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INTEGRAL observations of SS433: Results of a coordinated campaign
Bikmaev, I. F.; Sunyaev, R. A.; Sakhibullin, N. A. +18 more
Results of simultaneous INTEGRAL and optical observations of the galactic microquasar SS433 in May 2003 and INTEGRAL /RXTE observations in March 2004 are presented. Persistent precessional variability with a maximum to minimum uneclipsed hard X-ray flux ratio of ∼ 4 is discovered. The 18 60 keV X-ray eclipse is found to be in phase with optical an…
Measurement of the Energy Release Rate and the Reconnection Rate in Solar Flares
Shibata, Kazunari; Isobe, Hiroaki; Takasaki, Hiroyuki
By using the method presented by Isobe et al., the nondimensional reconnection rate vin/vA has been determined for the impulsive phase of three two-ribbon flares, where vin is the velocity of the reconnection inflow and vA is the Alfvén velocity. The nondimensional reconnection rate is important to make …
The Chandra view of extended X-ray emission from Pictor A
Hardcastle, M. J.; Croston, J. H.
We discuss the extended X-ray emission seen in three archival Chandra observations, and one archival XMM-Newton observation, of the Fanaroff-Riley type II radio galaxy, Pictor A. The overall properties of the X-ray lobes are consistent with the conclusions of earlier works that the extended X-ray emission is largely due to the inverse-Compton proc…
The Link between Star Formation and Accretion in LINERs: A Comparison with Other Active Galactic Nucleus Subclasses
O'Halloran, B.; Dudik, R. P.; Satyapal, S. +1 more
We present archival high-resolution X-ray imaging observations of 25 nearby LINERs observed by ACIS on board Chandra. This sample builds on our previously published proprietary and archival X-ray observations and includes the complete set of LINERs with published black hole masses and FIR luminosities that have been observed by Chandra. Of the 82 …
Equatorial electron density measurements in Saturn's inner magnetosphere
Gurnett, D. A.; Persoon, A. M.; Dougherty, M. K. +4 more
Upper hybrid resonance emissions detected by the Radio and Plasma Wave Science (RPWS) instrument on the Cassini spacecraft are used to obtain electron densities on five equatorial orbits of Saturn at radial distances ranging from 3 to 9 saturnian radii (RS). The electron density profiles for these orbits show a highly repeatable radial …
Halos of Spiral Galaxies. I. The Tip of the Red Giant Branch as a Distance Indicator
Ferguson, H. C.; Rich, R. M.; Mouhcine, M. +2 more
We have imaged the halo populations of a sample of nearby spiral galaxies using the Wide Field Planetary Camera 2 on board the Hubble Space Telescope with the aim of studying the stellar population properties and relating them to those of the host galaxies. In four galaxies, the red giant branch is sufficiently well populated to measure the magnit…
A Coherent Timing Solution for the Nearby Isolated Neutron Star RX J0720.4-3125
van Kerkwijk, M. H.; Kaplan, D. L.
We present the results of a dedicated effort to measure the spin-down rate of the nearby isolated neutron star RX J0720.4-3125. Comparing arrival times of the 8.39 s pulsations for data from Chandra, we derive an unambiguous timing solution for RX J0720.4-3125 that is accurate to <0.1 cycles over >5 years. Adding data from XMM and ROSAT, the…
X-Ray Properties of Lyman Break Galaxies in the Great Observatories Origins Deep Survey
Lehmer, B. D.; Alexander, D. M.; Giavalisco, M. +9 more
We constrain the X-ray emission properties of Lyman break galaxies (LBGs) at z~3-6 using the ~2 Ms Chandra Deep Field North and ~1 Ms Chandra Deep Field South. Large samples of LBGs were discovered using the Hubble Space Telescope as part of the Great Observatories Origins Deep Survey (GOODS). Deep optical and X-ray imaging over the GOODS fields h…
The exceptional X-ray variability of the dwarf Seyfert nucleus NGC 4395
Iwasawa, K.; Vaughan, S.; Fabian, A. C. +1 more
An analysis of the X-ray variability of the low-luminosity Seyfert nucleus NGC 4395, based on a long XMM-Newton observation, is presented. The power spectrum shows a clear break from a flat spectrum (α~ 1) to a steeper spectrum (α~ 2) at a frequency fbr= 0.5-3.0 × 10-3 Hz, comparable to the highest characteristic frequency fo…
Moving Magnetic Features as Prolongation of Penumbral Filaments
Martínez Pillet, V.; Sainz Dalda, A.
A sequence of 633 high spatial resolution magnetograms and continuum images from SOHO MDI of NOAA AR 0330 is used to study moving magnetic feature (MMF) activity in the moat surrounding a mature leader sunspot. The time-averaged frame shows that the moat region is covered by a magnetic field that exhibits the same polarity distribution as that obs…