Search Publications
Pseudobulges in the Disk Galaxies NGC 7690 and NGC 4593
Kormendy, John; Knapen, Johan H.; Cornell, Mark E. +2 more
We present Ks-band surface photometry of NGC 7690 (Hubble type Sab) and NGC 4593 (SBb). We find that, in both galaxies, a major part of the ``bulge'' is as flat as the disk and has approximately the same color as the inner disk. In other words, the ``bulges'' of these galaxies have disklike properties. We conclude that these are example…
Footpoint Motion of the Continuum Emission in the 2002 September 30 White-Light Flare
Ding, M. D.; Chen, Q. R.
We present observations of the 2002 September 30 white-light flare, in which the optical continuum emission near the Hα line is enhanced by ~10%. The continuum emission exhibits a close temporal and spatial coincidence with the hard X-ray (HXR) footpoint observed by RHESSI. We find a systematic motion of the flare footpoint seen in the continuum e…
INTEGRAL and RXTE Observations of Centaurus A
Rothschild, Richard E.; Staubert, Rüdiger; Wilms, Jörn +6 more
INTEGRAL and RXTE performed three simultaneous observations of the nearby radio galaxy Centaurus A in 2003 March, 2004 January, and 2004 February with the goals of investigating the geometry and emission processes via the spectral/temporal variability of the X-ray/low-energy gamma-ray flux, and intercalibration of the INTEGRAL instruments with res…
Capella Corona Revisited: A Combined View from XMM-Newton RGS and Chandra HETGS and LETGS
Sako, M.; Kahn, S. M.; Gupta, R. +2 more
We present a combined analysis of the X-ray emission of the Capella corona obtained with XMM-Newton RGS and Chandra HETGS and LETGS. An improved atomic line database and a new differential emission measure (DEM) deconvolution method are developed for this purpose. Our new atomic database is based on the Astrophysical Plasma Emission Database and i…
Long-lived Solar Neutron Emission in Comparison with Electron-produced Radiation in the 2005 September 7 Solar Flare
Tanaka, Y. T.; Yoshikawa, I.; Mukai, T. +23 more
Strong signals of neutral emissions were detected in association with a solar flare that occurred on 2005 September 7. They were produced by both relativistic ions and electrons. In particular, relativistic neutrons were observed with the solar neutron telescopes (SNTs) located at Mount Chacaltaya in Bolivia and Mount Sierra Negra in Mexico and wi…
The Evolution of Rest-Frame K-Band Properties of Early-Type Galaxies from z = 1 to the Present1,
Rix, H. -W.; van der Wel, A.; Illingworth, G. D. +3 more
We measure the evolution of the rest-frame K-band fundamental plane from z=1 to the present by using IRAC imaging of a sample of early-type galaxies in the Chandra Deep Field-South at z~1 with accurately measured dynamical masses. We find that M/LK evolves as Δln(M/LK)=(-1.18+/-0.10)z, which is slower than in the B band [Δln(…
Hidden Trigger for the Giant Starburst Arc in M83?
Mediavilla, Evencio; Díaz, Rubén J.; Dottori, Horacio +3 more
The huge star formation events that occur at some galactic centers do not provide enough clues as to their origin, since the morphological signatures of the triggering mechanism are smeared out in the timescale of a few orbital revolutions of the galaxy core. Our high spatial resolution three-dimensional near-infrared spectroscopy for the first ti…
The H I Content of E+A Galaxies
Dejonghe, H.; Pisano, D. J.; Freeman, K. +3 more
We present deep single-dish H I observations of a sample of six nearby E+A galaxies (0.05<z<0.1). A nonnegligible fraction of a local sample of E+As are detected in H I. In four galaxies, we have detected up to a few times 109 Msolar of neutral gas. These E+A galaxies are almost as gas-rich as spiral galaxies with compa…
Density Diagnostics of the Hot Plasma in AE Aquarii with XMM-Newton
Ishida, Manabu; Kunieda, Hideyo; Okada, Shunsaku +1 more
We report on XMM-Newton observations of the magnetic CV AE Aqr. High-resolution spectroscopy of the He-like triplet of N and O with the RGS has enabled us to measure the electron number density of the plasma as ~1011 cm-3. Incorporating this with the emission measure, we estimate the geometrical scale of the plasma emitting t…
A Time-dependent Leptonic Model for Microquasar Jets: Application to LS I +61 303
Gupta, S.; Böttcher, M.
The Galactic high-mass X-ray binary and jet source (microquasar) LS I +61 303 has recently been detected at TeV γ-ray energies by the MAGIC telescope. We have applied a time-dependent leptonic jet model to the broadband spectral energy distribution (SED), and we have suggested (although not unambiguously detected) an orbital modulation of the very…