A Narrowband Imaging Survey for High Redshift Galaxies in the Near Infrared

A narrowband imaging survey of 276 square minutes of arc was carried out at near infrared wavelengths to search for emission line objects at high redshifts. Most of the fields contained a known quasar or radio galaxy at a redshift that placed one of the strong, restframe optical emission lines (H-alpha, [O III], H-beta, or [O II]) in the bandpass of the narrowband filter. The area weighted line flux limit over the entire survey was 3.4x10e-16 erg/cm2/s (3-sigma), while the most sensitive limits reached 1.4x10e-16 erg/cm2/s. Integrating the volume covered by all four optical emission lines in each image yields a total comoving volume surveyed of 1.4x10e5 cubic megaparsecs. Considering only H-alpha emission in the K band (2.05 < z < 2.65), where the survey is most sensitive, the survey covered a comoving volume of 3.0x10e4 cubic megaparsecs to a volume-weighted average star formation rate of 112 M-solar/yr (for Ho = 50 km/s/Mpc, Omega = 1). This is the most extensive near-infrared survey which is deep enough to have a reasonable chance at detecting strong line emission from an actively star-forming population of galaxies, when d against simple models of galaxy formation. One emission line candidate was identified in this survey, and subsequently confirmed spectroscopically.Comment: To appear in the Astronomical Journal, November 1996. 23 pages, including 2 tables and 7 figure

The Influence of Magnetic Field Geometry on the Evolution of Black Hole Accretion Flows: Similar Disks, Drastically Different Jets

Because the magneto-rotational instability is capable of exponentially amplifying weak preexisting magnetic fields, it might be hoped that the character of the magnetic field in accretion disks is independent of the nature of the seed field. However, the divergence-free nature of magnetic fields in highly conducting fluids ensures that their large-scale topology is preserved, no matter how greatly the field intensity is changed. By performing global two-dimensional and three-dimensional general relativistic magnetohydrodynamic disk simulations with several different topologies for the initial magnetic field, we explore the degree to which the character of the flows around black holes depends on the initial topology. We find that while the qualitative properties of the accretion flow are nearly independent of field topology, jet-launching is very sensitive to it: a sense of vertical field consistent for at least an inner disk inflow time is essential to the support of strong jets.Comment: 42 pages; 17 figures; Accepted for publication in ApJ (some new discussion and 2 new figures

Symptomatology under storm conditions in the north atlantic in control subjects and in persons with bilateral labyrinthine defects

Motion sickness under conditions of stress and anxiety - role of vestibular apparatu

Exploring the parameter space of MagLIF implosions using similarity scaling. I. Theoretical framework

Magneto-inertial fusion (MIF) concepts, such as the Magnetized Liner Inertial Fusion (MagLIF) platform [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)], constitute a promising path for achieving ignition and significant fusion yields in the laboratory. The space of experimental input parameters defining a MagLIF load is highly multi-dimensional, and the implosion itself is a complex event involving many physical processes. In the first paper of this series, we develop a simplified analytical model that identifies the main physical processes at play during a MagLIF implosion. Using non-dimensional analysis, we determine the most important dimensionless parameters characterizing MagLIF implosions and provide estimates of such parameters using typical fielded or experimentally observed quantities for MagLIF. We then show that MagLIF loads can be "incompletely" similarity scaled, meaning that the experimental input parameters of MagLIF can be varied such that many (but not all) of the dimensionless quantities are conserved. Based on similarity-scaling arguments, we can explore the parameter space of MagLIF loads and estimate the performance of the scaled loads. In the follow-up papers of this series, we test the similar scaling theory for MagLIF loads against simulations for two different scaling "vectors", which include current scaling and rise-time scaling.Comment: 24 pages, submitted to Physics of Plasma

