Search Publications
The Disk-wind-Jet Connection in the Black Hole H 1743-322
Fabian, A. C.; Miller, J. M.; Reynolds, C. S. +6 more
X-ray disk winds are detected in spectrally soft, disk-dominated phases of stellar-mass black hole outbursts. In contrast, compact, steady, relativistic jets are detected in spectrally hard states that are dominated by non-thermal X-ray emission. Although these distinctive outflows appear to be almost mutually exclusive, it is possible that a disk…
Assembly of the Red Sequence in Infrared-selected Galaxy Clusters from the IRAC Shallow Cluster Survey
Dey, Arjun; Jannuzi, Buell; Eisenhardt, Peter R. M. +9 more
We present results for the assembly and star formation histories (SFHs) of massive (~L*) red sequence galaxies (RSGs) in 11 spectroscopically confirmed, infrared-selected galaxy clusters at 1.0 < z < 1.5, the precursors to present-day massive clusters with M ~ 1015 M ⊙. Using rest-frame optical photometry, we investigat…
Behavior of Solar Cycles 23 and 24 Revealed by Microwave Observations
Gopalswamy, N.; Michalek, G.; Shibasaki, K. +3 more
Using magnetic and microwave butterfly diagrams, we compare the behavior of solar polar regions to show that (1) the polar magnetic field and the microwave brightness temperature during solar minimum substantially diminished during the cycle 23/24 minimum compared to the 22/23 minimum. (2) The polar microwave brightness temperature (Tb) seems to b…
Spectroscopic Signature of Alfvén Waves Damping in a Polar Coronal Hole up to 0.4 Solar Radii
Bemporad, A.; Abbo, L.
Between 2009 February 24 and 25, the EUV Imaging Spectrometer (EIS) spectrometer on board the Hinode spacecraft performed special "sit and stare" observations above the south polar coronal hole continuously over more than 22 hr. Spectra were acquired with the 1'' slit placed off-limb covering altitudes up to 0.48 R ⊙ (3.34 × 102
The Rest-frame UV-to-optical Colors and Spectral Energy Distributions of z ~ 4-7 Galaxies
Franx, Marijn; Labbé, Ivo; Bouwens, Rychard J. +4 more
We use the ultra-deep HUDF09 and the deep Early Release Science data from the HST WFC3/IR camera, along with the wide-area Spitzer/IRAC data from GOODS-S to derive spectral energy distributions (SEDs) of star-forming galaxies from the rest-frame UV to the optical over a wide luminosity range (M 1500 ~ -21 to M 1500 ~ -18) fro…
The Early Early Type: Discovery of a Passive Galaxy at z spec ~ 3
Cimatti, A.; Daddi, E.; Béthermin, M. +6 more
We present the discovery of a massive, quiescent galaxy at z = 2.99. We have obtained an Hubble Space Telescope WFC3 spectrum of this object and measured its redshift from the detection of a deep 4000 Å break consistent with an old population and a high metallicity. By stellar population modeling of both its grism spectrum and broadband photometry…
Hinode/EIS Spectroscopic Validation of Very Hot Plasma Imaged with the Solar Dynamics Observatory in Non-flaring Active Region Cores
Testa, Paola; Reale, Fabio
We use coronal imaging observations with the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), and Hinode/Extreme-ultraviolet Imaging Spectrometer (EIS) spectral data to explore the potential of narrowband EUV imaging data for diagnosing the presence of hot (T >~ 5 MK) coronal plasma in active regions. We analyze observations of tw…
Variability and Star Formation in Leo T, the Lowest Luminosity Star-forming Galaxy Known Today
Cignoni, Michele; Marconi, Marcella; Ripepi, Vincenzo +5 more
We present results from the first combined study of variable stars and star formation history (SFH) of the Milky Way "ultra-faint" dwarf (UFD) galaxy Leo T, based on F606W and F814W multi-epoch archive observations obtained with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. We have detected 14 variable stars in the galaxy.…
Rapid Sunspot Rotation Associated with the X2.2 Flare on 2011 February 15
Yang, Jiayan; Hong, Junchao; Zheng, Ruisheng +3 more
We present observations of sunspot evolution associated with the first X-class flare of the present solar cycle 24, which occurred in AR 11158 on 2011 February 15. The active region consisted of four emerging bipoles that showed complicated sunspot motion. The preceding spot of a bipole underwent the fastest movement. It not only passed through th…
A Brightest Cluster Galaxy with an Extremely Large Flat Core
Donahue, Megan; Broadhurst, Tom; Moustakas, John +14 more
Hubble Space Telescope images of the galaxy cluster A2261, obtained as part of the Cluster Lensing And Supernova survey with Hubble, show that the brightest galaxy in the cluster, A2261-BCG, has the largest core yet detected in any galaxy. The cusp radius of A2261-BCG is 3.2 kpc, twice as big as the next largest core known, and ~3 × bigger than th…