Search Publications
Precise Timing and Phase-resolved Spectroscopy of the Young Pulsar J1617-5055 with NuSTAR
Pavlov, George G.; Kargaltsev, Oleg; Hare, Jeremy +2 more
We report on a Nuclear Spectroscopic Telescope Array (NuSTAR) observation of the young, energetic pulsar PSR J1617-5055. Parkes Observatory 3 GHz radio observations of the pulsar (taken about 7 yr before the NuSTAR observations) are also reported here. NuSTAR detected pulsations at a frequency of f ≈ 14.4 Hz (P ≈ 69.44 ms) and, in addition, the ob…
Energy Budget of Plasma Motions, Heating, and Electron Acceleration in a Three-loop Solar Flare
Kontar, Eduard P.; Fleishman, Gregory D.; Nita, Gelu M. +2 more
Nonpotential magnetic energy promptly released in solar flares is converted to other forms of energy. This may include nonthermal energy of flare-accelerated particles, thermal energy of heated flaring plasma, and kinetic energy of eruptions, jets, upflows/downflows, and stochastic (turbulent) plasma motions. The processes or parameters governing …
Is the eclipsing binary RR Dra dancing with a hidden tertiary black hole candidate?
Zhu, Li-Ying; Wang, Zhi-Hua
Analysis of timing variation of the eclipsing binary RR Dra implies the existence of an additional object with mass of no less than 3.5(±0.2) M⊙. This third object is orbiting around the central eclipsing pair once every 98(±1) yr, making the whole a hierarchical triple system. However, reliable photometric solutions based on light curv…
Remote sensing of cometary bow shocks: modelled asymmetric outgassing and pickup ion observations
Alho, Markku; Jarvinen, Riku; Simon Wedlund, Cyril +3 more
Despite the long escort by the ESA Rosetta mission, direct observations of a fully developed bow shock around 67P/Churyumov-Gerasimenko have not been reported. Expanding on our previous work on indirect observations of a shock, we model the large-scale features in cometary pickup ions, and compare the results with the ESA Rosetta Plasma Consortium…
Mars Methane Sources in Northwestern Gale Crater Inferred From Back Trajectory Modeling
Yung, Y. L.; Luo, Y.; Lin, J. C. +3 more
During its first seven years of operation, the Sample Analysis at Mars Tunable Laser Spectrometer (TLS) on board the Curiosity rover has detected seven methane spikes above a low background abundance in Gale crater. The methane spikes are likely sourced by surface emission within or around Gale crater. Here, we use inverse Lagrangian modeling tech…
The Dynamic Formation of Pseudostreamers
Antiochos, Spiro K.; Scott, Roger B.; Pontin, David I. +2 more
Streamers and pseudostreamers structure the corona at the largest scales, as seen in both eclipse and coronagraph white-light images. Their inverted-goblet appearance encloses broad coronal loops at the Sun and tapers to a narrow radial stalk away from the star. The streamer associated with the global solar dipole magnetic field is long-lived, pre…
The effect of phased recurrent units in the classification of multiple catalogues of astronomical light curves
Cabrera-Vives, G.; Protopapas, P.; Carrasco-Davis, R. +2 more
In the new era of very large telescopes, where data are crucial to expand scientific knowledge, we have witnessed many deep learning applications for the automatic classification of light curves. Recurrent neural networks (RNNs) are one of the models used for these applications, and the Long Short-Term Memory (LSTM) unit stands out for being an ex…
Study of the Inner Structure of the Molecular Torus in IRAS 08572+3915 NW with Velocity Decomposition of CO Rovibrational Absorption Lines
Onishi, Shusuke; Nakagawa, Takao; Baba, Shunsuke +6 more
Understanding the inner structure of the clumpy molecular torus surrounding the active galactic nucleus is essential in revealing the forming mechanism. However, spatially resolving the torus is difficult because of its size of a few parsecs. Thus, to probe the clump conditions in the torus, we performed the velocity decomposition of the CO rovibr…
Neglected X-ray discovered polars. III. RX J0154.0-5947, RX J0600.5-2709, RX J0859.1+0537, RX J0953.1+1458, and RX J1002.2-1925
Burwitz, V.; Beuermann, K.; Schwope, A. +2 more
We report results on the ROSAT-discovered noneclipsing short-period polars RX J0154.0-5947, RX J0600.5-2709, RX J0859.1+0537, RX J0953.1+1458, and RX J1002.2-1925 collected over 30 years. We present accurate linear orbital ephemerides that allow a correct phasing of data taken decades apart. Three of the systems show cyclotron and Zeeman lines tha…
Interferometric Imaging of λ Andromedae: Evidence of Starspots and Rotation
White, R. J.; Baron, F.; Parks, J. R. +14 more
Presented are the first interferometric images of cool starspots on the chromospherically active giant λ Andromedae. Using the Michigan Infra-Red Combiner coupled to the Center for High Angular Resolution Astronomy Array, 26 interferometric observations were made between 2008 August 17 and 2011 September 24. The photometric time series acquired at…