Search Publications
The Inconvenient Truth About Coronal Dimmings
McIntosh, Scott W.
We investigate the occurrence of a coronal mass ejection (CME)-driven coronal dimming using unique high-resolution spectral images of the corona from the Hinode spacecraft. Over the course of the dimming event, we observe the dynamic increase of nonthermal line broadening in the 195.12 Å emission line of Fe XII as the corona opens. As the corona b…
Determining the Galactic Halo's Emission Measure from UV and X-Ray Observations
Lei, Shijun; Henley, David B.; Shelton, Robin L.
We analyze a pair of Suzaku shadowing observations in order to determine the X-ray spectrum of the Galaxy's gaseous halo. Our data consist of an observation toward an absorbing filament in the southern Galactic hemisphere and an observation toward an unobscured region adjacent to the filament. We simultaneously fit the spectra with models having h…
Galaxy Clusters in the IRAC Dark Field. II. Mid-Infrared Sources
Surace, J. A.; Yan, L.; Krick, J. E. +4 more
We present infrared (IR) luminosities, star formation rates (SFR), colors, morphologies, locations, and active galactic nuclei (AGNs) properties of 24 µm detected sources in photometrically detected high-redshift clusters in order to understand the impact of environment on star formation (SF) and AGN evolution in cluster galaxies. We use thr…
The Spectral Energy Distributions of Red Two Micron All Sky Survey Active Galactic Nuclei
Wilkes, Belinda J.; McDowell, Jonathan C.; Schmidt, Gary +7 more
We present infrared (IR) to X-ray spectral energy distributions (SEDs) for 44 red active galactic nuclei (AGNs) selected from the Two Micron All Sky Survey (2MASS) survey on the basis of their red J - KS color (>2 mag) and later observed by Chandra. In comparison with optically-, radio-, and X-ray-selected AGNs, their median SEDs are…
Using HINODE/Extreme-Ultraviolet Imaging Spectrometer to Confirm a Seismologically Inferred Coronal Temperature
Marsh, M. S.; Walsh, R. W.
The Extreme-Ultraviolet Imaging Spectrometer on board the HINODE satellite is used to examine the loop system described in Marsh et al. by applying spectroscopic diagnostic methods. A simple isothermal mapping algorithm is applied to determine where the assumption of isothermal plasma may be valid, and the emission measure locii technique is used …
Gauging the Dark Matter Fraction in an L * S0 Galaxy at z = 0.47 Through Gravitational Lensing from Deep Hubble Space Telescope/Advanced Camera for Surveys Imaging
Kneib, J. -P.; Paolillo, M.; Jullo, E. +9 more
We analyze a new gravitational lens OAC-GL J1223-1239, serendipitously found in a deep I 814-band image of the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS). The lens is an L*, edge-on S0 galaxy at z l = 0.4656. The gravitational arc has a radius of 0farcs42 sime 1.74 h -1 kpc. We have determined t…
Swift GRB GRB071010B: Outlier of the E src peak - E γ and E iso - E src peak - t src jet Correlations
Yamaoka, Kazutaka; Ohno, Masanori; Sugita, Satoshi +12 more
We present multi-band results for GRB071010B based on Swift, Suzaku, and ground-based optical observations. This burst is an ideal target to evaluate the robustness of the E src peak - E iso and E src peak - E γ relations, whose studies have been in stagnation due to the lack of the…
Detection of the Central Star of the Planetary Nebula NGC 6302
Tsamis, Y. G.; Walsh, J. R.; Zijlstra, Albert A. +1 more
NGC 6302 is one of the highest ionization planetary nebulae (PNe) known and shows emission from species with ionization potential > 300 eV. The temperature of the central star must be > 200,000 K to photoionize the nebula, and has been suggested to be up to ~400,000 K. On account of the dense dust and molecular disk, the central star has not…
Multi-Epoch Multi-Wavelength Study of an Ultraluminous X-ray Source in M101: The Nature of the Secondary
Liu, Jifeng
Ultraluminous X-ray sources are non-nuclear point sources in external galaxies with LX = 2 × 1039-1041 erg s-1, and thus are possibly stellar black holes with special radiation mechanisms or intermediate mass black holes of 100-105 M sun. To measure their dynamical mass, one needs t…
The Extragalactic Distance Scale Without Cepheids. II. Surface Brightness Fluctuations
Sakai, Shoko; Mould, Jeremy
Distances of galaxies in the Hubble Space Telescope (HST) Key Project are based on the Cepheid period-luminosity relation. An alternative basis is the tip of the red giant branch (TRGB). Using archival HST data, we calibrate surface brightness fluctuations using 16 galaxies with TRGB branch measurements. The TRGB and Cepheid distance scales are sh…