1384985
HerMES: SPECTRAL ENERGY DISTRIBUTIONS OF SUBMILLIMETER GALAXIES AT z > 4*
We present a study of the infrared properties for a sample of seven spectroscopically confirmed submillimeter galaxies (SMGs) at z > 4.0. By combining ground-based near-infrared, Spitzer IRAC and MIPS, Herschel SPIRE, and ground-based submillimeter/millimeter photometry, we construct their spectral energy distributions (SEDs) and a composite model to fit the SEDs. The model includes a stellar emission component at λ_(rest) 50 μm. Six objects in the sample are detected at 250 and 350 μm. The dust temperatures for the sources in this sample are in the range of 40-80 K, and their L_(FIR) ~ 10^(13) L_☉ qualifies them as hyper-luminous infrared galaxies. The mean FIR-radio index for this sample is around 〈q〉 = 2.2 indicating no radio excess in their radio emission. Most sources in the sample have 24 μm detections corresponding to a rest-frame 4.5 μm luminosity of Log_(10)(L_(4.5)/L_☉) = 11 ~ 11.5. Their L_(4.5)/L_(FIR) ratios are very similar to those of starburst-dominated SMGs at z ~ 2. The L_(CO) – L_(FIR) relation for this sample is consistent with that determined for local ULIRGs and SMGs at z ~ 2. We conclude that SMGs at z > 4 are hotter and more luminous in the FIR but otherwise very similar to those at z ~ 2. None of these sources show any sign of the strong QSO phase being triggered.
119086309
Global extinction in spiral galaxies
Magnitude-limited samples of spiral galaxies drawn from the Ursa Major and Pisces Clusters are used to determine their extinction properties as a function of inclination. Imaging photometry is available for 87 spirals in the B, R, I, and K' bands. Extinction causes systematic scatter in color-magnitude plots. A strong luminosity dependence is found. Relative edge-on to face-on extinction of up to 1.7 mag is found at B for the most luminous galaxies but is unmeasurably small for faint galaxies. At R the differential absorption with inclination reaches 1.3 mag, at I it reaches 1.0 mag, and at K' the differential absorption can in the extreme be as great as 0.3 mag. The luminosity dependence of reddening can be translated into a dependence on rotation rate, which is a distance-independent observable. Hence, corrections can be made that are useful for distance measurements. The strong dependence of the corrections on luminosity act to steepen luminosity-line width correlations. The effect is greatest toward the blue, with the consequence that luminosity-line width slope dependencies are now only weakly a function of color.
121252165
PROTON--PROTON ELASTIC SCATTERING AT HIGH ENERGIES AND LARGE ANGLES, AND THE INCOHERENT DROPLET MODEL.
A study has been made of the elastic proton-proton scattering at high energies and large angles, using a model first proposed by K. Huang. This model decomposes a proton during collision into $N$ subunits and recombines them after collision in an incoherent combinatorial manner. The technique used is more general than the asymptotic methods used by Huang in obtaining the probabilities for the final states. The new procedure allows us to extend the range of validity for the model, since asymptotic expansions are no longer used. The analysis is limited to spinless protons, and to regions of high energy where there exists no discontinuity in the shape of the angular distribution such as was found by Allaby et al. around ${P}_{L}=8 \mathrm{to} 11$ BeV/c. The theoretical curves are in good agreement with the experimental results from ${\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}=65\ifmmode^\circ\else\textdegree\fi{} \mathrm{to} 90\ifmmode^\circ\else\textdegree\fi{}$ and ${P}_{L}=14 \mathrm{to} 27$ BeV/c, while the asymptotic expressions are in good agreement only from around 76\ifmmode^\circ\else\textdegree\fi{} to 90\ifmmode^\circ\else\textdegree\fi{}. The experimentally observed quenching of large-momentum-transfer states as the energy increases is reproduced.
119212268
Broadband radio spectral observations of the solar eclipse on 2008-08-01 and its implications on the quiet Sun atmospheric model
Based on the joint-observations of the radio broadband spectral emissions of the solar eclipse on August 1, 2008 at Jiuquan (total eclipse) and Huairou (partial eclipse) at the frequencies of 2.00–5.60 GHz (Jiuquan), 2.60–3.80 GHZ (Chinese solar broadband radiospectrometer, SBRS/Huairou), and 5.20–7.60 GHz (SBRS/Huairou), the authors assemble a successive series of broadband spectra with a frequency of 2.60–7.60 GHz to observe the solar eclipse synchronously. This is the first attempt to analyze the solar eclipse radio emission under the two telescopes located at different places with broadband frequencies in the periods of total and partial eclipses. With these analyses, the authorsmade a semiempirical model of the coronal plasma density of the quiet Sun, which can be expressed as ne ≃ 1.42×109(r−2+1.93r−5) (cm−3), in the space range of r=1.039–1.212 R⊙, and made a comparison with the classic model.
118242012
Multi-TeV gamma-ray emission from the Crab Nebula observed with the new Tibet-III air-shower array
Using a high density air-shower array (Tibet-HD array), we succeeded in detecting multi-TeV -ray signals from the Crab Nebula in 1999. In the late fall of 1999, the HD array was enlarged from 5175 m up to 22000 m (TibetIII array). Using the 316 live-day data taken between 1999 November and 2001 May with this enlarged new array, we studied the emission of TeV -rays from the Crab Nebula. A preliminary analysis gives the excess -ray signal at the statistical significance of 4.8 . The energy spectrum of rays observed is consistent with the previous observation. We report the result on the study of the Crab flux.
122896246
Performance of the Tibet II/HD air shower array
Tibet II Air Shower Array consisting of scintillation counters with lattice of 15 m spacing has been operated with very high trigger rate of about 200 Hz. The threshold enegy of this array is estimated to be about 8 TeV for proton induced showers. Tibet High Density (HD) Array with 7.5 m spacing has been operated with the trigger rate of 115 Hz. The Mode energy of this array is estimated to be about 3 TeV for proton showers. Angular resolution of the arrays are estimated to be 0.9 degree above 10 TeV for Tibet II array, and 0.85 degree above TeV for HD array, resepectively. The angular resolution of these arrays and other array performances are examined by observing the Moon shadow resulting from the cosmic ray deficit in the direction of the Moon. Using the deflection of the Moon shadow to the east-west direction, the error of the array can be estimated by observing the displacement of the shadow in the north-south direction, because it is free from the effect of geomagnetic field, especially at Yangbaji...
122132298
On the Green's Functions for the Bethe‐Salpeter Equation
Considering the Bethe‐Salpeter equation as a relativistic equation, we have studied the free particle Green's functions for unequal mass scalar bosons, interacting via a translationally invariant potential. The scattering Green's function found by Huang and DeFacio (HD) is presented for all possible Ω‐plane contours for the unequal masses case. Only two k‐plane contours are found to be physically interesting. The causal, advanced, and retarded Green's functions are listed in an appendix for unequal masses for the physical contour. The timelike Green's functions again require severe restrictions on the interaction potential as found by HD, and possible Bethe‐Salpeter bound states are briefly discussed.