Search Publications
Inner-shell ionization, radiative losses and thermal conductivity in young SNRs
Kosenko, D. I.
Self-consistent treatment of time-dependent ionization in hydrodynamical calculations of the X-ray emission from young supernova remnants (SNRs) has been performed. The novel feature of the calculations is that Kα lines from species produced by inner-shell collisional ionization are included. Parameters of the shocked ejecta are found from fitting…
Did galaxy assembly and supermassive black-hole growth go hand-in-hand?
Ryan, R. E.; Koekemoer, A. M.; Mobasher, B. +10 more
In this paper, we address whether the growth of supermassive black-holes has kept pace with the process of galaxy assembly. For this purpose, we first searched the Hubble Ultra Deep Field (HUDF) for "tadpole galaxies", which have a knot at one end plus an extended tail. They appear dynamically unrelaxed-presumably early-stage mergers-and make up ∼…
The globular cluster system of NGC 5846 revisited: colours, sizes and X-ray counterparts
Santiago, B. X.; Pastoriza, M. G.; Chies-Santos, A. L. +1 more
Context.NGC 5846 is a giant elliptical galaxy with a previously well studied globular cluster system (GCS), known to have a bimodal colour distribution with a remarkably high red fraction.
Aims.Here we revisit the central galaxy regions searching for new globular cluster (GC) candidates, and measure magnitudes, colours and sizes for them. We al…
Resonance-enhanced two-photon ionization (RETPI) of Si II and an anomalous, variable intensity of the λ1892 Si III] line in the Weigelt blobs of η Carinae
Johansson, S.; Hartman, H.; Letokhov, V. S.
Context: .The Si III] 1892 Å intercombination line shows an anomalously high intensity in spectra of the radiation-rich Weigelt blobs in the vicinity of Eta Carinae. The line disappears during the 100 days long spectral events occurring every 5.5 years.
Aims: .The aim is to investigate whether resonance-enhanced two-photon ionization (RETPI) i…
A tidal explanation for the Titan haze layers
Schubert, Gerald; Walterscheid, Richard L.
Though Titan is in synchronous rotation around Saturn, it experiences gravitational tides as a consequence of its eccentric orbit. It is proposed that the vertical transport of aerosols by these tides produces the haze layers in Titan's upper atmosphere. Analysis shows that the zonal winds in Titan's superrotating atmosphere have a profound influe…
Soft X-Ray Absorption Due to the Photo-Ionized Plasma in the Low-Mass X-Ray Binary EXO 0748-676 Observed with XMM-Newton Observatory
Asai, Kazumi; Dotani, Tadayasu
We analyzed an effect of the photo-ionization on the continuum spectra using the XMM-Newton archive data of the low-mass X-ray binary EXO 0748-676. We found that the ionization degree of the circumstellar plasma, which modifies the soft X-ray spectrum through absorption, changes largely in association with the X-ray bursts and the dips. The burst …
Carrington Maps of the Upper Photosphere
Warren, H. P.; Sheeley, N. R., Jr.
We have used images of the Sun's disk, obtained in the 6767 Å continuum with the Michelson Doppler Interferometer (MDI) on the Solar and Heliospheric Observatory (SOHO), to make Carrington maps of the upper photosphere during the years 1996-2005. Each map is constructed from observations near the limb where the continuum radiation originates relat…
Period Change, Spot Migration and Orbital Solution for the Eclipsing Binary AR Lac
Munari, U.; Siviero, A.; Dallaporta, S.
We present a new large set of photoelectric photometric measurements (1806 in V and 1367 in B passbands) of the eclipsing RS CVn-type system AR Lac covering the period 2000 June 28 to 2005 October 13. 13 new epochs of minima have been derived that allows us to update the complex O--C pattern of this binary, now monitored for more than a hundred ye…
The Olympus volcano on Mars: Geometry and characteristics of lava flows
Neukum, G.; HRSC Co-Investigator Team; Basilevskaya, E. A.
The HRSC (image 0037) and MOC imagery and MOLA altimetry were used to determine the following parameters of the lava flows typical of the southern slope of the Martian volcano Olympus: the length (13-35 km), the width (0.2-4.8 km), and the angles of ground slopes along which these flows advanced (3.4°-6.9°). To measure the thickness of the flows, …
Two distinct energetic electron populations of different origin in the Earth's magnetotail: a Cluster case study
Zong, Q. -G.; Sarris, E. T.; Fritz, T. A. +1 more
Energetic electrons (E≥30 keV) travelling along and perpendicular to the magnetic field lines have been observed in the magnetotail at L~17:00 and 22:00 MLT during the recovery phase of a storm-time substorm on 7 October 2002. Three-dimensional electron distributions of the full unit sphere obtained from the IES/RAPID sensor system demonstrated a …