Search Publications
Timing of 29 Pulsars Discovered in the PALFA Survey
Camilo, F.; Ransom, S. M.; Chatterjee, S. +38 more
We report on the discovery and timing observations of 29 distant long-period pulsars found in the ongoing Arecibo L-band Feed Array pulsar survey. Following discovery with the Arecibo Telescope, confirmation and timing observations of these pulsars over several years at Jodrell Bank Observatory have yielded high-precision positions and measurement…
Where are the Binaries? Results of a Long-term Search for Radial Velocity Binaries in Proto-planetary Nebulae
Lu, Wenxian; Van Winckel, Hans; Hrivnak, Bruce J. +3 more
We present the results of an expanded, long-term radial velocity search (25 years) for evidence of binarity in a sample of seven bright proto-planetary nebulae (PPNe). The goal is to investigate the widely held view that the bipolar or point-symmetric shapes of planetary nebulae (PNe) and PPNe are due to binary interactions. Observations from thre…
Structure, Propagation, and Expansion of a CME-driven Shock in the Heliosphere: A Revisit of the 2012 July 23 Extreme Storm
Vourlidas, Angelos; Liu, Ying D.; Hu, Huidong +2 more
We examine the structure, propagation, and expansion of the shock associated with the 2012 July 23 extreme coronal mass ejection. Characteristics of the shock determined from multi-point imaging observations are compared to in situ measurements at different locations and a complex radio type II burst, which according to our definition has multiple…
Modifying the Standard Disk Model for the Ultraviolet Spectral Analysis of Disk-dominated Cataclysmic Variables. I. The Novalikes MV Lyrae, BZ Camelopardalis, and V592 Cassiopeiae
Blair, William P.; Sion, Edward M.; Balman, Şölen +1 more
The standard disk is often inadequate to model disk-dominated cataclysmic variables (CVs) and generates a spectrum that is bluer than the observed UV spectra. X-ray observations of these systems reveal an optically thin boundary layer (BL) expected to appear as an inner hole in the disk. Consequently, we truncate the inner disk. However, instead o…
Anisotropies of the Magnetic Field Fluctuations at Kinetic Scales in the Solar Wind: Cluster Observations
Alexandrova, Olga; Matteini, Lorenzo; Lacombe, Catherine
We present the first statistical study of the anisotropy of the magnetic field turbulence in the solar wind between 1 and 200 Hz, I.e., from proton to sub-electron scales. We consider 93 ten-minute intervals of the Cluster/STAFF measurements. We find that the fluctuations δ {B}\perp 2 are not gyrotropic at a given frequency f…
The Presence of Thermally Unstable X-Ray Filaments and the Production of Cold Gas in the NGC 5044 Group
Jones, Christine; David, Laurence P.; Sun, Ming +3 more
We present the results of a deep Chandra observation of the X-ray bright moderate-cooling flow group NGC 5044 along with the observed correlations between the ionized, atomic, and molecular gas in this system. The Chandra observation shows that the central AGN has undergone two outbursts in the past 108 years, based on the presence of t…
Testing the Recovery of Intrinsic Galaxy Sizes and Masses of z ∼ 2 Massive Galaxies Using Cosmological Simulations
Barro, Guillermo; Faucher-Giguère, Claude-André; Kriek, Mariska +5 more
Accurate measurements of galaxy masses and sizes are key to tracing galaxy evolution over time. Cosmological zoom-in simulations provide an ideal test bed for assessing the recovery of galaxy properties from observations. Here, we utilize galaxies with {M}* ∼ {10}10{--}{10}11.5 {M}⊙ at z ∼ 1.7-2 from th…
The Green Bank Ammonia Survey: Observations of Hierarchical Dense Gas Structures in Cepheus-L1251
Caselli, Paola; Di Francesco, James; Rosolowsky, Erik +20 more
We use Green Bank Ammonia Survey observations of NH3 (1, 1) and (2, 2) emission with 32″ FWHM resolution from a ∼10 pc2 portion of the Cepheus-L1251 molecular cloud to identify hierarchical dense gas structures. Our dendrogram analysis of the NH3 data results in 22 top-level structures, which reside within 13 lower…
Sagittarius A* High-energy X-Ray Flare Properties during NuSTAR Monitoring of the Galactic Center from 2012 to 2015
Hailey, Charles J.; Mori, Kaya; Zhang, Shuo +17 more
Understanding the origin of the flaring activity from the Galactic center supermassive black hole Sagittarius A* is a major scientific goal of the NuSTAR Galactic plane survey campaign. We report on the data obtained between 2012 July and 2015 April, including 27 observations on Sgr A*, with a total exposure of ≃ 1 Ms. We found a total of 10 X-ray…
Neutral ISM, Lyα, and Lyman-continuum in the Nearby Starburst Haro11
Hayes, Matthew; Östlin, Göran; Rivera-Thorsen, T. Emil +1 more
Star-forming galaxies are believed to be a major source of Lyman continuum (LyC) radiation responsible for reionizing the early universe. Direct observations of escaping ionizing radiation have however been sparse and with low escape fractions. In the local universe, only 10 emitters have been observed, with typical escape fractions of a few perce…