Search Publications
Astrometry, Radial Velocity, and Photometry: The HD 128311 System Remixed with Data from HST, HET, and APT
Cochran, William D.; Henry, Gregory W.; Benedict, G. Fritz +5 more
We have used high-cadence radial velocity measurements from the Hobby-Eberly Telescope with published velocities from the Lick 3 m Shane Telescope, combined with astrometric data from the Hubble Space Telescope (HST) Fine Guidance Sensors to refine the orbital parameters of the HD 128311 system, and determine an inclination of 55.°95 ± 14.°55 and …
High-energy X-Ray Detection of G359.89-0.08 (Sgr A-E): Magnetic Flux Tube Emission Powered by Cosmic Rays?
Hailey, Charles J.; Mori, Kaya; Bauer, Franz E. +11 more
We report the first detection of high-energy X-ray (E > 10 keV) emission from the Galactic center non-thermal filament G359.89-0.08 (Sgr A-E) using data acquired with the Nuclear Spectroscopic Telescope Array (NuSTAR). The bright filament was detected up to ~50 keV during a NuSTAR Galactic center monitoring campaign. The featureless power-law s…
The X-Ray Spectrum of the Cooling-flow Quasar H1821+643: A Massive Black Hole Feeding Off the Intracluster Medium
Fabian, Andrew C.; Babul, Arif; Reynolds, Christopher S. +4 more
We present a deep Suzaku observation of H1821+643, an extremely rare example of a powerful quasar hosted by the central massive galaxy of a rich cooling-core cluster of galaxies. Informed by previous Chandra studies of the cluster, we achieve a spectral separation of emission from the active galactic nucleus (AGN) and the intracluster medium (ICM)…
Swift/BAT Detection of Hard X-Rays from Tycho's Supernova Remnant: Evidence for Titanium-44
Troja, E.; Cusumano, G.; Gehrels, N. +6 more
We report Swift/Burst Alert Telescope survey observations of the Tycho's supernova remnant, performed over a period of 104 months since the mission's launch. The remnant is detected with high significance (>10σ) below 50 keV. We detect significant hard X-ray emission in the 60-85 keV band, above the continuum level predicted by a simple synchro…
Joint XMM-Newton and Chandra Observations of the NGC 1407/1400 Complex: A Tail of an Early-Type Galaxy and a Tale of a Nearby Merging Group
Gu, Liyi; White, Raymond E., III; Su, Yuanyuan +1 more
The nearby group centered on its bright central galaxy NGC 1407 has been suggested by previous kinematic studies to be an unusually dark system. It is also known for hosting a bright galaxy, NGC 1400, with a large radial velocity (1200 km s-1) with respect to the group center. Previous ROSAT X-ray observations revealed an extended regio…
NuSTAR and INTEGRAL Observations of a Low/Hard State of 1E1740.7-2942
Hailey, Charles J.; Fürst, Felix; Pottschmidt, Katja +19 more
The microquasar 1E1740.7-2942, also known as the "Great Annihilator," was observed by NuSTAR in the summer of 2012. We have analyzed in detail two observations taken ~2 weeks apart, for which we measure hard and smooth spectra typical of the low/hard state. A few weeks later the source flux declined significantly. Nearly simultaneous coverage by I…
Recombining Plasma in the Gamma-Ray-emitting Mixed-morphology Supernova Remnant 3C 391
Ercan, E. N.; Chatterjee, A.; Majumdar, P. +4 more
A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MCs) has been discovered to be strong GeV gamma-ray emitters by the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these int…
The Mid-infrared Appearance of the Galactic Mini-starburst W49A
Peeters, E.; Stock, D. J.; Shannon, M. J. +1 more
The massive star-forming region W49A represents one of the largest complexes of massive star formation present in the Milky Way and contains at least 50 young massive stars still enshrouded in their natal molecular cloud. We employ Spitzer/Infrared Spectrometer spectral mapping observations of the northern part of W49A to investigate the mid-infra…
On the Puzzling High-Energy Pulsations of the Energetic Radio-Quiet γ-Ray Pulsar J1813-1246
Marelli, M.; Saz Parkinson, P. M.; Wood, K. S. +6 more
We have analyzed the new deep XMM-Newton and Chandra observations of the energetic, radio-quiet pulsar J1813-1246. The X-ray spectrum is nonthermal, very hard, and absorbed. Based on spectral considerations, we propose that J1813 is located at a distance further than 2.5 kpc. J1813 is highly pulsed in the X-ray domain, with a light curve character…
A Hubble Space Telescope Search for a Sub-Earth-sized Exoplanet in the GJ 436 System
Stevenson, Kevin B.; Kreidberg, Laura; Bean, Jacob L. +1 more
The detection of small planets orbiting nearby stars is an important step toward the identification of Earth twins. In previous work using the Spitzer Space Telescope, we found evidence to support at least one sub-Earth-sized exoplanet orbiting the nearby mid-M dwarf star GJ 436. As a follow up, here we used the Hubble Space Telescope (HST) to inv…