Communication

Visualizing the functional interactions of biomolecules such as proteins and nucleic acids is key to understanding cellular life on the molecular scale. Spatial proximity is often used as a proxy for the direct interaction of biomolecules. However, current techniques to visualize spatial proximity are either limited by spatial resolution, dynamic range, or lack of single-molecule sensitivity. Here, we introduce Proximity-PAINT (pPAINT), a variation of the super-resolution microscopy technique DNA-PAINT. pPAINT uses a split-docking-site configuration to detect spatial proximity with high sensitivity, low false-positive rates, and tunable detection distances. We benchmark and optimize pPAINT using designer DNA nanostructures and demonstrate its cellular applicability by visualizing the spatial proximity of alpha- and beta-tubulin in microtubules using super-resolution detection. © 2020 Wiley-VCH GmbH

Critical Protoplanetary Core Masses in Protoplanetary Disks and the Formation of Short-Period Giant Planets

We study a solid protoplanetary core of 1-10 earth masses migrating through a disk. We suppose the core luminosity is generated as a result of planetesimal accretion and calculate the structure of the gaseous envelope assuming equilibrium. This is a good approximation when the core mass is less than the critical value, M_{crit}, above which rapid gas accretion begins. We model the structure of the protoplanetary nebula as an accretion disk with constant \alpha. We present analytic fits for the steady state relation between disk surface density and mass accretion rate as a function of radius r. We calculate M_{crit} as a function of r, gas accretion rate through the disk, and planetesimal accretion rate onto the core \dot{M}. For a fixed \dot{M}, M_{crit} increases inwards, and it decreases with \dot{M}. We find that \dot{M} onto cores migrating inwards in a time 10^3-10^5 yr at 1 AU is sufficient to prevent the attainment of M_{crit} during the migration process. Only at small radii where planetesimals no longer exist can M_{crit} be attained. At small radii, the runaway gas accretion phase may become longer than the disk lifetime if the core mass is too small. However, massive cores can be built-up through the merger of additional incoming cores on a timescale shorter than for in situ formation. Therefore, feeding zone depletion in the neighborhood of a fixed orbit may be avoided. Accordingly, we suggest that giant planets may begin to form early in the life of the protostellar disk at small radii, on a timescale that may be significantly shorter than for in situ formation. (abridged)Comment: 24 pages (including 9 figures), LaTeX, uses emulateapj.sty, to be published in ApJ, also available at http://www.ucolick.org/~ct/home.htm

An Infrared Emission Line Galaxy at z = 2.43

An object discovered during an infrared survey of the field near the quasar B2 0149+33 has an emission line at 2.25$\mu$m that we interpret as H$\alpha$ at a redshift of 2.43. The K-band image shows two compact components 10 kpc apart surrounded by more extended emission over ~20 kpc. The H$\alpha$ emission appears to be extended over ~15 kpc (2") in a coarsely sampled (0".8/pixel) image. The star formation rate may be as high as 250 - 1000 M$_\odot$ yr$^{-1}$, depending on the extinction. Alternatively, the line may be powered by an active nucleus, although the probability of serendipitously discovering an AGN in the survey volume is only ~0.02. The increasing number of similar objects reported in the literature indicate that they may be an important, unstudied population in the high redshift universe.Comment: ApJ in press, 21 pages, 2 figures. Also available at http://www.mpia-hd.mpg.de/MPIA/Projects/STARS/preprints.htm

Formation and structure of the three Neptune-mass planets system around HD69830

Since the discovery of the first giant planet outside the solar system in 1995 (Mayor & Queloz 1995), more than 180 extrasolar planets have been discovered. With improving detection capabilities, a new class of planets with masses 5-20 times larger than the Earth, at close distance from their parent star is rapidly emerging. Recently, the first system of three Neptune-mass planets has been discovered around the solar type star HD69830 (Lovis et al. 2006). Here, we present and discuss a possible formation scenario for this planetary system based on a consistent coupling between the extended core accretion model and evolutionary models (Alibert et al. 2005a, Baraffe et al. 2004,2006). We show that the innermost planet formed from an embryo having started inside the iceline is composed essentially of a rocky core surrounded by a tiny gaseous envelope. The two outermost planets started their formation beyond the iceline and, as a consequence, accrete a substantial amount of water ice during their formation. We calculate the present day thermodynamical conditions inside these two latter planets and show that they are made of a rocky core surrounded by a shell of fluid water and a gaseous envelope.Comment: Accepted in AA Letter