Search Publications
Unbiased TGAS×LAMOST distances and the role of binarity
Rix, Hans-Walter; Coronado, Johanna; Trick, Wilma H.
Spectrophotometric distances to stars observed by large spectroscopic surveys offer a crucial complement to parallax distances that remain very important also after the future Gaia data releases. Here, we present a probabilistic approach to modelling spectroscopic information for a subset of 4000 main sequence stars with good parallaxes (σϖ
Constraints on the Distance Moduli, Helium and Metal Abundances, and Ages of Globular Clusters from their RR Lyrae and Non-variable Horizontal-branch Stars. III. M55 and NGC 6362
VandenBerg, Don A.; Denissenkov, P. A.
M55 (NGC 6809) and NGC 6362 are among the few globular clusters for which masses and radii have been derived to high precision for member binary stars. They also contain RR Lyrae variables, which, together with their non-variable horizontal-branch (HB) populations, provide tight constraints on the cluster reddenings and distance moduli through fit…
Statistical Relation between Solar Flares and Coronal Mass Ejections with Respect to Sigmoidal Structures in Active Regions
Akiyama, Sachiko; Yashiro, Seiji; Shimizu, Toshifumi +3 more
Statistical dependences among features of coronal mass ejections (CMEs), solar flares, and sigmoidal structures in soft-X-ray images were investigated. We applied analysis methods to all the features in the same way in order to investigate the reproducibility of the correlations among them, which may be found from previous statistical studies. Sam…
NuSTAR + XMM-Newton monitoring of the neutron star transient AX J1745.6-2901
Hailey, C.; Stern, D.; Bianchi, S. +12 more
AX J1745.6-2901 is a high-inclination (eclipsing) transient neutron star (NS) low-mass X-ray binary showcasing intense ionized Fe K absorption. We present here the analysis of 11 XMM-Newton and 15 NuSTAR new data sets (obtained between 2013 and 2016), therefore tripling the number of observations of AX J1745.6-2901 in outburst. Thanks to simultane…
Light scattering by hierarchical aggregates
Kolokolova, Ludmilla; Nagdimunov, Lev; Mackowski, Daniel
Recent in-situ studies of the environment of comet 67P/Churyumov-Gerasimenko by the dust instruments onboard the Rosetta spacecraft have indicated a complex structure of cometary dust particles. The majority of those particles appeared to be large aggregates of hierarchical structure, i.e. aggregates of particles, which, in turn, were aggregates o…
ZFIRE: 3D Modeling of Rotation, Dispersion, and Angular Momentum of Star-forming Galaxies at z ∼ 2
Kewley, Lisa J.; Kacprzak, Glenn G.; Glazebrook, Karl +10 more
We perform a kinematic and morphological analysis of 44 star-forming galaxies at z ∼ 2 in the COSMOS legacy field using near-infrared spectroscopy from Keck/MOSFIRE and F160W imaging from CANDELS/3D-HST as part of the ZFIRE survey. Our sample consists of cluster and field galaxies from 2.0 < z < 2.5 with K-band multi-object slit spectroscopi…
Molecular Cloud Structures and Massive Star Formation in N159
Nayak, O.; Meixner, M.; Fukui, Y. +5 more
The N159 star-forming region is one of the most massive giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC). We show the 12CO, 13CO, CS molecular gas lines observed with ALMA in N159 west (N159W) and N159 east (N159E). We relate the structure of the gas clumps to the properties of 24 massive young stellar object…
A Deep Near-infrared [Fe II]+[Si I] Emission Line Image of the Supernova Remnant Cassiopeia A
Koo, Bon-Chul; Lee, Jae-Joon; Moon, Dae-Sik +4 more
We present a long-exposure (∼10 hr), narrowband image of the supernova (SN) remnant Cassiopeia A (Cas A) centered at 1.644 µm emission. The passband contains [Fe II] 1.644 µm and [Si I] 1.645 µm lines, and our “deep [Fe II]+[Si I] image” provides an unprecedented panoramic view of Cas A, showing both shocked and unshocked SN ejec…
Limits on turbulent propagation of energy in cool-core clusters of galaxies
Fabian, A. C.; Reynolds, C. S.; Pinto, C. +2 more
We place constraints on the propagation velocity of bulk turbulence within the intracluster medium of three clusters and an elliptical galaxy. Using Reflection Grating Spectrometer measurements of turbulent line broadening, we show that for these clusters, the 90 per cent upper limit on turbulent velocities when accounting for instrumental broaden…
Short arc orbit determination and imminent impactors in the Gaia era
Mignard, F.; Tanga, P.; Carry, B. +6 more
Short-arc orbit determination is crucial when an asteroid is first discovered. In these cases usually the observations are so few that the differential correction procedure may not converge. We developed an initial orbit computation method, based on systematic ranging, which is an orbit determination technique that systematically explores a raster…