Search Publications
On the Magnetic Flux Budget in Low-Corona Magnetic Reconnection and Interplanetary Coronal Mass Ejections
Qiu, Jiong; Hu, Qiang; Howard, Timothy A. +1 more
We present the first quantitative comparison between the total magnetic reconnection flux in the low corona in the wake of coronal mass ejections (CMEs) and the magnetic flux in magnetic clouds (MCs) that reach 1 AU 2-3 days after CME onset. The total reconnection flux is measured from flare ribbons, and the MC flux is computed using in situ obser…
Using Stellar Limb-Darkening to Refine the Properties of HD 209458b
Knutson, Heather A.; Gilliland, Ronald L.; Charbonneau, David +2 more
We use multiband photometry to refine estimates for the planetary radius and orbital inclination of the transiting planet system HD 209458. We gathered 1066 spectra over four distinct transits with the STIS spectrometer on the Hubble Space Telescope using two gratings with a resolution R=1500 and a combined wavelength range of 290-1030 nm. We divi…
Hubble Space Telescope and Spitzer Imaging of Red and Blue Galaxies at z ~ 2.5: A Correlation between Size and Star Formation Activity from Compact Quiescent Galaxies to Extended Star-forming Galaxies
Wuyts, S.; Förster Schreiber, N. M.; Papovich, C. +13 more
We present HST NICMOS+ACS and Spitzer IRAC+MIPS observations of 41 galaxies at 2<z<3.5 in the FIRES MS 1054 field with red and blue rest-frame optical colors. About half of the galaxies are very compact (effective radii re<1 kpc) at rest-frame optical wavelengths; the others are extended (1 kpc<re<10 kpc). For …
Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs
Zuckerman, B.; Song, Inseok; McElwain, Michael +1 more
Dusty debris disks around main-sequence stars are signposts for the existence of planetesimals and exoplanets. From cross-correlating Hipparcos stars with the IRAS catalogs, we identify 146 stars within 120 pc of Earth that show excess emission at 60 µm. This search took special precautions to avoid false positives. Our sample is reasonably …
C IV λ1549 as an Eigenvector 1 Parameter for Active Galactic Nuclei
Sulentic, Jack W.; Marziani, Paola; Negrete, C. Alenka +2 more
We are exploring a spectroscopic unification for all types of broad-line emitting AGNs. The four-dimensional Eigenvector 1 (4DE1) parameter space organizes quasar diversity in a sequence primarily governed by Eddington ratio. This paper considers the role of C IV λ1549 measures as 4DE1 diagnostics. We use HST archival spectra for 130 sources with …
Coronal ``Wave'': Magnetic Footprint of a Coronal Mass Ejection?
Harra, Louise K.; Attrill, Gemma D. R.; van Driel-Gesztelyi, Lidia +1 more
We investigate the properties of two ``classical'' EUV Imaging Telescope (EIT) coronal waves. The two source regions of the associated coronal mass ejections (CMEs) possess opposite helicities, and the coronal waves display rotations in opposite senses. We observe deep core dimmings near the flare site and also widespread diffuse dimming, accompan…
The Centers of Early-Type Galaxies with Hubble Space Telescope. VI. Bimodal Central Surface Brightness Profiles
Filippenko, Alexei V.; Ho, Luis C.; Gebhardt, Karl +9 more
We combine several HST investigations on the central structure of early-type galaxies to generate a large sample of surface photometry. The studies selected were those that used the ``Nuker law'' to characterize the inner light distributions of the galaxies. The sample comprises WFPC1 and WFPC2 V-band observations published earlier by our group, R…
A Log-Quadratic Relation for Predicting Supermassive Black Hole Masses from the Host Bulge Sérsic Index
Graham, Alister W.; Driver, Simon P.
We reinvestigate the correlation between black hole mass and bulge concentration. With an increased galaxy sample (totaling 27) and updated estimates of galaxy distances, black hole masses, and Sérsic indices n-a measure of concentration-we perform a least-squares regression analysis to obtain a relation suitable for the purpose of predicting blac…
The Stellar Mass Tully-Fisher Relation to z = 1.2 from AEGIS
Weiner, Benjamin J.; Faber, S. M.; Lotz, Jennifer M. +12 more
We combine newly measured rotation velocities, velocity dispersions, and stellar masses to construct stellar mass Tully-Fisher relations (M*TFRs) for 544 galaxies with strong emission lines at 0.1<z<1.2 from the All-Wavelength Extended Groth Strip International Survey (AEGIS) and the Deep Extragalactic Evolutionary Probe 2 (DEEP2)…
Quiet-Sun Internetwork Magnetic Fields from the Inversion of Hinode Measurements
Lites, B. W.; Ichimoto, K.; Bellot Rubio, L. R. +10 more
We analyze Fe I 630 nm observations of the quiet Sun at disk center taken with the spectropolarimeter of the Solar Optical Telescope aboard the Hinode satellite. A significant fraction of the scanned area, including granules, turns out to be covered by magnetic fields. We derive field strength and inclination probability density functions from a M…