Search Publications
Multiple Plasma Ejections and Intermittent Nature of Magnetic Reconnection in Solar Chromospheric Anemone Jets
Shibata, K.; Isobe, H.; Singh, K. A. P. +2 more
The recent discovery of chromospheric anemone jets with the Solar Optical Telescope (SOT) on board Hinode has shown an indirect evidence of magnetic reconnection in the solar chromosphere. However, the basic nature of magnetic reconnection in chromosphere is still unclear. We studied nine chromospheric anemone jets from SOT/Hinode using Ca II H fi…
Probing the Role of Carbon in Ultraviolet Extinction along Galactic Sight Lines
Murthy, J.; Babu, B. R. S.; Parvathi, V. S. +1 more
We report previously undetermined interstellar gas and dust-phase carbon abundances along 15 Galactic sight lines based on archival data of the strong 1334.5323 Å transition observed with the Space Telescope Imaging Spectrograph. These are combined with previously reported carbon measurements along six sight lines to produce a complete sample of i…
Variability-selected Low-luminosity Active Galactic Nuclei in the 4 Ms Chandra Deep Field-South
Lehmer, B. D.; Alexander, D. M.; Bauer, F. E. +8 more
The 4 Ms Chandra Deep Field-South (CDF-S) and other deep X-ray surveys have been highly effective at selecting active galactic nuclei (AGNs). However, cosmologically distant low-luminosity AGNs (LLAGNs) have remained a challenge to identify due to significant contribution from the host galaxy. We identify long-term X-ray variability (~month-years,…
Defining the "Blind Spot" of Hinode EIS and XRT Temperature Measurements
Golub, Leon; Winebarger, Amy R.; Warren, Harry P. +4 more
Observing high-temperature, low emission measure plasma is key to unlocking the coronal heating problem. With current instrumentation, a combination of EUV spectral data from Hinode Extreme-ultraviolet Imaging Spectrometer (EIS; sensitive to temperatures up to 4 MK) and broadband filter data from Hinode X-ray Telescope (XRT; sensitive to higher te…
Rapid Coeval Black Hole and Host Galaxy Growth in MRC 1138-262: The Hungry Spider
Altieri, B.; Valtchanov, I.; Stern, D. +30 more
We present a detailed study of the infrared spectral energy distribution of the high-redshift radio galaxy MRC 1138-26 at z = 2.156, also known as the Spiderweb Galaxy. By combining photometry from Spitzer, Herschel, and LABOCA we fit the rest-frame 5-300 µm emission using a two-component, starburst, and active galactic nucleus (AGN) model. …
A Global Two-temperature Corona and Inner Heliosphere Model: A Comprehensive Validation Study
Fedorov, A.; Llebaria, A.; Lamy, P. L. +9 more
The recent solar minimum with very low activity provides us a unique opportunity for validating solar wind models. During CR2077 (2008 November 20 through December 17), the number of sunspots was near the absolute minimum of solar cycle 23. For this solar rotation, we perform a multi-spacecraft validation study for the recently developed three-dim…
Broadband Spectral Analysis of the Galactic Ridge X-Ray Emission
Makishima, Kazuo; Nakazawa, Kazuhiro; Yuasa, Takayuki
Detailed spectral analysis of the Galactic X-ray background emission, or the Galactic Ridge X-ray Emission (GRXE), is presented. To study the origin of the emission, broadband and high-quality GRXE spectra were produced from 18 pointing observations with Suzaku in the Galactic bulge region, with a total exposure of 1 Ms. The spectra were successfu…
Search for Gamma-ray Emission from X-Ray-selected Seyfert Galaxies with Fermi-LAT
Ozaki, M.; Troja, E.; Caraveo, P. A. +133 more
We report on a systematic investigation of the γ-ray properties of 120 hard X-ray-selected Seyfert galaxies classified as "radio-quiet" objects, utilizing the three-year accumulation of Fermi Large Area Telescope (LAT) data. Our sample of Seyfert galaxies is selected using the Swift Burst Alert Telescope 58 month catalog, restricting the analysis …
Tracing the Gas to the Virial Radius (R 100) in a Fossil Group
Humphrey, Philip J.; Buote, David A.; Brighenti, Fabrizio +3 more
We present a Chandra, Suzaku, and ROSAT study of the hot intragroup medium (IGrM) of the relaxed fossil group/poor cluster RX J1159+5531. This group exhibits an advantageous combination of flat surface brightness profile, high luminosity, and optimal distance, allowing the gas to be detected out to the virial radius (R vir≡ R 108
Analyzing Star Cluster Populations with Stochastic Models: The Hubble Space Telescope/Wide Field Camera 3 Sample of Clusters in M83
Whitmore, Bradley C.; Chandar, Rupali; Fouesneau, Morgan +1 more
The majority of clusters in the universe have masses well below 105 M ⊙. Hence, their integrated fluxes and colors can be affected by the presence or absence of a few bright stars introduced by stochastic sampling of the stellar mass function. Specific methods are being developed to extend the analysis of cluster energy distr…