Search Publications
Photometric investigation of the K-type extremely shallow contact binary V1799 Orion
Qian, Sheng-Bang; Liao, Wen-Ping; He, Jia-Jia +3 more
New multi-color light curves of the very short period K-type eclipsing binary V1799 Ori were obtained and analyzed with the Wilson-Devinney code. The photometric solutions reveal that the system is a W-type shallow-contact binary with a mass ratio of q = 1.335(±0.005) and a degree of contact of about f = 3.5(±1.1)%. In general, the results are in …
Temporal variations and spectral properties of the Be/X-ray pulsar GRO J1008—57 studied by INTEGRAL
Wang, Wei
The spin period variations and hard X-ray spectral properties of the Be/X-ray pulsar GRO J1008—57 are studied with INTEGRAL observations during two outbursts in 2004 June and 2009 March. The pulsation periods of ~ 93.66 s in 2004 and ~ 93.73 s in 2009 are determined. Pulse profiles of GRO J1008—57 during outbursts are strongly energy dependent wit…
Association of CMEs with solar surface activity during the rise and maximum phases of solar cycles 23 and 24
Li, Ting; Zhang, Jun; Gao, Peng-Xin
The cyclical behaviors of sunspots, flares and coronal mass ejections (CMEs) for 54 months from 2008 November to 2013 April after the onset of Solar Cycle (SC) 24 are compared, for the first time, with those of SC 23 from 1996 November to 2001 April. The results are summarized below. (i) During the maximum phase, the number of sunspots in SC 24 is…
On the line profile changes observed during the X2.2 class flare in the active region NOAA 11158
Raja Bayanna, Ankala; Kumar, Brajesh; Venkatakrishnan, Parameswaran +4 more
The solar active region NOAA 11158 produced a series of flares during its passage through the solar disk. The first major flare (of class X2.2) of the current solar cycle occurred in this active region on 2011 February 15 around 01:50 UT. We have analyzed the Dopplergrams and magnetograms obtained by the Helioseismic and Magnetic Imager (HMI) inst…
Identification of emission sources of umbral flashes using phase congruency
Feng, Song; Ji, Kai-Fan; Yang, Yun-Fei +1 more
The emission sources of umbral flashes (UFs) are believed to be closely related to running umbral and penumbral waves, and are concluded to be associated with umbral dots in the solar photosphere. Accurate identification of emission sources of UFs is crucial for investigating these physical phenomena and their inherent relationships. A relatively …
Spacecraft Doppler tracking with possible violations of LLI and LPI: preliminary bounds on LLI from Mars Express
Xie, Yi; Huang, Yong; Zhang, Yu-Fei +2 more
Three-way spacecraft Doppler tracking is currently widely used and it plays an important role in the control and navigation of deep space missions. Using the theory of three-way Doppler tracking, including possible violations of the local Lorentz invariance (LLI) and the local position invariance (LPI), we analyze the post-fit residuals of three-w…
The star formation history of redshift z ~ 2 galaxies: the role of the infrared prior
Nonino, Mario; Lapi, Andrea; De Zotti, Gianfranco +3 more
We build a sample of 298 spectroscopically-confirmed galaxies at redshift z ~ 2, selected in the z850-band from the GOODS-MUSIC catalog. By utilizing the rest frame 8 µm luminosity as a proxy of the star formation rate (SFR), we check the accuracy of the standard SED-fitting technique, finding it is not accurate enough to provide …
Revisiting the dichotomy of early-type galaxies
Hao, Cai-Na; Xia, Xiao-Yang; He, Yan-Qin
We study the relationship between isophotal shapes, central light profiles and kinematic properties of early-type galaxies (ETGs) based on a compiled sample of 184 ETGs. These sample galaxies are included in Data Release 8 of the Sloan Digital Sky Survey and have central light profiles and kinematic properties available from the literature, which …
Investigation of star formation toward the Sharpless 155 H II region
Fan, Zhou; Li, Jin-Zeng; Huang, Ya-Fang +1 more
We present a comprehensive study of star formation toward the H II region Sharpless 155 (S155). Star-formation activities therein were investigated based on multi-wavelength data from optical to the far-infrared. The surface density distribution of selected 2MASS sources toward S155 indicates the existence of a compact cluster, which is spatially …
A study of the relation between intensity oscillations and magnetic field parameters in a sunspot: Hinode observations
Venkatakrishnan, P.; Kumar, Brajesh; Mathew, Shibu K. +2 more
We present properties of intensity oscillations of a sunspot in the photosphere and chromosphere using G band and Ca II H filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequency reveal reduction of power in the G band with an increase in photospheric magnetic field strength at all frequencies. In Ca II H,…