Search Publications
INTEGRAL observations of Scorpius X-1: evidence for Comptonization up to 200 keV
Maiolino, T.; Braga, J.; D'Amico, F.
We have analyzed a long-term database for Sco X-1 obtained with the telescope IBIS onboard the INTEGRAL satellite in order to study the hard X-ray behavior of Sco X-1 from 20 up to 200 keV. Besides the data used for producing of the INTEGRAL catalog of sources, this is the longest (412 ks) database of IBIS on Sco X-1 up to date. The production of …
Narrow-line H i and cold structures in the interstellar medium
Haud, U.
Context. Studying the H i line profiles in the Leiden-Argentina-Bonn (LAB) all-sky database, we have found a population of very cold H i clouds. So far, the role of these clouds in the interstellar medium (ISM) has remained unclear.
Aims: In this paper, we attempt to confirm the existence of the narrow-line H i emission (NHIE) clouds by using…
A near-infrared variability campaign of TMR-1: New light on the nature of the candidate protoplanet TMR-1C
Martín, E. L.; Monin, J. -L.; Riaz, B. +1 more
We present a near-infrared (NIR) photometric variability study of the TMR-1 system, a Class I protobinary located in the Taurus molecular cloud. Our aim is to confirm NIR variability for the candidate protoplanet, TMR-1C, located at a separation of about 10″ (~1000 AU) from the protobinary. We conducted a photometric monitoring campaign between Oc…
3.3 µm PAH observations of the central kiloparsecs of Centaurus A
Sturm, E.; Tacconi-Garman, L. E.
Aims: The aim of this work is to further investigate the nature of polycyclic aromatic hydrocarbon (PAH) excitation and emission especially in the context of tracing star formation in a variety of extragalactic environments. Here we turn our attention to the energetic environment of the closest active galactic nucleus (AGN) in our sample, Cen…
Astrometric mock observations for determining the local dark matter density
Inoue, S.; Gouda, N.
Context. To determine the local dark matter density of the solar system is a classical problem in astronomy. Recently, a novel method of determining the local dark matter density from stellar distribution and vertical velocity dispersion profiles perpendicular to the Galactic plane was devised. This method has the advantage of abolishing conventio…
X-ray view of four high-luminosity Swift/BAT AGN: Unveiling obscuration and reflection with Suzaku
Malaguti, G.; Mushotzky, R. F.; Koss, M. +2 more
Aims: A complete census of obscured active galactic nuclei (AGN) is necessary to reveal the history of the super massive black hole (SMBH) growth and galaxy evolution in the Universe given the complex feedback processes and the fact that much of this growth occurs in an obscured phase. In this context, hard X-ray surveys and dedicated follow-…
Coronal magnetic topology and the production of solar impulsive energetic electrons
Li, C.; Wang, X. Y.; Sun, L. P. +1 more
We investigate two candidate solar sources or active regions (ARs) in association with a solar impulsive energetic electron (SIEE) event on 2002 October 20. The solar particle release (SPR) times of SIEEs are derived by using their velocity dispersion with consideration of the instrumental effect. It is found that there are double electron injecti…
Polarization of Saturn's moon Iapetus. II. Comparison of the dark and the bright sides
Muinonen, K.; Tozzi, G. P.; Boehnhardt, H. +3 more
Context. The surface properties of atmosphereless solar system objects can be constrained by investigating the nature of the polarized light scattered from their surfaces.
Aims: We provide new and precise measurements of the phase angle and the wavelength dependence of linear polarization on the leading side of Iapetus over the maximum phase …
INTEGRAL/SPI data segmentation to retrieve source intensity variations
Bouchet, L.; Chauvin, M.; Amestoy, P. R. +2 more
Context. The INTEGRAL/SPI, X/γ-ray spectrometer (20 keV-8 MeV) is an instrument for which recovering source intensity variations is not straightforward and can constitute a difficulty for data analysis. In most cases, determining the source intensity changes between exposures is largely based on a priori information.
Aims: We propose techniqu…
Direct model fitting to combine dithered ACS images
Wucknitz, O.; Mahmoudian, H.
The information lost in images of undersampled CCD cameras can be recovered with the technique of "dithering". A number of subexposures is taken with sub-pixel shifts in order to record structures on scales smaller than a pixel. The standard method to combine such exposures, "Drizzle", averages after reversing the displacements, including rotation…