Physics Commons^™

Dynamical Pattern Formation During Growth Of A Dual-Species Bose-Einstein Condensate, Shai Ronen, John L. Bohn, Laura Elisa Halmo, Mark Edwards

Department of Physics and Astronomy Faculty Publications

We simulate the growth of a dual species Bose-Einstein condensate using a Gross-Pitaevskii equation with an additional gain term giving rise to the growth. Such growth occurs during simultaneous evaporative cooling of a mixture of two gases. The ground state of a dual condensate is normally either a miscible mixture, or an immiscible phase with two spatially separated components. In a cigar trap the ground state typically consists of one component in the center, and the other component flanking it. Our simulations show that when the condensates are formed in a cigar trap and the mixture is phase separated, then …

Erasing Dark Matter Cusps In Cosmological Galactic Halos With Baryons, Emilio Romano-Diaz, Isaac Shlosman, Yehuda Hoffman, Clayton Heller

Department of Physics and Astronomy Faculty Publications

We study the central dark matter (DM) cusp evolution in cosmologically grown galactic halos. Numerical models with and without baryons (baryons+DM, hereafter BDM model, and pure DM, PDM model, respectively) are advanced from identical initial conditions, obtained using the Constrained Realization method. The DM cusp properties are contrasted by a direct comparison of pure DM and baryonic models. We find a divergent evolution between the PDM and BDM models within the inner few × 10 kpc region. The PDM model forms an R−1 cusp as expected, while the DM in the BDM model forms a larger isothermal cusp R …

A 500 Kpc Hi Extension Of The Virgo Pair Ngc4532/Ddo137 Detected By The Arecibo Legacy Fast Alfa (Alfalfa) Survey, Rebecca A. Koopmann, Riccardo Giovanelli, Martha P. Haynes, Brian R. Kent, Thomas J. Balonek, Noah Brosch, James L. Higdon, John J. Salzer, Oded Spector

Department of Physics and Astronomy Faculty Publications

We report the discovery of a ~500 kpc H I extension southwest of the Virgo Cluster H I-rich pair NGC 4532/DDO 137, detected as part of the Arecibo Legacy Fast ALFA (ALFALFA) Survey. The feature is the longest and most massive H I tail structure so far found in the Virgo Cluster and, at 1.8 Mpc from M87, the most distant from the main concentration of the intracluster medium. The structure is spatially and spectrally separated into two ridges and is defined by diffuse emission and discrete clumps of mass (2.5–6.8) × 107 M☉. All emission is blueshifted with …

Radio And Infrared Selected Optically Invisible Sources In The Boötes Ndwfs, James L. Higdon, Sarah J.U. Higdon, Steven P. Willner, Michael J. I. Brown, D. Stern, Emeric Le Floc'h, Peter Eisenhardt

Department of Physics and Astronomy Faculty Publications

We have combined data from the NOAO Deep Wide-Field Survey in Bo¨otes and the Spitzer Space Telescope to determine basic properties for sixteen optically “invisible” MIPS 24 µm (OIMS) and thirty-five optically “invisible” radio (OIRS) sources, including their spectral energy distributions (SED) and luminosities. Most OIMSs possess steep power-law SEDs over λrest = 1 − 10 µm, indicating the presence of obscured AGN in agreement with Spitzer spectroscopy. These objects are extremely luminous at rest-frame near and mid-IR (νLν(5 µm) ≈ 1038 − 1039 W), consistent with accretion near the Eddington limit and further implying that they host buried QSOs. …

Radio Continuum Imaging Of The R Cra Star-Forming Region With The Atca, Olli Miettinen, S. Kontinen, J. Harju, James L. Higdon

Department of Physics and Astronomy Faculty Publications

Aims. The aim of this study is to investigate the nature of radio sources associated with young stellar objects (YSOs) belonging to the R CrA cluster. By combining the centimetre radio data with the wealth of shorter wavelength data accumulated recently we wish to refine estimates of the evolutionary stages of the YSOs.

Methods. The region was imaged at 3, 6, and 20 cm using the Australia Telescope Compact Array. Fluxes and spectral indices for the brightest radio sources were derived from these observations. Some of the 3 and 6 cm data were obtained simultaneously, which is useful for reliable …

Spitzer Observations Of Tidal Dwarf Galaxies, Sarah J.U. Higdon, James L. Higdon

Department of Physics and Astronomy Faculty Publications

We present Spitzer observations of Tidal Dwarf Galaxies (TDGs) in three interacting systems: NGC 5291, Arp 105 & Stephan’s Quintet. The spectra show bright emission from polyaromatic hydrocarbons (PAHs), nebular lines and warm molecular hydrogen, characteristic of recent episodes of star formation. The PAH emission that falls in the IRAC 8.0 µm band leads to the TDGs having an extremely red IRAC color, with [4.5] − [8.0] > 3. The emission from PAHs is characterized by a model with mainly neutral 100-C PAH atoms.

A Significant Population Of Very Luminous Dust-Obscured Galaxies At Redshift Z ~ 2, Arjun Dey, B.T. Soifer, Vandana Desai, Kate Brand, Emeric Le Floc'h, Michael J. I. Brown, Buell T. Jannuzi, Lee Armus, R. Shane Bussmann, Mark Brodwin, Chao Bian, Peter Eisenhardt, Sarah J.U. Higdon, Daniel Weedman, S. P. Willner

Department of Physics and Astronomy Faculty Publications

Observations with the Spitzer Space Telescope have recently revealed a significant population of high-redshift (z ∼ 2) dust-obscured galaxies (DOGs) with large (rest-frame) mid-infrared to ultraviolet luminosity ratios. Due to their optical faintness, these galaxies have been previously missed in traditional optical studies of the distant universe. We present a simple method for selecting this high-redshift population based solely on the ratio of the observed mid-infrared 24µm to optical R-band flux density. We apply this method to observations of the ≈ 8.6 deg2 Bo¨otes Field of the NOAO Deep Wide-Field Survey, and uncover ≈2,600 DOG candidates (i.e., a surface density …

Tunneling Phase Gate For Neutral Atoms In A Double-Well Lattice, Frederick W. Strauch, Mark Edwards, Eite Tiesinga, Carl Williams, Charles W. Clark

Department of Physics and Astronomy Faculty Publications

We propose a two-qubit phase gate for ultracold atoms in a tilted double-well optical lattice. Such a lattice is capable of confining pairs of atoms in a two-dimensional array of double-well potentials where both the barrier height and the energy difference of the minima of the two wells (known as the “tilt”) can be controlled. The four lowest single-particle motional states can be used to form spatially separated qubits. We present a time-dependent scheme to manipulate the tilt to induce tunneling oscillations which produce a collisional phase gate. Numerical simulations demonstrate that this gate can be performed with high fidelity.