Search Publications
Chandra Observations of Abell 2261 Brightest Cluster Galaxy, a Candidate Host to a Recoiling Black Hole
Lauer, Tod R.; Ogle, Patrick; Postman, Marc +4 more
We use Chandra X-ray observations to look for evidence of a recoiling black hole from the brightest cluster galaxy in Abell 2261 (A2261-BCG). A2261-BCG is a strong candidate for a recoiling black hole because of its large, flat stellar core, revealed by Hubble Space Telescope imaging observations. We took 100 ks observations with Chandra and combi…
Radiative Transfer Modeling of an SN 1987A Light Echo-AT 2019xis
Wang, Lifan; Brown, Peter; Ding, Jiachen +1 more
We use a Monte Carlo radiative transfer model (MCRTM) to simulate the UBVRI light curves, images, and linear polarization of a light echo from supernova SN 1987A in the Large Magellanic Cloud (LMC) using various dust cloud shapes, sizes, and optical properties. We compare the theoretical simulations to the observations of AT 2019xis, a light echo …
Fresh Insights on the Kinematics of M49's Globular Cluster System with MMT/Hectospec Spectroscopy
Zhang, Hongxin; Liu, Chengze; Zabludoff, Ann +10 more
We present the first results of an MMT/Hectospec campaign to measure the kinematics of globular clusters (GCs) around M49-the brightest galaxy in the Virgo galaxy cluster, which dominates the Virgo B subcluster. The data include kinematic tracers beyond 95 kpc (~5.2 effective radii) for M49 for the first time, enabling us to achieve three key insi…
Chemically Fresh Gas Inflows Detected in a Nearby High-mass Star-forming Region
Kim, Kee-Tae; Liu, Tie; Mei, Ying +9 more
We report the detection of a chemically fresh inflow that is feeding high-mass young-stellar-object (HMYSO) growth in the nearby high-mass star-forming region G352.63 made with both the Atacama Large Millimeter/submillimeter Array (ALMA) and the Submillimeter Array (SMA). High-quality images of the dust and molecular lines from both ALMA and SMA h…
A Multiwavelength Study of the Formation of the AFGL 333-Ridge
Wang, Jun-Jie; Xu, Jin-Long; Xu, Ye +1 more
We presented a multiwavelength study of the AFGL 333-Ridge. The molecular line data reveals that the AFGL 333-Ridge has two independent velocity components at -50.5 and -48.0 km s-1. In the position-velocity diagram, the bridge feature connects with two parts that are spatially correlated but separated in velocity. This observational ev…
The Solar-cycle Variations of the Anisotropy of Taylor Scale and Correlation Scale in the Solar Wind Turbulence
Zhou, G.; He, H. -Q.
The field-aligned anisotropy of the solar wind turbulence, which is quantified by the ratio of the parallel to the perpendicular correlation (and Taylor) length scales, is determined by simultaneous two-point correlation measurements during the time period 2001-2017. Our results show that the correlation scale along the magnetic field is the large…
Radial Velocity Monitoring of the Young Star Hubble 4: Disentangling Star-spot Lifetimes from Orbital Motion
Anderson, Jay; Johns-Krull, Christopher M.; Prato, L. +1 more
We studied the weak-lined T Tauri star Hubble 4, a known long-period binary, and its star-spot phenomena. We used optical radial velocity (RV) data taken over a span of 14 yr (2004-2010, 2017-2019) at the McDonald Observatory 2.7 m Harlan J. Smith Telescope and single epoch imaging from the Hubble Space Telescope (HST)/Wide Field Camera 3 instrume…
A Rotating Azimuthally Distributed Auroral Current System on Saturn Revealed by the Cassini Spacecraft
Coates, A. J.; Krupp, N.; Dougherty, M. K. +14 more
Stunning aurorae are mainly produced when accelerated electrons travel along magnetic field lines to collide with the atmosphere. The motion of electrons often corresponds to the evolution of a magnetic field-aligned current system. In the terrestrial magnetosphere, the current system is formed at the night-side sector, and thus produces an aurora…
Space Telescope and Optical Reverberation Mapping Project. XIII. An Atlas of UV and X-Ray Spectroscopic Signatures of the Disk Wind in NGC 5548
Kriss, G. A.; Mehdipour, M.; Peterson, B. M. +8 more
The unusual behavior of the spectral lines of NGC5548 during the STORM campaign demonstrated a missing piece in the structure of AGNs. For a two-month period in the middle of the campaign, the spectral lines showed a deficit in flux and a reduced response to the variations of the UV continuum. This was the first time that this behavior was unequiv…
Interplanetary Shock Candidates Observed at Venus's Orbit
Wang, Yuming; Shen, Chenglong; Xu, Mengjiao +2 more
The measurements from the Venus Express spacecraft are analyzed for the basic properties of fast forward interplanetary shocks at Venus's orbit (∼0.72 au). A total of 143 fast forward interplanetary shock candidates during 2006-2014 are identified. The shock angle ΘBn, defined as the angle between the shock normal and the upstream magne…