Search Publications
Kinematic Structure of the Milky Way Galaxy, Near the Spiral Arm Tangents
Vallée, Jacques P.
We compare the observed radial velocity of different arm tracers, taken near the tangent to a spiral arm. A slight difference is predicted by the density wave theory, given the shock predicted at the entrance to the inner spiral arm. In many of these spiral arms, the observed velocity offset confirms the prediction of the density wave theory (with…
The Expansion of the X-Ray Nebula Around η Car
Corcoran, Michael F.; Russell, C. M. P.; Hamaguchi, K. +8 more
The massive colliding wind binary system η Car is embedded in an X-ray emitting region having a characteristic temperature of a few million degrees, associated with ejecta produced during the 1840s, and in earlier outbursts. We use CHANDRA X-ray imaging observations obtained over the past two decades to directly measure the expansion of the X-ray …
The Warm Gas in the Milky Way: The Kinematical Model of C IV and Its Connection to Si IV
Bregman, Joel N.; Qu, Zhijie; Lindley, Ryan
We compose a 265-sight-line Milky Way C IV line-shape sample using the Hubble Space Telescope/Cosmic Origins Spectrograph archive, which is complementary to the existing Si IV samples. C IV has a higher ionization potential (47-64 eV) than Si IV (33-45 eV), so it also traces warm gas, which is roughly cospatial with Si IV. The spatial density dist…
First photometric and orbital period investigations of the total-eclipse contact binary V0339 Com
Yu, Yun-Xia; Hu, Ke; Xiang, Fu-Yuan +2 more
We presented the first photometric and orbital period investigation for the W UMa-type binary V0339 Com. The multi-bands light curves were obtained and analyzed with the Wilson-Devinney Code. The photometric solutions suggested that V0339 Com is an A-subtype shallow contact binary with a degree of contact f = 12 . 0% . The total eclipse of V0339 C…
Cyanopolyyne line survey towards high-mass star-forming regions with TMRT
Wang, Y. X.; Zhang, J. S.; Yan, Y. T. +8 more
Context. Cyanopolyynes (HC2n+1 N, n = 1,2,3), which are the linear carbon chain molecules, are precursors for the prebiotic synthesis of simple amino acids. They are important for understanding prebiotic chemistry and may be good tracers of the star formation sequence.
Aims: We aim to search for cyanopolyynes in high-mass star-form…
Uranus's and Neptune's Stratospheric Water Abundance and Vertical Profile from Herschel-HIFI
Irwin, P. G. J.; Teanby, N. A.; Nixon, C. A. +2 more
Here we present new constraints on Uranus's and Neptune's externally sourced stratospheric water abundance using disk-averaged observations of the 557 GHz emission line from Herschel's Heterodyne Instrument for the Far-Infrared. Derived stratospheric column water abundances are × 1014 cm‑2 for Uranus and ×1014 cm
Precise Positions of Triton in 2010-2014 based on Gaia-DR2
Yu, Yong; Tang, Kai; Zhang, Huiyan +2 more
With unique orbital and physical characteristics, Triton is a very important target because it may contain information of the origin and evolution of the solar system. Besides space explorations, ground-based observations over long time also play a key role on research of Triton. High-precision positions of Triton obtained from ground telescopes a…
Data-driven Model of Temporal Evolution of Solar Mg II h and k Profiles over the Solar Cycle
Heinzel, Petr; Gunár, Stanislav; Koza, Július +2 more
The solar radiation in the cores of the Mg II h and k spectral lines plays a significant role in the illumination of prominences, coronal mass ejections (CMEs), spicules, flare loops, and surges. Moreover, the radiation in these lines strongly correlates with solar magnetic activity and the ultraviolet solar spectral irradiance affecting the photo…
Investigation of rocket effect in bright-rimmed clouds using Gaia EDR3
Ojha, D. K.; Maheswar, G.; Saha, Piyali +2 more
Bright-rimmed clouds (BRCs) are excellent laboratories to explore the radiation-driven implosion mode of star formation because they show evidence of triggered star formation. In our previous study, BRC 18 has been found to accelerate away from the direction of the ionizing H II region because of the well-known 'Rocket Effect'. Based on the assump…
J01020100-7122208: an accreted evolved blue straggler that was not ejected from a supermassive black hole
Hawkins, Keith; Jofré, Paula; Prieto, Jose L. +3 more
J01020100-7122208 is a star whose origin and nature still challenges us. It was first believed to be a yellow supergiant ejected from the Small Magellanic Cloud, but it was more recently claimed to be a red giant accelerated by the Milky Way's central black hole. In order to unveil its nature, we analysed photometric, astrometric, and high-resolut…