Search Publications
Extragalactic archeology with the GHOSTS Survey. I. Age-resolved disk structure of nearby low-mass galaxies
Bell, Eric F.; Holwerda, Benne W.; Monachesi, Antonela +5 more
Aims: We study the individual evolution histories of three nearby low-mass edge-on galaxies (IC 5052, NGC 4244, and NGC 5023).
Methods: Using resolved stellar populations, we constructed star count density maps for populations of different ages and analyzed the change of structural parameters with stellar age within each galaxy.
Res…
On the Evolution of the Inner Disk Radius with Flux in the Neutron Star Low-mass X-Ray Binary Serpens X-1
Miller, Jon M.; Cackett, Edward M.; Strohmayer, Tod E. +3 more
We analyze the latest Suzaku observation of the bright neutron star (NS) low-mass X-ray binary Serpens X-1 taken in 2013 October and 2014 April. The observation was taken using the burst mode and only suffered mild pile-up effects. A broad iron line is clearly detected in the X-ray spectrum. We test different models and find that the iron line is …
Multi-wavelength Polarimetry and Spectral Study of the M87 Jet During 2002-2008
Perlman, Eric S.; Cara, Mihai; Sparks, William B. +4 more
We present a multi-wavelength polarimetric and spectral study of the M87 jet obtained at sub-arcsecond resolution between 2002 and 2008. The observations include multi-band archival VLA polarimetry data sets along with Hubble Space Telescope (HST) imaging polarimetry. These observations have better angular resolution than previous work by factors …
Saturn's auroral morphology and field-aligned currents during a solar wind compression
Brown, R. H.; Baines, K. H.; Dougherty, M. K. +12 more
On 21-22 April 2013, during a coordinated auroral observing campaign, instruments onboard Cassini and the Hubble Space Telescope observed Saturn's aurora while Cassini traversed Saturn's high latitude auroral field lines. Signatures of upward and downward field-aligned currents were detected in the nightside magnetosphere in the magnetic field and…
Observed and simulated power spectra of kinetic and magnetic energy retrieved with 2D inversions
Danilovic, S.; van Noort, M.; Rempel, M. +1 more
Context. Information on the origin of internetwork magnetic field is hidden at the smallest spatial scales.
Aims: We try to retrieve the power spectra with certainty to the highest spatial frequencies allowed by current instrumentation.
Methods: To accomplish this, we use a 2D inversion code that is able to recover information up to the …
Cosmic infrared background anisotropies as a window into primordial non-Gaussianity
Kunz, Martin; Tucci, Marco; Desjacques, Vincent
The angular power spectrum of the cosmic infrared background (CIB) is a sensitive probe of the local primordial bispectrum. CIB measurements are integrated over a large volume so that the scale-dependent bias from the primordial non-Gaussianity leaves a strong signal in the CIB power spectrum. Although Galactic dust dominates over the non-Gaussian…
Gas of 96 Planck Cold Clumps in the Second Quadrant
Liu, Tie; Wu, Yuefang; Meng, Fanyi +1 more
Ninety-six Planck cold dust clumps in the second quadrant were mapped with 12CO (1-0), 13CO (1-0), and C18O (1-0) lines at the 13.7 m telescope of Purple Mountain Observatory. 12CO (1-0) and 13CO (1-0) emissions were detected for all 96 clumps, while C18O (1-0) emissions were detect…
Gaussianization for fast and accurate inference from cosmological data
Peiris, Hiranya V.; Joachimi, Benjamin; Schuhmann, Robert L.
We present a method to transform multivariate unimodal non-Gaussian posterior probability densities into approximately Gaussian ones via non-linear mappings, such as Box-Cox transformations and generalizations thereof. This permits an analytical reconstruction of the posterior from a point sample, like a Markov chain, and simplifies the subsequent…
Global magnetohydrodynamic simulation of the 15 March 2013 coronal mass ejection event—Interpretation of the 30-80 MeV proton flux
Wu, S. T.; Vourlidas, Angelos; Wu, Chin-Chun +4 more
The coronal mass ejection (CME) event on 15 March 2013 is one of the few solar events in Cycle 24 that produced a large solar energetic particle (SEP) event and severe geomagnetic activity. Observations of SEP from the ACE spacecraft show a complex time-intensity SEP profile that is not easily understood with current empirical SEP models. In this …
Testing for new physics: neutrinos and the primordial power spectrum
Aslanyan, Grigor; Easther, Richard; Price, Layne C. +2 more
We test the sensitivity of neutrino parameter constraints from combinations of CMB and LSS data sets to the assumed form of the primordial power spectrum (PPS) using Bayesian model selection. Significantly, none of the tested combinations, including recent high-precision local measurements of H0 and cluster abundances, indicate a signal…