Search Publications
Theoretical basis for operational ensemble forecasting of coronal mass ejections
Odstrcil, D.; Biesecker, D. A.; Millward, G. +5 more
We lay out the theoretical underpinnings for the application of the Wang-Sheeley-Arge-Enlil modeling system to ensemble forecasting of coronal mass ejections (CMEs) in an operational environment. In such models, there is no magnetic cloud component, so our results pertain only to CME front properties, such as transit time to Earth. Within this fra…
Measuring the Largest Angular Scale CMB B-mode Polarization with Galactic Foregrounds on a Cut Sky
Marriage, Tobias A.; Wollack, Edward J.; Watts, Duncan J. +9 more
We consider the effectiveness of foreground cleaning in the recovery of Cosmic Microwave Background (CMB) polarization sourced by gravitational waves for tensor-to-scalar ratios in the range 0\lt r\lt 0.1. Using the planned survey area, frequency bands, and sensitivity of the Cosmology Large Angular Scale Surveyor (CLASS), we simulate maps of Stok…
Continuous Mid-Infrared Star Formation Rate Indicators: Diagnostics for 0 < z < 3 Star-Forming Galaxies
Elbaz, D.; Calzetti, D.; Johnson, B. D. +1 more
We present continuous, monochromatic star formation rate (SFR) indicators over the mid-infrared wavelength range of 6-70 µm. We use a sample of 58 star-forming galaxies (SFGs) in the Spitzer-SDSS-GALEX Spectroscopic Survey at z < 0.2, for which there is a rich suite of multi-wavelength photometry and spectroscopy from the ultraviolet thro…
Generalized self-similarity of intermittent plasma turbulence in space and laboratory plasmas
Zelenyi, L. M.; Savin, S. P.; Budaev, V. P.
> Statistical characteristics of plasma fluctuations in the solar wind (SW), the Earth's magnetosphere and fusion devices are reviewed. The turbulence in all these media has a complicated multiscale structure and exhibits a generalized self-similarity in an extended scale range. The anomalous transport of mass and momentum is intermittent and i…
Variability of Disk Emission in Pre-main Sequence and Related Stars. III. Exploring Structural Changes in the Pre-transitional Disk in HD 169142
Inoue, Akio K.; Brown, Alexander; Russell, Ray W. +17 more
We present near-IR (NIR) and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between ~1.5-10 µm over a maximum t…
The role of massive halos in the star formation history of the Universe
Finoguenov, A.; Berta, S.; Magnelli, B. +21 more
Context. The most striking feature of the cosmic star formation history (CSFH) of the Universe is a dramatic drop in the star formation (SF) activity after z ~ 1.
Aims: In this work we investigate whether the very same process of assembly and growth of structures is one of the major drivers of the observed decline in the Universe's SF activit…
A census of variability in globular cluster M 68 (NGC 4590)
Surdej, J.; Arellano Ferro, A.; Steele, I. A. +34 more
Aims: We analyse 20 nights of CCD observations in the V and I bands of the globular cluster M 68 (NGC 4590) and use them to detect variable objects. We also obtained electron-multiplying CCD (EMCCD) observations for this cluster in order to explore its core with unprecedented spatial resolution from the ground.
Methods: We reduced our da…
Deep rest-frame far-UV spectroscopy of the giant Lyman α emitter `Himiko'
Nørgaard-Nielsen, H. U.; Fynbo, J. P. U.; Ouchi, M. +3 more
We present deep 10 h VLT/XSHOOTER spectroscopy for an extraordinarily luminous and extended Ly α emitter at z = 6.595 referred to as Himiko and first discussed by Ouchi et al., with the purpose of constraining the mechanisms powering its strong emission. Complementary to the spectrum, we discuss near-infrared imaging data from the CANDELS survey. …
On the Origin of Wind Line Variability in O Stars
Massa, D.; Prinja, R. K.
We analyze 10 UV time series for five stars that fulfill specific sampling and spectral criteria to constrain the origin of large-scale wind structure in O stars. We argue that excited state lines must arise close to the stellar surface and are an excellent diagnostic complement to resonance lines which, due to radiative transfer effects, rarely s…
Late Noachian fluvial erosion on Mars: Cumulative water volumes required to carve the valley networks and grain size of bed-sediment
Rosenberg, Eliott N.; Head, James W., III
Our goal is to quantify the cumulative water volume that was required to carve the Late Noachian valley networks on Mars. We employ an improved methodology in which fluid/sediment flux ratios are based on empirical data, not assumed. We use a large quantity of data from terrestrial rivers to assess the variability of actual fluid/sediment flux sed…