119271798
An Investigation of the Dust Content in the Galaxy pair NGC 1512/1510 from Near-Infrared to Millimeter Wavelengths
We combine new ASTE/AzTEC 1.1 mm maps of the galaxy pair NGC 1512/1510 with archival Spitzer IRAC and MIPS images covering the wavelength range 3.6-160 ?m from the SINGS project. The availability of the 1.1?mm map enables us to measure the long-wavelength tail of the dust emission in each galaxy, and in sub-galactic regions in NGC 1512, and to derive accurate dust masses. The two galaxies form a pair consisting of a large, high-metallicity spiral (NGC 1512) and a low-metallicity, blue compact dwarf (NGC 1510), which we use to compare similarities and contrast differences. Using the models of Draine and Li, the derived total dust masses are (2.4 ? 0.6) ? 107 M ? and (1.7 ? 3.6) ? 105 M ? for NGC 1512 and NGC 1510, respectively. The derived ratio of dust mass to H I gas mass for the galaxy pair, 0.0034, is much lower (by at least a factor of 3) than expected, as previously found by Draine et?al. In contrast, regions within NGC 1512, specifically the central region and the arms, do not show such unusually low ratios; furthermore, the dust-to-gas ratio is within expectations for NGC 1510. These results suggest that a fraction of the H I included in the determination of the ratio of the NGC?1512/NGC 1510 pair is not associated with the star-forming disks/regions of either galaxy. Using the dust masses derived from the models of Draine & Li as references, we perform simple two-temperature modified blackbody fits to the far-infrared/millimeter data of the two galaxies and the sub-regions of NGC 1512, in order to derive and compare the dust masses associated with warm and cool dust temperature components. As generally expected, the warm dust temperature of the low-metallicity, low-mass NGC 1510 (Tw ~ 36 K) is substantially higher than the corresponding warm temperature of the high-metallicity spiral NGC 1512 (Tw ~ 24 K). In both galaxies (albeit with a large uncertainty for NGC 1510), our fits indicate that a substantial fraction (>93%) of the total dust mass is in a cool dust component, with temperatures ~14-16 K for NGC 1512 and ~15-24 K for NGC 1510. This result is similar to what is determined for a few other nearby galaxies. In contrast, the warm dust component in the sub-galactic regions of NGC 1512 represents a much larger fraction of the total dust content, in agreement with the fact that all three regions have higher specific star formation rates than the average in the galaxy; in the center, the warm dust represents about 40% of the total, while in the arms the fractions are close to ~20%.
16415445
Spitzer Observations of z ~ 3 Lyman Break Galaxies: Stellar Masses and Mid-Infrared Properties
We describe the spectral energy distributions (SEDs) of Lyman break galaxies (LBGs) at z ~ 3, using deep mid-infrared and optical observations of the extended Groth strip, obtained with IRAC and MIPS on board Spitzer and from the ground, respectively. We focus on LBGs with detections at all four IRAC bands, in particular the 26 galaxies with IRAC 8 μm band (rest-frame K-band) detections. We use stellar population-synthesis models and probe the stellar content of these galaxies. Based on best-fit continuous star formation models, we derive estimates of the stellar mass for these LBGs. As in previous studies, we find that a fraction of LBGs have very red colors and large estimated stellar masses (M_* > 5 × 10^(10) M_⊙); the current Spitzer data allow us, for the first time, to study these massive LBGs in detail. We discuss the link between these LBGs and submillimeter-luminous galaxies, and we find that the number density of these massive LBGs at high redshift is higher than predicted by current semianalytic models of galaxy evolution.
16530248
Direct Evidence from Spitzer for a Low-Luminosity AGN at the Center of the Elliptical Galaxy NGC 315
We present Spitzer Space Telescope InfraRed Array Camera (IRAC) and Multiband Imaging Photometer (MIPS) 
observations of the elliptical galaxy NGC 315. After removal of the host galaxy’s stellar emission, we detected 
for the first time an infrared-red nucleus in NGC 315. We measured the spectral energy distribution (SED) for 
this active nucleus with a wavelength range from radio to X-ray, and obtained a bolometric luminosity of 
Lbol ≈ 1.9 x 10^43 ergs s^(-1), corresponding to an extremely low Eddington ratio L/L_(Edd) of 4.97 x 10^(-4). Our results 
confirm that the physical nature of the nucleus of NGC 315 is a low-luminosity AGN, consistent with recent 
optical and Chandra X-ray observations.
119195551
Molecular Outflows from the Protocluster Serpens South
We present the results of CO (J = 3-2) and HCO+ (J = 4-3) mapping observations toward a nearby embedded cluster, Serpens South, using the ASTE 10 m telescope. Our CO (J = 3-2) map reveals that many outflows are crowded in the dense cluster-forming clump that can be recognized as an HCO+ clump with a size of ~0.2 pc and mass of ~80 M ☉. The clump contains several subfragments with sizes of ~0.05 pc. By comparing the CO (J = 3-2) map with the 1.1 mm dust continuum image taken by AzTEC on ASTE, we find that the spatial extents of the outflow lobes are sometimes anti-correlated with the distribution of the dense gas, and some of the outflow lobes apparently collide with the dense gas. The total outflow mass, momentum, and energy are estimated to be 0.6 M ☉, 8 M ☉ km s–1, and 64 M ☉ km2 s–2, respectively. The energy injection rate due to the outflows is comparable to the turbulence dissipation rate in the clump, implying that the protostellar outflows can maintain the supersonic turbulence in this region. The total outflow energy seems only about 10% of the clump gravitational energy. We conclude that the current outflow activity is not enough to destroy the whole cluster-forming clump, and therefore star formation is likely to continue for several or many local dynamical times.
