Search Publications
Implications of X-ray Observations for Electron Acceleration and Propagation in Solar Flares
Aschwanden, M. J.; Liu, W.; Zharkova, V. V. +6 more
High-energy X-rays and γ-rays from solar flares were discovered just over fifty years ago. Since that time, the standard for the interpretation of spatially integrated flare X-ray spectra at energies above several tens of keV has been the collisional thick-target model. After the launch of the Reuven Ramaty High Energy Solar Spectroscopic Imager (…
An XMM-Newton spectral survey of 12 µm selected galaxies - I. X-ray data
Nandra, Kirpal; Brightman, Murray
We present an X-ray spectral analysis of 126 galaxies of the 12 µm galaxy sample. By studying this sample at X-ray wavelengths, we aim to determine the intrinsic power, continuum shape and obscuration level in these sources. We improve upon previous works by the use of superior data in the form of higher signal-to-noise ratio spectra, finer …
Three-year Swift-BAT Survey of Active Galactic Nuclei: Reconciling Theory and Observations?
Greiner, J.; Merloni, A.; Comastri, A. +3 more
It is well accepted that unabsorbed as well as absorbed active galactic nuclei (AGNs) are needed to explain the nature and shape of the Cosmic X-ray background (CXB), even if the fraction of highly absorbed objects (dubbed Compton-thick sources) still substantially escapes detection. We derive and analyze the absorption distribution using a comple…
A candidate redshift z~10 galaxy and rapid changes in that population at an age of 500Myr
Trenti, M.; Oesch, P. A.; Carollo, C. M. +9 more
Searches for very-high-redshift galaxies over the past decade have yielded a large sample of more than 6,000 galaxies existing just 900-2,000million years (Myr) after the Big Bang (redshifts 6>z>3 ref. 1). The Hubble Ultra Deep Field (HUDF09) data have yielded the first reliable detections of z~8 galaxies that, together with reports of a γ-r…
Luminous blue variable eruptions and related transients: diversity of progenitors and outburst properties
Filippenko, Alexei V.; Smith, Nathan; Li, Weidong +2 more
We present new light curves and optical spectra for a number of extragalactic optical transients or 'supernova impostors' related to giant eruptions of luminous blue variables (LBVs), and we provide a comparative discussion of LBV-like giant eruptions known thus far. New data include photometry and spectroscopy of supernovae (SNe) 1999bw, 2000ch, …
The Hubble Space Telescope Wide Field Camera 3 Early Release Science Data: Panchromatic Faint Object Counts for 0.2-2 µm Wavelength
Hathi, Nimish P.; Koekemoer, Anton M.; Mutchler, Max +36 more
We describe the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Early Release Science (ERS) observations in the Great Observatories Origins Deep Survey (GOODS) South field. The new WFC3 ERS data provide calibrated, drizzled mosaics in the UV filters F225W, F275W, and F336W, as well as in the near-IR filters F098M (Ys ), F125W (J…
Probing the Intergalactic Medium/Galaxy Connection. V. On the Origin of Lyα and O VI Absorption at z < 0.2
Prochaska, J. Xavier; Mulchaey, J.; Weiner, B. +2 more
We analyze the association of galaxies with Lyα and O VI absorption, the most commonly detected transitions of the low-z intergalactic medium (IGM), in the fields of 14 quasars with z em = 0.06-0.57. Confirming previous studies, we observe a high covering fraction for Lyα absorption to impact parameter ρ = 300 h -1 72
Flow of mass and energy in the magnetospheres of Jupiter and Saturn
Delamere, Peter A.; Bagenal, Fran
We present simple models of the plasma disks surrounding Jupiter and Saturn based on published measurements of plasma properties. We calculate radial profiles of the distribution of plasma mass, pressure, thermal energy density, kinetic energy density, and energy density of the suprathermal ion populations. We estimate the mass outflow rate as wel…
Planck early results. VII. The Early Release Compact Source Catalogue
Kneissl, R.; Miville-Deschênes, M. -A.; Bernard, J. -P. +228 more
A brief description of the methodology of construction, contents and usage of the Planck Early Release Compact Source Catalogue (ERCSC), including the Early Cold Cores (ECC) and the Early Sunyaev-Zeldovich (ESZ) cluster catalogue is provided. The catalogue is based on data that consist of mapping the entire sky once and 60% of the sky a second tim…
Baryons at the Edge of the X-ray-Brightest Galaxy Cluster
Fabian, Andrew C.; Sanders, Jeremy S.; Allen, Steven W. +8 more
Studies of the diffuse x-ray-emitting gas in galaxy clusters have provided powerful constraints on cosmological parameters and insights into plasma astrophysics. However, measurements of the faint cluster outskirts have become possible only recently. Using data from the Suzaku x-ray telescope, we determined an accurate, spatially resolved census o…