Search Publications
SHARDS Frontier Fields: Physical Properties of a Low-mass Lyα Emitter at z = 5.75
Pérez-González, Pablo G.; Richard, Johan; Conselice, Christopher J. +20 more
We analyze the properties of a multiply imaged Lyα (Lyα) emitter at z = 5.75 identified through SHARDS Frontier Fields intermediate-band imaging of the Hubble Frontier Fields (HFF) cluster Abell 370. The source, A370-L57, has low intrinsic luminosity (M UV ∼ -16.5), steep UV spectral index (β = -2.4 ± 0.1), and extreme rest-frame equiva…
Calibrating the Planck Cluster Mass Scale with Cluster Velocity Dispersions
Chary, Ranga-Ram; Stern, Daniel; Shim, Hyunjin +7 more
We measure the Planck cluster mass bias using dynamical mass measurements based on velocity dispersions of a subsample of 17 Planck-detected clusters. The velocity dispersions were calculated using redshifts determined from spectra that were obtained at the Gemini observatory with the GMOS multi-object spectrograph. We correct our estimates for ef…
The Deflection of the Cartwheel CME: ForeCAT Results
Landi, Enrico; Kay, Christina; Capannolo, Luisa +1 more
We analyze the Cartwheel coronal mass ejection's (CME; 2008 April 9) trajectory in the low corona with the ForeCAT model. This complex event presented a significant rotation in the low corona and a reversal in its original latitude direction. We successfully reproduce the observed CME’s trajectory (latitude and longitude deflection) and speed. Thr…
A Multi-band Study of the Remarkable Jet in Quasar 4C+19.44
Cheung, C. C.; Uchiyama, Y.; Siemiginowska, A. +14 more
We present arcsecond-resolution data in the radio, IR, optical, and X-ray for 4C+19.44 (=PKS 1354+195), the longest and straightest quasar jet with deep X-ray observations. We report results from radio images with half to one arcsecond angular resolution at three frequencies, plus Hubble Space Telescope and Spitzer data. The Chandra data allow us …
The 2013 February 17 Sunquake in the Context of the Active Region's Magnetic Field Configuration
Guglielmino, S. L.; Green, L. M.; Valori, G. +3 more
Sunquakes are created by the hydrodynamic response of the lower atmosphere to a sudden deposition of energy and momentum. In this study, we investigate a sunquake that occurred in NOAA active region 11675 on 2013 February 17. Observations of the corona, chromosphere, and photosphere are brought together for the first time with a nonlinear force-fr…
No Evidence for Feedback: Unexceptional Low-ionization Winds in Host Galaxies of Low Luminosity Active Galactic Nuclei at Redshift z ∼ 1
Prochaska, J. Xavier; Faber, S. M.; Coil, Alison L. +6 more
We study winds in 12 X-ray AGN host galaxies at z∼ 1. We find, using the low-ionization Fe II λ2586 absorption in the stacked spectra, that the probability distribution function (PDF) of the centroid-velocity shift in AGNs has 50th (median), 16th, and 84th percentiles of (-87, -251, +86) km s-1 respectively. The PDF of the velocity disp…
Variations between Dust and Gas in the Diffuse Interstellar Medium. III. Changes in Dust Properties
Heiles, Carl; Reach, William T.; Bernard, Jean-Philippe +1 more
We study infrared emission of 17 isolated, diffuse clouds with masses of order {10}2 {M}⊙ to test the hypothesis that grain property variations cause the apparently low gas-to-dust ratios that have been measured in those clouds. Maps of the clouds were constructed from Wide-field Infrared Survey Explorer (WISE) data and dire…
Shocks and Spatially Offset Active Galactic Nuclei Produce Velocity Offsets in Emission Lines
Greene, Jenny E.; Comerford, Julia M.; Barrows, R. Scott +1 more
While 2% of active galactic nuclei (AGNs) exhibit narrow emission lines with line-of-sight velocities that are significantly offset from the velocity of the host galaxy’s stars, the nature of these velocity offsets is unknown. We investigate this question with Chandra/ACIS and Hubble Space Telescope/Wide Field Camera 3 observations of seven veloci…
Spectral Variability of Two Rapidly Rotating Brown Dwarfs: 2MASS J08354256-0819237 and 2MASS J18212815+1414010
Schlawin, E.; Burgasser, Adam J.; Gizis, J. E. +2 more
L dwarfs exhibit low-level, rotationally modulated photometric variability generally associated with heterogeneous, cloud-covered atmospheres. The spectral character of these variations yields insight into the particle sizes and vertical structure of the clouds. Here, we present the results of a high-precision, ground-based, near-infrared, spectra…
A Suzaku View of Accretion-powered X-Ray Pulsar GX 1+4
Hoshino, Akio; Naik, Sachindra; Kitamoto, Shunji +3 more
We present results obtained from a Suzaku observation of the accretion-powered X-ray pulsar GX 1+4. A broadband continuum spectrum of the pulsar was found to be better described by a simple model consisting of a blackbody component and an exponential cutoff power law than the previously used compTT continuum model. Though the pulse profile had a s…