Search Publications
A Deprojection Analysis of Abell 1650 with XMM-Newton
Chen, Li; Jia, Shu-Mei; Chen, Yong
We revisit the XMM-Newton observation of the galaxy cluster Abell 1650 with a deprojection technique. We find that the radial deprojected spectra of Abell 1650 can be marginally fitted by a single-temperature model. In order to study the properties of the central gas, we fit the spectra of the central two regions with a two-temperature model. The …
Velocity Space of Galactic O-B Stars
Zhu, Zi
Based on the Hipparcos proper motions and available radial velocity data of O-B stars, we have re-examined the local kinematical structure of the young disk population of ~1500 O-B stars not including the Gould-belt stars. A systematic warping motion of the stars about the direction to the Galactic center has been reconfirmed. A negative K-term im…
A Multiwavelength Study of the Jets in FR-I Radio Galaxies: I. Data and Analysis
Zhou, Hong-Yan; Meng, Da-Min
We compile a sample of 11 Fanaroff-Riley type I Radio Galaxies (FR-I RGs) with multi-wavelength observations to address the dynamic behavior of jets in these objects. Optical images acquired by the Hubble Space Telescope (HST) are carefully analyzed. The method and reduction procedure are described in detail. Unresolved optical cores emerge after …
Two Sympathetic Homologous CMEs on 2002 May 22
Ding, Ming-De; Fang, Cheng; Cheng, Jian-Xia +1 more
Sympathetic coronal mass ejections (CMEs) usually occur in different active regions connected by interconnecting magnetic loops, while homologous CMEs occur within the same active region with an almost the same background magnetic field, and so are similar in shapes. Two sympathetic CMEs erupted within 3 hours on 2002 May 22, originating from the …
Latitudinal Distribution of Solar Flares and Their Association with Coronal Mass Ejections
Shrivastava, Pankaj K.; Singh, Neelam
Major solar flare events have been utilised to study the latitudinal frequency distribution of solar flares in northern and southern hemispheres for the period of 1986 to 2003. A statistical analysis has been performed to obtain the correlation between Coronal Mass Ejections (CMEs) and Forbush decrease (Fds) of cosmic ray intensity. Almost the sam…
Resonant Heating of Ions by Parallel Propagating Alfvén Waves in Solar Coronal Holes
Xiao, Chi-Jie; Wang, Jing-Xiu; Zhang, Tian-Xi
Resonant heating of H, O+5, and Mg+9 by parallel propagating ion-cyclotron Alfvén waves in solar coronal holes at a heliocentric distance is studied using the heating rate derived from the quasilinear theory. It is shown that the particle-Alfvén-wave interaction is a significant microscopic process. The temperatures of the io…
Waiting Time Distribution of Coronal Mass Ejections
Ding, Ming-De; Chen, Peng-Fei; Yeh, Chin-Teh
Inspired by the finding that the large waiting time of solar flares presents a power-law distribution, we investigate the waiting time distribution (WTD) of coronal mass ejections (CMEs). SOHO/LASCO CME observations from 1996 to 2003 are used in this study. It is shown that the observed CMEs have a similar power-law behavior to the flares, with an…
Polar Coronal Holes During Solar Cycles 22 and 23
Woch, J.; Zhang, Jun; Solanki, S.
Data from the Solar Wind Ion Composition Spectrometer (SWICS) on Ulysses and synoptic maps from Kitt Peak are used to analyze the polar coronal holes of solar activity cycles 22 and 23 (from 1990 to end of 2003). In the beginning of the declining phase of solar cycles 22 and 23, the north polar coronal holes (PCHs) appear about one year earlier th…
Chromospheric Internetwork Oscillations at Various Locations of the Quiet Sun
Ning, Zong-Jun; Ming-DeDing
We analyze oscillation behaviours in chromospheric internetwork regions using spectral observations of the CII 1334 Å line obtained with the Solar Ultraviolet Measurements of Emitted Radiation spectrograph (SUMER) aboard Solar and Heliospheric Observatory (SOHO). Three areas, 26×120arcsec2 each, at the various latitudes from …
The Status of ROSAT X-ray Active Young Stars toward Taurus-Auriga
Li, Jin-Zeng
We present an astrometric study of the candidates of T Tauri stars (TTS) and non-TTS X-ray sources around Tau-Aur, based on the Hipparcos Catalogue and the ACT Reference Catalogue. The ROSAT selected X-ray sources are found to be a mixed population. A few of them are associated with the Tau-Aur or Orion Star Forming Regions (SFR). Some, with dista…