Laser-Doppler gas-velocity instrument

Three-D instrument using a laser light source measures both turbulence and mean velocity of subsonic and supersonic gas flows. This instrument is based on the measurement of the Doppler frequency shift of light waves scattered by moving particles in the gas stream

Towards a Comprehensive Fueling-Controlled Theory on the Growth of Massive Black Holes and Host Spheroids

We study the relation between nuclear massive black holes and their host spheroid gravitational potential. Using AMR numerical simulations, we analyze how gas is transported in the nuclear (central kpc) regions of galaxies. We study the gas fueling onto the inner accretion disk (sub-pc scale) and the star formation in a massive nuclear disk like those generally found in proto-spheroids (ULIRGs, SCUBA Galaxies). These sub-pc resolution simulation of gas fueling that is mainly depleted by star formation naturally satisfy the `M_BH - $M_virial' relation, with a scatter considerably less than the observed one. We found a generalized version of Kennicutt-Schmidt Law for starbursts is satisfied, in which the total gas depletion rate (dot{M}_gas = dot{M}_BH + dot{M}_SF) is the one that scales as M_gas/t_orbital. We also found that the `M_BH - sigma' relation is a byproduct of the `M_BH - M_virial' relation in the fueling controlled scenario.Comment: 12 pages, figures, submited to ApJ, email: [email protected]

Improvement of Pheromone Trapping in Low Density Populations of \u3ci\u3eChoristoneura Pinus Pinus\u3c/i\u3e (Lepidoptera: Tortricidae)

Pheromone baited bucket traps (e.g., Multipher) are popular as a monitoring tool for the jack pine budworm, Choristoneura pinus pinus Freeman (Lepidoptera: Tortricidae), in Canada. However, there is no evidence to support their use when budworm populations are low. We therefore evaluated the capture rate of bucket traps at two placement heights (2 vs 6 m) in two jack pine forests in 2011, having low (≤5 fifth instars per mfoliated branch length) budworm populations. Compared to wing traps (e.g., Pherocon 1C), the trap design used initially to evaluate efficacy of the C. pinus pheromone, bucket traps caught fewer C. pinus and capture rates of both trap designs did not differ significantly between the two heights tested. Loss of bucket traps at 2 m, due to black bears, suggested that higher placement of traps was warranted to maintain the integrity of the array. However, wing traps are recommended due to their ability to consistently catch more moths when C. pinus populations are low

Laser Doppler velocity instrument

Laser Doppler velocity instrument for measuring turbulence and mean velocity in subsonic and supersonic gas flow

Reionization Constraints on the Contribution of Primordial Compact Objects to Dark Matter

Many lines of evidence suggest that nonbaryonic dark matter constitutes roughly 30% of the critical closure density, but the composition of this dark matter is unknown. One class of candidates for the dark matter is compact objects formed in the early universe, with typical masses M between 0.1 and 1 solar masses to correspond to the mass scale of objects found with microlensing observing projects. Specific candidates of this type include black holes formed at the epoch of the QCD phase transition, quark stars, and boson stars. Here we show that accretion onto these objects produces substantial ionization in the early universe, with an optical depth to Thomson scattering out to z=1100 of approximately tau=2-4 [f_CO\epsilon_{-1}(M/Msun)]^{1/2} (H_0/65)^{-1}, where \epsilon_{-1} is the accretion efficiency \epsilon\equiv L/{\dot M}c^2 divided by 0.1 and f_CO is the fraction of matter in the compact objects. The current upper limit to the scattering optical depth, based on the anisotropy of the microwave background, is approximately 0.4. Therefore, if accretion onto these objects is relatively efficient, they cannot be the main component of nonbaryonic dark matter.Comment: 12 pages including one figure, uses aaspp4, submitted to Ap

Recent star formation in high-redshift early-type galaxies: insights from the rest-frame UV

We combine deep UBVRIzJK photometry from the MUSYC survey with redshifts from the COMBO-17 survey to study the rest-frame ultraviolet (UV) properties of 674 high-redshift (0.5<z<1) early-type galaxies, drawn from the Extended Chandra Deep Field South (E-CDFS). Galaxy morphologies are determined through visual inspection of Hubble Space Telescope (HST) images taken from the GEMS survey. We harness the sensitivity of the UV to young (<1 Gyrs old) stars to quantify the recent star formation history of the early-type population. We find compelling evidence that early-types of all luminosities form stars over the lifetime of the Universe, although the bulk of their star formation is already complete at high redshift. Luminous (-23<M(V)<-20.5) early-types form 10-15 percent of their mass after z=1, while their less luminous (M(V)>-20.5) counterparts form 30-60 percent of their mass in the same redshift range.Comment: To appear in the proceedings of the IAU 245, eds. M. Bureau, E. Athanassoula, and B. Barbu

Angular Sizes of Faint Field Disk Galaxies: Intrinsic Luminosity Evolution

In order to explain the small scale-lengths detected in the recent deep field observations performed from large ground-based telescopes and from the Hubble Space Telescope, we investigate the predictions at high redshifts for disk galaxies that formed by infall. Changes with redshift in the observed properties of field galaxies are directly related to the evolution of the disks and of the stellar populations. We see that changes in the rest frame luminosity of a galaxy induce smaller values of half-light radii than are predicted assuming no evolution. Comparisons are presented with two observed samples from Mutz et al. (1994) and Smail et al. (1995).Comment: plain tex file + 3 postscript figures. To be published in ApJ