Search Publications
Optical Observations Reveal Strong Evidence for High-energy Neutrino Progenitor
Rebolo, R.; Buckley, D. A. H.; Böttcher, M. +32 more
We present the earliest astronomical observation of a high-energy neutrino error box of which the variability was discovered after high-energy-neutrino detection. The one robotic telescope of the MASTER global international networks automatically imaged the error box of the very high-energy-neutrino event IceCube-170922A. Observations were carried…
FEDReD. II. 3D extinction map with 2MASS and Gaia DR2 data
Arenou, F.; Babusiaux, C.; Hottier, C.
Aims: We aim to map the 3D distribution of the interstellar extinction of the Milky Way disc up to distances larger than those probed with the Gaia parallax alone.
Methods: We applied the FEDReD (Field Extinction-Distance Relation Deconvolver) algorithm to the 2MASS near-infrared photometry together with the Gaia DR2 astrometry and photo…
Ondřejov Echelle Spectrograph, Ground Based Support Facility for Exoplanet Missions
Sabotta, S.; Skarka, M.; Kabáth, P. +18 more
Fulfilling the goals of space-based exoplanetary transit surveys, like Kepler and TESS, is impossible without ground-based spectroscopic follow-up. In particular, the first-step vetting of candidates could easily necessitate several hundreds of hours of telescope time - an area where 2 m class telescopes can play a crucial role. Here, we describe …
The AMBRE Project: Spectrum normalisation influence on Mg abundances in the metal-rich Galactic disc
Recio-Blanco, A.; de Laverny, P.; Ordenovic, C. +2 more
Context. The abundance of α-elements provides an important fossil signature in Galactic archaeology to trace the chemical evolution of the different disc populations. High-precision chemical abundances are crucial to improving our understanding of the chemodynamical properties present in the Galaxy. However, deriving precise abundance estimations …
Optical and X-ray discovery of the changing-look AGN IRAS 23226-3843 showing extremely broad and double-peaked Balmer profiles
Schartel, N.; Komossa, S.; Kollatschny, W. +6 more
Aims: We detected a very strong X-ray decline in the galaxy IRAS 23226-3843 within the XMM-Newton slew survey in 2017. Subsequently, we carried out multi-band follow-up studies to investigate this fading galaxy in more detail.
Methods: We took deep follow-up Swift, XMM-Newton, and NuSTAR observations in combination with optical SALT spec…
Discovery of a Young Stellar Snake with Two Dissolving Cores in the Solar Neighborhood
Tian, Hai-Jun
We report the discovery of a young (only 30-40 Myr) snake-like structure (dubbed a stellar snake) in the solar neighborhood from Gaia DR2. The average distance of this structure is about 310 pc from us. Both the length and width are over 200 pc, but the thickness is only about 80 pc. The snake has one tail and two dissolving cores, which can be cl…
IRIS Si IV Line Profiles at Flare Ribbons as Indications of Chromospheric Condensation
Ding, M. D.; Li, Y.; Li, D. +3 more
We present temporal variations of the Si IV line profiles at the flare ribbons in three solar flares observed by the Interface Region Imaging Spectrograph. In the M1.1 flare on 2014 September 6 and the X1.6 flare on 2014 September 10, the Si IV line profiles evolve from wholly redshifted to red-wing enhanced with the flare development. However, in…
A plague of magnetic spots among the hot stars of globular clusters
Gullieuszik, M.; Milone, A. P.; Stetson, P. B. +15 more
For more than six decades, the quest to understand the formation of hot (about 20,000-30,000 K) extreme horizontal branch (EHB) stars in Galactic globular clusters has remained one of the most elusive in stellar evolutionary theory. Here we report on two discoveries that challenge the idea of the stable luminosity of EHB stars. The first mode of E…
Investigating the growing population of massive quiescent galaxies at cosmic noon
Papovich, Casey; Finkelstein, Steven L.; Stevans, Matthew L. +10 more
We explore the build-up of quiescent galaxies using a sample of 28 469 massive (M⋆ ≥ 1011 M⊙) galaxies at redshifts 1.5 < $z$ < 3.0, drawn from a 17.5 deg2 area (0.33 Gpc3 comoving volume at these redshifts). This allows for a robust study of the quiescent fraction as a function of mass …
Nature of Compton-thick Active Galactic Nuclei in "Nonmerging" Luminous Infrared Galaxies UGC 2608 and NGC 5135 Revealed with Broadband X-Ray Spectroscopy
Imanishi, Masatoshi; Tanimoto, Atsushi; Ueda, Yoshihiro +4 more
We have analyzed the broadband X-ray spectra of active galactic nuclei (AGNs) in two "nonmerging" luminous infrared galaxies (LIRGs), UGC 2608 and NGC 5135, utilizing the data of Nuclear Spectroscopic Telescope Array, Suzaku, XMM-Newton, and Chandra. Applying the X-ray clumpy-torus model (XCLUMPY), we find that both sources have similar spectra ch…