Search Publications
X-Ray Thermal Coronae of Galaxies in Hot Clusters: Ubiquity of Embedded Mini-Cooling Cores
Vikhlinin, A.; Forman, W.; Sun, M. +3 more
We present a systematic investigation of X-ray thermal coronae in 157 early-type and 22 late-type galaxies from a survey of 25 hot (kT>3 keV), nearby (z<0.05) clusters, based on Chandra archival data. Cool galactic coronae (kT=0.5-1.1 keV generally) have been found to be common, >60% in LKs>2L* galaxies…
An unusually brilliant transient in the galaxy M85
Cenko, S. B.; Sanders, D. B.; Gal-Yam, A. +11 more
Historically, variable and transient sources have both surprised astronomers and provided new views of the heavens. Here we report the discovery of an optical transient in the outskirts of the lenticular galaxy Messier 85 in the Virgo cluster. With a peak absolute R magnitude of -12, this event is distinctly brighter than novae, but fainter than t…
The XMM-LSS survey: the Class 1 cluster sample over the initial 5 deg2 and its cosmological modelling
Maccagni, D.; Chiappetti, L.; Altieri, B. +30 more
We present a sample of 29 galaxy clusters from the XMM-LSS survey over an area of some 5 deg2 out to a redshift of z= 1.05. The sample clusters, which represent about half of the X-ray clusters identified in the region, follow well-defined X-ray selection criteria and are all spectroscopically confirmed. For all clusters, we provide X-r…
A Survey of Local Group Galaxies Currently Forming Stars. II. UBVRI Photometry of Stars in Seven Dwarfs and a Comparison of the Entire Sample
Smith, R. C.; Massey, Philip; Hodge, Paul W. +4 more
We have obtained UBVRI images with the Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory 4 m telescopes and Mosaic cameras of seven dwarfs in (or near) the Local Group, all of which have known evidence of recent star formation: IC 10, NGC 6822, WLM, Sextans B, Sextans A, Pegasus, and Phoenix. We construct color-magnitude d…
Flare Irradiance Spectral Model (FISM): Daily component algorithms and results
Chamberlin, Phillip C.; Woods, Thomas N.; Eparvier, Francis G.
The solar photon output from the Sun was once thought to be constant but is now known to vary considerably over timescales from seconds during solar flares to years due to the solar cycle. This is especially true in the wavelengths shorter than 208 nm (Al ionization edge), where measurements and models of the solar irradiance at these short wavele…
Polarisation studies of the prompt gamma-ray emission from GRB 041219a using the spectrometer aboard INTEGRAL
McGlynn, S.; McBreen, S.; Foley, S. +6 more
Context: Linear polarisation in gamma-ray burst prompt emission is an important diagnostic with the potential to significantly constrain models. The spectrometer aboard INTEGRAL, SPI, has the capability to detect the signature of polarised emission from a bright γ-ray source. GRB 041219a is the most intense burst localised by INTEGRAL with a fluen…
Discovery of a flux-related change of the cyclotron line energy in Hercules X-1
Klochkov, D.; Wilms, J.; Staubert, R. +5 more
Aims: We present the results of ten years of repeated measurements of the Cyclotron Resonance Scattering Feature (CRSF) in the spectrum of the binary X-ray pulsar
Molecular Hydrogen Emission from Protoplanetary Disks. II. Effects of X-Ray Irradiation and Dust Evolution
Tsujimoto, M.; Nomura, H.; Aikawa, Y. +2 more
Detailed models for the density and temperature profiles of gas and dust in protoplanetary disks are constructed by taking into account X-ray and UV irradiation from a central T Tauri star, as well as dust size growth and settling toward the disk midplane. The spatial and size distributions of dust grains are numerically computed by solving the co…
Cosmic Evolution of Black Holes and Spheroids. II. Scaling Relations at z=0.36
Treu, Tommaso; Malkan, Matthew A.; Blandford, Roger D. +1 more
We use high-resolution images obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope to determine morphology, nuclear luminosity, and structural parameters of the spheroidal component for a sample of 20 Seyfert galaxies at z=0.36. We combine these measurements with spectroscopic information from the Keck Telescope to det…
Quantitative Forecasting of Major Solar Flares
Rust, David M.; Georgoulis, Manolis K.
We define the effective connected magnetic field, Beff, a single metric of the flaring potential in solar active regions. We calculated Beff for 298 active regions (93 X- and M-flaring, 205 nonflaring) as recorded by SOHO/MDI during a 10 yr period covering much of solar cycle 23. We find that Beff is a robust crite…