Search Publications
Geomorphology and spectrophotometry of Philae's landing site on comet 67P/Churyumov-Gerasimenko
Jorda, L.; Bertaux, J. -L.; Lamy, P. +52 more
Context. On 12 November 2014 the European mission Rosetta succeeded in delivering a lander, named Philae, on the surface of one of the smallest, low-gravity and most primitive bodies of the solar system, the comet 67P/Churyumov-Gerasimenko (67P).
Aims: The aim of this paper is to provide a comprehensive geomorphological and spectrophotometric…
Non-conservative evolution in Algols: where is the matter?
Baes, M.; Jorissen, A.; Siess, L. +3 more
Context. There is indirect evidence of non-conservative evolutions in Algols. However, the systemic mass-loss rate is poorly constrained by observations and generally set as a free parameter in binary-star evolution simulations. Moreover, systemic mass loss may lead to observational signatures that still need to be found.
Aims: Within the "ho…
Stellar cycles from photometric data: CoRoT stars
Catelan, M.; Ferreira Lopes, C. E.; De Medeiros, J. R. +3 more
Context. Until a few years ago, the amplitude variation in the photometric data had been explored to a limited extent mainly because of time resolution and photometric sensitivity limitations. This investigation is now possible thanks to the Kepler and CoRoT databases which provide a unique set of data for studying the nature of stellar variabilit…
Outflow of low-energy ions and the solar cycle
André, M.; Eriksson, A. I.; Li, K.
Magnetospheric ions with energies less than tens of eV originate from the ionosphere. Positive low-energy ions are complicated to detect onboard sunlit spacecraft at higher altitudes, which often become positively charged to several tens of volts. We use two Cluster spacecraft and study low-energy ions with a technique based on the detection of th…
Overturning the Case for Gravitational Powering in the Prototypical Cooling Lyα Nebula
Momcheva, Ivelina; Brammer, Gabriel B.; Fynbo, Johan P. U. +2 more
The Nilsson et al. Lyα nebula has often been cited as the most plausible example of an Lyα nebula powered by gravitational cooling. In this paper, we bring together new data from the Hubble Space Telescope and the Herschel Space Observatory as well as comparisons to recent theoretical simulations in order to revisit the questions of the local envi…
The Host Galaxies of X-Ray Quasars are Not Strong Star Formers
Hasinger, G.; Li, Y.; Owen, F. N. +4 more
We use ultradeep SCUBA-2 850 µm observations (∼0.37 mJy rms) of the 2 Ms Chandra Deep Field-North (CDF-N) and 4 Ms Chandra Deep Field-South X-ray fields to examine the amount of dusty star formation taking place in the host galaxies of high-redshift X-ray active galactic nuclei (AGNs). Supplementing with COSMOS, we measure the submillimeter …
A Connection between Plasma Conditions near Black Hole Event Horizons and Outflow Properties
Gandhi, P.; Bernardini, F.; Casella, P. +9 more
Accreting black holes are responsible for producing the fastest, most powerful outflows of matter in the universe. The formation process of powerful jets close to black holes is poorly understood, and the conditions leading to jet formation are currently hotly debated. In this paper, we report an unambiguous empirical correlation between the prope…
Deep NuSTAR and Swift Monitoring Observations of the Magnetar 1E 1841-045
An, Hongjun; Hailey, Charles J.; Kaspi, Victoria M. +15 more
We report on a 350 ks NuSTAR observation of the magnetar 1E 1841-045 taken in 2013 September. During the observation, NuSTAR detected six bursts of short duration, with T90 ≲ 1 s. An elevated level of emission tail is detected after the brightest burst, persisting for ∼1 ks. The emission showed a power-law decay with a temporal index of…
ALMA observations of α Centauri. First detection of main-sequence stars at 3 mm wavelength
Olofsson, G.; Eiroa, C.; Marshall, J. P. +19 more
Context. The precise mechanisms that provide the non-radiative energy for heating the chromosphere and the corona of the Sun and those of other stars constitute an active field of research. By studying stellar chromospheres one aims at identifying the relevant physical processes. Defining the permittable extent of the parameter space can also serv…
Debris Distribution in HD 95086—A Young Analog of HR 8799
Rieke, George H.; Su, Kate Y. L.; Malhotra, Renu +3 more
HD 95086 is a young early-type star that hosts (1) a 5 MJ planet at the projected distance of 56 AU revealed by direct imaging, and (2) a prominent debris disk. Here we report the detection of 69 µm crystalline olivine feature from the disk using the Spitzer/MIPS-SED data covering 55-95 µm. Due to the low resolution of the M…