Search Publications
Magnetoseismological Determination of Magnetic Field and Plasma Density Height Variation in a Solar Spicule
Goossens, M.; Verth, G.; He, J. -S.
The variation of magnetic field strength and plasma density along a solar spicule is determined by the use of magnetoseismology. From Solar Optical Telescope observations of a kink wave propagating along a spicule, by estimating the spatial change in phase speed and velocity amplitude, a novel approach is demonstrated to determine the chromospheri…
The Sloan Lens ACS Survey. XI. Beyond Hubble Resolution: Size, Luminosity, and Stellar Mass of Compact Lensed Galaxies at Intermediate Redshift
Treu, Tommaso; Marshall, Philip J.; Auger, Matthew W. +5 more
We exploit the strong lensing effect to explore the properties of intrinsically faint and compact galaxies at intermediate redshift (z s ~= 0.4-0.8) at the highest possible resolution at optical wavelengths. Our sample consists of 46 strongly lensed emission line galaxies (ELGs) discovered by the Sloan Lens ACS Survey (SLACS). The galax…
Arrival Time Calculation for Interplanetary Coronal Mass Ejections with Circular Fronts and Application to STEREO Observations of the 2009 February 13 Eruption
Luhmann, J. G.; Zhang, T. L.; Möstl, C. +11 more
One of the goals of the NASA Solar TErestrial RElations Observatory (STEREO) mission is to study the feasibility of forecasting the direction, arrival time, and internal structure of solar coronal mass ejections (CMEs) from a vantage point outside the Sun-Earth line. Through a case study, we discuss the arrival time calculation of interplanetary C…
How Typical Are the Local Group Dwarf Galaxies?
McQuinn, Kristen B. W.; Dolphin, Andrew E.; Skillman, Evan D. +11 more
We compare the cumulative star formation histories (SFHs) of Local Group (LG) dwarf galaxies with those in the volume-limited ACS Nearby Galaxy Survey Treasury (ANGST) sample (D <~ 4 Mpc), in order to understand how typical the LG dwarf galaxies are relative to those in the nearby universe. The SFHs were derived in a uniform manner from high-qu…
Discovery of the First Giant Double Radio Relic in a Galaxy Cluster Found in the Planck Sunyaev-Zel'dovich Cluster Survey: PLCK G287.0+32.9
Werner, Norbert; Ishwara-Chandra, C. H.; Joshi, Santosh +6 more
We report the discovery of large-scale diffuse non-thermal radio emission in PLCK G287.0+32.9, an exceptionally hot (T ~ 13 keV), massive, and luminous galaxy cluster, strongly detected by the Planck satellite in a recent, all-sky blind search for new clusters through Sunyaev-Zel'dovich effect. Giant Metrewave Radio Telescope 150 MHz and Very Larg…
The Evolution of the Mass-Size Relation to z = 3.5 for UV-bright Galaxies and Submillimeter Galaxies in the GOODS-North Field
Franx, Marijn; Kriek, Mariska; Williams, Rik J. +1 more
We study the evolution of the size-stellar mass relation for a large spectroscopic sample of galaxies in the GOODS-North field up to z ~ 3.5. The sizes of the galaxies are measured from Ks -band images (corresponding to rest-frame optical/NIR) from the Subaru 8 m telescope. We reproduce earlier results based on photometric redshifts tha…
Photometric Determination of the Mass Accretion Rates of Pre-main-sequence Stars. II. NGC 346 in the Small Magellanic Cloud
Panagia, Nino; Sabbi, Elena; De Marchi, Guido +4 more
We have studied the properties of the stellar populations in the field of the NGC 346 cluster in the Small Magellanic Cloud, using a novel self-consistent method that allows us to reliably identify pre-main-sequence (PMS) objects actively undergoing mass accretion, regardless of their age. The method does not require spectroscopy and combines broa…
Scale Dependence of Magnetic Helicity in the Solar Wind
Brandenburg, Axel; Balogh, André; Subramanian, Kandaswamy +1 more
We determine the magnetic helicity, along with the magnetic energy, at high latitudes using data from the Ulysses mission. The data set spans the time period from 1993 to 1996. The basic assumption of the analysis is that the solar wind is homogeneous. Because the solar wind speed is high, we follow the approach first pioneered by Matthaeus et al.…
Physical Properties of the Circumnuclear Starburst Ring in the Barred Galaxy NGC 1097
Ho, Paul T. P.; Matsushita, Satoki; Oi, Nagisa +3 more
We report high-resolution 12CO(J = 2-1), 13CO(J = 2-1), and 12CO(J = 3-2) imaging of the Seyfert 1/starburst ring galaxy NGC 1097 with the Submillimeter Array for the purpose of studying the physical and kinematic properties of the 1 kpc circumnuclear starburst ring. Individual star clusters as detected in the Hubb…
The Dissipation of Solar Wind Turbulent Fluctuations at Electron Scales
Burgess, David; Camporeale, Enrico
We present two-dimensional fully kinetic particle-in-cell simulations of decaying electromagnetic fluctuations. The computational box is such that wavelengths ranging from electron to ion gyroradii are resolved. The parameters used are realistic for the solar wind, and the ion-to-electron mass ratio is physical. The dissipation of turbulent fluctu…