Search Publications
Monte Carlo simulations of the broad-band X-ray continuum of SS433
Postnov, K. A.; Cherepashchuk, A. M.; Bisnovatyi-Kogan, G. S. +1 more
We develop a Monte Carlo technique based on L.B. Lucy's indivisible photon packets method to calculate X-ray continuum spectra of Comptonized thermal plasma in arbitrary geometry and apply it to describe the broad-band X-ray continuum of the galactic superaccreting microquasar SS433 observed by INTEGRAL. A physical model of the X-ray emitting regi…
AKARI observations of the ISM in our Galaxy and nearby galaxies
Takahashi, H.; Onaka, T.; Kaneda, H. +1 more
With AKARI, we have systematically performed near- to far-infrared (NIR-FIR) observations of the interstellar medium (ISM) in our Galaxy and nearby galaxies as one of AKARI mission programs called ISMGN (ISM in our Galaxy and Nearby galaxies). Our scientific objective is to increase our knowledge on the properties of the ISM exposed to an extensiv…
A Suzaku Observation of NGC 4593: Illuminating the Truncated Disk
Reeves, J. N.; Markowitz, A. G.
We report results from a 2007 Suzaku observation of the Seyfert 1 AGN NGC 4593. The narrow Fe Kα emission line has a FWHM width ~ 4000 km s-1, indicating emission from gsim 5000 R g. There is no evidence for a relativistically broadened Fe K line, consistent with the presence of a radiatively efficient outer disk which is tru…
51 Pegasi - a planet-bearing Maunder minimum candidate
Schmitt, J. H. M. M.; Robrade, J.; Poppenhäger, K. +1 more
We observed 51 Peg, the first detected planet-bearing star, in a 55 ks XMM-Newton pointing and in 5 ks pointings each with Chandra HRC-I and ACIS-S. The star has a very low count rate in the XMM observation, but is clearly visible in the Chandra images due to the detectors' different sensitivity at low X-ray energies. This allows a temperature est…
The evolution of field early-type galaxies in the FDF and WHDF
Böhm, Asmus; Ziegler, Bodo L.; Fritz, Alexander
We explore the properties of 24 field early-type galaxies in the redshift range 0.20 < z < 0.75 down to MB <= -19.30 in a sample extracted from the FORS Deep Field and the William Herschel Deep Field. Target galaxies were selected on the basis of a combination of luminosity, spectrophotometric type, morphology and photometric r…
Turbulence and intermittency in the heliospheric magnetic field in fast and slow solar wind
Balogh, A.; Noullez, A.; von Steiger, R. +1 more
We study the nonuniform solar wind turbulence using high-resolution Ulysses magnetic field data measured at different solar activity level, heliospheric latitudes, and distance. We define several types of solar wind dependent of the coronal region of origin and also of the dynamical behavior of the different streams, namely, “pure” fast wind, fast…
Asteroseismology and interferometry of the red giant star ɛ Ophiuchi
Goupil, M. -J.; Baudin, F.; Kervella, P. +16 more
The GIII red giant star ɛ Oph has been found to exhibit several modes of oscillation by the MOST mission. We interpret the observed frequencies of oscillation in terms of theoretical radial p-mode frequencies of stellar models. Evolutionary models of this star, in both shell H-burning and core He-burning phases of evolution, are constructed using …
Nobeyama Millimeter Array Observations of the Nuclear Starburst of M 83: A GMA Scale Correlation between Dense Gas Fraction and Star Formation Efficiency
Kohno, Kotaro; Kuno, Nario; Nakanishi, Kouichiro +6 more
We present aperture synthesis high-resolution (∼7'' × 3'') observations in CO (J = 1--0), HCN (J = 1--0), and 95GHz continuum emission toward the central (∼1.5 kpc) region of the nearby barred spiral galaxy M 83 with the Nobeyama Millimeter Array. Our high-resolution CO (J = 1--0) mosaic map depicts the presence of molecular ridges along the leadi…
Measurements of Absorption, Emissivity Reduction, and Local Suppression of Solar Acoustic Waves in Sunspots
Zhao, Hui; Liang, Zhi-Chao; Chou, Dean-Yi +2 more
The power of solar acoustic waves in magnetic regions is lower relative to the quiet Sun. Absorption, emissivity reduction, and local suppression of acoustic waves contribute to the observed power reduction in magnetic regions. We propose a model for the energy budget of acoustic waves propagating through a sunspot in terms of the coefficients of …
The origin of the diffuse non-thermal X-ray and radio emission in the Ophiuchus cluster of galaxies
Panessa, F.; Guerrero, M. A.; Profumo, S. +4 more
We present high-resolution 240 and 607 MHz Giant Metrewave Radio Telescope radio observations, complemented with 74 MHz archival Very Large Array radio observations of the Ophiuchus cluster of galaxies, whose radio mini-halo has been recently detected at 1400 MHz. We also present archival Chandra and XMM-Newton data of the Ophiuchus cluster. Our o…