Search Publications
On the nature of the progenitors of three Type II-P supernovae: 2004et, 2006my and 2006ov
Smartt, S. J.; Maund, J. R.; Mattila, S. +4 more
The pre-explosion observations of the Type II-P supernovae 2006my, 2006ov and 2004et are re-analysed. In the cases of supernovae 2006my and 2006ov we argue that the published candidate progenitors are not coincident with their respective supernova sites in pre-explosion Hubble Space Telescope observations. We therefore derive upper luminosity and …
Eruption history of the Elysium Volcanic Province, Mars
Platz, Thomas; Michael, Gregory
Volcanism has played a significant role in shaping the surface of Mars. Volatiles released during eruptions profoundly altered the composition and density of the Martian atmosphere in the past. Quantifying the amounts of volcanic outgassing has been attempted regionally and globally, however, volume estimates of erupted volcanic material in time a…
Evolution of an MHD-scale Kelvin-Helmholtz vortex accompanied by magnetic reconnection: Two-dimensional particle simulations
Hasegawa, H.; Fujimoto, M.; Shinohara, I. +1 more
We have performed 2.5-dimensional full particle simulations of an MHD-scale Kelvin-Helmholtz (KH) vortex and accompanying magnetic reconnection. This is the first study of so-called vortex-induced reconnection (VIR) using kinetic simulations. First, as a key property of the VIR, we found that magnetic reconnection occurs at multiple points in the …
Contemporaneous Chandra HETG and Suzaku X-ray observations of NGC 4051
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +4 more
We present the results of a deep 300 ks Chandra High Energy Transmission Grating (HETG) observation of the highly variable narrow-line Seyfert Type 1 galaxy NGC 4051. The HETG spectrum reveals 28 significant soft X-ray ionized lines in either emission or absorption; primarily originating from H-like and He-like K-shell transitions of O, Ne, Mg and…
Simulation of electromagnetic ion cyclotron triggered emissions in the Earth's inner magnetosphere
Omura, Yoshiharu; Shoji, Masafumi
In a recent observation by the Cluster spacecraft, emissions triggered by electromagnetic ion cyclotron (EMIC) waves were discovered in the inner magnetosphere. We perform hybrid simulations to reproduce the EMIC triggered emissions. We develop a self-consistent one-dimensional hybrid code with a cylindrical geometry of the background magnetic fie…
A Deep Chandra ACIS Study of NGC 4151. I. The X-ray Morphology of the 3 kpc Diameter Circum-nuclear Region and Relation to the Cold Interstellar Medium
Elvis, Martin; Zezas, Andreas; Schinnerer, Eva +6 more
We report on the imaging analysis of ~200 ks sub-arcsecond resolution Chandra Advanced CCD Imaging Spectrometer (ACIS-S) observations of the nearby Seyfert 1 galaxy NGC 4151. Bright, structured soft X-ray emission is observed to extend from 30 pc to 1.3 kpc in the southwest from the nucleus, much farther than seen in earlier X-ray studies. The ter…
X-ray Properties of Narrow-line Seyfert 1 Galaxies with Very Small Broadline Widths
Wang, T. G.; Yuan, W.; Zhou, H. Y. +2 more
Narrow-line Seyfert 1 galaxies (NLS1s) with very small broadline widths (say, FWHM(Hβ) lsim1200 km s-1) represent the extreme type of Seyfert 1 galaxies that have small black hole masses (M BH) and/or high Eddington ratios (L/L Edd). Here, we study the X-ray properties of a homogeneously and optically selected samp…
GRB 091127/SN 2009nz and the VLT/X-shooter spectroscopy of its host galaxy: probing the faint end of the mass-metallicity relation
Covino, S.; D'Avanzo, P.; Sánchez-Ramírez, R. +36 more
We perform a detailed study of the gamma-ray burst GRB 091127/SN 2009nz host galaxy at z = 0.490 using the VLT/X-shooter spectrograph in slit and integral-field unit (IFU) mode. From the analysis of the optical and X-ray afterglow data obtained from ground-based telescopes and Swift-XRT, we confirm the presence of a bump associated with SN 2009nz …
XMM-Newton observations of IGR J18410-0535: the ingestion of a clump by a supergiant fast X-ray transient
Campana, S.; Cusumano, G.; Israel, G. +6 more
Context. IGR J18410-0535 is a supergiant fast X-ray transients. This subclass of supergiant X-ray binaries typically undergoes few-hour-long outbursts reaching luminosities of 1036-1037 erg s-1, the occurrence of which has been ascribed to the combined effect of the intense magnetic field and rotation of the compac…
Multiwavelength Observations of A0620-00 in Quiescence
Prochaska, J. Xavier; Maccarone, Thomas J.; Danforth, Charles W. +17 more
We present contemporaneous X-ray, ultraviolet, optical, near-infrared, and radio observations of the black hole binary system, A0620-00, acquired in 2010 March. Using the Cosmic Origins Spectrograph on the Hubble Space Telescope, we have obtained the first FUV spectrum of A0620-00 as well as NUV observations with the Space Telescope Imaging Spectr…