Search Publications
Compact solar UV burst triggered in a magnetic field with a fan-spine topology
Peter, H.; Chitta, L. P.; Young, P. R. +1 more
Context. Solar ultraviolet (UV) bursts are small-scale features that exhibit intermittent brightenings that are thought to be due to magnetic reconnection. They are observed abundantly in the chromosphere and transition region, in particular in active regions.
Aims: We investigate in detail a UV burst related to a magnetic feature that is adv…
The magnetic connectivity of coronal shocks from behind-the-limb flares to the visible solar surface during γ-ray events
Rouillard, A. P.; Plotnikov, I.; Share, G. H.
Context. The observation of >100 MeV γ-rays in the minutes to hours following solar flares suggests that high-energy particles interacting in the solar atmosphere can be stored and/or accelerated for long time periods. The occasions when γ-rays are detected even when the solar eruptions occurred beyond the solar limb as viewed from Earth provid…
Statistical simulations of the dust foreground to cosmic microwave background polarization
Boulanger, F.; Aumont, J.; Ghosh, T. +6 more
The characterization of the dust polarization foreground to the cosmic microwave background (CMB) is a necessary step toward the detection of the B-mode signal associated with primordial gravitational waves. We present a method to simulate maps of polarized dust emission on the sphere that is similar to the approach used for CMB anisotropies. This…
SNR 1E 0102.2-7219 as an X-ray calibration standard in the 0.5-1.0 keV bandpass and its application to the CCD instruments aboard Chandra, Suzaku, Swift and XMM-Newton
Miller, Eric D.; Haberl, Frank; Plucinsky, Paul P. +4 more
Context. The flight calibration of the spectral response of charge-coupled device (CCD) instruments below 1.5 keV is difficult in general because of the lack of strong lines in the on-board calibration sources typically available. This calibration is also a function of time due to the effects of radiation damage on the CCDs and/or the accumulation…
Revealing the structure of the outer disks of Be stars
Carciofi, A. C.; Štefl, S.; Vieira, R. G. +9 more
Context. The structure of the inner parts of Be star disks (≲ 20 stellar radii) is well explained by the viscous decretion disk (VDD) model, which is able to reproduce the observable properties of most of the objects studied so far. The outer parts, on the other hand, are not observationally well-explored, as they are observable only at radio wave…
A Unified tool to estimate Distances, Ages, and Masses (UniDAM) from spectrophotometric data
Hekker, Saskia; Mints, Alexey
Context. Galactic archaeology, the study of the formation and evolution of the Milky Way by reconstructing its past from its current constituents, requires precise and accurate knowledge of stellar parameters for as many stars as possible. To achieve this, a number of large spectroscopic surveys have been undertaken and are still ongoing.
Aim…
Neutral gas heating by X-rays in primitive galaxies: Infrared observations of the blue compact dwarf I Zw 18 with Herschel
Kunth, D.; Lebouteiller, V.; Galliano, F. +8 more
Context. The neutral interstellar medium of galaxies acts as a reservoir to fuel star formation. The dominant heating and cooling mechanisms in this phase are uncertain in extremely metal-poor star-forming galaxies. The low dust-to-gas mass ratio and low polycyclic aromatic hydrocarbon abundance in such objects suggest that the traditional photoel…
The faint radio sky: VLBA observations of the COSMOS field
Smolčić, V.; Momjian, E.; Schinnerer, E. +10 more
Context. Quantifying the fraction of active galactic nuclei (AGN) in the faint radio population and understanding their relation with star-forming activity are fundamental to studies of galaxy evolution. Very long baseline interferometry (VLBI) observations are able to identify AGN above relatively low redshifts (z> 0.1) since they provide mill…
The VLT-FLAMES Tarantula Survey. XXVI. Properties of the O-dwarf population in 30 Doradus
Crowther, P. A.; Lennon, D. J.; Herrero, A. +21 more
Context. The VLT-FLAMES Tarantula Survey has observed hundreds of O-type stars in the 30 Doradus region of the Large Magellanic Cloud (LMC).
Aims: We study the properties of a statistically significant sample of O-type dwarfs in the same star-forming region and test the latest atmospheric and evolutionary models of the early main-sequence pha…
How primordial is the structure of comet 67P?. Combined collisional and dynamical models suggest a late formation
Benz, W.; Morbidelli, A.; Jutzi, M. +2 more
Context. There is an active debate about whether the properties of comets as observed today are primordial or, alternatively, if they are a result of collisional evolution or other processes.
Aims: We investigate the effects of collisions on a comet with a structure like 67P/Churyumov-Gerasimenko (67P). We develop scaling laws for the critica…