Search Publications
Chirality of Intermediate Filaments and Magnetic Helicity of Active Regions
Chae, Jongchul; Lim, Eun-Kyung
Filaments that form either between or around active regions (ARs) are called intermediate filaments. Even though there have been many theoretical studies, the origin of the chirality of filaments is still unknown. We investigated how intermediate filaments are related to their associated ARs, especially from the point of view of magnetic helicity …
Photometric selection of z ~ 5 Lyman break galaxies in the ESO Remote Galaxy Survey
Bremer, M. N.; Lehnert, M. D.; Stanway, E. R. +2 more
We describe the selection of a sample of photometrically defined Lyman break galaxies (LBGs) at z ~ 5 using the multiwavelength imaging data of the ESO (European Southern Observatory) Remote Galaxy Survey. The data are drawn from 10 widely separated fields covering a total sky area of 275arcmin2. Starting with a simple colour (R - I >…
Suzaku Observation of 30 Dor C: A Supernova Remnant with the Largest Non-Thermal Shell
Yamaguchi, Hiroya; Koyama, Katsuji; Bamba, Aya
This paper reports on the Suzaku results of thermal and non-thermal features of 30 Dor C, a supernova remnant (SNR) in a superbubble of the Large Magellanic Cloud (LMC). The west rim exhibits a non-thermal X-ray spectrum with no thermal component. A single power-law model is rejected, but a power-law model with spectral cutoff is accepted. The cut…
The jet of the BL Lacertae object PKS 0521-365 in the near-IR: MAD adaptive optics observations
Pian, E.; Moretti, A.; Falomo, R. +14 more
Context: BL Lac objects are low-power active nuclei exhibiting a variety of peculiar properties caused by the presence of a relativistic jet and orientation effects.
Aims: We present adaptive optics near-IR images at high spatial resolution of the nearby BL Lac object PKS 0521-365, which is known to display a prominent jet both at radio and op…
Rates of Photospheric Magnetic Flux Cancellation Measured with Hinode
Chae, Jongchul; Litvinenko, Yuri E.; Park, Soyoung
Photospheric magnetic flux cancellation on the Sun is generally believed to be caused by magnetic reconnection occurring in the low solar atmosphere. Individual canceling magnetic features are observationally characterized by the rate of flux cancellation. The specific cancellation rate, defined as the rate of flux cancellation divided by the inte…
Magnetic Nested-Wind Scenarios for Bipolar Outflows: Preplanetary and YSO Nebular Shaping
Frank, Adam; Balick, Bruce; De Marco, Orsola +3 more
We present results of a series of magnetohydrodynamic (MHD) and hydrodynamic (HD) 2.5 dimensional simulations of the morphology of outflows driven by nested wide-angle winds, i.e., winds that emanate from a central star as well as from an orbiting accretion disk. While our results are broadly relevant to nested-wind systems, we have tuned the para…
Host Galaxies of z = 4 Quasars
McLeod, K. K.; Bechtold, Jill
We have undertaken a project to investigate the host galaxies and environments of a sample of quasars at z ~ 4. In this paper, we describe deep near-infrared imaging of 34 targets using the Magellan I and Gemini North telescopes. We discuss in detail special challenges of distortion and nonlinearity that must be addressed when performing point-spr…
A Cross-Comparison of Cotemporal Magnetograms Obtained with MDI/SOHO and SP/ Hinode
Li, H.; Zhang, H. Q.; Zhang, M. +1 more
We compared a set of cotemporal magnetograms of active regions obtained with the Michelson Doppler Imager (MDI) aboard SOHO and the Spectro-Polarimeter (SP) of the Solar Optical Telescope (SOT) on board Hinode. The comparison shows that even with the recent calibration of level-1.8 data, the magnetic flux density derived from the MDI data is still…
Towards multiple-star population synthesis
Eggleton, P. P.
The multiplicities of stars, and some other properties, were collected recently by Eggleton & Tokovinin, for the set of 4559 stars with Hipparcos magnitude brighter than 6.0 (4558 excluding the Sun). In this paper I give a numerical recipe for constructing, by a Monte Carlo technique, a theoretical ensemble of multiple stars that resembles the…
Time Variability in the Outer Edge of Saturn's A-Ring Revealed by Cassini Imaging
Porco, C. C.; Spitale, J. N.
We examine the outer edge of Saturn's A-ring, whose shape is strongly influenced by the co-orbital satellites Janus and Epimetheus, during the period from day 2005-121 to day 2009-036. Twenty-four Cassini imaging data sets are used, each one giving a picture of the ring during a short interval, allowing us to explore its time variability in detail…