Search Publications
The Impact of Stellar Distances on Habitable Zone Planets
Kane, Stephen R.
Among the most highly valued of exoplanetary discoveries are those of terrestrial planets found to reside within the habitable zone (HZ) of the host star. In particular, those HZ planets with relatively bright host stars will serve as priority targets for characterization observations, such as those involving mass determinations, transmission spec…
Using Machine Learning Methods to Forecast if Solar Flares Will Be Associated with CMEs and SEPs
Karoff, Christoffer; Inceoglu, Fadil; Jeppesen, Jacob H. +3 more
Among the eruptive activity phenomena observed on the Sun, those that threaten human technology the most are flares with associated coronal mass ejections (CMEs) and solar energetic particles (SEPs). Flares with associated CMEs and SEPs are produced by magnetohydrodynamical processes in magnetically active regions (ARs) on the Sun. However, these …
On the CGM Fundamental Plane: The Halo Mass Dependency of Circumgalactic H I
Tripp, Todd M.; Prochaska, J. Xavier; Tumlinson, Jason +3 more
We analyze the equivalent widths of H I {{Ly}}α ({W}Lyα }) absorption from the inner (R < 160 kpc) circumgalactic medium (CGM) of 85 galaxies at z ∼ 0 with stellar masses M * ranging 8≤slant {log} {M}* /{M}⊙ ≤slant 11.6. Across three orders of magnitude in stellar mass, the CGM of present-day galaxies…
The Carnegie-Chicago Hubble Program. IV. The Distance to NGC 4424, NGC 4526, and NGC 4356 via the Tip of the Red Giant Branch
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +8 more
The Carnegie-Chicago Hubble Program is undertaking a re-calibration of the extragalactic distance scale, using SNe Ia that are tied to Tip of the Red Giant Branch (TRGB) distances to local galaxies. We present here deep Hubble Space Telescope ACS/WFC imaging of the resolved stellar populations in the metal-poor halos of the SN Ia-host galaxies NGC…
Cosmological Constraints from the Redshift Dependence of the Alcock-Paczynski Effect: Dynamical Dark Energy
Park, Changbom; Sabiu, Cristiano G.; Shafieloo, Arman +6 more
We perform an anisotropic clustering analysis of 1,133,326 galaxies from the Sloan Digital Sky Survey (SDSS-III) Baryon Oscillation Spectroscopic Survey Data Release 12 covering the redshift range 0.15 < z < 0.69. The geometrical distortions of the galaxy positions, caused by incorrect assumptions in the cosmological model, are captured in t…
Modeling the Thermodynamic Evolution of Coronal Mass Ejections Using Their Kinematics
Wang, Yuming; Mishra, Wageesh
Earlier studies on coronal mass ejections (CMEs), using remote sensing and in situ observations, have attempted to determine some internal properties of CMEs, which were limited to a certain position or a certain time. To understand the evolution of the internal thermodynamic state of CMEs during their heliospheric propagation, we improve the self…
Texas Spectroscopic Search for Lyα Emission at the End of Reionization I. Constraining the Lyα Equivalent-width Distribution at 6.0 < z < 7.0
Papovich, Casey; Finkelstein, Steven L.; Dickinson, Mark +6 more
The distribution of Lyα emission is a presently accessible method for studying the state of the intergalactic medium (IGM) into the reionization era. We carried out deep spectroscopic observations in order to search for Lyα emission from galaxies with photometric redshifts z = 5.5-8.3 selected from the Cosmic Assembly Near-infrared Deep Extragalac…
Chandra and XMM-Newton Observations of the Abell 3395/Abell 3391 Intercluster Filament
Jones, Christine; Randall, Scott W.; Bourdin, Hervé +2 more
We present Chandra and XMM-Newton X-ray observations of the Abell 3391/Abell 3395 intercluster filament. It has been suggested that the galaxy clusters Abell 3395, Abell 3391, and the galaxy group ESO-161 -IG 006 located between the two clusters, are in alignment along a large-scale intercluster filament. We find that the filament is aligned close…
Constraints on the Mass, Concentration, and Nonthermal Pressure Support of Six CLASH Clusters from a Joint Analysis of X-Ray, SZ, and Lensing Data
Koekemoer, Anton M.; Donahue, Megan; Koch, Patrick M. +17 more
We present a joint analysis of Chandra X-ray observations, Bolocam thermal Sunyaev-Zel’dovich (SZ) effect observations, Hubble Space Telescope (HST) strong-lensing data, and HST and Subaru Suprime-Cam weak-lensing data. The multiwavelength data set is used to constrain parametric models for the distribution of dark and baryonic matter in a sample …
The Hot, Accreted Halo of NGC 891
Bregman, Joel N.; Hodges-Kluck, Edmund J.; Li, Jiang-tao
Galaxies are surrounded by halos of hot gas whose mass and origin remain unknown. One of the most challenging properties to measure is the metallicity, which constrains both of these. We present a measurement of the metallicity around NGC 891, a nearby, edge-on, Milky Way analog. We find that the hot gas is dominated by low-metallicity gas near th…