations of the formation of the solar wind halo from the strahl
Fazakerley, A. N.; Gurgiolo, C.; Goldstein, M. L. +1 more
Observations of a continual erosion of the strahl and build up of the halo with distance from the sun suggests that, at least in part, the halo may be formed as a result of scattering of the strahl. This hypothesis is supported in this paper by observation of intense scattering of strahl electrons, which gives rise to a proto-halo electron populat…
What influence will future solar activity changes over the 21st century have on projected global near-surface temperature changes?
Lockwood, Mike; Jones, Gareth S.; Stott, Peter A.
During the 20th century, solar activity increased in magnitude to a so-called grand maximum. It is probable that this high level of solar activity is at or near its end. It is of great interest whether any future reduction in solar activity could have a significant impact on climate that could partially offset the projected anthropogenic warming. …
Atomic oxygen distributions in the Venus thermosphere: Comparisons between Venus Express observations and global model simulations
Gérard, J. -C.; Soret, L.; Brecht, A. S. +1 more
Nightglow emissions provide insight into the global thermospheric circulation, specifically in the transition region (∼70-120 km). The O 2 IR nightglow statistical map created from Venus Express (VEx) Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS) observations has been used to deduce a three-dimensional atomic oxygen density…
Shape and orientation of the gas distribution in A1689
Ettori, S.; Baldi, A.; Sereno, M.
Knowledge of intrinsic shape and orientation of galaxy clusters is crucial to understand their formation and evolution. We propose a novel model which uses Bayesian inference to determine the intrinsic form of the hot intracluster medium of galaxy clusters. The method exploits X-ray spectroscopic and photometric data plus measurements of the Sunya…
Large-scale Star-formation-driven Outflows at 1 < z < 2 in the 3D-HST Survey
Franx, Marijn; Labbé, Ivo; van Dokkum, Pieter +18 more
We present evidence of large-scale outflows from three low-mass (log(M */M ⊙) ~ 9.75) star-forming (SFR > 4 M ⊙ yr-1) galaxies observed at z = 1.24, z = 1.35, and z = 1.75 in the 3D-HST Survey. Each of these galaxies is located within a projected physical distance of 60 kpc around the sight line to th…
Is IGR J11014-6103 a Pulsar with the Highest Known Kick Velocity?
Rahoui, Farid; Bodaghee, Arash; Tomsick, John A. +4 more
We report on Chandra X-ray and Parkes radio observations of IGR J11014-6103, which is a possible pulsar wind nebula with a complex X-ray morphology and a likely radio counterpart. With the superb angular resolution of Chandra, we find evidence that a portion of the extended emission may be related to a bow shock due to the putative pulsar moving t…
Revealing the Millimeter Environment of the New FU Orionis Candidate HBC722 with the Submillimeter Array
Bourke, Tyler L.; Dunham, Michael M.; Chen, Xuepeng +3 more
We present 230 GHz Submillimeter Array continuum and molecular line observations of the newly discovered FU Orionis candidate HBC722. We report the detection of seven 1.3 mm continuum sources in the vicinity of HBC722, none of which corresponds to HBC722 itself. We compile infrared and submillimeter continuum photometry of each source from previou…
The reawakening of the sleeping X-ray pulsar XTE J1946+274
Wilms, J.; Ferrigno, C.; Pottschmidt, K. +9 more
We report on a series of outbursts of the high-mass X-ray binary XTE J1946+274 in 2010/2011 observed with INTEGRAL, RXTE, and Swift. We discuss possible mechanisms resulting in the extraordinary outburst behavior of this source. The X-ray spectra can be described by standard phenomenological models, enhanced by an absorption feature of unknown ori…
Disentangling AGN and Star Formation in Soft X-Rays
Ptak, A.; Heckman, T. M.; LaMassa, Stephanie M.
We have explored the interplay of star formation and active galactic nucleus (AGN) activity in soft X-rays (0.5-2 keV) in two samples of Seyfert 2 galaxies (Sy2s). Using a combination of low-resolution CCD spectra from Chandra and XMM-Newton, we modeled the soft emission of 34 Sy2s using power-law and thermal models. For the 11 sources with high s…
Winds and tides of Ligeia Mare, with application to the drift of the proposed time TiME (Titan Mare Explorer) capsule
Lorenz, Ralph D.; Tokano, Tetsuya; Newman, Claire E.
We use two independent General Circulation Models (GCMs) to estimate surface winds at Titan’s Ligeia Mare (78° N, 250° W), motivated by a proposed mission to land a floating capsule in this ∼500 km hydrocarbon sea. The models agree on the overall magnitude (∼0.5-1 m/s) and seasonal variation (strongest in summer) of windspeeds, but details of seas…