Search Publications
Highly ionized region surrounding SN Refsdal revealed by MUSE
Treu, T.; Grillo, C.; Balestra, I. +9 more
Supernova (SN) Refsdal is the first multiply imaged, highly magnified, and spatially resolved SN ever observed. The SN exploded in a highly magnified spiral galaxy at z = 1.49 behind the Frontier Fields cluster MACS1149, and provides a unique opportunity to study the environment of SNe at high z. We exploit the time delay between multiple images t…
Physical properties and dynamical relation of the circular depressions on comet 67P/Churyumov-Gerasimenko
Jorda, L.; Lamy, P. L.; Lara, L. M. +52 more
Aims: We aim to characterize the circular depressions of comet 67P/Churyumov-Gerasimenko and investigate whether such surface morphology of a comet nucleus is related to the cumulative sublimation effect since becoming a Jupiter family comet (JFC).
Methods: The images from the Rosetta/OSIRIS science camera experiment are used to construc…
Determination of Coronal Mass Ejection Physical Parameters from a Combination of Polarized Visible Light and UV Lyα Observations
Bemporad, A.; Susino, R.
Visible-light observations of Coronal Mass Ejections (CMEs) performed with coronagraphs and heliospheric imagers (in primis on board the Solar and Heliospheric Observatory and STEREO missions) have offered the best way to study the kinematics and geometrical structure of these fundamental events so far. Nevertheless, it has been widely demonstrate…
Rings and arcs around evolved stars - I. Fingerprints of the last gasps in the formation process of planetary nebulae
Guerrero, M. A.; Toalá, J. A.; Santamaría, E. +3 more
Evolved stars such as asymptotic giant branch stars (AGB), post-AGB stars, proto-planetary nebulae (proto-PNe), and planetary nebulae (PNe) show rings and arcs around them and their nebular shells. We have searched for these morphological features in optical Hubble Space Telescope and mid-infrared Spitzer Space Telescope images of ∼650 proto-PNe a…
Mid-IR spectra of pre-main sequence Herbig stars: An explanation for the non-detections of water lines
Woitke, P.; Kamp, I.; Güdel, M. +7 more
Context. The mid-IR detection rate of water lines in disks around Herbig stars disks is about 5%, while it is around 50% for disks around T Tauri stars. The reason for this is still unclear.
Aims: In this study, we want to find an explanation for the different detection rates between low mass and high mass pre-main-sequence stars in the mid-I…
The CHIANTI atomic database
Young, P. R.; Mason, H. E.; Del Zanna, G. +2 more
The freely available CHIANTI atomic database was first released in 1996 and has had a huge impact on the analysis and modeling of emissions from astrophysical plasmas. It contains data and software for modeling optically thin atom and positive ion emission from low density (≲1013 cm-3) plasmas from x-ray to infrared wavelengt…
Effects of flare definitions on the statistics of derived flare distributions
Stegen, K.; Dominique, M.; Ryan, D. F. +2 more
The statistical examination of solar flares is crucial to revealing their global characteristics and behaviour. Such examinations can tackle large-scale science questions or give context to detailed single-event studies. However, they are often performed using standard but basic flare detection algorithms relying on arbitrary thresholds. This arbi…
Simulation tests of galaxy cluster constraints on chameleon gravity
Zhao, Gong-Bo; Bacon, David; Romer, A. Kathy +3 more
We use two new hydrodynamical simulations of Λ cold dark matter (ΛCDM) and f(R) gravity to test the methodology used by Wilcox et al. (W15) in constraining the effects of a fifth force on the profiles of clusters of galaxies. We construct realistic simulated stacked weak lensing and X-ray surface brightness cluster profiles from these cosmological…
Quantum cosmology and the evolution of inflationary spectra
Kamenshchik, Alexander Y.; Tronconi, Alessandro; Venturi, Giovanni
We illustrate how it is possible to calculate the quantum gravitational effects on the spectra of primordial scalar/tensor perturbations starting from the canonical, Wheeler-De Witt, approach to quantum cosmology. The composite matter-gravity system is analyzed through a Born-Oppenheimer approach in which gravitation is associated with the heavy d…
Differences in the Structural Properties and Star-formation Rates of Field and Cluster Galaxies at z~1
Allen, Rebecca J.; Kacprzak, Glenn G.; Glazebrook, Karl +5 more
We investigate the dependence of galaxy sizes and star formation rates (SFRs) on their environment using a mass-limited sample of quiescent and star-forming galaxies with log(M */{M}⊙ ) ≥ 9.5 at \bar{z}=0.92 selected from the NEWFIRM medium-band Survey (NMBS). Using the Galaxy Environment Evolution Collaboration 2 spectroscop…