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Search for tidal dwarf galaxy candidates in a sample of ultraluminous infrared galaxies
Colina, L.; Monreal-Ibero, A.; Arribas, S. +1 more
Context: Small star-forming galaxies made out of collisional debris have been found in a variety of merging systems. So far only a few of them are known in Ultraluminous Infrared Galaxies (ULIRGs) although they show clear signs of interactions. Whether external star formation may take place in such objects in an open question.
Aims: The aim of…
Saturn's auroral/polar H +3 infrared emission . I. General morphology and ion velocity structure
Melin, Henrik; Miller, Steve; Stallard, Tom +3 more
We present an analysis of an extensive dataset of observations of the auroral/polar regions of Saturn, carried out in 2004 and 2005 using the high-resolution facility spectrometer CSHELL on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. The paper outlines the morphology of emission in the H +3νQ(1,0) line a…
The X-Ray Structure and Spectrum of the Pulsar Wind Nebula Surrounding PSR B0540-69.3
Safi-Harb, S.; Holt, S. S.; Williams, R. M. +2 more
We present the first spatially resolved spectral study of an extragalactic pulsar wind nebula (PWN), that surrounding the 50 ms pulsar B0540-69.3 in the Large Magellanic Cloud, using the ACIS instrument on board the Chandra X-ray Observatory. The spectral properties of the PWN change at a radius of ~5", corresponding to a shell detected optically …
Elemental Abundances of Nearby Galaxies through High Signal-to-Noise Ratio XMM-Newton Observations of Ultraluminous X-Ray Sources
Reynolds, Christopher S.; Mushotzky, Richard F.; Winter, Lisa M.
In this paper we examined XMM-Newton EPIC spectra of 14 ultraluminous X-ray sources (ULXs) in addition to the XMM-Newton RGS spectra of two sources (Holmberg II X-1 and Holmberg IX X-1). We determined oxygen and iron abundances of the host galaxy's ISM using K-shell (O) and L-shell (Fe) X-ray photoionization edges toward these ULXs. We found that …
Saturn's neutral torus versus Jupiter's plasma torus
Delamere, P. A.; Bagenal, F.; Ray, L. C. +1 more
With the recent discovery of an atmospheric plume of H2O it is thought that Enceladus could deliver as much as 300 kg/s of neutral gas to Saturn's inner magnetosphere. Io is the source of roughly 1 ton/s of sulfur and oxygen gas at Jupiter. Despite the apparent similarity, the neutral/ion ratio at Saturn is 3 orders of magnitude higher …
D/H and Nearby Interstellar Cloud Structures
Linsky, J. L.
Analysis of UV spectra obtained with the HST, FUSE and other satellites provides a new understanding of the deuterium abundance in the local region of the galactic disk. The wide range of gas-phase D/H measurements obtained outside of the Local Bubble can now be explained as due to different amounts of deuterium depletion on carbonaceous grains. T…
Effects of a large convective storm on Saturn's equatorial jet
Showman, Adam P.; Sayanagi, Kunio M.
Hubble Space Telescope observations revealed that Saturn's equatorial jet at the cloud level blows at ∼275 m s -1 today, approximately half the ∼470 m s -1 wind during the Voyager flybys in 1980-1981. Radiative transfer calculations estimate the clouds to be significantly higher today than in 1980. The higher clouds make it d…
High-resolution X-ray spectroscopy and imaging of the nuclear outflow of the starburst galaxy NGC 253
Pietsch, W.; Ehle, M.; Bauer, M. +3 more
Aims:Using XMM-Newton data, we have studied the nuclear outflow of the nearby starburst galaxy NGC 253 in X-rays with respect to its morphology and to spectral variations along the outflow.
Methods: We analysed XMM-Newton RGS spectra, RGS brightness profiles in cross-dispersion direction, narrow-band RGS and EPIC images, and EPIC PN brightness…
Chandra and Spitzer observations of CDFS X-ray obscured QSOs
Georgakakis, A.; Georgantopoulos, I.; Akylas, A.
We present Chandra and Spitzer data for the 186, extragalactic, hard 2-10 keV X-ray selected sources, which lie in the central part of the Chandra Deep Field South (CDFS). For the vast majority of sources (99.5%), there is a spectroscopic or photometric redshift available. We classify 17 sources as X-ray obscured QSOs, strictly according to X-ray …
A Galaxy in Transition: Structure, Globular Clusters, and Distance of the Star-Forming S0 Galaxy NGC 1533 in Dorado
Meurer, Gerhardt R.; Blakeslee, John P.; Putman, Mary E. +1 more
We use two-band imaging data from the Advanced Camera for Surveys onboard the Hubble Space Telescope for a detailed study of NGC 1533, an SB0 galaxy in the Dorado group surrounded by a ring of H I. NGC 1533 appears to be completing a transition from late to early type: it is red, but not quite dead. Faint spiral structure becomes visible following…