119203971
X-ray detections of submillimetre galaxies: active galactic nuclei versus starburst contribution
We present a large-scale study of the X-ray properties and near-IR-to-radio SEDs of submillimetre galaxies (SMGs) detected at 1.1mm with the AzTEC instrument across a ~1.2 square degree area of the sky. Combining deep 2-4 Ms Chandra data with Spitzer IRAC/MIPS and VLA data within the GOODS-N/S and COSMOS fields, we find evidence for AGN activity in ~14 percent of 271 AzTEC SMGs, ~28 percent considering only the two GOODS fields. Through X-ray spectral modeling and SED fitting using Monte Carlo Markov Chain techniques to Siebenmorgen et al. (2004) (AGN) and Efstathiou et al. (2000) (starburst) templates, we find that while star formation dominates the IR emission, with SFRs ~100-1000 M_sun/yr, the X-ray emission for most sources is almost exclusively from obscured AGNs, with column densities in excess of 10^23 cm^-2. Only for ~6 percent of our sources do we find an X-ray-derived SFR consistent with NIR-to-radio SED derived SFRs. Inclusion of the X-ray luminosities as a prior to the NIR-to-radio SED effectively sets the AGN luminosity and SFR, preventing significant contribution from the AGN template. Our SED modeling further shows that the AGN and starburst templates typically lack the required 1.1 mm emission necessary to match observations, arguing for an extended, cool dust component. The cross correlation function between the full samples of X-ray sources and SMGs in these fields does not indicate a strong correlation between the two populations at large scales, suggesting that SMGs and AGNs do not necessarily trace the same underlying large scale structure. Combined with the remaining X-ray-dim SMGs, this suggests that sub-mm bright sources may evolve along multiple tracks, with X-ray-detected SMGs representing transitionary objects between periods of high star formation and AGN activity while X-ray-faint SMGs represent a brief starburst phase of more normal galaxies.
19025519
Extragalactic Source Counts at 24 Microns in the Spitzer First Look Survey
We present the Spitzer Multiband Imaging Photometer 24 μm source counts in the Extragalactic First Look Survey (FLS) main, verification, and European Large Area ISO Survey N1 fields. Spitzer's increased sensitivity and efficiency in large areal coverage over previous infrared telescopes, coupled with the enhanced sensitivity of the 24 μm band to sources at intermediate redshift, dramatically improve the quality and statistics of number counts in the mid-infrared. The FLS observations cover areas of 4.4, 0.26, and 0.015 deg^2, respectively, and reach 3 σ depths of 0.11, 0.08, and 0.03 mJy. The extragalactic counts derived for each survey agree remarkably well. The counts can be fitted by a super-Euclidean power law of index α = -2.9 from 0.2 to 0.9 mJy, with a flattening of the counts at fluxes fainter than 0.2 mJy. Comparison with infrared galaxy evolution models reveals a peak's displacement in the 24 μm counts. This is probably due to the detection of a new population of galaxies with redshift between 1 and 2, previously unseen in the 15 μm deep counts.
121469905
D0 Results and Combined Tevatron Results on Standard Model Higgs
Abstract Results from the D0 experiment on the search for the Higgs boson of the Standard Model (SM) are presented with particular emphasis on testing the compatibility with recent LHC results on the observation of a Higgs-like particle. The D0 SM Higgs results, their combination and the Tevatron combination of CDF and D0 SM Higgs results are summarized. The article also puts recent developments in a historical context. The combined results from the Tevatron experiments give a local p-value of 0.4% for the background-only hypothesis at a mass of 125 GeV indicating that the combined Tevatron data strongly prefer the presence of a new particle with Standard Model Higgs-like properties in this mass region.
117846935
Completing the sparticle spectrum at a multi-TeV linear collider?
If supersymmetry is realised in nature, the approved LHC and the planned sub-TeV linear collider should unravel some, maybe many, of the features of the sparticle world. We survey in this paper the task of comprehensively identifying, understanding and measuring all the particles predicted by the model. We start to address whether a multi-TeV linear collider such as CLIC whose energy may well exceed all the new particle production thresholds is suited to completing this challenging task.
184776927
Searches for new particles at LEP2 and 4-jet status
119005178
Standard model processes
118510993
Multi-lepton signals from the top-prime quark at the LHC
A bstractWe analyze the collider signatures of models with a vector-like top-prime quark and a massive color-octet boson. The top-prime quark mixes with the top quark in the Standard Model, leading to richer final states than ones that are investigated by experimental collaborations. We discuss the multi-lepton final states, and show that they can provide increased sensitivity to models with a top-prime quark and gluon-prime. Searches for new physics in high multiplicity events are an important component of the LHC program and complementary to analyses that have been performed.