6100820
A possible mechanism for the mass ratio limitation in early type galaxies
There is an interesting correlation between the central objects and their host galaxies in recent high resolution HST photometry of early type galaxies and Near-IR images of nearby quasar hosts. It has been shown that a) the hosts of these very luminous quasars are likely to be early type galaxies and that b) the mass ratio of central black holes (BHs) and their host spheroidal components (M-bh/M-spheroid) is similar to 0.002 within a factor of three. Using the hierarchical galaxy evolution scheme for the formation of early-type galaxies, we present here a general viscous accretion disk model to trace the star formation and central engine evolution before and after mergers. In our model, starbursts and AGN coexist; these two activities compete for the gas supply, interact with each other, probably feed back on each other and lock into a final status. They thus constrain the ratio of central black hole mass and its host spheroidal mass to a universal value of order 10(-3).
5811604
Extrasolar transiting planet search with subaru suprime-cam
We report the results of a prototype photometric search for transiting extrasolar planets using Subaru Suprime-Cam. Out of about 100,000 stars monitored around the Galactic plane (l=90 degree,b=0 degree), we find that 7,700 (27,000) stars show the photometric precision below 1% (3%) for 60 second exposures which is required to detect extrasolar planets by the transit method. Thus Suprime-Cam has the photometric stability and accuracy required for a transiting planet survey. During this observing run, we detected three transiting planetary candidates (i'-band magnitude around 18.5) which exhibit a single full transit-like light curve with a fractional depth of <5%. While future photometric and/or spectroscopic follow-ups remain to be done, the estimated parameters for the three systems are consistent with planetary companions around main-sequence stars. We also found two eclipsing binary candidates and eleven variable stars exhibiting W UMa-like light curves.
119206095
The First Infrared Telescope in Tibet Plateau, China
We plan to install an infrared telescope at the new site of Tibet, China. The primary mirror diameter is 50cm, and the focal ratio F8. The Xenics 640\times512 near infrared camera is employed, equipped with a dedicated high speed InGaAs detector array, working up to 1.7{\mu}m. The new site is located on 5100m mountain, near Gar town, Ali, where is an excellent site for both infrared and submillimeter observations. The telescope will be remotely controlled through internet. The goal of IRT is to make site testing, detect variable stars, and search for extrasolar planets.
17522079
Black hole energy release to the Gaseous Universe
We estimate the energy release of black hole formation to the intra-cluster medium of the Coma cluster and find that this is comparable to the present day energy content. Therefore an energetic and maybe hydrostatic influence is possible. Our calculations rely on the assumption of an universal black hole to galaxy mass ratio (more exactly: spheroidal mass component of the stellar population), for which there is growing evidence. On a cosmological scale, there is also an energy release of black hole formation comparable to what is expected to be present within the thermal gas, caused by the process of structure formation. This indicates an important dynamical influence, neglected by present day structure formation simulations. This estimate of cosmological black hole energy release is independent of the black hole to galaxy mass ratio, but consistent with its value.
219555605
Subaru high resolution spectroscopy of complex metal absorption lines of QSO HS1603+38201
We present a high resolution spectrum of the quasar, HS1603+3820 (zem=2.542), observed with the High Dispersion Spectrograph (HDS) on Subaru Telescope. This quasar, first discovered in the Hamburg/CfA Quasar Survey, has 11 C iv lines at 1.96 < zabs< 2.55. Our spectrum covers 8 of the 11 C iv lines at zabs > 2.29 and resolves some of them into multiple narrow components with b < 25 km s−1 because of the high spectral resolution R=45000, while other lines show broad profiles (b > 65 km s−1). We use three properties of C iv lines, specifically, time variability, covering factor, and absorption line profile, to classify them into quasar intrinsic absorption lines (QIALs) and spatially intervening absorption lines (SIALs). The C iv lines at 2.42 < zabs< 2.45 are classified as QIALs in spite of their large velocity shifts from the quasar. Perhaps they are produced by gas clouds ejected from the quasar with the velocity of vej = 8000 km s−1− 10000 km s−1. On the other hand, three C iv lines at 2.48 < zabs< 2.55 are classified as SIALs, which suggests there exist intervening absorbers near the quasar. We, however, cannot rule out QIALs for the two lines at zabs ∼ 2.54 and 2.55, because their velocity shifts, 430 km s−1 blueward and 950 km s−1 redward of the quasar, are very small. The C iv line at zabs ∼ 2.48 consists of many narrow components, and has also corresponding low-ionization metal lines (Al ii, Si ii, and Fe ii). The velocity distribution of these low-ionization ions is concentrated at the center of the system compared to that of high-ionization C iv ion. Therefore we ascribe this system of absorption lines to an intervening galaxy. Subject headings: quasars: absorption lines — quasars: individual (HS1603+3820)
16675675
Effects of galaxy mergers on the faint IRAS source counts and the background
Binary merging constitutes a complementary mode of galaxy evolution to the canonical hierarchical clustering theory. This merger-driven evolution not only influences the galaxy mass distribution function, but may drive the main galactic activity cycles, such as starbursts and the activity in the nuclei (AGNs). In this paper, we use galaxy aggregation dynamics together with a possible merger-driven starburst and AGN phenomena, to study the effects of evolution of these consequential activities for the faint IRAS source counts and the infra-red background. We find that the strong evolution of IRAS 60 mu m source count at flux range of 10 mJy similar to 1 Jy is difficult to be explained only by the merger rate decrease with cosmic time. We need to assume a redshift dependent infrared burst phase of ultraluminous infrared galaxies (ULIGs) from the gas rich mergers at high redshift and the gas poor mergers at low redshift. The background intensity at 60 mu m which we get from this aggregation evolution is a lower Limit of only 1.9 nW m(-2) sr(-1), about half of those estimated by some previous models, but close to the lower end of the range derived by Malkan & Stecker (1998).
