Search Publications
The CME Acceleration Problem: Error Estimates in LASCO Coronal Mass Ejection Measurements
Wen, Yayuan; Wang, Jingxiu; Maia, Dalmiro Jorge Filipe
The properties of the coronal mass ejections (CMEs) observed by the Large Angle and Spectrometric Coronagraph Experiment (LASCO) on the Solar and Heliospheric Observatory (SOHO) spacecraft are kept in an online catalog that has been widely used in a series of analyses of individual events and in statistical overviews of CME properties. A subject o…
Multiple Coaxial Rings in the Bipolar Nebula Hubble 12
Kwok, Sun; Hsia, Chih Hao
A series of two-dimensional rings along a common axis aligned with the bipolar lobes is found in the planetary nebula Hb 12. The rings have separations of about 0.3", which can be translated into physical separations of ~1000 AU, or time separations of the order of 50 yr. We suggest that the existence of the rings is a manifestation of the interac…
Magnetic Evolution and Temperature Variation in a Coronal Hole
Zhang, Jun; Wang, Haimin; Wang, Jingxiu +1 more
We have explored the magnetic flux evolution and temperature variation in a coronal hole region, using Big Bear Solar Observatory deep magnetograms and SOHO EIT images observed from 2005 October 10 to 14. For comparison, we also investigated a neighboring quiet region of the Sun. The coronal hole evolved from its mature stage to its disappearance …
A Far-Ultraviolet Study of the Nova-like V794 Aquilae
Szkody, Paula; Sion, Edward M.; Godon, Patrick +1 more
V794 Aql was observed in a high state with the Hubble Space Telescope Space Telescope Imaging Spectrograph (HST STIS) on 2003 August 28, and with the Far Ultraviolet Spectroscopic Explorer (FUSE) on 2004 May 13. We present here a spectral analysis of the FUSE and HST STIS spectra. For a 0.9 Msolar, the best fit is an accretion disk with…
AEGIS: A Panchromatic Study of IRAC-selected Extremely Red Objects with Confirmed Spectroscopic Redshifts
Barmby, P.; Papovich, C.; Rigopoulou, D. +17 more
We study 87 extremely red objects (EROs), selected both to have color redder than R-[3.6]=4.0 and to have confirmed spectroscopic redshifts. Together, these two constraints result in this sample populating a fairly narrow redshift range at 0.76<z<1.42. The key new ingredient included here is deep Spitzer Space Telescope Infrared Array Camera…
Micro-Type III Radio Bursts
Morioka, Akira; Miyoshi, Yoshizumi; Masuda, Satoshi +5 more
We present a detailed description of the features of solar ``micro-type III'' radio bursts, which are elements of the so-called type III storms, using long-term observations made by the Geotail and Akebono satellites. Micro-type III bursts are characterized by short-lived, continuous, and weak emission. Their average power is estimated to be well …
The Radio Emission, X-Ray Emission, and Hydrodynamics of G328.4+0.2: A Comprehensive Analysis of a Luminous Pulsar Wind Nebula, Its Neutron Star, and the Progenitor Supernova Explosion
Gelfand, Joseph D.; Hughes, John P.; Gaensler, B. M. +3 more
We present new observational and modeling results obtained for the Galactic nonthermal radio source G328.4+0.2. Using X-ray data obtained by XMM-Newton, we confirm that its X-ray emission is heavily absorbed, has a spectrum best fitted by a power-law model of photon index Γ=2 with no evidence for a thermal component, comes from a region significan…
A Common Origin for Quasar Extended Emission-Line Regions and Their Broad-Line Regions
Fu, Hai; Stockton, Alan
We present a correlation between the presence of luminous extended emission-line regions (EELRs) and the metallicity of the broad-line regions (BLRs) of low-redshift quasars. The result is based on ground-based [O III] λ5007 narrowband imaging and Hubble Space Telescope UV spectra of 12 quasars at 0.20<=z<=0.45. Quasars showing luminous EELR…
Hubble Space Telescope Multiepoch Imaging of the PSR B0540-69 System Unveils a Highly Dynamic Synchrotron Nebula
Caraveo, P. A.; Bignami, G. F.; De Luca, A. +1 more
PSR B0540-69 is the Crab twin in the Large Magellanic Cloud. The age and energetic and overall behavior of the two pulsars are very similar. The same is true for the general appearance of their pulsar wind nebulae (PWNe). Analysis of Hubble Space Telescope images spanning 10 yr unveiled significant variability in the PWN surrounding PSR B0540-69, …
The Post-Coronal Mass Ejection Solar Atmosphere and Radio Noise Storm Activity
Ramesh, R.; Kathiravan, C.; Nataraj, H. S.
We carried out a statistical study of solar radio noise storms whose onset was in the aftermath of coronal mass ejections (CMEs) that occurred during 1997-2004, the first half of present solar cycle 23. The work is an attempt to understand the post-CME corona through observations of noise storms since the latter are considered to be closely relate…