Search Publications
Giant H II Regions in M101. I. X-Ray Analysis of Hot Gas
Feng, Li; Chu, You-Hua; Wang, Q. Daniel +4 more
We performed a Chandra X-ray study of three giant H II regions (GHRs), NGC 5461, NGC 5462, and NGC 5471, in the spiral galaxy M101. The X-ray spectra of the three GHRs all contain a prominent thermal component with a temperature of ~0.2 keV. In NGC 5461, the spatial distribution of the soft (<1.5 keV) X-ray emission is generally in agreement wi…
Coupling between whistler waves and slow-mode solitary waves
Le Contel, O.; Tenerani, A.; Califano, F. +1 more
The interplay between electron- and ion-scale phenomena is of general interest for both laboratory and space plasma physics. In this paper, we investigate the linear coupling between whistler waves and slow magnetosonic solitons through two-fluid numerical simulations. Whistler waves can be trapped in the presence of inhomogeneous external fields …
Allen Telescope Array Multi-frequency Observations of the Sun
Hurford, G. J.; Saint-Hilaire, P.; Bower, G. C. +2 more
We present the first observations of the Sun with the Allen Telescope Array (ATA). We used up to six frequencies, from 1.43 to 6 GHz, and baselines from 6 to 300 m. To our knowledge, these are the first simultaneous multi-frequency full-Sun maps obtained at microwave frequencies without mosaicing. The observations took place when the Sun was relat…
The Asymmetrical Eruption of a Quiescent Filament and Associated Halo CME
Li, H.; Hong, J.; Yang, J. +5 more
We will present detailed observations of the asymmetrical eruption of a large quiescent filament on 24 November 2002, which was followed by a two-ribbon flare, three coronal dimmings, endpoint brightenings, and a very fast halo-type coronal mass ejection (CME). Before the eruption, the filament lay along the main neutral line (MNL) underneath a si…
Suzaku X-Ray Observation of the Dwarf Nova Z Camelopardalis at the Onset of an Optical Outburst
Ishida, Manabu; Tsujimoto, Masahiro; Ebisawa, Ken +1 more
We present the result of a Suzaku X-ray spectroscopic observation of the dwarf nova Z Cam, which was conducted by chance at the onset of an optical outburst. We used the X-ray Imaging Spectrometer (a 38 ks exposure) and the Hard X-ray Detector (34 ks) to obtain a 0.35-40 keV spectrum simultaneously. Spectral characteristics suggest that the source…
Unveiling the New Generation of Stars in NGC 604 with Gemini-NIRI
Barbá, Rodolfo H.; Fariña, Cecilia; Bosch, Guillermo L.
We present a near-infrared study focused on the detection and characterization of the youngest stellar component of the NGC 604 giant star-forming region in the Triangulum galaxy (M 33). By means of color-color diagrams derived from the photometry of JHKs images taken with the Gemini Near Infrared Imaging and Spectrometer (NIRI), we hav…
Does the contribution of infrared and submillimeter sources reveal itself at low harmonics of the CMB?
Verkhodanov, O. V.; Naiden, Ya. V.
We have computed and studied the mosaic correlation maps of the ILC WMAP microwave background data with the positions of infrared and submillimeter sources. Using the histograms of the signal values in pixels and angular power spectra, we studied the statistical properties of these maps. We discovered similar behavior of a number of harmonics in t…
The dusty environment of HD 97300 as seen by Herschel and Spitzer
Prusti, T.; Pilbratt, G. L.; André, Ph. +9 more
Aims: We analyze the surroundings of HD 97300, one of two intermediate-mass stars in the Chamaeleon I star-forming region. The star is known to be surrounded by a conspicuous ring of polycyclic aromatic hydrocarbons (PAHs).
Methods: We present infrared images taken with Herschel and Spitzer using 11 different broad-band filters between 3…
Post-starburst Tidal Tails in the Archetypical Ultra Luminous Infrared Galaxy Arp 220
Murayama, T.; Taniguchi, Y.; Kajisawa, M. +6 more
We present our new deep optical imaging and long-slit spectroscopy for Arp 220, the archetypical ultra luminous infrared galaxy in the local universe. Our sensitive Hα imaging has newly revealed large-scale Hα absorption, i.e., post-starburst regions in this merger. One is found in the eastern superbubble and the other is in the two tidal tails th…
Ion acceleration by multiple reflections at Martian bow shock
Fedorov, A.; Barabash, S.; Lundin, R. +7 more
The ion mass analyzer (IMA) on board Mars Express revealed bundled structures of ions in the energy domain within a distance of a proton gyroradius from the Martian bow shock. Seven prominent traversals during 2005 were examined when the energy-bunched structure was observed together with pick-up ions of exospheric origin, the latter of which is u…