Search Publications
A hybrid approach to cosmic microwave background lensing reconstruction from all-sky intensity maps
Perotto, L.; Plaszczynski, S.; Starck, J. -L. +1 more
On the basis of realistic simulations, we propose a hybrid method to reconstruct the lensing potential power spectrum, directly on Planck-like cosmic microwave background frequency maps. This involves the use of a large Galactic mask and the treatment of strong inhomogeneous noise. For ℓ ≲ 100, we show that a full-sky inpainting method, which was …
High-resolution spectroscopy and high-density monitoring in X-rays of novae
Ness, J. U.
The 21st century X-ray observatories XMM-Newton, Chandra, and Swift gave us completely new insights into the X-ray behaviour of nova outbursts. These new-generation X-ray observatories provide particularly high spectral resolution and high density in monitoring campaigns, simultaneously in X-rays and UV/optical. The entire evolution of several nov…
Preprocessing Magnetic Fields with Chromospheric Longitudinal Fields
Kusano, K.; Yamamoto, Tetsuya T.
Nonlinear force-free field (NLFFF) extrapolation is a powerful tool for the modeling of the magnetic field in the solar corona. However, since the photospheric magnetic field does not in general satisfy the force-free condition, some kind of processing is required to assimilate data into the model. In this paper, we report the results of new prepr…
Studying the asymmetry of the globular cluster population of NGC 4261
Zezas, A.; Wolter, A.; O'Sullivan, E. +5 more
We present an analysis of the globular cluster (GC) population of the elliptical galaxy NGC 4261 based on Hubble Space Telescope Wide Field Planetary Camera 2 data in the B, V and I bands. We study the spatial distribution of the GCs in order to probe the anisotropy in the azimuthal distribution of the discrete X-ray sources in the galaxy revealed…
Electron optical depths and temperatures of symbiotic nebulae from Thomson scattering
Skopal, A.; Sekeráš, M.
Symbiotic binaries are comprised of nebulae, whose densest portions have electron concentrations of 108-1012 cm-3 and extend to a few astronomical units. They are optically thick enough to cause a measurable effect of the scattering of photons on free electrons. In this paper, we model the extended wings of strong …
The X-ray variability history of Markarian 3
Guainazzi, M.; Miniutti, G.; La Parola, V. +2 more
Context. The unified scenario for active galactic nuclei (AGN) postulates that our orientation with respect to a parsec-scale azimuthally-symmetric gas and dust system causes the difference in their phenomenology in the optical/UV and X-ray bands. Only recently have high-resolution radio (VLBI) and IR interferometric observations provided direct c…
Spatially Resolved HST Grism Spectroscopy of a Lensed Emission Line Galaxy at z ~ 1
Broadhurst, Tom; Frye, Brenda L.; Bowen, David V. +6 more
We take advantage of gravitational lensing amplification by A1689 (z = 0.187) to undertake the first space-based census of emission line galaxies (ELGs) in the field of a massive lensing cluster. Forty-three ELGs are identified to a flux of i 775 = 27.3 via slitless grism spectroscopy. One ELG (at z = 0.7895) is very bright owing to len…
The Central Blue Straggler Population in Four Outer-halo Globular Clusters
Lützgendorf, Nora; Ferraro, Francesco R.; Lanzoni, Barbara +6 more
Using Hubble Space Telescope/Wide Field Planetary Camera 2 data, we have performed a comparative study of the Blue Straggler Star (BSS) populations in the central regions of the globular clusters (GCs) AM 1, Eridanus, Palomar 3, and Palomar 4. Located at distances R GC > 50 kpc from the Galactic center, these are (together with Palom…
Detection of the 3.3 µm Aromatic Feature in the Supernova Remnant N49 with AKARI
Onaka, Takashi; Seok, Ji Yeon; Koo, Bon-Chul
We present an infrared (IR) study of the supernova remnant (SNR) N49 in the Large Magellanic Cloud with the near-IR (NIR; 2.5-5 µm) spectroscopic observations performed by AKARI. The observations were performed as a coarse spectral mapping to cover most of the bright region in the east, which enables us to compare the distribution of various…
Distance and reddening of the Local Group dwarf irregular galaxy NGC 6822
Bono, G.; Pietrinferni, A.; Monelli, M. +3 more
On the basis of a new photometric analysis of the Local Group dwarf irregular galaxy NCG 6822 based on observations obtained with the Advanced Camera for Surveys onboard the Hubble Space Telescope, we have obtained a new estimate of the extinction of two fields located in the southeast region of the galaxy. Because of significant differences in th…