arXiv subjects

Ai-jun Dong

Publications and source records attributed to Ai-jun Dong.

2 recordsLinked to original sources

arXiv2018

NSVS 01286630: A Detached Binary with a Close-in Companion

New photometric observations of NSVS 01286630 were performed and two sets of four-color (B, V , Rc, Ic) light curves (LCs) were obtained. Using the 2013 version of the Wilson-Devinney (W-D) code, we analyzed these data. The photometric solutions reveal that NSVS 01286630 is an active detached eclipsing binary (EB) with a high orbit inclination. Remarkably, the temperature of the primary component (the hotter star) is higher than the secondary one, but, the value of mass ratio q(M2/M1) for NSVS 0128663 is more than 1, which can be explained that the surface of the secondary component of NSVS 01286630 is covered with big cool-star-spots. Based on our new CCD mid-eclipse times and the data published until now, the variations of the mid-eclipse times were reanalyzed in detail using a weighted least-squares method. It is discovered that the (O-C) diagram of the system shows a cyclic oscillation with a period of 3.61 yr and an amplitude of 0.001 days. The cyclic variation may be caused by the light travel time effect (LTTE) due to the presence of a third companion, whose mass we calculated is about 0.11 solar mass. The third body may affect the orbital evolution of the central binary system by transferring the angular momentum.

astro-ph.SR↗

arXiv2016

The universal "heartbeat" oscillations in black hole systems accross the mass-scale

The hyperluminous X-ray source (HLX-1, the peak X-ray luminosity $\sim 10^{42}\rm erg\ s^{-1}$) near the spiral galaxy ESO 243-49 is possibly the best candidate for intermediate mass black hole (IMBH), which underwent recurrent outbursts with a period of $\sim 400$ days. The physical reason for this quasi-periodic variability is still unclear. We explore the possibility of radiation-pressure instability in accretion disk by modeling the light curve of HLX-1, and find that it can roughly reproduce the duration, period and amplitude of the recurrent outbursts HLX-1 with an IMBH of ~10^5Msun. Our result provides a possible mechanism to explain the recurrent outbursts in HLX-1. We further find a universal correlation between the outburst duration and the bolometric luminosity for the BH sources with a very broad mass range (e.g., X-ray binaries, XRBs, HLX-1 and active galactic nuclei, AGNs), which is roughly consistent with the prediction of radiation-pressure instability of the accretion disk. These results imply that "heartbeat" oscillations triggered by radiation-pressure instability may appears in different-scale BH systems.

astro-ph.HE↗