123544625
A new design of large area MCP-PMT for the next generation neutrino experiment
This manuscript discusses a new design of large area MCP-PMT for the next generation neutrino experiments. The main motivation of the design is to improve the quantum efficiency (photo detection efficiency) of the PMT. Two sets of small MCP units, the transmission photocathode coated on the front hemisphere and the reflection photocathode coated on the rear hemisphere are assembled in the same glass envelope to form nearly 4 pi viewing angle to enhance the efficiency of the photoelectron detection. The photoelectrons from the 4 pi photocathode are collected and amplified by two sets of MCP units. Our goal is eventually to produce 20 in. diameter PMT following such an approach. We will report preliminary results of our ptoelectronic simulation and the results of a 5 in. diameter prototype PMT. Future plans and prospects are discussed at the end. (C) 2011 Elsevier B.V. All rights reserved.
36793805
False vacuum decay in Jordan-Brans-Dicke cosmologies
Abstract We examine the bubble nucleation rate in a first-order phase transition taking place in a background Jordan-Brans-Dicke cosmology. We compute the leading order terms in the nucleation rate when the Jordan-Brans-Dicke field is large (i.e., late times) by means of a Weyl rescaling of the fields in the theory. We find that despite the fact that the Jordan-Brans-Dicke field (hence the effective gravitational constant) has a time dependence in the false vacuum, at late times the nucleation rate is time independent.
119207378
Effects of temperature on thick branes and the fermion (quasi-)localization
Following Campos’s work [Phys. Rev. Lett. 88 (2002) 141602], we investigate the effects of temperature on flat, de Sitter (dS), and anti-de Sitter (AdS) thick branes in five-dimensional (5D) warped spacetime, and on the fermion (quasi-)localization. First, in the case of flat brane, when the critical temperature reaches, the solution of the background scalar field and the warp factor is not unique. So the thickness of the flat thick brane is uncertain at the critical value of the temperature parameter, which is found to be lower than the one in flat 5D spacetime. The mass spectra of the fermion Kaluza-Klein (KK) modes are continuous, and there is a series of fermion resonances. The number and lifetime of the resonances are finite and increase with the temperature parameter, but the mass of the resonances decreases with the temperature parameter. Second, in the case of dS brane, we do not find such a critical value of the temperature parameter. The mass spectra of the fermion KK modes are also continuous, and there is a series of fermion resonances. The effects of temperature on resonance number, lifetime, and mass are the same with the case of flat brane. Last, in the case of AdS brane, the critical value of the temperature parameter can less or greater than the one in the flat 5D spacetime. The spectra of fermion KK modes are discrete, and the mass of fermion KK modes does not decrease monotonically with increasing temperature parameter.
17712450
Cosmic star formation history associated with quasar activity: An approach using the black hole-to-bulge mass correlation
The tight correlation between the masses of central black holes and their host spheroids in nearby galaxies and active galactic nuclei (AGNs) suggests that black hole growth is closely related to their spheroid formation. Based on our previous work regarding such a joint evolutionary scheme and the consequential black hole-to-bulge mass correlation, we use the X-ray luminosity function of AGN and the cosmological evolution rate, which are from ROSAT X-ray surveys, to estimate the cosmic star formation history associated with the black hole growth. By the basic assumption that the major black hole growth occurs during the luminous AGN phase, the luminosity function of AGNs as a function of redshift traces not only the accretion history of the black holes but also the cosmic star formation history of the spheroids. Although the space density of the especially luminous quasars is very low, we show that the total amount of star formation associated with the massive black hole growth is almost the same as that of Lyman break galaxies detected by the current optical deep surveys. We thus argue that the optical deep surveys may miss about half of the net star formation in our universe. This is probably due in part to significant dust extinction, as well as the small field of view of previous optical surveys, which cannot sample such rare events with relatively short timescale. However, the far-infrared emission from the dust heated by ongoing star formation during the black hole growth could sufficiently account for the observed SCUBA number counts and would be the probable dominating energy source of the SCUBA population.
17261464
Black hole to bulge mass correlation in Active Galactic Nuclei: a test for the simple unified formation scheme
A mass correlation of central black holes and their spheroids similar to 0.002 (within a factor of three) is suggested by Hubble Space Telescope (HST) and various ground-based CCD photometries of early type galaxies. The near-IR images of quasar hosts and the emission line measurements of Broad Line Region for bright QSOs present a similar correlation, which supports the speculation of an evolutionary linkage between the early active QSO phase and the central black holes in normal galaxies. On the other hand, recent reverberation mapping of a sample of Seyferts shows a broad distribution of black hole to bulge mass ratio with a mean of similar to 10(-3.5), about one magnitude lower than the value in early type galaxies and bright QSOs. Adopting a simple unified formation scheme for QSOs and Seyferts, we will discuss in this letter the dependence of the black hole to bulge mass ratio in Active Galactic Nuclei (AGNs) on the environmental parameters of the host galaxies. We show a broad distribution of the mass correlation could be due to different velocity dispersion of the accreting gas from different Formation mechanism, and the mass ratio in normal galaxies and bright QSOs is probably a limit case of black hole evolution by merger enhanced accretion close to Eddington limit.