Search Publications
Two Extrasolar Asteroids with Low Volatile-element Mass Fractions
Koester, D.; Zuckerman, B.; Xu, S. +2 more
Using ultraviolet spectra obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope, we extend our previous ground-based optical determinations of the composition of the extrasolar asteroids accreted onto two white dwarfs, GD 40 and G241-6. Combining optical and ultraviolet spectra of these stars with He-dominated atmospheres, 13…
Dynamics of the Solar Magnetic Bright Points Derived from Their Horizontal Motions
Chitta, L. P.; Kariyappa, R.; van Ballegooijen, A. A. +2 more
The subarcsecond bright points (BPs) associated with the small-scale magnetic fields in the lower solar atmosphere are advected by the evolution of the photospheric granules. We measure various quantities related to the horizontal motions of the BPs observed in two wavelengths, including the velocity autocorrelation function. A 1 hr time sequence …
LoCuSS: A Dynamical Analysis of X-Ray Active Galactic Nuclei in Local Clusters
Finoguenov, A.; Smith, G. P.; Okabe, N. +7 more
We present a study of the distribution of X-ray active galactic nuclei (AGNs) in a representative sample of 26 massive clusters at 0.15 < z < 0.30, combining Chandra observations sensitive to X-ray point sources of luminosity LX ~ 1042 erg s-1 at the cluster redshift with extensive and highly complete spectro…
Three-dimensional Evolution of Solar Wind during Solar Cycles 22-24
Manoharan, P. K.
This paper presents an analysis of three-dimensional evolution of solar wind density turbulence and speed at various levels of solar activity between solar cycles 22 and 24. The solar wind data used in this study have been obtained from the interplanetary scintillation (IPS) measurements made at the Ooty Radio Telescope, operating at 327 MHz. Resu…
Spitzer Observations of Young Red Quasars
Lacy, Mark; Schulz, Bernhard; Urrutia, Tanya +3 more
We present mid-infrared spectra and photometry of 13 redshift 0.4 < z < 1 dust reddened quasars obtained with Spitzer IRS and MIPS. We compare properties derived from their infrared spectral energy distributions (intrinsic active galactic nucleus (AGN) luminosity and far-infrared luminosity from star formation) to the host luminosities and m…
Kinematic Signatures of Bulges Correlate with Bulge Morphologies and Sérsic Index
Bender, Ralf; Drory, Niv; Fisher, David B. +3 more
We use the Marcario Low Resolution Spectrograph at the Hobby-Eberly Telescope to study the kinematics of pseudobulges and classical bulges in the nearby universe. We present major axis rotational velocities, velocity dispersions, and h 3 and h 4 moments derived from high-resolution (σinst ≈ 39 km s-1) sp…
IDCS J1433.2+3306: An Infrared-selected Galaxy Cluster at z = 1.89
Dey, Arjun; Gonzalez, Anthony H.; Stanford, S. A. +6 more
We report the discovery of an IR-selected galaxy cluster in the IRAC Distant Cluster Survey (IDCS). New data from the Hubble Space Telescope spectroscopically confirm IDCS J1433.2+3306 at z = 1.89 with robust spectroscopic redshifts for seven members, two of which are based on the 4000 Å break. Detected emission lines such as [O II] and Hβ indicat…
Evidence of Wave Damping at Low Heights in a Polar Coronal Hole
Hahn, M.; Savin, D. W.; Landi, E.
We have measured the widths of spectral lines from a polar coronal hole using the Extreme Ultraviolet Imaging Spectrometer on board Hinode. Polar coronal holes are regions of open magnetic field and the source of the fast solar wind. We find that the line widths decrease at relatively low heights. Previous observations have attributed such decreas…
A Young Massive Stellar Population around the Intermediate-mass Black Hole ESO 243-49 HLX-1
Maccarone, T. J.; Knigge, C.; Farrell, S. A. +9 more
We present Hubble Space Telescope and simultaneous Swift X-ray Telescope observations of the strongest candidate intermediate-mass black hole (IMBH) ESO 243-49 HLX-1. Fitting the spectral energy distribution from X-ray to near-infrared wavelengths showed that the broadband spectrum is not consistent with simple and irradiated disk models, but is w…
3D-HST Grism Spectroscopy of a Gravitationally Lensed, Low-metallicity Starburst Galaxy at z = 1.847
Schmidt, Kasper B.; van Dokkum, Pieter G.; Franx, Marijn +17 more
We present Hubble Space Telescope (HST) imaging and spectroscopy of the gravitational lens SL2SJ02176-0513, a cusp arc at z = 1.847. The UV continuum of the lensed galaxy is very blue, which is seemingly at odds with its redder optical colors. The 3D-HST WFC3/G141 near-infrared spectrum of the lens reveals the source of this discrepancy to be extr…