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.
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).
119215482
LOCAL LUMINOUS INFRARED GALAXIES. III. CO-EVOLUTION OF BLACK HOLE GROWTH AND STAR FORMATION ACTIVITY?*
Local luminous infrared (IR) galaxies (LIRGs) have both high star formation rates (SFR) and a high AGN (Seyfert and AGN/starburst composite) incidence. Therefore, they are ideal candidates to explore the co-evolution of black hole (BH) growth and star formation (SF) activity, not necessarily associated with major mergers. Here, we use Spitzer/IRS spectroscopy of a complete volume-limited sample of local LIRGs (distances of <78 Mpc). We estimate typical BH masses of 3 × 10 7 Musing (Neiii) 15.56 μm and optical (Oiii) λ5007 gas velocity dispersions and literature stellar velocity dispersions. We find that in a large fraction of local LIRGs, the current SFR is taking place not only in the inner nuclear ∼1.5 kpc region, as estimated from the nuclear 11.3 μm PAH luminosities, but also in the host galaxy. We next use the ratios between the SFRs and BH accretion rates (BHAR) to study whether the SF activity and BH growth are contemporaneous in local LIRGs. On average, local LIRGs have SFR to BHAR ratios higher than those of optically selected Seyferts of similar active galactic nucleus (AGN) luminosities. However, the majority of the IR-bright galaxies in the revised-Shapley-Ames Seyfert sample behave like local LIRGs. Moreover, the AGN incidence tends to be higher in local LIRGs with the lowest SFRs. All of this suggests that in local LIRGs there is a distinct IR-bright star-forming phase taking place prior to the bulk of the current BH growth (i.e., AGN phase). The latter is reflected first as a composite and then as a Seyfert, and later as a non-LIRG optically identified Seyfert nucleus with moderate SF in its host galaxy.
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.
135660011
Hybrid photodiode tube
We report the first test results on a new breed of light detector based on a photocathode followed by a silicon diode working in the bombarding mode.
121882392
First results on the Spaghetti Calorimeter projective prototype
Abstract The performances of a projective lead/scintillating fibres (“spaghetti”) calorimeter made out of rectangular cross-section (32 × 32 mm 2 ) straight modules alternated with tapering modules at 2.5° are described. Beam test results on energy resolution, constant term suppression, lineshape, uniformity of response, shower position resolution, and electron-pion discrimination are presented. The readout of the fibres in the straight modules, which are sensitive to most of the electromagnetic showers and to part of the hadronic showers, is kept separate from the readout of the fibres of the wedged sections, which are sensitive only to hadronic showers. The lead-to-fibre volume ratio is kept at about 4 to 1 in order to obtain an equal-amplitude response from electrons and hadrons (usually called “compensation”). The origin of the energy resolution constant term has been better understood. This allowed the reduction of the constant term to 0.5%, down from 1.2% measured in older prototypes. The probability of faking abnormally large signals because of channelling effects is also discussed. The position resolution has been measured to range from 0.5 to 1 mm depending on the hit position of the particle. A comparison with the larger hexagonal module design is also made. The efficiency of a hardware thresholding of the wedges' signal as a level one trigger pion veto is discussed along with off-line electron/pion discrimination performances. Since the wedges start at 26 X 0 from the calorimeter front face they should show no signal for electromagnetic showers. It was found that electromagnetic showers of 50 GeV generate wedge signals of a maximum of a few tens of MeV. It was also found that the discriminating power is angle dependent, mainly because at small particle-to-fibre angles (≤ 1°) some electrons can penetrate the calorimeter through channeling, thus exciting a signal in the wedges. At slightly higher tilt angle it is possible to use a lower wedge threshold without loss in electron efficiency. With a beam-to-fibre angle of 3°, 99.6% of pions are rejected with a 98.5% electron efficiency. More recent and preliminary results on energy resolution at energies up to 100 GeV, and on radiation damage of scintillating fibres are also presented.
121916723
OPERATOR FORMS OF THE CLASSICAL YANG–BAXTER EQUATION IN LIE SUPERALGEBRAS
In this paper, we study the operator forms of the classical Yang–Baxter equation (CYBE) in Lie superalgebras. We introduce the notion of super -operators and give their relationship with the (standard) tensor form. There are close relationships between the CYBE in Lie superalgebras and left-symmetric superalgebras which can be interpreted through the super -operators. In particular, there are natural and explicit solutions of the CYBE in Lie superalgebras constructed from left-symmetric superalgebras.
128673519
Tibet air shower array: results and future plan
The Tibet air shower array, which has an effective area of 36,900 m2, has been in operation at Yangbajing in Tibet, China at an altitude of 4,300 m above sea level. In this paper, we will briefly introduce the recent gamma-ray observation with the present Tibet air shower array and our future plan which is called the Tibet muon detector (MD) project.
124567745
Observation of the 2005 January 20 GLE event using Yangbajing. solar neutron telescope & neutron monitor
A solar cosmic rays Ground Level Enhancement (GLE) event associated with a X7.1/2b solar flare in 2005 January 20 was observed by the Yangbajing solar neutron telescope(SNT) and neutron monitor(NM), located at Yangbajing Tibet(90.53 degrees E, 30.11 degrees N, 4310m a.s.l) with the highest vertical geomagnetic cut-off rigidity of 14.1GV in NM network. The statistical significance of the counting rate enhancement recorded by solar neutron telescope in > 40MeV channel was 3.7 sigma in the time window of 07:00-07:05UT and 6.0 sigma in the time window of 07:00-07:20UT, respectively. The onset time of 06:51-06:52UT for this GLE event was clearly observed by the Yangbajing NM. Our observation indicates that solar protons have been accelerated up to energies of > 10GeV during this solar event.