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Measuring Sizes of Ultra-faint Dwarf Galaxies
Geha, Marla; Padmanabhan, Nikhil; Muñoz, Ricardo R.
The discovery of ultra-faint dwarf (UFD) galaxies in the halo of the Milky Way extends the faint end of the galaxy luminosity function to a few hundred solar luminosities. This extremely low luminosity regime poses a significant challenge for the photometric characterization of these systems. We present a suite of simulations aimed at understandin…
Lagrangian coherent structures in photospheric flows and their implications for coronal magnetic structure
Yeates, A. R.; Welsch, B. T.; Hornig, G.
Aims: We show how the build-up of magnetic gradients in the Sun's corona may be inferred directly from photospheric velocity data. This enables computation of magnetic connectivity measures such as the squashing factor without recourse to magnetic field extrapolation.
Methods: Assuming an ideal evolution in the corona, and an initially u…
Galactic annihilation emission from nucleosynthesis positrons
Strong, A. W.; Diehl, R.; Jean, P. +2 more
Context. The Galaxy hosts a widespread population of low-energy positrons revealed by successive generations of gamma-ray telescopes through a bright annihilation emission from the bulge region, with a fainter contribution from the inner disk. The exact origin of these particles remains currently unknown.
Aims: We estimate the contribution to…
Solar migrating atmospheric tides in the winds of the polar region of Venus
Hueso, R.; Sánchez-Lavega, A.; Drossart, P. +5 more
We study the effects of migrating solar tides on the winds at the cloud tops of the polar region of Venus. The winds were measured using cloud tracking on images obtained at wavelengths of 3.9 and 5.0 µm by the instrument VIRTIS-M onboard Venus Express. These wavelengths probe about the same altitude close to the cloud tops, allowing for the…
Detection of multiple modes in a new double-mode RR Lyrae star
Chadid, M.
Context. We present the first long-time coverage of high precision and uninterrupted light curve of a new double-mode RR Lyrae star allowing the determination of accurate Fourier components and the estimatation of fundamental parameters.
Aims: We used high-precision space data of a new star CoRoT ID 0101368812, obtained by the satellite CoRoT…
Density and lithospheric thickness of the Tharsis Province from MEX MaRS and MRO gravity data
Pätzold, M.; Rosenblatt, P.; Le Maistre, S. +2 more
Radio science tracking of Mars Express (MaRS experiment) and Mars Reconnaissance Orbiter produced high resolution Martian gravity data. Applying localized spectral analysis on the new gravity data sets, we study the surface density and lithospheric elastic thickness in the Tharsis province. The gravity signal is predicted with geophysical models e…
Spectral and petrologic analyses of basaltic sands in Ka'u Desert (Hawaii) - implications for the dark dunes on Mars
Jaumann, Ralf; Tirsch, Daniela; Helbert, Jörn +3 more
The spectral energy distributions, host galaxies and environments of variability-selected active galactic nuclei in GOODS-South
Koekemoer, Anton; Sarajedini, Vicki; Villforth, Carolin
Variability selection has been proposed as a powerful tool for identifying both low-luminosity active galactic nuclei (AGN) and those with unusual spectral energy distributions. However, a systematic study of sources selected in such a way has been lacking. In this paper, we present the multiwavelength properties of the variability-selected AGN in…
X-ray emitting hot plasma in solar active regions observed by the SphinX spectrometer
Miceli, M.; Reale, F.; Sylwester, J. +7 more
Aims: The detection of very hot plasma in the quiescent corona is important for diagnosing heating mechanisms. The presence and the amount of such hot plasma is currently debated. The SphinX instrument on-board the CORONAS-PHOTON mission is sensitive to X-ray emission of energies well above 1 keV and provides the opportunity to detect the hot…
Characterization of the non-Gaussianity of radio and IR point sources at CMB frequencies
Aghanim, N.; Kunz, M.; Lacasa, F. +1 more
This study, using publicly available simulations, focuses on the characterization of the non-Gaussianity produced by radio point sources and by infrared (IR) sources in the frequency range of the cosmic microwave background from 30 to 350 GHz.
We propose a simple prescription to infer the angular bispectrum from the power spectrum of point so…