Search Publications
The Infrared Luminosity Functions of Rich Clusters
Rieke, George H.; Zabludoff, Ann I.; Rieke, Marcia J. +2 more
We present Multiband Imaging Photometer observations of the cluster A3266. About 100 spectroscopic cluster members have been detected at 24 µm. The infrared (IR) luminosity function (LF) in A3266 is very similar to that in the Coma cluster down to the detection limit L IR ~ 1043 erg s-1, suggesting a universa…
XMM-Newton Observations of a Complete Sample of Optically Selected Type 2 Seyfert Galaxies
Heckman, Timothy M.; Hornschemeier, Ann; Tremonti, Christy +4 more
The majority of active galactic nuclei (AGNs) suffer from significant obscuration by surrounding dust and gas. The penetrating power and sensitivity of hard X-ray observations allow obscured AGNs to be probed out to high redshifts. However, X-ray surveys in the 2-10 keV band will miss the most heavily obscured AGNs in which the absorbing column de…
A Suzaku Search for Nonthermal Emission at Hard X-Ray Energies in the Coma Cluster
Sarazin, Craig L.; Nakazawa, Kazuhiro; Wik, Daniel R. +3 more
The brightest cluster radio halo known resides in the Coma cluster of galaxies. The relativistic electrons producing this diffuse synchrotron emission should also produce inverse Compton emission that becomes competitive with thermal emission from the intracluster medium (ICM) at hard X-ray energies. Thus far, claimed detections of this emission i…
The Optical Structure of the Starburst Galaxy M82. II. Nebular Properties of the Disk and Inner Wind
Bastian, N.; Gallagher, J. S.; Smith, L. J. +3 more
In this second paper of the series, we present the results from optical Gemini-North GMOS-IFU and WIYN DensePak IFU spectroscopic observations of the starburst and inner wind zones of M82, with a focus on the state of the T ~ 104 K ionized interstellar medium. Our electron density maps show peaks of a few 1000 cm-3 (implying …
A New View of Coronal Waves from STEREO
Golub, L.; Chen, P. F.; Lin, J. +6 more
On 2007 December 7, there was an eruption from AR 10977, which also hosted a sigmoid. An EUV Imaging Telescope (EIT) wave associated with this eruption was observed by EUVI on board the Solar Terrestrial Relations Observatory (STEREO). Using EUVI images in the 171 Å and the 195 Å passbands from both STEREO A and B, we study the morphology and kine…
Flare Energy Build-up in a Decaying Active Region Near a Coronal Hole
Golub, Leon; van Ballegooijen, Adriaan; Schmieder, Brigitte +4 more
A B1.7 two-ribbon flare occurred in a highly non-potential decaying active region near a coronal hole at 10:00 UT on 2008 May 17. This flare is "large" in the sense that it involves the entire region, and it is associated with both a filament eruption and a coronal mass ejection. We present multi-wavelength observations from EUV (TRACE, STEREO/EUV…
Observational Signatures of Simulated Reconnection Events in the Solar Chromosphere and Transition Region
De Pontieu, B.; Hansteen, V. H.; Heggland, L.
We present the results of numerical simulations of wave-induced magnetic reconnection in a model of the solar atmosphere. In the magnetic field geometry we study in this paper, the waves, driven by a monochromatic piston and a driver taken from Hinode observations, induce periodic reconnection of the magnetic field, and this reconnection appears t…
X-Ray and Ultraviolet Spectroscopy of Galactic Diffuse Hot Gas Along the Large Magellanic Cloud X-3 Sight Line
Yao, Y.; Mitsuda, K.; Wang, Q. D. +3 more
We present Suzaku spectra of X-ray emission in the fields just off the LMC X-3 sight line. O VII, O VIII, and Ne IX emission lines are clearly detected, suggesting the presence of an optically thin thermal plasma with an average temperature of 2.4 × 106 K. This temperature is significantly higher than that inferred from existing X-ray a…
Subsurface Circulations within Active Regions
Toomre, Juri; Hindman, Bradley W.; Haber, Deborah A.
Using high-resolution ring analysis, we deduce subsurface flows within magnetic active regions and within the quiet Sun. With this procedure, we are capable of measuring flows with a horizontal spatial resolution of 2° in heliographic angle (or roughly 20 Mm). From the resulting flow fields we deduce mean inflow rates into active regions, mean cir…
An X-Ray/Optical Study of the Complex Dynamics of the Core of the Massive Intermediate-Redshift Cluster MACSJ0717.5+3745
Ebeling, Harald; Ma, Cheng-Jiun; Barrett, Elizabeth
Using CHANDRA, we investigate the spatial temperature distribution of the intracluster medium (ICM) within 700 kpc of the center of the massive merging cluster MACSJ0717.5+3745 at z = 0.55. Combining the X-ray evidence with information about the distribution and velocities of the cluster galaxies near the core provides us with a snapshot of the th…