Search Publications
Furiously fast and red: sub-second optical flaring in V404 Cyg during the 2015 outburst peak
Altamirano, D.; Knigge, C.; Dhillon, V. S. +25 more
We present observations of rapid (sub-second) optical flux variability in V404 Cyg during its 2015 June outburst. Simultaneous three-band observations with the ULTRACAM fast imager on four nights show steep power spectra dominated by slow variations on ∼100-1000 s time-scales. Near the peak of the outburst on June 26, a dramatic change occurs and …
Inversion of the radiative transfer equation for polarized light
Ruiz Cobo, Basilio; del Toro Iniesta, Jose Carlos
Since the early 1970s, inversion techniques have become the most useful tool for inferring the magnetic, dynamic, and thermodynamic properties of the solar atmosphere. Inversions have been proposed in the literature with a sequential increase in model complexity: astrophysical inferences depend not only on measurements but also on the physics assu…
Baryon content of massive galaxy clusters at 0.57 < z < 1.33
Schrabback, T.; Zenteno, A.; Desai, S. +22 more
We study the stellar, brightest cluster galaxy (BCG) and intracluster medium (ICM) masses of 14 South Pole Telescope (SPT) selected galaxy clusters with median redshift z = 0.9 and mass M500 = 6 × 1014 M⊙. We estimate stellar masses for each cluster and BCG using six photometric bands, the ICM mass using X-ray obse…
Measurements of Water Surface Snow Lines in Classical Protoplanetary Disks
Zhang, Ke; Banzatti, Andrea; Najita, Joan R. +5 more
We present deep Herschel-PACS spectroscopy of far-infrared water lines from a sample of four protoplanetary disks around solar-mass stars, selected to have strong water emission at mid-infrared wavelengths. By combining the new Herschel spectra with archival Spitzer-IRS spectroscopy, we retrieve a parameterized radial surface water vapor distribut…
The MOSDEF Survey: Detection of [O III]λ4363 and the Direct-method Oxygen Abundance of a Star-forming Galaxy at z = 3.08
Siana, Brian; Shapley, Alice E.; Reddy, Naveen A. +8 more
We present measurements of the electron-temperature-based oxygen abundance for a highly star-forming galaxy at z = 3.08, COSMOS-1908. This is the highest redshift at which [O III]λ4363 has been detected and the first time that this line has been measured at z\gt 2. We estimate an oxygen abundance of 12+{log}({{O}}/{{H}})={8.00}-0.14
Bright Galaxies at Hubble’s Redshift Detection Frontier: Preliminary Results and Design from the Redshift z ~ 9-10 BoRG Pure-Parallel HST Survey
Shull, J. M.; Brammer, G.; Treu, T. +14 more
We present the first results and design from the redshift z ∼ 9-10 Brightest of the Reionizing Galaxies Hubble Space Telescope survey BoRG[z9-10], aimed at searching for intrinsically luminous unlensed galaxies during the first 700 Myr after the Big Bang. BoRG[z9-10] is the continuation of a multi-year pure-parallel near-IR and optical imaging cam…
Measurements of Non-thermal Line Widths in Solar Active Regions
Warren, Harry P.; Brooks, David H.
Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal heating. Here we present a survey of non-thermal velocities measured in the high temperature loops (1-4 MK) o…
Predicting the amplitude and hemispheric asymmetry of solar cycle 25 with surface flux transport
Hathaway, David H.; Upton, Lisa A.
Evidence strongly indicates that the strength of the Sun's polar fields near the time of a sunspot cycle minimum determines the strength of the following solar activity cycle. We use our Advective Flux Transport code, with flows well constrained by observations, to simulate the evolution of the Sun's polar magnetic fields from early 2016 to the en…
Probing interstellar turbulence in cirrus with deep optical imaging: no sign of energy dissipation at 0.01 pc scale
Miville-Deschênes, M. -A.; Duc, P. -A.; Cuillandre, J. -C. +4 more
Diffuse Galactic light has been observed in the optical since the 1930s. We propose that, when observed in the optical with deep imaging surveys, it can be used as a tracer of the turbulent cascade in the diffuse interstellar medium (ISM), down to scales of about 1 arcsec. Here we present a power spectrum analysis of the dust column density of a d…
Investigation into the disparate origin of CO2 and H2O outgassing for Comet 67/P
Piccioni, Giuseppe; De Sanctis, Maria Cristina; Filacchione, Gianrico +15 more
We present an investigation of the emission intensity of CO2 and H2O and their distribution in the coma of 67P/ Churyumov-Gerasimenko obtained by the VIRTIS-M imaging spectrometer on the Rosetta mission. We analyze 4 data cubes from Feb. 28, and 7 data cubes from April 27, 2015. For both data sets the spacecraft was at a suff…