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Evolutionary signatures in complex ejecta and their driven shocks
Farrugia, C.; Berdichevsky, D.
We examine interplanetary signatures of ejecta-ejecta interactions. To this end, two time intervals of inner-heliospheric (≤1AU) observations separated by 2 solar cycles are chosen where ejecta/magnetic clouds are in the process of interacting to form complex ejecta. At the Sun, both intervals are characterized by many coronal mass ejections (CMEs…
X-ray emission from the nuclei, lobes and hot-gas environments of two FR II radio galaxies
Hardcastle, M. J.; Croston, J. H.; Birkinshaw, M. +1 more
We report on the detection of multiple components of X-ray emission from the two FR II radio galaxies, 3C 223 and 3C 284, based on new XMM-Newton observations. We attribute the detected X-ray emission from the lobes of both sources to inverse-Compton scattering of cosmic microwave background photons. With this model, we find that the magnetic fiel…
The Globular Cluster Systems of Five Nearby Spiral Galaxies: New Insights from Hubble Space Telescope Imaging
Chandar, Rupali; Lee, Myung Gyoon; Whitmore, Bradley
We use available multifilter Hubble Space Telescope (HST) WFPC2 imaging of five (M81, M83, NGC 6946, M101, and M51, in order of distance) low-inclination, nearby spiral galaxies to study ancient star cluster populations. Combining rigorous selection criteria to reject contaminants (individual stars, background galaxies, and blends) with optical ph…
The diameter and evolutionary state of Procyon A. Multi-technique modeling using asteroseismic and interferometric constraints
Bordé, P.; Provost, J.; Berthomieu, G. +3 more
We report the angular diameter measurement obtained with the VINCI/VLTI instrument on the nearby star Procyon A (α CMi A, F5IV-V), at a relative precision of ± 0.9%. We obtain a uniform disk angular diameter in the K band of θUD = 5.376±0.047 mas and a limb darkened value of θLD = 5.448±0.053 mas. Together with the HIPPARCOS …
The interstellar N2 abundance towards HD 124314 from far-ultraviolet observations
Andersson, B. -G.; McCandliss, Stephan R.; Knauth, David C. +1 more
The abundance of interstellar molecular nitrogen (N2) is of considerable importance: models of steady-state gas-phase interstellar chemistry, together with millimetre-wavelength observations of interstellar N2H+ in dense molecular clouds predict that N2 should be the most abundant nitrogen-bearing molecu…
Coronal plasma flows and magnetic fields in solar active regions. Combined observations from SOHO and NSO/Kitt Peak
Marsch, E.; Xia, L. D.; Wiegelmann, T.
During the early days of the SOHO mission, SUMER observed a few active regions (ARs) connected with sunspots on the Sun and took their images and spectra in various EUV emission lines. In addition to these spectroscopic data magnetograms of the photospheric footpoint regions of the AR loops were available from the MDI on SOHO and the National Sola…
X-ray reprocessing in Seyfert galaxies: Simultaneous XMM-Newton/BeppoSAX observations
Perola, G. C.; Bianchi, S.; Guainazzi, M. +2 more
We selected a sample of eight bright unobscured (at least at the iron line energy) Seyfert galaxies observed simultaneously by XMM-Newton and BeppoSAX, taking advantage of the complementary characteristics of the two missions. The main results of our analysis can be summarized as follows: narrow neutral iron lines are confirmed to be an ubiquitous…
Dawn: A journey in space and time
Russell, C. T.; Jaumann, R.; Keller, H. U. +18 more
By successively orbiting both 4 Vesta and 1 Ceres the Dawn mission directly addresses the long-standing goals of understanding the origin and evolution of the solar system. Ceres and Vesta are two complementary terrestrial protoplanets (one apparently ;wet; and the other ;dry;), whose accretion was probably terminated by the formation of Jupiter. …
Going Slitless: Images of Forbidden-Line Emission Regions of Classical T Tauri Stars Observed with the Hubble Space Telescope
Edwards, Suzan; Hartigan, Patrick; Pierson, Rachel
We have observed five classical T Tauri stars known to have strong forbidden-line emission with STIS in slitless mode on the Hubble Space Telescope. This technique makes it possible to image jets within a few tens of AU of their exciting sources, a region of great interest for models of accretion disks and jets. Slitless images generate emission-l…
Imaging of the Supernova Remnant Cassiopeia A with the Multiband Imaging Photometer for Spitzer (MIPS)
Egami, E.; Gehrz, R. D.; Krause, O. +20 more
We present new images of the supernova remnant (SNR) Cas A observed in the 24 and 70 µm bands of the Spitzer Space Telescope (Spitzer). The IR emission correlates well with the Si X-ray and optical [S II] emission but poorly with either the synchrotron-dominated radio structure or the continuum X-ray emission. The IR is therefore dominated b…