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Dynamics of solar active regions. II. Oscillations observed with MDI and their relation to the magnetic field topology
Muglach, K.; Staude, J.; Hofmann, A.
We present new results of an international joint observing campaign, which was carried out in September 2000 to study the oscillatory behaviour of solar active regions. We concentrate on oscillations in the lower layers of the solar atmosphere as observed with the Michelson Doppler Imager (MDI, Scherrer et al. 1995, Sol. Phys., 162, 129). The resu…
An XMM-Newton observation of A3921: An off-axis merger
Pratt, G. W.; Bourdin, H.; Sauvageot, J. -L. +1 more
We present the results of a detailed analysis of the XMM-Newton observation of the galaxy cluster Abell 3921. The X-ray morphology of the cluster is elliptical, with the centroid offset from the brightest cluster galaxy by 17 arcsec, and with a pronounced extension toward the NW. Subtraction of a 2D β-model fit to the main cluster emission reveals…
Disk populations from HIPPARCOS kinematic data. Discontinuities in the local velocity distribution
Cubarsi, R.; Alcobé, S.
The full space motions including radial velocities of a stellar sample drawn from HIPPARCOS catalogue are used to discriminate differentiated statistical behaviours that are associated with stellar populations in the solar neighbourhood. A sampling parameter is used to build a hierarchical set of nested samples, where a discontinuous pattern, base…
Dust properties of UV bright galaxies at z ~ 2
Noll, S.; Pierini, D.
We investigate the properties of the extinction curve in the rest-frame UV for a sample of 34 UV-luminous galaxies at 2 < z < 2.5, selected from the FORS Deep Field (FDF) spectroscopic survey. A new parametric description of the rest-frame UV spectral energy distribution is adopted; its sensitivity to properties of the stellar populations or…
1E 1740.7-2942: Temporal and spectral evolution from INTEGRAL and RXTE observations
Capitanio, F.; Bird, A. J.; Ubertini, P. +13 more
We present results of the monitoring of the black hole candidate 1E 1740.7-2942 with INTEGRAL, in combination with simultaneous observations by RXTE. We concentrate on broad-band spectra from INTEGRAL/IBIS and RXTE/PCA instruments. During our observations, the source spent most of its time in the canonical low/hard state with the measured flux var…
INTEGRAL observations of the field of the BL Lacertae object S5 0716+714
Maraschi, L.; Tagliaferri, G.; Ghisellini, G. +29 more
We have performed observations of the blazar S5 0716+714 with INTEGRAL on 2-6 April 2004. In the first months of 2004, the source had increased steadily in optical brightness and had undergone two outbursts. During the latter outburst, that occurred in March, it reached the extreme level of R = 12.1 mag, which triggered our INTEGRAL program. The t…
The opacity of spiral galaxy disks. VI. Extinction, stellar light and color
Holwerda, B. W.; Allen, R. J.; van der Kruit, P. C. +1 more
In this paper we explore the relation between dust extinction and stellar light distribution in disks of spiral galaxies. Extinction influences our dynamical and photometric perception of disks, since it can distort our measurement of the contribution of the stellar component. To characterize the total extinction by a foreground disk, González et …
INTEGRAL high energy observations of 2S 0114+65
Bonning, E. W.; Falanga, M.
We report the first INTEGRAL timing and spectral analysis of the high mass X-ray binary source 2S 0114+65 at high energies (5-100 keV). The pulse period was found at 2.668 h with a high pulsed fraction, 80% in both the 20-40 keV and 40-80 keV energy bands. The spin-up trend over 8 years was measured to be dot P = -8.9 × 10-7 s s-1<…
Looking for obscured QSOs in the X-ray emitting ERO population
Braito, V.; Mannucci, F.; Bender, R. +8 more
We present XMM-Newton data centered on one of the MUNICS Near Infrared Cluster Survey fields (S2F1) and we discuss the X-ray properties of the 6 X-ray emitting EROs found. For one of them we have already obtained the redshift using near-infrared spectroscopic data, while for the remaining 5 EROs the analysis is based on photometric redshifts. We f…
Unveiling the nature of the high energy source IGRJ19140+0951
Rodriguez, J.; Schultz, J.; Beckmann, V. +3 more
We report on high energy observations of IGR J19140+0951 performed with RXTE on three occasions in 2002, 2003 and 2004, and INTEGRAL during a very well sampled and unprecedented high energy coverage of this source from early-March to mid-May 2003. Our analysis shows that IGR J19140+0951 spends most of its time in a very low luminosity state, proba…