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Application of beam deconvolution technique to power spectrum estimation for CMB measurements
Keihänen, E.; Kurki-Suonio, H.; Reinecke, M. +1 more
We present two novel methods for the estimation of the angular power spectrum of cosmic microwave background (CMB) anisotropies. We assume an absolute CMB experiment with arbitrary asymmetric beams and arbitrary sky coverage. The methods differ from the earlier ones in that the power spectrum is estimated directly from the time-ordered data, witho…
A Novel Pixel-Level Image Matching Method for Mars Express HRSC Linear Pushbroom Imagery Using Approximate Orthophotos
Geng, Xun; Xu, Qing; Lan, Chaozhen +2 more
Mars topographic data, such as digital orthophoto maps (DOMs) and digital elevation models (DEMs) are essential to planetary science and exploration missions. The main objective of our study is to generate a higher resolution DEM using the Mars Express (MEX) High Resolution Stereo Camera (HRSC). This paper presents a novel pixel-level image matchi…
Distant clusters of galaxies in the 2XMM/SDSS footprint: follow-up observations with the LBT
Takey, A.; Schwope, A.; Lamer, G. +1 more
Context. Galaxy clusters at high redshift are important to test cosmological models and models for the growth of structure. They are difficult to find in wide-angle optical surveys, however, leaving dedicated follow-up of X-ray selected candidates as one promising identification route.
Aims: We aim to increase the number of galaxy clusters be…
30 years of the Vega mission: Comparison of some properties of the 1P/Halley and 67P/Churyumov-Gerasimenko comets
Ksanfomality, L. V.
On March 6 and 9, 1986, for the first time in the history of science, the Russian spacecraft Vega-1 and Vega-2 approached and closely passed by the nucleus of Halley’s comet (1P/Halley). A few days later, on March 14, 1986, the same was done by the European Space Agency’s (ESA) Giotto spacecraft. These missions, together with the Japanese Suisei (…
V2551 Cyg: a pulsating star with enigmatic peculiarities
Popov, Velimir A.; Petrov, Nikola I.; Kjurkchieva, Diana P. +2 more
Intensive photometric and spectral observations of the variable star V2551 Cyg are presented. The light curve shape reveals that the target is a pulsating star, contrary to its previous classification as an eclipsing binary. The period and amplitude of the light curve, the amplitudes of color changes and the radial velocity curve of V2551 Cyg are …
OB Stars and Cepheids From the Gaia TGAS Catalogue: Test of their Distances and Proper Motions
Bobylev, Vadim V.; Bajkova, Anisa T.
We consider young distant stars from the Gaia TGAS catalog. These are 250 classical Cepheids and 244 OB stars located at distances up to 4 kpc from the Sun. These stars are used to determine the Galactic rotation parameters using both trigonometric parallaxes and proper motions of the TGAS stars. In this case the considered stars have relative par…
The highly ionized, high-velocity gas in NGC 6231
Massa, Derck
It is well known that clusters of massive stars are influenced by the presence of strong winds, that they are sources of diffuse X-rays from shocked gas, and that this gas can be vented into the surrounding region or the halo through the champagne effect. However, the details of how these different environments interact and evolve are far from com…
Relationship between electron field-aligned anisotropy and dawn-dusk magnetic field: Nine years of Cluster observations in the Earth magnetotail
Nakamura, R.; Artemyev, A.; Petrukovich, A. +1 more
We investigate the distribution and possible origins of thermal anisotropic electrons in the Earth's magnetotail, using 9 years of Cluster observations. We mainly focus on relation between electron anisotropy and Bz and By magnetic field components (in GSM coordinates). The anisotropy of electron population is characterized b…
Leveraging high‑resolution spectra to understand black hole spectra
Nowak, M. A.
For the past 17 years, both XMM-Newton and Chandra have brought the powerful combination of high spatial and spectral resolution to the study of black hole systems. Each of these attributes requires special consideration--- in comparison to lower spatial resolution, CCD quality spectra--- when modeling observations obtained by these spacecraft. A …
Discovery of H2O megamasers in obscured active galactic nuclei
Terashima, Yuichi; Salak, Dragan; Nakai, Naomasa +9 more
A new method to discover obscured active galactic nuclei (AGNs) by utilizing X-ray and infrared data has recently been developed. We carried out a survey of H2O maser emission toward 10 obscured AGNs with the Nobeyama 45 m telescope. We newly detected the maser emission with a signal-noise-ratio (SNR) of above 4 from two AGNs; NGC 1402 …