Search Publications
On the High-energy Emissions of Compact Objects Observed with INTEGRAL SPI: Event Selection Impact on Source Spectra and Scientific Results for the Bright Sources Crab Nebula, GS 2023+338 and MAXI J1820+070
Jourdain, Elisabeth; Roques, Jean-Pierre
The Spectrometer on INTEGRAL (SPI) instrument has observed the hard X-ray sky from 20 keV up to a few MeV for more than 15 yr. In this energy domain, the main emitters are compact objects for which SPI provides spectral information of prime interest. Recently, two transient sources reached very unusual flux levels and have been detected up to a fe…
On migration of dust and ice grains on the surface of the rotating comet nucleus
Wesołowski, M.; Gronkowski, P.; Tralle, I.
In the paper the migration of dust and ice grains over the surface of the comet nucleus is considered and analysed. This phenomenon is a consequence of interplay between the components of three forces tangential to the surface of comet nucleus and acting on the comet's grain. These forces are the gravity of the comet's nucleus, the frictional forc…
Chemical and Kinematic Analysis of CN-strong Metal-poor Field Stars in LAMOST DR3
Shi, Jianrong; Fernández-Trincado, J. G.; Zamora, Olga +5 more
The large amount of chemical and kinematic information available in large spectroscopic surveys has inspired the search for chemically peculiar stars in the field. Though these metal-poor field stars ([Fe/H] < -1) are commonly enriched in nitrogen, their detailed spatial, kinematic, and chemical distributions suggest that various groups may exi…
High-resolution Optical Spectroscopy of Stars in the Sylgr Stellar Stream
Roederer, Ian U.; Gnedin, Oleg Y.
We observe two metal-poor main-sequence stars that are members of the recently discovered Sylgr stellar stream. We present radial velocities, stellar parameters, and abundances for 13 elements derived from high-resolution optical spectra collected using the Magellan Inamori Kyocera Echelle spectrograph. The two stars have identical compositions (w…
K2 observations of the sdBV + dM/bd binaries PHL 457 and EQ Psc
Reed, M. D.; Jeffery, C. S.; Baran, A. S. +5 more
We present an analysis of two pulsating subdwarf B stars PHL 457 and EQ Psc observed during the K2 mission. The K2 light curves of both stars show variation consistent with irradiation of a cooler companion by the hot subdwarf. They also show higher frequency oscillations consistent with pulsation. Using new spectroscopic data, we measured the rad…
Spectroscopic Confirmation of Five Galaxy Clusters at z > 1.25 in the 2500 deg2 SPT-SZ Survey
Bayliss, M. B.; Sharon, K.; Gladders, M. D. +29 more
We present spectroscopic confirmation of five galaxy clusters at 1.25 < z < 1.5, discovered in the 2500 deg2 South Pole Telescope Sunyaev-Zel’dovich (SZ) survey. These clusters, taken from a mass-limited sample with a nearly redshift-independent selection function, have multiwavelength follow-up imaging data from the X-ray to near…
Effective Temperatures of Low-mass Stars from High-resolution H-band Spectroscopy
Kesseli, Aurora Y.; Muirhead, Philip S.; Johns-Krull, Christopher M. +9 more
High-resolution, near-infrared spectra will be the primary tool for finding and characterizing Earth-like planets around low-mass stars. Yet, the properties of exoplanets cannot be precisely determined without accurate and precise measurements of the host star. Spectra obtained with the Immersion Grating Infrared Spectrometer simultaneously provid…
Titan Surface Temperatures during the Cassini Mission
Flasar, F. M.; Coustenis, A.; Achterberg, R. K. +11 more
By the close of the Cassini mission in 2017 the Composite Infrared Spectrometer had recorded surface brightness temperatures on Titan for 13 yr (almost half a Titan year). We mapped temperatures in latitude from pole to pole in seven time segments from northern mid-winter to northern summer solstice. At the beginning of the mission the warmest tem…
Fast-cadence TESS Photometry and Doppler Tomography of the Asynchronous Polar CD Ind: A Revised Accretion Geometry from Newly Proposed Spin and Orbital Periods
Garnavich, Peter; Littlefield, Colin; Szkody, Paula +5 more
The Transiting Exoplanet Survey Satellite observed the asynchronous polar (AP) CD Ind at a 2 min cadence almost continuously for 28 days in 2018, covering parts of five consecutive cycles of the system’s 7.3 day beat period. These observations provide the first uninterrupted photometry of a full spin-orbit beat cycle of an AP. Twice per beat cycle…
Radial Velocity Discovery of an Eccentric Jovian World Orbiting at 18 au
Vanderburg, Andrew; Cochran, William D.; Endl, Michael +25 more
Based on two decades of radial velocity (RV) observations using Keck/High Resolution Echelle Spectrometer (HIRES) and McDonald/Tull, and more recent observations using the Automated Planet Finder, we found that the nearby star HR 5183 (HD 120066) hosts a 3 {M}{{J}} minimum mass planet with an orbital period of {74}-22+43…