Search Publications
X-ray study of the merging galaxy cluster Abell 3411-3412 with XMM-Newton and Suzaku
Simionescu, A.; Kaastra, J. S.; Zhang, X. +3 more
Context. Previous Chandra observations of the
Sunquake with a second bounce, other sunquakes, and emission associated with the X9.3 flare of 6 September 2017. I. Observations
Dammasch, Ingolf E.; Matthews, Sarah; Inoue, Satoshi +4 more
Aims: The 6 September 2017 X9.3 solar flare produced very unique observations of magnetic field transients and a few seismic responses, or sunquakes, detected by the Helioseismic and Magnetic Imager (HMI) instrument aboard Solar Dynamic Observatory (SDO) spacecraft, including the strongest sunquake ever reported. This flare was one of a few f…
The elusive tidal tails of the Milky Way globular cluster NGC 7099
Carballo-Bello, Julio A.; Piatti, Andrés E.; Catelan, Márcio +3 more
We present results on the extra-tidal features of the Milky Way globular cluster NGC 7099, using deep gr photometry obtained with the Dark Energy Camera (DECam). We reached nearly 6 mag below the cluster's main sequence (MS) turnoff, so that we dealt with the most suitable candidates to trace any stellar structure located beyond the cluster tidal …
USuRPER: Unit-sphere representation periodogram for full spectra
Zucker, S.; Binnenfeld, A.; Shahaf, S.
We introduce an extension of the periodogram concept to time-resolved spectroscopy. USuRPER, the unit-sphere representation periodogram, is a novel technique that opens new horizons in the analysis of astronomical spectra. It can be used to detect a wide range of periodic variability of the spectrum shape. Essentially, the technique is based on re…
The GAPS programme at TNG. XXVI. Magnetic activity in M stars: spectroscopic monitoring of AD Leonis
Scandariato, G.; Lanza, A. F.; Maldonado, J. +7 more
Context. Understanding stellar activity in M dwarfs is fundamental to improving our knowledge of the physics of stellar atmospheres and for planet search programmes. High levels of stellar activity (also frequently associated with flare events) can cause additional variations in the stellar emission that contaminate the signal induced by a planet …
VIBES: Visual Binary Exoplanet survey with SPHERE. Upper limits on wide S-planet and S-BD frequencies, triple system discovery, and astrometric confirmation of 20 stellar binaries and three triple systems
Quanz, S. P.; Meyer, M.; Jayawardhana, R. +7 more
Context. Recent surveys indicate that planets in binary systems are more abundant than previously thought, which is in agreement with theoretical work on disc dynamics and planet formation in binaries. So far, most observational surveys, however, have focused on short-period planets in binaries, thus little is known about the occurrence rates of p…
A qualitative classification of extraterrestrial civilizations
Minniti, Dante; Ivanov, Valentin D.; Cáceres, Claudio +1 more
Context. Interest in searches for extraterrestrial civilizations (ETCs) has been boosted in recent decades by the discovery of thousands of exoplanets.
Aims: We turn to the classification of ETCs for new considerations that may help to design better strategies for searching for ETCs.
Methods: This study is based on analogies with our own…
Hard X-ray properties of radio-selected blazars
Gehrels, N.; Wilms, J.; Kadler, M. +6 more
Context. Hard X-ray properties of beamed active galactic nuclei have been published in the 105-month Swift/BAT catalog, but there have not been any studies carried out so far on a well-defined, radio-selected sample of low-peaked blazars in the hard X-ray band.
Aims: Using the statistically complete MOJAVE-1 sample, we aim to determine the ha…
The XXL Survey. XL. Obscuration properties of red AGNs in XXL-N
Chiappetti, L.; Paltani, S.; Pierre, M. +6 more
The combination of optical and mid-infrared (MIR) photometry has been extensively used to select red active galactic nuclei (AGNs). Our aim is to explore the obscuration properties of these red AGNs with both X-ray spectroscopy and spectral energy distributions (SEDs). In this study, we re-visit the relation between optical/MIR extinction and X-ra…
Joint XMM-Newton and NuSTAR observations of the reflection spectrum of III Zw 2
Savolainen, Tuomas; Chamani, Wara; Koljonen, Karri
Detecting and modeling the reprocessed hard X-ray emission component in the accretion flow, the so-called reflection spectrum, is a main tool used to estimate black hole spins in a wide range of astrophysical black holes, regardless of their mass or distance. In this work, we study the X-ray spectra of the Seyfert I galaxy III Zw 2 by using multie…