Search Publications
Discovery of a Makemakean Moon
Buie, Marc W.; Noll, Keith S.; Parker, Alex H. +1 more
We describe the discovery of a satellite in orbit about the dwarf planet (136472) Makemake. This satellite, provisionally designated S/2015 (136472) 1, was detected in imaging data collected with the Hubble Space Telescope’s Wide Field Camera 3 on UTC 2015 April 27 at 7.80 ± 0.04 mag fainter than Makemake and at a separation of 0.″57. It likely ev…
A New Perspective of the Radio Bright Zone at The Galactic Center: Feedback from Nuclear Activities
Morris, Mark R.; Goss, W. M.; Zhao, Jun-Hui
New observations of Sgr A have been carried out with the Jansky VLA in the B and C arrays using the broadband (2 GHz) continuum mode at 5.5 GHz. The field of view covers the central 13‧ (30 pc) region of the radio-bright zone at the Galactic center. Using the multi-scale and multi-frequency-synthesis (MS-MFS) algorithms in CASA, we have imaged Sgr…
Molecular Hydrogen Absorption from the Halo of a z ∼ 0.4 Galaxy
Charlton, Jane C.; Kacprzak, Glenn G.; Churchill, Christopher W. +1 more
Lyman- and Werner-band absorption of molecular hydrogen ({{{H}}}2) is detected in ∼50% of low-redshift (z\lt 1) DLAs/sub-DLAs with N({{{H}}}2) \gt {10}14.4 cm-2. However, the true origin(s) of the {{{H}}}2-bearing gas remain elusive. Here we report a new detection of an {{{H}}}2 abs…
Modeling the Solar Wind at the Ulysses, Voyager, and New Horizons Spacecraft
McComas, D. J.; Pogorelov, N. V.; Zank, G. P. +2 more
The outer heliosphere is a dynamic region shaped largely by the interaction between the solar wind and the interstellar medium. While interplanetary magnetic field and plasma observations by the Voyager spacecraft have significantly improved our understanding of this vast region, modeling the outer heliosphere still remains a challenge. We simulat…
Broadband Observations of High Redshift Blazars
Stalin, C. S.; Fabian, A. C.; Parker, M. L. +1 more
We present a multi-wavelength study of four high redshift blazars, S5 0014+81 (z = 3.37), CGRaBS J0225+1846 (z = 2.69), BZQ J1430+4205 (z = 4.72), and 3FGL J1656.2-3303 (z = 2.40) using quasi-simultaneous data from the Swift, Nuclear Spectroscopic Telescope Array (NuSTAR) and the Fermi-Large Area Telescope (LAT) and also archival XMM-Newton observ…
The Reverberation Lag in the Low-mass X-ray Binary H1743-322
Ponti, Gabriele; De Marco, Barbara
The evolution of the inner accretion flow of a black hole X-ray binary during an outburst is still a matter of active research. X-ray reverberation lags are powerful tools for constraining disk-corona geometry. We present a study of X-ray lags in the black hole transient H1743-322. We compared the results obtained from analysis of all the publicly…
Two Eclipsing Ultraluminous X-Ray Sources in M51
Soria, R.; Urquhart, R.
We present the discovery, from archival Chandra and XMM-Newton data, of X-ray eclipses in two ultraluminous X-ray sources (ULXs), located in the same region of the galaxy M51: CXOM51 J132940.0+471237 (ULX-1, for simplicity) and CXOM51 J132939.5+471244 (ULX-2). Three eclipses were detected for ULX-1 and two for ULX-2. The presence of eclipses puts …
Using ForeCAT Deflections and Rotations to Constrain the Early Evolution of CMEs
Vourlidas, A.; Kay, C.; Opher, M. +1 more
To accurately predict the space weather effects of the impacts of coronal mass ejection (CME) at Earth one must know if and when a CME will impact Earth and the CME parameters upon impact. In 2015 Kay et al. presented Forecasting a CME’s Altered Trajectory (ForeCAT), a model for CME deflections based on the magnetic forces from the background sola…
Chain Reconnections Observed in Sympathetic Eruptions
Joshi, Navin Chandra; Magara, Tetsuya; Aulanier, Guillaume +2 more
The nature of various plausible causal links between sympathetic events is still a controversial issue. In this work, we present multiwavelength observations of sympathetic eruptions, associated flares, and coronal mass ejections (CMEs) occurring on 2013 November 17 in two close active regions. Two filaments, I.e., F1 and F2, are observed in betwe…
The Milky Way's Hot Gas Kinematics: Signatures in Current and Future OVII Absorption Line Observations
Bregman, Joel N.; Miller, Matthew J.; Hodges-Kluck, Edmund J.
Detections of z ≈ 0 oxygen absorption and emission lines indicate the Milky Way hosts a hot (∼ {10}6 K), low-density plasma extending ≳ 50 {{kpc}} into the Mily Way’s halo. Current X-ray telescopes cannot resolve the line profiles, but the variation of their strengths on the sky constrains the radial gas distribution. Interpreting the O…