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UV Spectra, Bombs, and the Solar Atmosphere
Judge, Philip G.
A recent analysis of UV data from the Interface Region Imaging Spectrograph (IRIS) reports plasma “bombs” with temperatures near 8 × 104 K within the solar photosphere. This is a curious result, first because most bomb plasma pressures p (the largest reported case exceeds 103 dyn cm-2) fall well below photospheric …
Identification of a Class of Low-mass Asymptotic Giant Branch Stars Struggling to Become Carbon Stars in the Magellanic Clouds
Boyer, Martha L.; Sonneborn, George; van Loon, Jacco Th. +4 more
We have identified a new class of Asymptotic Giant Branch (AGB) stars in the Small and Large Magellanic Clouds (SMC/LMC) using optical to infrared photometry, light curves, and optical spectroscopy. The strong dust production and long-period pulsations of these stars indicate that they are at the very end of their AGB evolution. Period-mass-radius…
Synthesized Spectra of Optically Thin Emission Lines
De Pontieu, B.; Hansteen, V. H.; Olluri, K. +1 more
In recent years realistic 3D numerical models of the solar atmosphere have become available. The models attempt to recreate the solar atmosphere and mimic observations in the best way, in order to make it possible to couple complicated observations with physical properties such as the temperatures, densities, velocities, and magnetic fields. We he…
Physical properties of solar polar jets. A statistical study with Hinode XRT data
Bemporad, A.; Sterling, A. C.; Paraschiv, A. R.
Aims: The target of this work is to investigate the physical nature of polar jets in the solar corona and their possible contribution to coronal heating and solar wind flow based on the analysis of X-ray images acquired by the Hinode XRT telescope. We estimate the different forms of energy associated with many of these small-scale eruptions, …
A magnetic reconnection model for explaining the multiwavelength emission of the microquasars Cyg X-1 and Cyg X-3
del Valle, M. V.; de Gouveia Dal Pino, E. M.; Khiali, B.
Recent studies have indicated that cosmic ray acceleration by a first-order Fermi process in magnetic reconnection current sheets can be efficient enough in the surrounds of compact sources. In this work, we discuss this acceleration mechanism operating in the core region of galactic black hole binaries (or microquasars) and show the conditions un…
Are the total mass density and the low-mass end slope of the IMF anticorrelated?
Koopmans, L. V. E.; Spiniello, C.; Trager, S. C. +1 more
We conduct a detailed lensing, dynamics and stellar population analysis of nine massive lens early-type galaxies (ETGs) from the X-Shooter Lens Survey (XLENS). Combining gravitational lensing constraints from HST imaging with spatially-resolved kinematics and line-indices constraints from Very Large Telescope (VLT) X-Shooter spectra, we infer the …
Internetwork Chromospheric Bright Grains Observed With IRIS and SST
Golub, Leon; Testa, Paola; Martínez-Sykora, Juan +18 more
The Interface Region Imaging Spectrograph (IRIS) reveals small-scale rapid brightenings in the form of bright grains all over coronal holes and the quiet Sun. These bright grains are seen with the IRIS 1330, 1400, and 2796 Å slit-jaw filters. We combine coordinated observations with IRIS and from the ground with the Swedish 1 m Solar Telescope (SS…
High-resolution ALMA observations of SDP.81. II. Molecular clump properties of a lensed submillimeter galaxy at z = 3.042
Tamura, Yoichi; Oguri, Masamune; Hayashi, Masao +3 more
We present spatially resolved properties of molecular gas and dust in a gravitationally lensed submillimeter galaxy H-ATLAS J090311.6+003906 (SDP.81) at z = 3.042 revealed by the Atacama Large Millimeter/submillimeter Array (ALMA). We identified 14 molecular clumps in the CO(5-4) line data. The surface density of molecular gas (Σ _H_2) and star-fo…
Dynamics of Saturn's polar regions
Hueso, R.; Sánchez-Lavega, A.; Antuñano, A. +1 more
We analyze data retrieved by the imaging science system onboard the Cassini spacecraft to study the horizontal velocity and vorticity fields of Saturn's polar regions (latitudes 60-90°N in June-December 2013 and 60-90°S in October 2006 and July-December 2008), including the northern region where the hexagonal wave is prominent. With the aid of an …
Search for features in the spectrum of primordial perturbations using Planck and other datasets
Sarkar, Subir; Hunt, Paul
We reconstruct the power spectrum of primordial curvature perturbations by applying a well-validated non-parametric technique employing Tikhonov regularisation to the first data release from the Planck satellite. To improve the reconstruction on small spatial scales we include data from the ground-based ACT and SPT experiments, the WiggleZ galaxy …