Search Publications
Updating the orbital ephemeris of the dipping source XB 1254-690 and the distance to the source
Pintore, Fabio; Sanna, Andrea; Gambino, Angelo F. +5 more
XB 1254-690 is a dipping low mass X-ray binary system hosting a neutron star and showing type I X-ray bursts. We aim at obtaining a more accurate orbital ephemeris and at constraining the orbital period derivative of the system for the first time. In addition, we want to better constrain the distance to the source in order to locate the system in …
Joint fit of Warm Absorbers in COS and HETG spectra of NGC 3783
Sun, Wei; Ji, Li; Fu, Xiao-Dan +2 more
Warm Absorbers (WAs), as an important form of AGN outflows, show absorption in both the UV and X-ray bands. Using XSTAR generated photoionization models, for the first time we present a joint fit to the simultaneous observations of HST/COS and Chandra/HETG on NGC 3783. A total of five WAs explain well all absorption features from the AGN outflows,…
Quasars in the Galactic Anti-Center Area from LAMOST DR3
Zhang, Yong; Yuan, Hai-Bo; Huang, Yang +11 more
We present a sample of quasars discovered in an area near the Galactic Anti-Center covering 150^\circ ≤ l≤ 210^\circ and | b| ≤ 30^\circ , based on LAMOST Data Release 3 (DR3). This sample contains 151 spectroscopically confirmed quasars. Among them 80 are newly discovered with LAMOST. All these quasars are very bright, with i magnitudes peaking a…
An application of the KNND method for detecting nearby open clusters based on Gaia-DR1
Gao, Xin-Hua
This paper presents a preliminary test of the k-th nearest neighbor distance (KNND) method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars (< 100 {pc}) from the Gaia-DR1 catalog, and then use the KNND method to detect overdense regions in three-dimensional space. We find two overdense regions (the Hyades and …
Peak flux of flares associated with coronal mass ejections
Suryanarayana, Gadikere Sheshagiriyappa; Balakrishna, Kagalagodu Manjunathayya
Features of flares that occur in association with coronal mass ejections (CMEs) have often displayed variations compared to flares with no associated CMEs. A comparative estimation of peak flux values of flares associated with CMEs and those without CMEs is made. Peak flux values of flares associated with CMEs show distinctly higher values in comp…
Identification of candidate millisecond pulsars from Fermi LAT observations II
Wang, Zhong-Xiang; Xing, Yi; Vadakkumthani, Jithesh +1 more
On the basis of the properties of known γ-ray millisecond pulsars (MSPs), we have selected 77 un-associated sources from the Fermi Large Area Telescope (LAT) third source catalog for the purpose of finding likely candidate MSPs. Previously, detailed LAT data analysis for 39 of them was reported, and here we report the analysis for the remaining 38…
Gas emission and dynamics in the infrared dark cloud G31.23+0.05
Zhang, Chuan-Peng; Wang, Jun-Jie; Xu, Jin-Long +1 more
We performed a multiwavelength study towards the infrared dark cloud (IRDC) G31.23+0.05 with new CO observations from Purple Mountain Observatory and archival data (the GLIMPSE, MIPSGAL, HERSCHEL, ATLASGAL, BGPS and NVSS surveys). From these observations, we identified three IRDCs with systemic velocities of 108.36+/- 0.06 (cloud A), 104.22+/- 0.1…
V2551 Cyg: a pulsating star with enigmatic peculiarities
Popov, Velimir A.; Petrov, Nikola I.; Kjurkchieva, Diana P. +2 more
Intensive photometric and spectral observations of the variable star V2551 Cyg are presented. The light curve shape reveals that the target is a pulsating star, contrary to its previous classification as an eclipsing binary. The period and amplitude of the light curve, the amplitudes of color changes and the radial velocity curve of V2551 Cyg are …
An improved solution to geometric distortion using an orthogonal method
Wang, Na; Peng, Huan-Wen; Peng, Qing-Yu
The geometric distortion of a CCD field of view has a direct influence on the positional measurements of CCD observations. In order to obtain high precision astrometric results, the geometric distortion should be derived and corrected precisely. As presented in our previous work, a convenient solution has been carried out and has also been applied…
Multi-transition study of the peculiar merger Arp 299
Zhu, Ming; Jiao, Qian
We present a multi-transition study to investigate the physical properties of dust and molecular gas in the archetypical merger Arp 299 by using data including James Clerk Maxwell Telescope (JCMT) 850 and 450 µm observations, Herschel 500, 350, 250, 160 and 70 µm continuum maps, as well as the CO(3-2), CO(4-3) low-J CO lines and CO(11-…