The Study On The Fundamental Plane Of Black Hole Activity

The issues of the black hole (BH) and the related compact objects (e.g., X-ray binaries, XRBs, active galactic nuclei, AGNs, gamma-ray bursts, GRBs, etc.) are the hot topics in high-energy physics Up to now, there are two main pupulations of BH, which are the stellar mass BHs (3 - 20M(?) in X-ray binary, XRB) and supermassive BHs (106-10M(?), SMBH) in the center of the galaxy. The putative intermediate mass BH (102-4M(?)) is still a matter of debate, where the ultra-luminosity X-ray source with X-ray luminosity larger than 1042 erg/s (e.g, HLX-1) may be the best candidate. AGN is a compact region at the center of the galaxy that has much higher luminosity than that of the host galaxy. It is believed that the active nuclei should be caused by the gravitational energy of the accretion disk surrounding the SMBH in the galactic center. XRB is a class of binary star that is luminous in X-ray waveband, where the X-rays emissions are also contributed by the accreting matter. Beside the accretion, the jet/outflow is also found in both XRBs and AGNs (and possibly also ULXs). It is believed that BH may be scale free and the similar phenomena may exist in different-scale BH systems. In this thesis, we try to explore the physical properties in these BHs, where we especially investigate the possible universal correlations for these different-scale BHs. I will list my main work as follows,In Chapter 1, we firstly introduce the observational properties of XRBs, AGNs, and ULXs. We further present a review for the possible similarities in them, which include the similarities in central engine (e.g., X-ray properties), the correlation of radio-X-ray correlation and the fundamental plane of black hole activity. At last, we simply review the accretion and jet physics, such as the main accretion disk models (eg, SSD, ADAF and slim disc), the physical mechanism for jet and the coupling of disk and jet.In Chapter 2, we try to explore the possible physical reason that regulated the different radio-X-ray correlations as found in XRBs, where the "outlier" track is much steeper than the former universal correlation. It was suggested that this difference may be triggered by different accretion processes. In this work, we explore the hard X-ray spectral evolution in four black-hole X-ray binaries with multiple, quasi-simultaneous radio and X-ray observations, and find that hard X-ray photon indices, ?, are negatively and positively correlated with X-ray fluxes when the X-ray flux, F3-9kev, is below and above a critical flux, Fx,crit, which are consistent with predictions of the advection-dominated accretion flow and the SSD-corona model, respectively. And most importantly, we find that the radio-X-ray correlations are also changed simultaneously at this critical X-ray flux. The data points with positive ?-F3-gkeV correlation have a steeper radio-X-ray correlation (FR ? FbX, b?1.1-1.4, the so-called he "outlier" track), while the data points with anti-correlation of ?-F3-9keV either stay in universal tracks or stay in transition tracks. As we known that the anti- and positive correlations of hard X-ray photon index and Eddington ratio are most possibly triggered by different accretion processes. Therefore, this work gives the direct evidence that the different tracks of radio-X-ray correlation may be triggered by different accretion processes.In Chapter 3, we investigate the fundamental plane of rediatively efficient black hole sources. There are two different radio-X-ray correlations as found in XRBs, which are speculated to be triggered by different accretion processes. The former fundamental plane is mainly applied to low-luminosity AGNs and low/hard state XRBs. Therefore, it is useful to explore this issue for radiatively efficient BHs. We firstly construct a sample consisting the bright radio-quiet AGNs and outliers of XRBs. We find these two populations follow a similar and steeper correlation of hard X-ray photon indices and Eddington ratios, and their Eddington ratios ? 1%. We find that the radio-X-ray correlation in bright AGNs is also steep, which is quite similar to that of outliers of XRBs. Both the positively correlated X-ray spectral evolution and the steeper radio-X-ray correlation of AGNs and outliers can be regulated by a radiatively efficient accretion flow. Based on these similarities, we further present a new fundamental plane of radiatively efficient black hole activity, that is, log LR= 1.59+0.28-0.22logLx-0.22+0.19-0.20logMBH-28.97+0.45-0.45 with a scatter of ?R= 0.51 dex. The fundamental is mainly suitable for radiatively efficient BH sources, while the former is mainly suitable for radiatively inefficient BHs.In Chapter 4, we study physical properties of the BH source in quiescent state. It is controversial whether radio-X-ray correlation as defined in low-hard state of X-ray binaries (XRBs) can extend to quiescent state (e.g. X-ray luminosity less than a critical value of LX,c?10-5 LEdd) or not. In this work, we firstly construct a sample consisting XRBs and low luminosity active galaxy nuclei (LLAGNs) with wide distribution of Eddington ratios (LX/LEdd?10-9--10-3) to re-explore the fundamental plane of black hole activity. We find that there are similar fundamental plane (?x?0.6) for Lx ?X?crit and LX? LX,crit black hole sources, and the FR Is have a steeper slope comparing the other sources. We further select two sub-samples of AGNs with BH mass in narrow range (FR Is with MBH= 108.8±0.4M(?) and other LLAGNs with MBH= 108.0±0.4M(?)) to simulate the behavior of a single supermassive BH evolving from sub-Eddington to quiescent state. We find that the highly sub-Eddington sources with Lx/LEdd?10-9 -10-6 still roughly stay on the extension of radio-X-ray correlation as defined by other sub-Eddington BHs, which is similar to the observation of XRBs. Therefore, our results seem to be support that the properties of quiescent BHs still similar to those of low/hard state.In Chapter 5, we study the spectral evolution of XRBs in a whole outburst and try to constrain the possible accretion physics based on spectral evolution. Due to part of the work is still ongoing, we only present an example here. We find that there are two different spectral evolutions in the rising and the decay of the 2007/2008 outburst, (i) On the rising of the outburst, the relation of ?- F2-10kev is positive and negative correlation when Lbol? 7.5% LEdd and Lbol ? 7.5% LEdd, respectively, (ii) On the decay of the outburst, the relation of ?-F2-10keV can be divided into three part, the relation of ? - F2-10keV is positive when 1% LEdd ? Lbol?1.5%L Edd and the photon index is about constant when Lbol-1.5% LEdd and Lbol?1% LEdd. Theoretically, the evolution of ?- m is related to the magnetic stress tensor ?r? in disk-corona systems. We can roughly constrain the magnetic stress tensor based on the data in bright state. Furthermore, the evolution of the hard X-ray indices in rising stage of an outburst will also put constraints on the accretion models even it is still not very clear now.In Chapter 6, I give a brief summary for my works in this thesis and present some simple plans for near future.