Search Publications
Galaxy Size Problem at z = 3: Simulated Galaxies are too Small
Bryan, Greg L.; Cen, Renyue; Joung, M. Ryan
Using state-of-the-art adaptive mesh refinement cosmological hydrodynamic simulations with a spatial resolution of proper 0.21h -1 73 kpc in refined subregions embedded within a comoving cosmological volume (27.4h -1 73 Mpc)3, we investigate the sizes of galaxies at z = 3 in the standard cold …
Properties of Newly Formed Dust by SN 2006JC Based on Near- to Mid-Infrared Observation With AKARI
Tanaka, M.; Ohyama, Y.; Matsuhara, H. +18 more
We present our latest results on near- to mid-infrared (MIR) observation of supernova (SN) 2006jc at 200 days after the discovery using the Infrared Camera (IRC) on board AKARI. The near-infrared (2-5 µm) spectrum of SN 2006jc is obtained for the first time and is found to be well interpreted in terms of the thermal emission from amorphous c…
A Self-Consistent Nonlinear Force-Free Solution for a Solar Active Region Magnetic Field
Régnier, S.; Wheatland, M. S.
Nonlinear force-free solutions for the magnetic field in the solar corona constructed using photospheric vector magnetic field boundary data suffer from a basic problem: the observed boundary data are inconsistent with the nonlinear force-free model. Specifically, there are two possible choices of boundary conditions on vertical current provided b…
Spitzer View of Young Massive Stars in the Large Magellanic Cloud H II Complex N 44
Gordon, Karl D.; Chu, You-Hua; Gruendl, Robert A. +2 more
The H II complex N 44 in the Large Magellanic Cloud (LMC) provides an excellent site to perform a detailed study of star formation in a mild starburst, as it hosts three regions of star formation at different evolutionary stages, and it is not as complicated and confusing as the 30 Doradus giant H II region. We have obtained Spitzer Space Telescop…
Revealing the Structure of a Pre-Transitional Disk: The Case of the Herbig F Star SAO 206462 (HD 135344B)
Ménard, F.; Apai, D.; Hamaguchi, K. +23 more
SAO 206462 (HD 135344B) has previously been identified as a Herbig F star with a circumstellar disk with a dip in its infrared excess near 10 µm. In combination with a low accretion rate estimated from Br γ, it may represent a gapped, but otherwise primordial or "pre-transitional" disk. We test this hypothesis with Hubble Space Telescope cor…
Current Buildup in Emerging Serpentine Flux Tubes
Aulanier, G.; Masson, S.; Pariat, E.
The increase of magnetic flux in the solar atmosphere during active-region formation involves the transport of the magnetic field from the solar convection zone through the lowest layers of the solar atmosphere, through which the plasma β changes from >1 to <1 with altitude. The crossing of this magnetic transition zone requires the magnetic…
The NGC 300 Transient: An Alternative Method for Measuring Progenitor Masses
Williams, Benjamin F.; Dolphin, Andrew; Dalcanton, Julianne J. +3 more
We present an alternative technique for measuring the precursor masses of transient events in stars undergoing late stage stellar evolution. We use the well-established techniques of stellar population modeling to age-date the stars surrounding the site of the recent transient event in NGC 300 (NGC 300 OT2008-1). The surrounding stars must share a…
Correlated X-Ray and Very High Energy Emission in the Gamma-Ray Binary LS I +61 303
Maraschi, L.; Covino, S.; Antonelli, L. A. +153 more
The discovery of very high energy (VHE) gamma-ray emitting X-ray binaries has triggered an intense effort to better understand the particle acceleration, absorption, and emission mechanisms in compact binary systems, which provide variable conditions along eccentric orbits. Despite this, the nature of some of these systems, and of the accelerated …
Some Like It Hot: Coronal Heating Observations from Hinode X-ray Telescope and RHESSI
Lin, L.; Golub, L.; Schmelz, J. T. +7 more
We have used Hinode X-Ray Telescope observations and RHESSI upper limits together to characterize the differential emission measure (DEM) from a quiescent active region. We find a relatively smooth DEM curve with the expected active region peak at log T = 6.4. We also find a high-temperature component with significant emission measure at log T gsi…
New Observation of Failed Filament Eruptions: The Influence of Asymmetric Coronal Background Fields on Solar Eruptions
Liu, Y.; Shibata, K.; Lin, H. +3 more
Failed filament eruptions not associated with a coronal mass ejection (CME) have been observed and reported as evidence for solar coronal field confinement on erupting flux ropes. In those events, each filament eventually returns to its origin on the solar surface. In this Letter, a new observation of two failed filament eruptions is reported whic…