Search Publications
Photospheric Magnetic Evolution in the WHI Active Regions
Welsch, B. T.; McTiernan, J. M.; Christe, S.
Sequences of line-of-sight (LOS) magnetograms recorded by the Michelson Doppler Imager are used to quantitatively characterize photospheric magnetic structure and evolution in three active regions that rotated across the Sun's disk during the Whole Heliosphere Interval (WHI), in an attempt to relate the photospheric magnetic properties of these ac…
The 100 Myr Star Formation History of NGC 5471 from Cluster and Resolved Stellar Photometry
Pérez, Enrique; Cerviño, Miguel; Díaz, Ángeles I. +2 more
We show that star formation in the giant H II region NGC 5471 has been ongoing during the past 100 Myr. Using Hubble Space Telescope/Wide-Field Planetary Camera 2 F547M and F675W, ground-based JHK s , and GALEX FUV and NUV images, we have conducted a photometric study of the star formation history (SFH) in the massive giant extragalact…
The UV-continuum Properties of Lyα-selected Galaxies at z = 6.5
Cowie, Lennox L.; Hu, Esther M.; Songaila, Antoinette
We report the first space-based very deep near-infrared continuum observations of a uniform sample of z = 6.5 galaxies with log(L(Lyα)) = 42.5-43 erg s-1 selected from narrowband line searches and with spectroscopically confirmed Lyα emission. The 1.4 µm Hubble Space Telescope WFC3 observations are deep enough (AB(1σ) = 28.75) to …
Spectroscopic Analysis of Interaction between an Extreme-ultraviolet Imaging Telescope Wave and a Coronal Upflow Region
Ding, M. D.; Chen, P. F.; Harra, L. K. +1 more
We report a spectroscopic analysis of an EUV Imaging Telescope (EIT) wave event that occurred in active region 11081 on 2010 June 12 and was associated with an M2.0 class flare. The wave propagated nearly circularly. The southeastern part of the wave front passed over an upflow region near a magnetic bipole. Using EUV Imaging Spectrometer raster o…
Strong Variable Ultraviolet Emission from Y Gem: Accretion Activity in an Asymptotic Giant Branch Star with a Binary Companion?
Gil de Paz, Armando; Neill, James D.; Sahai, Raghvendra +1 more
Binarity is believed to dramatically affect the history and geometry of mass loss in asymptotic giant branch (AGB) and post-AGB stars, but observational evidence of binarity is sorely lacking. As part of a project to look for hot binary companions to cool AGB stars using the Galaxy Evolution Explorer archive, we have discovered a late-M star, Y Ge…
Optical dropout galaxies lensed by the cluster A2667
Schaerer, D.; Laporte, N.; Pelló, R. +8 more
Context. We investigate the nature and the physical properties of ten z, Y, and J-dropout galaxies selected in the field of the lensing cluster A2667.
Aims: This cluster is part of our project aimed at obtaining deep photometry at ~0.8-2.5 microns with ESO/VLT HAWK-I and FORS2 on a representative sample of lensing clusters extracted from our …
A Rotating Disk in the HH 111 Protostellar System
Lee, Chin-Fei
The HH 111 protostellar system is a young Class I system with two sources, VLA 1 and VLA 2, at a distance of 400 pc. Previously, a flattened envelope has been seen in C18O to be in transition to a rotationally supported disk near the VLA 1 source. The follow-up study here is to confirm the rotationally supported disk at 2-3 times higher…
Residual rotation of the Hipparcos/Tycho-2 system as determined from the data of the XPM catalogue
Bobylev, V. V.; Akhmetov, V. S.; Fedorov, P. N.
From a comparison of absolute proper motions of stars from the XPM catalogue with those of the same stars from the PPMXL, UCAC3, Tycho-2 and XC1 catalogues, the equatorial components of the rotation vector of these coordinate systems are determined with respect to the coordinate system specified by positions and proper motions of XPM. These parame…
Magnetospheric mapping of the dayside UV auroral oval at Saturn using simultaneous HST images, Cassini IMF data, and a global magnetic field model
Belenkaya, E. S.; Nichols, J. D.; Cowley, S. W. H. +2 more
We determine the field-aligned mapping of Saturn's auroras into the magnetosphere by combining UV images of the southern dayside oval obtained by the Hubble Space Telescope (HST) with a global model of the magnetospheric magnetic field. The model is tailored to simulate prevailing conditions in the interplanetary medium, corresponding to high sola…
Hubble Space Telescope Imaging of the Outburst Site of M31 RV. II. No Blue Remnant in Quiescence
Bond, Howard E.
M31 RV is a red transient that erupted in 1988 in the Andromeda bulge, reaching a luminosity intermediate between novae and supernovae. It was cool throughout its outburst, unlike a normal classical nova. In 2006, Bond & Siegel examined archival Hubble Space Telescope (HST) optical images of the M31 RV site, obtained in 1999. We found only old…