Search Publications
Distances to the Globular Clusters 47 Tucanae and NGC 362 Using Gaia DR2 Parallaxes
Caiazzo, Ilaria; Chen, Seery; Heyl, Jeremy +1 more
Using parallaxes from Gaia Data Release 2 (Gaia DR2), we estimate the distance to the globular clusters 47 Tuc and NGC 362, taking advantage of the background stars in the Small Magellanic Cloud and quasars to account for various parallax systematics. We found the parallax to be dependent on the Gaia DR2 G-band apparent magnitude for stars with 13…
A Review of Alfvénic Turbulence in High-Speed Solar Wind Streams: Hints From Cometary Plasma Turbulence
Hellinger, Petr; Tsurutani, Bruce T.; Glassmeier, Karl-Heinz +3 more
Solar wind turbulence within high-speed streams is reviewed from the point of view of embedded single nonlinear Alfvén wave cycles, discontinuities, magnetic decreases (MDs), and shocks. For comparison and guidance, cometary plasma turbulence is also briefly reviewed. It is demonstrated that cometary nonlinear magnetosonic waves phase-steepen, wit…
The Rotation and Interior Structure Experiment on the InSight Mission to Mars
Golombek, Matthew P.; Asmar, Sami W.; Yseboodt, Marie +5 more
The Rotation and Interior Structure Experiment (RISE) on-board the InSight mission will use the lander's X-band (8 GHz) radio system in combination with tracking stations of the NASA Deep Space Network (DSN) to determine the rotation of Mars. RISE will measure the nutation of the Martian spin axis, detecting for the first time the effect of the li…
The structure of post-starburst galaxies at 0.5 < z < 2: evidence for two distinct quenching routes at different epochs
Simpson, Chris; Wild, Vivienne; Almaini, Omar +5 more
We present an analysis of the structure of post-starburst (PSB) galaxies in the redshift range 0.5 < z < 2, using a photometrically selected sample identified in the Ultra Deep Survey field. We examine the structure of ∼80 of these transient galaxies using radial light µ(r) profiles obtained from CANDELS Hubble Space Telescope near-inf…
Successive Flux Rope Eruptions from δ-sunspots Region of NOAA 12673 and Associated X-class Eruptive Flares on 2017 September 6
Joshi, Bhuwan; Veronig, Astrid M.; Mitra, Prabir K. +2 more
In this article, we present a multiwavelength analysis of two X-class solar eruptive flares of classes X2.2 and X9.3 that occurred in the sigmoidal active region NOAA 12673 on 2017 September 6, by combining observations of Atmospheric Imaging Assembly and Helioseismic Magnetic Imager instruments on board the Solar Dynamics Observatory. On the day …
LOFAR-Boötes: properties of high- and low-excitation radio galaxies at 0.5 < z < 2.0
Prandoni, I.; White, G. J.; Tasse, C. +13 more
This paper presents a study of the redshift evolution of radio-loud active galactic nuclei (AGN) as a function of the properties of their galaxy hosts in the Boötes field. To achieve this we match low-frequency radio sources from deep 150-MHz LOFAR (LOw Frequency ARray) observations to an I-band-selected catalogue of galaxies, for which we have de…
Hydrogen and Sodium Absorption in the Optical Transmission Spectrum of WASP-12b
Cochran, William D.; Endl, Michael; Redfield, Seth +2 more
We have obtained >10 hr of medium-resolution (R ∼ 15,000) spectroscopic exposures on the transiting exoplanet host star WASP-12, including ∼2 hr while its planet, WASP-12b, is in transit, with the Hobby-Eberly Telescope. The out-of-transit and in-transit spectra are coadded into master out-of-transit and in-transit spectra, from which we create…
Direct imaging of an ultracool substellar companion to the exoplanet host star HD 4113 A
Ségransan, D.; Delisle, J. -B.; Udry, S. +7 more
Using high-contrast imaging with the SPHERE instrument at the Very Large Telescope (VLT), we report the first images of a cold brown dwarf companion to the exoplanet host star HD 4113A. The brown dwarf HD 4113C is part of a complex dynamical system consisting of a giant planet, a stellar host, and a known wide M-dwarf companion. Its separation of …
Does the X-ray outflow quasar PDS 456 have a UV outflow at 0.3c?
Hamann, Fred; Nardini, Emanuele; Reeves, James +1 more
The quasar PDS 456 (at redshift ∼0.184) has a prototype ultra-fast outflow (UFO) measured in X-rays. This outflow is highly ionized with relativistic speeds, large total column densities log NH(cm-2) > 23, and large kinetic energies that could be important for feedback to the host galaxy. A UV spectrum of PDS 456 obtained …
The Carnegie-Chicago Hubble Program. III. The Distance to NGC 1365 via the Tip of the Red Giant Branch
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +8 more
The Carnegie-Chicago Hubble Program (CCHP) seeks to anchor the distance scale of Type Ia supernovae via the Tip of the Red Giant Branch (TRGB) method. Based on deep Hubble Space Telescope ACS/WFC imaging, we present an analysis of the TRGB for the metal-poor halo of NGC 1365, a giant spiral galaxy in the Fornax cluster that was host to the Type Ia…