Search Publications
A Unique X-Ray Unabsorbed Seyfert 2 Galaxy: IRAS F01475-0740
Wang, Jun-Xian; Yang, Huan; Huang, Ya-Fang +2 more
X-ray unabsorbed Seyfert 2 galaxies appear to have X-ray absorption column densities that are too low (N H < 1022 cm-2) to explain the absence of broad emission lines in their optical spectra, challenging the standard active galactic nucleus (AGN) unification model. In this Letter, we report Suzaku exposure on t…
Observation and modelling of main-sequence star chromospheres - XV. New constraints on the dynamo mechanisms for dM1 stars
Houdebine, E. R.
With the help of measures of rotation, radius and metallicity for a selected sample of dM1 stars (with Teff= 3460 ± 60 K), we aim to set new constraints on the dynamo mechanisms.
We recover 913 high-resolution spectra for 97 different M1 dwarfs from the European Southern Observatory and Observatoire de Haute Provence data bases. We…Mid-J CO Emission from NGC 891: Microturbulent Molecular Shocks in Normal Star-forming Galaxies
Tucker, C.; Stacey, G. J.; Brisbin, D. +4 more
We have detected the CO(6-5), CO(7-6), and [C I] 370 µm lines from the nuclear region of NGC 891 with our submillimeter grating spectrometer ZEUS on the Caltech Submillimeter Observatory. These lines provide constraints on photodissociation region (PDR) and shock models that have been invoked to explain the H2 S(0), S(1), and S(2)…
The double galaxy cluster Abell 2465 - I. Basic properties: optical imaging and spectroscopy
Wegner, Gary A.
Optical imaging and spectroscopic observations of the z= 0.245 double galaxy cluster Abell 2465 are described. This object appears to be undergoing a major merger. It is a double X-ray source and is detected in the radio at 1.4 GHz. The purpose of this paper is to investigate signatures of the interaction of the two components. Redshifts were meas…
X-rays, clumping and wind structures
Ignace, Richard; Oskinova, Lidia; Hamann, Wolf-Rainer +1 more
X-ray emission is ubiquitous among massive stars. In the last decade, X-ray observations revolutionized our perception of stellar winds but opened a Pandora's box of urgent problems. X-rays penetrating stellar winds suffer mainly continuum absorption, which greatly simplifies the radiative transfer treatment. The small and large scale structures i…
The Interplanetary Network Supplement to the HETE-2 Gamma-Ray Burst Catalog
Frontera, F.; Cline, T.; Hurley, K. +45 more
Between 2000 November and 2006 May, one or more spacecraft of the interplanetary network (IPN) detected 226 cosmic gamma-ray bursts that were also detected by the French Gamma-Ray Telescope experiment on board the High Energy Transient Experiment 2 spacecraft. During this period, the IPN consisted of up to nine spacecraft, and using triangulation,…
Supermodel Analysis of the Hard X-ray Excess in the Coma Cluster
Orlandini, M.; Lapi, A.; Bonamente, M. +1 more
The Supermodel (SM) provides an accurate description of the thermal contribution by the hot intracluster plasma which is crucial for the analysis of the hard excess. In this paper, the thermal emissivity in the Coma cluster is derived starting from the intracluster gas temperature and density profiles obtained by the SM analysis of X-ray observabl…
The orbital solution and spectral classification of the high-mass X-ray binary IGR J01054-7253 in the Small Magellanic Cloud
Haberl, F.; Udalski, A.; Hill, A. B. +11 more
We present X-ray and optical data on the Be/X-ray binary (BeXRB) pulsar IGR J 01054-7253= SXP11.5 in the Small Magellanic Cloud (SMC). Rossi X-ray Timing Explorer (RXTE) observations of this source in a large X-ray outburst reveal an 11.483 ± 0.002 s pulse period and show both the accretion-driven spin-up of the neutron star and the motion of the …
Modified solar flux index for upper atmospheric applications
Maruyama, Takashi
The F10.7 solar flux index was modified in order to better describe short-term variations in solar extreme ultraviolet (EUV) irradiance for application in ionosphere and thermosphere studies. Several parameters were computed from the F10.7 time series with the assistance of an artificial neural network (ANN) technique, and th…
Occurrence rate of magnetic holes between 0.72 and 1 AU: comparative study of Cluster and VEX data
Zhang, T. L.; Walker, S. N.; Amariutei, O. A.
Localised depressions in the magnetic field magnitude, or magnetic holes, are common features in many regions of solar system plasma. Two distinct mechanisms for their generation have been proposed. The first proposed that the structures are generated locally, close to the point of observation. The alternative has been proposed by Russell et al. (…