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Predicting the number of giant arcs expected in the next-generation wide-field surveys from space
Meneghetti, Massimo; Giocoli, Carlo; Moscardini, Lauro +1 more
In this paper, we estimate the number of gravitational arcs detectable in a wide-field survey such as that which will be operated by the Euclid space mission, assuming a Λ cold dark matter cosmology. We use the publicly available code MOKA to obtain realistic deflection angle maps of mock gravitational lenses. The maps are processed by a ray-traci…
Hubble Space Telescope Observations of the Stellar Distribution near Sgr A*
Yusef-Zadeh, F.; Wardle, M.; Bushouse, H.
Sgr A* is embedded within the nuclear cluster, which consists of a mixture of evolved and young populations of stars dominating the light over a wide range of angular scales. Here we present Hubble Space Telescope/NICMOS data to study the surface brightness distribution of stellar light within the inner 10'' of Sgr A* at 1.45 µm, 1.7 µ…
The Resolved Stellar Population in 50 Regions of M83 from HST/WFC3 Early Release Science Observations
Mutchler, Max; McCarthy, Patrick J.; Calzetti, Daniela +22 more
We present a multi-wavelength photometric study of ~15,000 resolved stars in the nearby spiral galaxy M83 (NGC 5236, D = 4.61 Mpc) based on Hubble Space Telescope Wide Field Camera 3 observations using four filters: F336W, F438W, F555W, and F814W. We select 50 regions (an average size of 260 pc by 280 pc) in the spiral arm and inter-arm areas of M…
Power Spectra of Velocities and Magnetic Fields on the Solar Surface and their Dependence on the Unsigned Magnetic Flux Density
Katsukawa, Y.; Orozco Suárez, D.
We have performed power spectral analysis of surface temperatures, velocities, and magnetic fields, using spectropolarimetric data taken with the Hinode Solar Optical Telescope. When we make power spectra in a field of view covering the supergranular scale, kinetic and thermal power spectra have a prominent peak at the granular scale while the mag…
Small-scale variability in Saturn’s lower ionosphere
Matcheva, Katia I.; Barrow, Daniel J.
We perform and present a wavelet analysis on all 31 Cassini electron density profiles published to date (Nagy, A.F. et al. [2006]. J. Geophys. Res. 111 (A6), CiteID A06310; Kliore, A.J. et al. [2009]. J. Geophys. Res. 114 (A4), CiteID A04315). We detect several discrete scales of variability present in the observations. Small-scale variability (S …
Rosetta fly-by at asteroid (21) Lutetia: An overview
Sierks, H.; Küppers, M.; Schulz, R. +1 more
On the journey to its target comet 67P/Churyumov-Gerasimenko the ESA Rosetta spacecraft had a close fly-by at the main-belt asteroid (21) Lutetia at a heliocentric distance of r=2.72 AU, and a geocentric distance of Δ=3.05 AU. Closest approach occurred on 10 July 2010, 15:45 UT at a distance of ∼3170 km. Rosetta passed the asteroid with a relative…
A deep ATCA 20 cm radio survey of the AKARI Deep Field South near the South Ecliptic Pole
Goto, Tomotsugu; Nakagawa, Takao; Shirahata, Mai +18 more
The results of a deep radio survey at 20 cm wavelength are reported for a region containing the AKARI Deep Field South (ADF-S) near the South Ecliptic Pole (SEP), using the Australia Telescope Compact Array (ATCA). The survey (hereafter referred to as the ATCA-ADFS survey) has 1σ detection limits ranging from 18.7 to 50 µJy beam-1…
HST/ACS Photometry of Old Stars in NGC 1569: The Star Formation History of a nearby Starburst
Aloisi, Alessandra; van der Marel, Roeland P.; Tosi, Monica +3 more
We used Hubble Space Telescope/Advanced Camera for Surveys to obtain deep V- and I-band images of NGC 1569, one of the closest and strongest starburst galaxies in the universe. These data allowed us to study the underlying old stellar population, aimed at understanding NGC 1569's evolution over a full Hubble time. We focus on the less-crowded oute…
Detection and Tracking of Subtle Cloud Features on Uranus
Sromovsky, L. A.; Fry, P. M.; Hammel, H. B. +2 more
The recently updated Uranus zonal wind profile (Sromovsky et al.) samples latitudes from 71° S to 73° N. But many latitudes remain grossly undersampled (outside 20°-45° S and 20°-50° N) due to a lack of trackable cloud features. Offering some hope of filling these gaps is our recent discovery of low-contrast cloud that can be revealed by imaging a…
Empirical constraints of supergalactic winds at z≳ 0.5
Chen, Hsiao-Wen; Gauthier, Jean-René
Under the hypothesis that Mg II absorbers found near the minor axis of a disc galaxy originate in the cool phase of supergalactic winds, we carry out a study to constrain the properties of large-scale galactic outflows at redshift zgal ≳ 0.5 based on the observed relative motions of individual absorbing clouds with respect to the positi…