Search Publications
Solar Source Regions for 3He-rich Solar Energetic Particle Events Identified Using Imaging Radio, Optical, and Energetic Particle Observations
Pick, M.; Wang, L.; Mason, G. M. +2 more
We have identified the sources of six impulsive 3He-rich solar energetic particle events using imaging radio, optical, and energetic ion and electron data, together with calculated coronal fields obtained from extrapolating photospheric magnetograms using a potential field source surface (PFSS) model. These events were all studied in 20…
Two fluid effects on three-dimensional reconnection in the Swarthmore Spheromak Experiment with comparisons to space dataa)
Brown, M. R.; Cothran, C. D.; Fung, J.
Several new experimental results are reported from spheromak merging studies at the Swarthmore Spheromak Experiment [M. R. Brown, Phys. Plasmas 6, 1717 (1999)] with relevance to three-dimensional (3D) reconnection in laboratory and space plasmas. First, recent velocity measurements of impurity ions using ion Doppler spectroscopy are reported. Bidi…
Accretion and Nuclear Activity of Quiescent Supermassive Black Holes. II. Optical Study and Interpretation
Elvis, M.; Graham, Alister W.; Pellegrini, S. +5 more
Our X-ray study of the nuclear activity in a new sample of six quiescent early-type galaxies, as well as in a larger sample from the literature, confirmed (Paper I) that the Bondi accretion rate of diffuse hot gas is not a good indicator of the SMBH X-ray luminosity. Here we suggest that a more reliable estimate of the accretion rate must include …
The nature of the HE0450-2958 system
Robinson, Andrew; Storchi-Bergmann, Thaisa; Merritt, David +3 more
Magain et al. argued that the host galaxy of the quasar in HE0450-2958 is substantially underluminous given the quasar brightness. Using kinematical information from the spectra of the quasar and the companion galaxy, an ultraluminous infrared galaxy, we test the hypothesis that the black hole powering the quasar was ejected from the companion gal…
Near-Infrared and the Inner Regions of Protoplanetary Disks
Ivezić, Željko; Jurkić, Tomislav; Vinković, Dejan +1 more
We examine the ``puffed-up inner disk'' model proposed by Dullemond, Dominik, & Natta for explaining the near-IR excess radiation from Herbig Ae/Be stars. Detailed model computations show that the observed near-IR excess requires more hot dust than is contained in the puffed-up disk rim. The rim can produce the observed near-IR excess only if …
Optical and X-Ray Identification of Faint Radio Sources in the GOODS CDF-S Advanced Camera for Surveys Field
Koekemoer, A.; Mobasher, B.; Norris, R. P. +2 more
We present optical and X-ray identifications for the 64 radio sources in the Great Observatories Origins Deep Survey Chandra Deep Field-South Advanced Camera for Surveys (ACS) field revealed in the Australia Telescope Compact Array 1.4 GHz survey of the Chandra Deep Field-South. Optical identifications are made using the ACS images and catalogs, w…
A hard X-ray view of giga-hertz peaked spectrum radio galaxies
Guainazzi, M.; Piconcelli, E.; Grandi, P. +3 more
We present the first broadband X-ray observations of four Giga-Hertz Peaked Spectrum (GPS) radio galaxies at redshift ⪉1 performed by Chandra and XMM-Newton. These observations more than double the number of members of this class with measured spectra in hard (E > 2 keV) X-rays. All sources were detected. Their radio-to-X-ray spectral energy di…
Shapley Optical Survey - II. The effect of environment on the colour-magnitude relation and galaxy colours
Mercurio, A.; Capaccioli, M.; Gargiulo, A. +5 more
We present an analysis of the effects of environment on the photometric properties of galaxies in the core of the Shapley supercluster at z = 0.05, one of the most massive structures in the local universe. The Shapley Optical Survey (SOS) comprises archive Wide Field Imager (WFI) optical imaging of a 2.0deg2 region containing the rich c…
Relativistic blue- and red-shifted absorption lines in AGNs
Cappi, M.
Current, accumulating evidence for (mildly) relativistic blue- and red-shifted absorption lines in AGNs is reviewed. XMM-Newton and Chandra sensitive X-ray observations are starting to probe not only the kinematics (velocity) but also the dynamics (accelerations) of highly ionized gas flowing in-and-out from, likely, a few gravitational radii from…
Mars water vapor abundance from SPICAM IR spectrometer: Seasonal and geographic distributions
Bertaux, Jean-Loup; Korablev, Oleg; Fedorova, Anna +3 more
The near-IR channel of SPICAM experiment on Mars Express spacecraft is a 800-g acousto-optic tunable filter (AOTF)-based spectrometer operating in the spectral range of 1-1.7 µm with resolving power of ~2000. It was put aboard as an auxiliary channel dedicated to nadir H2O measurements in the 1.37-µm spectral band. This prim…