Search Publications
Exploring the Origin of Multiwavelength Activities of High-redshift Flat-spectrum Radio Quasar PKS 1502+106 during 2014-2018
Wang, X. Y.; Gu, Q. S.; Xiong, Ding-Rong +4 more
The origin of the multiband activities (outbursts/flares) of blazars is still a heavily debated topic. Shock and magnetic reconnection have long been considered as possible triggers of the multiband activities. In this paper, we present an exploration of the origin of multiband activities for a high-redshift (z = 1.8385) flat-spectrum radio quasar…
Characterization of the precision premium in astrometry
Lin, F. R.; Peng, Q. Y.; Zheng, Z. J. +1 more
The precision premium, a concept in astrometry that was first presented by Pascu in 1994, initially means that the relative positional measurement of the Galilean satellites of Jupiter will be more accurate when their separations are small. Correspondingly, many observations have been obtained of these Galilean satellites since it was introduced. …
Solar ultraviolet bursts in a coordinated observation of IRIS, Hinode and SDO
Tian, Hui; Samanta, Tanmoy; He, JianSen +3 more
Solar ultraviolet (UV) bursts are small-scale compact brightenings in transition region images. The spectral profiles of transition region lines in these bursts are significantly enhanced and broadened, often with chromospheric absorption lines such as Ni~{\sc{ii}} 1335.203 and 1393.330 Å superimposed. We investigate the properties of several UV b…
Unresolved Binaries and Galactic Clusters’ Mass Estimates
Carraro, Giovanni; Borodina, Olga I.; Seleznev, Anton F. +1 more
Binary stars are present in all stellar systems, yet their role is far from being fully understood. We investigate the effect of unresolved binaries in the derivation of open clusters’ mass by star counts. We start from the luminosity functions of five open clusters: IC 2714, NGC 1912, NGC 2099, NGC 6834, and NGC 7142. Luminosity functions are obt…
NuSTAR Observations of the Supernova Remnant RX J1713.7-3946
Uchiyama, Yasunobu; Tanaka, Takaaki; Aharonian, Felix +4 more
The shock waves of supernova remnants (SNRs) are prominent candidates for the acceleration of the Galactic cosmic rays. SNR RX J1713.7-3946 is one well-studied particle accelerator in our Galaxy because of its strong nonthermal X-ray and gamma-ray radiation. We have performed Nuclear Spectroscopic Telescope Array (3-79 keV) observations of the nor…
Properties of Density and Velocity Gaps Induced by a Planet in a Protoplanetary Disk
Han, Cheongho; Bae, Jaehan; Kim, Woong-Tae +1 more
Gravitational interactions between a protoplanetary disk and its embedded planet are one of the formation mechanisms of gaps and rings found in recent ALMA observations. To quantify the gap properties measured in not only surface density but also rotational velocity profiles, we run two-dimensional hydrodynamic simulations of protoplanetary disks …
Observations of Type Ia Supernova 2014J for Nearly 900 Days and Constraints on Its Progenitor System
Wang, Lifan; Elias-Rosa, Nancy; Benetti, Stefano +18 more
We present extensive ground-based and Hubble Space Telescope (HST) photometry of the highly reddened, very nearby SN Ia 2014J in M82, covering the phases from 9 days before to about 900 days after the B-band maximum. SN 2014J is similar to other normal SNe Ia near the maximum light, but it shows flux excess in the B band in the early nebular phase…
Swift-XRT Follow-up of Gravitational-wave Triggers in the Second Advanced LIGO/Virgo Observing Run
Troja, E.; Cenko, S. B.; Sakamoto, T. +37 more
The Neil Gehrels Swift Observatory carried out prompt searches for gravitational-wave (GW) events detected by the LIGO/Virgo Collaboration (LVC) during the second observing run (“O2”). Swift performed extensive tiling of eight LVC triggers, two of which had very low false-alarm rates (GW170814 and the epochal GW170817), indicating a high confidenc…
Herschel map of Saturn's stratospheric water, delivered by the plumes of Enceladus
Fletcher, L. N.; Hartogh, P.; Lellouch, E. +13 more
Context. The origin of water in the stratospheres of giant planets has been an outstanding question ever since its first detection by the Infrared Space Observatory some 20 years ago. Water can originate from interplanetary dust particles, icy rings and satellites, and large comet impacts. Analyses of Herschel Space Observatory observations have p…
Bow shocks, bow waves, and dust waves - III. Diagnostics
Henney, William J.; Arthur, S. J.
Stellar bow shocks, bow waves, and dust waves all result from the action of a star's wind and radiation pressure on a stream of dusty plasma that flows past it. The dust in these bows emits prominently at mid-infrared wavelengths in the range 8 to 60 µm. We propose a novel diagnostic method, the τ-η diagram, for analysing these bows, which i…