Search Publications
X-ray reverberation lags of the Fe-K line due to AGN disc winds
Done, Chris; Tsujimoto, Masahiro; Ebisawa, Ken +3 more
Short X-ray reverberation lags are seen across a broad Fe-K energy band in more than 20 active galactic nuclei (AGNs). This broad iron line feature in the lag spectrum is most significant in super-Eddington sources such as Ark 564 (L/LEdd ∼ 1) and 1H 0707-495 (L/LEdd ≳ 10). The observed lag time-scales correspond to very shor…
The long outburst of the black hole transient GRS 1716-249 observed in the X-ray and radio band
Motta, S. E.; Segreto, A.; Malzac, J. +9 more
We present the spectral and timing analysis of X-ray observations performed on the Galactic black hole transient GRS 1716-249 during the 2016-2017 outburst. The source was almost continuously observed with the Neil Gehrels Swift Observatory from 2016 December until 2017 October. The X-ray hardness ratio and timing evolution indicate that the sourc…
Coordinates and Maps of the Apollo 17 Landing Site
Oberst, Jürgen; Haase, Isabel; Wählisch, Marita +2 more
We carried out an extensive cartographic analysis of the Apollo 17 landing site and determined and mapped positions of the astronauts, their equipment, and lunar landmarks with accuracies of better than ±1 m in most cases. To determine coordinates in a lunar body-fixed coordinate frame, we applied least squares (2-D) network adjustments to angular…
Isochronal age-mass discrepancy of young stars: SCExAO/CHARIS integral field spectroscopy of the HIP 79124 triple system
Henning, Thomas; Nakagawa, Takao; Currie, Thayne +24 more
We present SCExAO/CHARIS 1.1-2.4 µm integral field direct spectroscopy of the young HIP 79124 triple system. HIP 79124 is a member of the Scorpius-Centaurus association, consisting of an A0V primary with two low-mass companions at a projected separation of < 1″. Thanks to the high quality wavefront corrections provided by SCExAO, both com…
Two Jovian Planets around the Giant Star HD 202696: A Growing Population of Packed Massive Planetary Pairs around Massive Stars?
Trifonov, Trifon; Stock, Stephan; Henning, Thomas +6 more
We present evidence for a new two-planet system around the giant star HD 202696 (=HIP 105056, BD +26 4118). The discovery is based on public HIRES radial velocity (RV) measurements taken at Keck Observatory between 2007 July and 2014 September. We estimate a stellar mass of {1.91}-0.14+0.09{M}⊙ for HD 202696, whic…
Global Parameters of 12 Totally Eclipsing W UMa Stars
Popov, Velimir A.; Petrov, Nikola I.; Kjurkchieva, Diana P.
Photometric observations of 12 totally eclipsing W UMa binaries (NSVS 3325547, V646 Lac, V1320 Cas, V539 Dra, V816 Cep, NSVS 9045055, V1115 Cas, V902 Cep, V596 Peg, NSVS 1768818, V619 Peg, and NSVS 3198272) are presented. We found that the longer (in phase units) the flat eclipses are, the smaller the mass ratios (or the reciprocal values) are. Th…
TESS Habitable Zone Star Catalog
Stassun, K.; Kaltenegger, L.; Pepper, J. +1 more
We present the Transiting Exoplanet Survey Satellite (TESS) Habitable Zone Stars Catalog, a list of 1822 nearby stars with a TESS magnitude brighter than T = 12 and reliable distances from Gaia DR2, around which the NASA’s TESS mission can detect transiting planets, which receive Earth-like irradiation. For all those stars TESS is sensitive down t…
The chemistry of stars in the bar of the Milky Way
Schultheis, M.; Rojas-Arriagada, A.; Wegg, C. +1 more
We use a sample of 938 red clump giant stars located in the direction of the Galactic long bar to study the chemistry of Milky Way bar stars. Kinematically separating stars on bar orbits from stars with inner disc orbits, we find that stars on bar-like orbits are more metal rich with a mean iron abundance of ⟨[Fe/H]⟩ = +0.30 compared to ⟨[Fe/H]⟩ =…
Quantifying the suppression of the (un)-obscured star formation in galaxy cluster cores at 0.2≲ z ≲0.9
Rodighiero, G.; Valtchanov, I.; Franceschini, A. +21 more
We quantify the star formation (SF) in the inner cores (R/R200 ≤0.3) of 24 massive galaxy clusters at 0.2≲ z ≲0.9 observed by the Herschel Lensing Survey and the Cluster Lensing and Supernova survey with Hubble. These programmes, covering the rest-frame ultraviolet to far-infrared regimes, allow us to accurately characterize stellar mas…
Masses, oxygen, and carbon abundances in CHEPS dwarf stars
Jones, H. R. A.; Jenkins, J. S.; Pavlenko, Y. V. +3 more
Context. We report the results from the determination of stellar masses, carbon, and oxygen abundances in the atmospheres of 107 stars from the Calan-Hertfordshire Extrasolar Planet Search (CHEPS) programme. Our stars are drawn from a population with a significantly super-solar metallicity. At least 10 of these stars are known to host orbiting pla…