Search Publications
More than two hundred and fifty thousand spectroscopic binary or variable star candidates discovered by LAMOST
Li, Lin-Jia; Qian, Sheng-Bang; Zhu, Li-Ying +7 more
About 786.4 thousand stars were observed by LAMOST twice or more during the first stage of its spectroscopic survey. The radial velocity differences for about 256 thousand targets are larger than 10 km s-1 and they are possible spectroscopic binary or variable candidates (SBVCs). It is shown that most SBVCs are slightly metal poorer tha…
Contrast sensitivities in the Gaia Data Release 2
Cataldi, Gianni; Brandeker, Alexis
The source detection sensitivity of Gaia is reduced near sources. To characterise this contrast sensitivity is important for understanding the completeness of the Gaia data products, in particular when evaluating source confusion in lower resolution surveys such as photometric monitoring for transits. Here, we statistically evaluate the catalogue …
Interstellar Neutral Gas Species and Their Pickup Ions inside the Heliospheric Termination Shock. Ionization Rates for H, O, Ne, and He
Tokumaru, Munetoshi; Bzowski, Maciej; Sokół, Justyna M.
Solar ionizing factors are responsible for modulation of interstellar neutral gas and its derivative populations inside the heliosphere. We provide an overview of the current state of knowledge about them for heliospheric particles inside the termination shock. We discuss charge exchange with solar wind particles, photoionization, and electron imp…
Torus model properties of an ultra-hard X-ray selected sample of Seyfert galaxies
Hernán-Caballero, A.; Carrera, F. J.; Acosta-Pulido, J. A. +15 more
We characterize for the first time the torus properties of an ultra-hard X-ray (14-195 keV) volume-limited (DL < 40 Mpc) sample of 24 Seyfert (Sy) galaxies (BCS40 sample). The sample was selected from the Swift/BAT nine-month catalogue. We use high angular resolution nuclear infrared (IR) photometry and N-band spectroscopy…
Binospec Software System
Chilingarian, Igor; Paegert, Martin; Fabricant, Daniel +6 more
Binospec is a high-throughput, 370 to 1000 nm, imaging spectrograph that addresses two adjacent 8‧ by 15‧ fields of view. Binospec was commissioned in late 2017 at the f/5 focus of the 6.5 m MMT and is now available to all MMT observers. Here we describe the Binospec software used for observation planning, instrument control, and data reduction. T…
Revisiting the 16 Cygni planet host at unprecedented precision and exploring automated tools for precise abundances
Spina, L.; Jofré, P.; Meléndez, J. +2 more
The binary system 16 Cygni is key in studies of the planet-star chemical composition connection, as only one of the stars is known to host a planet. This allows us to better assess the possible influence of planet interactions on the chemical composition of stars that are born from the same cloud and thus should have a similar abundance pattern. I…
Characterization of Ring Substructures in the Protoplanetary Disk of HD 169142 from Multiwavelength Atacama Large Millimeter/submillimeter Array Observations
Flock, Mario; Henning, Thomas; Dent, William R. F. +10 more
We present a detailed multiwavelength characterization of the multi-ring disk of HD 169142. We report new Atacama Large Millimeter/submillimeter Array (ALMA) observations at 3 mm and analyze them together with archival 0.89 and 1.3 mm data. Our observations resolve three out of the four rings in the disk previously seen in high-resolution ALMA dat…
Understanding the Limitations of Gyrochronology for Old Field Stars
Metcalfe, Travis S.; Egeland, Ricky
Nearly half a century has passed since the initial indications that stellar rotation slows while chromospheric activity weakens with a power-law dependence on age, the so-called Skumanich relations. Subsequent characterization of the mass-dependence of this behavior up to the age of the Sun led to the advent of gyrochronology, which uses the rotat…
Effects of Ducting on Whistler Mode Chorus or Exohiss in the Outer Radiation Belt
Hanzelka, Miroslav; Santolík, Ondřej
Previously published statistics based on Cluster spacecraft measurements surprisingly show that in the outer radiation belt, lower band whistler mode waves predominantly propagate unattenuated parallel to the magnetic field lines up to midlatitudes, where ray tracing simulations indicated highly attenuated waves with oblique wave vectors. We expla…
Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets
Bouchy, F.; Vanderburg, A.; Poretti, E. +34 more
Super-Earths belong to a class of planet not found in the Solar system, but which appear common in the Galaxy. Given that some super-Earths are rocky, while others retain substantial atmospheres, their study can provide clues as to the formation of both rocky and gaseous planets, and - in particular - they can help to constrain the role of photoev…