Search Publications
Analysis of the X-ray emission of OB stars: O stars
Ryspaeva, Elizaveta; Kholtygin, Alexander
We investigate the global properties of X-ray emission from O stars, analyzing the X-ray spectra of 32 O stars from archival data of the XMM-Newton space observatory. We examine two hypotheses about of the origin of X-ray emission from O stars. The first is a paradigm proposed by Pollock, that was revealed from an analysis of the ζ Ori X-ray obser…
Anisotropic power spectrum and the observed low-l power in PLANCK CMB data
Rath, Pranati K.; Zhao, Dong; Chang, Zhe +1 more
In this work, we study a direction dependent power spectrum in anisotropic Finsler space-time. We use this direction dependent power spectrum to address the low-l power observed in WMAP and PLANCK data. The angular power spectrum of the temperature fluctuations has a lower amplitude in comparison to the ΛCDM model in the multipole range l = 2 - 40…
The pc-scale radio structure of MIR-observed radio galaxies
Yuan, Ye; Gu, Min-Feng; Chen, Yong-Jun
We investigated the relationship between the accretion process and jet properties by utilizing very long baseline array (VLBA) and mid-infrared (MIR) data for a sample of 45 3CRR radio galaxies selected with a flux density at 178 MHz > 16.4 {Jy}, 5 GHz very large array (VLA) core flux density ≥ 7 {mJy} and MIR observations. The pc-scale radio s…
Gaia calibrated UV luminous stars in LAMOST
Bai, Yu; Wang, Song; Liu, Ji-Feng
We take advantage of Gaia Data Release 2 to present 275 and 1774 ultraviolet luminous stars in the far ultraviolet (FUV) and near ultraviolet (NUV), respectively. These stars exceed their expected values by 5σ with respect to over one million ultraviolet stars in the log g vs. T eff diagram. Galactic extinction is corrected with a 3D du…
Saturn’s gravitational field induced by its equatorially antisymmetric zonal winds
Anderson, John D.; Schubert, Gerald; Kong, Dali +1 more
The cloud-level zonal winds of Saturn are marked by a substantial equatorially antisymmetric component with a speed of about 50ms-1 which, if they are sufficiently deep, can produce measurable odd zonal gravitational coefficients ΔJ 2k+1, k = 1, 2, 3, 4. This study, based on solutions of the thermal-gravitational wind equatio…
Planetary nebulae in the circumnuclear region of M31: a spectroscopic sample
Dong, Hui; Li, An-Qi; Li, Zhi-Yuan +2 more
Planetary nebulae (PNe) are an important tool for studying the dynamics and chemical evolution of galaxies in the Local Universe, given their characteristic bright emission line spectra. The Andromeda Galaxy (M31) provides a unique laboratory for studying PNe in the circumnuclear region, thanks to its proximity and almost uniformly low line-of-sig…
Superpenumbral chromospheric flare
Srivastava, Abhishek K.; Liu, Suo; Zhang, Hong-Qi +2 more
We observed a C-class flare at the outer boundary of the superpenumbra of a sunspot. The flare was triggered by an emerging magnetic bipolar region that was obliquely oriented with respect to the superpenumbral fibrils. The flare started due to the low height magnetic reconnection of emerging magnetic flux with a superpenumbral field resulting in …
Gas compression and likely triggered star formation in the infrared bubble N107
Yuan, Jing-Hua; Li, Jin-Zeng; Ren, Zhi-Yuan +2 more
The expansion of HII regions can regulate the evolution of their natal clouds and the star formation therein. Infrared dust bubbles, which are frequently associated with HII regions, are ideal laboratories to test whether impulse(s) driven by the expanding bubbles enhances or suppresses star-formation. In this work, we present a comprehensive stud…
Matching CCD images to a stellar catalog using locality-sensitive hashing
Liu, Bo; Peng, Qing-Yu; Yu, Jia-Zong
The usage of a subset of observed stars in a CCD image to find their corresponding matched stars in a stellar catalog is an important issue in astronomical research. Subgraph isomorphic-based algorithms are the most widely used methods in star catalog matching. When more subgraph features are provided, the CCD images are recognized better. However…
Spectroscopic and photometric studies of a candidate pulsating star in an eclipsing binary: V948 Her
Kahraman Aliçavuş, Filiz
Eclipsing binary stars with a pulsating component are powerful tools that allow us to probe the stellar interior structure and the evolutionary statuses with a good accuracy. Therefore, in this study, spectroscopic and photometric examinations of an eclipsing binary system V948 Her are presented. The primary component of the system is classified t…