Search Publications
Multi-wavelength Probes of Obscuration Toward the Narrow-line Region in Seyfert Galaxies
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +4 more
We present a study of reddening and absorption toward the narrow line regions (NLRs) in active galactic nuclei (AGNs) selected from the Revised Shapley-Ames, 12 µm, and Swift/Burst Alert Telescope samples. For the sources in host galaxies with inclinations of b/a > 0.5, we find that the mean ratio of [O III] λ5007, from ground-based obser…
Spitzer Observations of Supernova Remnants. II. Physical Conditions and Comparison with HH7 and HH54
Yuan, Yuan; Neufeld, David A.
We have studied the shock-excited molecular regions associated with four supernova remnants (SNRs)—IC443C, W28, W44, and 3C391—and two Herbig-Haro objects—HH7 and HH54—using Spitzer's Infrared Spectrograph (IRS). The physical conditions within the observed areas (roughly ~1' × 1' in size) are inferred from spectroscopic data obtained from IRS and …
Extended X-Ray Emission in the Vicinity of the Microquasar LS 5039: Pulsar Wind Nebula?
Pavlov, George G.; Kargaltsev, Oleg; Garmire, Gordon P. +2 more
LS 5039 is a high-mass binary with a period of 4 days, containing a compact object and an O-star, one of the few high-mass binaries detected in γ-rays. Our Chandra Advanced CCD Imaging Spectrometer observation of LS 5039 provided a high-significance (≈10σ) detection of extended emission clearly visible for up to 1' from the point source. The spect…
Merging Galaxy Cluster A2255 in Mid-infrared
Goto, Tomotsugu; Kim, Seong Jin; Hwang, Narae +11 more
We present the mid-infrared (MIR) observation of a nearby galaxy cluster, A2255, by the AKARI space telescope. Using AKARI's continuous wavelength coverage between 3 and 24 µm and the wide field of view, we investigate the properties of cluster member galaxies to see how the infall of the galaxies, the cluster substructures, and the cluster-…
Observed Damping of the Slow Magnetoacoustic Mode
Marsh, M. S.; De Moortel, I.; Walsh, R. W.
Spectroscopic and stereoscopic imaging observations of slow magnetoacoustic wave propagation within a coronal loop are investigated to determine the decay length scale of the slow magnetoacoustic mode in three dimensions and the density profile within the loop system. The slow wave is found to have an e-folding decay length scale of 20,000+40…
Can a Long Nanoflare Storm Explain the Observed Emission Measure Distributions in Active Region Cores?
Winebarger, Amy R.; Warren, Harry P.; Mulu-Moore, Fana M.
All theories that attempt to explain the heating of the high-temperature plasma observed in the solar corona are based on short bursts of energy. The intensities and velocities measured in the cores of quiescent active regions, however, can be steady over many hours of observation. One heating scenario that has been proposed to reconcile such obse…
Deep Multiwaveband Observations of the Jets of 0208-512 and 1202-262
Perlman, Eric S.; Georganopoulos, Markos; Gelbord, Jonathan +8 more
We present deep Hubble Space Telescope, Chandra, Very Large Array, and Australia Telescope Compact Array images of the jets of PKS 0208-512 and PKS 1202-262, which were found in a Chandra survey of a flux-limited sample of flat-spectrum radio quasars with jets. We discuss in detail their X-ray morphologies and spectra. We find optical emission fro…
Carbon-chain Species in Warm-up Models
Herbst, Eric; Hassel, George E.; Harada, Nanase
In previous warm-up chemical models of the low-mass star-forming region L1527, we investigated the evolution of carbon-chain unsaturated hydrocarbon species when the envelope temperature is slightly elevated to T ≈ 30 K. These models demonstrated that enhanced abundances of such species can be explained by gas-phase ion-molecule chemistry followin…
Gravitational Lens Candidates in the E-CDFS
Barden, M.; Häußler, B.; Jahnke, K. +4 more
We report 10 lens candidates in the Extended Chandra Deep Field South from the GEMS survey. Nine of the systems are new detections and only one of the candidates is a known lens system. For the most promising five systems including the known lens system, we present results from preliminary lens mass modeling, which tests if the candidates are plau…
Submillimeter Sources behind the Massive Lensing Clusters A370 and A2390
Chen, Chian-Chou; Williams, Jonathan P.; Wang, Wei-Hao +2 more
We report 850 µm Submillimeter Array (SMA) observations of four gravitationally lensed submillimeter galaxies (SMGs), A370-2, A2390-1, A2390-3, and A2390-4, which were originally discovered with the Submillimeter Common-User Bolometer Array (SCUBA). Our SMA detection of A370-2 with a submillimeter flux of 7.95 ± 0.60 mJy unambiguously identi…