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Transverse Oscillations of Flowing Prominence Threads Observed with Hinode
Oliver, R.; Ballester, J. L.; Terradas, J. +1 more
Recent observations with the Hinode Solar Optical Telescope display an active region prominence whose fine threads oscillate in the vertical direction as they move along a path parallel to the photosphere. A seismological analysis of this event is carried out by taking advantage of the small radius of these structures compared to the total length …
The Nascent Red Sequence at z ~ 2
Demarco, R.; Pentericci, L.; Rosati, P. +12 more
We present new constraints on the evolution of the early-type galaxy color-magnitude relation (CMR) based on deep near-infrared imaging of a galaxy protocluster at z = 2.16 obtained using NICMOS on board the Hubble Space Telescope. This field contains a spectroscopically confirmed space overdensity of Lyα- and Hα-emitting galaxies that surrounds t…
Realistic Numerical Simulations of Solar Convection and Oscillations in Magnetic Regions
Kosovichev, A. G.; Mansour, N. N.; Jacoutot, L. +1 more
We have used 3D, compressible, nonlinear radiative magnetohydrodynamics simulation to study the influence of magnetic fields of various strengths on convective cells and on the excitation mechanisms of acoustic oscillations by calculating the spectral properties of the convective motions and oscillations. The results reveal substantial changes of …
The Puzzling White Dwarf Cooling Sequence in NGC 6791: A Simple Solution
Salaris, M.; Anderson, J.; Milone, A. P. +4 more
In this Letter we demonstrate that the puzzling bright peak in the luminosity function of the white dwarf (WD) cooling sequence of NGC 6791 can be naturally accounted for if ~34% of the observed WDs are WD+WD binary systems.
Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, whic…Timing the Nearby Isolated Neutron Star RX J1856.5-3754
van Kerkwijk, M. H.; Kaplan, D. L.
RX J1856.5-3754 is the X-ray brightest among the nearby isolated neutron stars. Its X-ray spectrum is thermal, and is reproduced remarkably well by a blackbody, but its interpretation has remained puzzling. One reason is that the source did not exhibit pulsations, and hence a magnetic field strength—vital input to atmosphere models—could not be es…
Galaxy Mergers at z gtrsim 1 in the HUDF: Evidence for a Peak in the Major Merger Rate of Massive Galaxies
Ryan, R. E., Jr.; Windhorst, R. A.; Silk, J. +1 more
We present a measurement of the galaxy merger fraction and number density from observations in the Hubble Ultra Deep Field (HUDF) for 0.5 <= z <= 2.5. We fit the combination of broadband data and slitless spectroscopy of 1308 galaxies with stellar population synthesis models to select merging systems based on a stellar mass of >=1010…
X-Ray Observations of Parsec-scale Tails behind Two Middle-Aged Pulsars
Garmire, G. P.; Pavlov, G. G.; Kargaltsev, O. +2 more
Chandra and XMM-Newton resolved extremely long tails behind two middle-aged pulsars, J1509-5850 and J1740+1000. The tail of PSR J1509-5850 is discernible up to 5.6' from the pulsar, which corresponds to the projected length l⊥ = 6.5d4 pc, where d = 4d4 kpc is the distance to the pulsar. The observed tail flux is 2 …
High-Ionization Mid-Infrared Lines as Black Hole Mass and Bolometric Luminosity Indicators in Active Galactic Nuclei
Lutz, D.; Sturm, E.; Helou, G. +6 more
We present relations of the black hole mass and the optical luminosity with the velocity dispersion and the luminosity of the [Ne V] and the [O IV] high-ionization lines in the mid-infrared (MIR) for 28 reverberation-mapped active galactic nuclei. We used high-resolution Spitzer Infrared Spectrograph and Infrared Space Observatory Short Wavelength…
The Formation of Coronal Loops by Thermal Instability in Three Dimensions
Linker, Jon A.; Mikić, Zoran; Mok, Yung +1 more
Plasma loops in solar active regions have been observed in EUV and soft X-rays for decades. Their formation mechanism and properties, however, are still not fully understood. Predictions by early models, based on 1D hydrostatic equilibria with uniform plasma heating, are not consistent with high-resolution measurements. In this Letter, we demonstr…
A New Determination of the High-Redshift Type Ia Supernova Rates with the Hubble Space Telescope Advanced Camera for Surveys
Wang, L.; Lidman, C.; Amanullah, R. +28 more
We present a new measurement of the volumetric rate of SNe Ia up to a redshift of 1.7, using the HST GOODS data combined with an additional HST data set covering the GOODS-North field collected in 2004. We employ a novel technique that does not require spectroscopic data for identifying SNe Ia (although spectroscopic measurements of redshifts are …