This white paper is a summarising report of the Forum on monitoring the transient X-ray Universe in the multi-messenger era organized by the International Space Science Institute in Beijing (ISSI-BJ) on May 6-7, 2014. Time-domain astronomy will enter
a golden era towards the end of this decade with the advent of major facilities across the electromagnetic spectrum and in the multi-messenger realms of gravitational wave and neutrino. In the soft X-ray regime, the novel micro-pore lobster-eye optics provides a promising technology to realise, for the first time, focusing X-ray optics for wide-angle monitors to achieve a good combination of sensitivity and wide field of view. In this context, Einstein Probe - a soft X-ray all-sky monitor - has been proposed and selected as a candidate mission of priority in the space science programme of the Chinese Academy of Sciences. This report summarises the most important science developments in this field towards 2020 and beyond and how to achieve them technologically, which were discussed at this brainstorming forum. It also introduces briefly the Einstein Probe mission, including its key science goals and mission definition, as well as some of the key technological issues.
We discuss two methods to estimate black hole (BH) masses using X-ray data only: from the X-ray variability amplitude and from the photon index Gamma. The first method is based on the anti-correlation between BH mass and X-ray variability amplitude.
Using a sample of AGN with BH masses from reverberation mapping, we show that this method shows small intrinsic scatter. The second method is based on the correlation between Gamma and both the Eddington ratio L_{bol}/L_{Edd} and the bolometric correction L_{bol}/L_{2-10keV}.
In the WISE all-sky source catalogue there are 76 million mid-infrared (MIR) point sources that were detected at the first three WISE bands and have association with only one 2MASS near-IR source within 3 arcsec. We search for their identifications i
n the SIMBAD database and find 3.2 million identified sources. Based on these known sources, we establish three criteria for selecting candidate AGB stars in the Galaxy, which are three defined occupation zones in a color-color diagram, Galactic latitude |gb|< 20 deg, and corrected WISE third-band W3c < 11. Applying these criteria to the WISE+2MASS sources, 1.37 million of them are selected. We analyze the WISE third-band W3 distribution of the selected sources, and further establish that W3 < 8 is required in order to exclude a large fraction of normal stars in them. We therefore find 0.47 million candidate AGB stars in our Galaxy from the WISE source catalogue. Using W3c, we estimate their distances and derive their Galactic distributions. The candidates are generally located around the Galactic center uniformly, with 68% (1-sigma) of them within approximately 8 kpc. We discuss that optical spectroscopy can be used to verify the C-rich AGB stars in our candidates, and they will be good targets for the LAMOST survey that is planned to start from fall of 2012.
Using a recently introduced method to quantify the time varying lead-lag dependencies between pairs of economic time series (the thermal optimal path method), we test two fundamental tenets of the theory of fixed income: (i) the stock market variatio
ns and the yield changes should be anti-correlated; (ii) the change in central bank rates, as a proxy of the monetary policy of the central bank, should be a predictor of the future stock market direction. Using both monthly and weekly data, we found very similar lead-lag dependence between the S&P500 stock market index and the yields of bonds inside two groups: bond yields of short-term maturities (Federal funds rate (FFR), 3M, 6M, 1Y, 2Y, and 3Y) and bond yields of long-term maturities (5Y, 7Y, 10Y, and 20Y). In all cases, we observe the opposite of (i) and (ii). First, the stock market and yields move in the same direction. Second, the stock market leads the yields, including and especially the FFR. Moreover, we find that the short-term yields in the first group lead the long-term yields in the second group before the financial crisis that started mid-2007 and the inverse relationship holds afterwards. These results suggest that the Federal Reserve is increasingly mindful of the stock market behavior, seen at key to the recovery and health of the economy. Long-term investors seem also to have been more reactive and mindful of the signals provided by the financial stock markets than the Federal Reserve itself after the start of the financial crisis. The lead of the S&P500 stock market index over the bond yields of all maturities is confirmed by the traditional lagged cross-correlation analysis.
A left-right symmetric model with two Higgs bi-doublet is shown to be a consistent model for both spontaneous P and CP violation. The flavor changing neutral currents can be suppressed by the mechanism of approximate global U(1) family symmetry. We c
alculate the constraints from neural $K$ meson mass difference $Delta m_K$ and demonstrate that a right-handed gauge boson $W_2$ contribution in box-diagrams with mass well below 1 TeV is allowed due to a cancellation caused by a light charged Higgs boson with a mass range $150 sim 300$ GeV. The $W_2$ contribution to $epsilon_K$ can be suppressed from appropriate choice of additional CP phases appearing in the right-handed Cabbibo-Kobayashi-Maskawa matrix. The model is also found to be fully consistent with $B^0$ mass difference $Delta m_B$, and the mixing-induced CP violation quantity $sin2beta_{J/psi}$, which is usually difficult for the model with only one Higgs bi-doublet. The new physics beyond the standard model can be directly searched at the colliders LHC and ILC.
