Day 844

Tuesday.


1411.5560
Solar panels as cosmic -ray detectors
Stella, et al

As the title says.  A way to develop large-effective area detectors.


1411.5018
Frequentism and Bayesianism: a Python-driven primer
VanderPlas

A brief, semi-techinal comparison of the essential features of the frequentist and Baysian approaches to statistical inference, with several examples implemented in Python.  The differences between frequents and Bayesianism fundamentally stem from different definitions of probability, a philosophical divide which leads to distinct approaches to the solution of statistical problems as well as contrasting ways of asking and answering questions about unknown parameters.  Briefly compare several leading Python statistical packages which implement frequentist inference using classical methods and Bayesian inference using Markov Chain Monte Carlo.


1411.3324
Comparing the observable properties of dwarf galaxies on and off the Andromeda plane
Collins, et al

No difference in off- and on-plane dwarf galaxies, arguing against vastly different formative and evolutionary histories for these two populations.


1503.00002
A dusty, normal galaxy in the epoch of reionization
Watson, et al

Candidates for the modest galaxies that formed most of the stars in the early universe, at z>7, have been found in large numbers with extremely deep rest frame-UV imaging.  But it has proved difficult for existing spectrographs to characterize them in the UV.  The detailed properties of these galaxies could be measured from dust and cool gas emission at FIR wavelengths if the galaxies have become sufficiently enriched in dust and metals.  So far, the most distant UV-selected galaxy detected in dust emission is only at z=3.25, and recent results have cast doubt on whether dust and molecules can be found in typical galaxies at this early epoch.  Report thermal dust emission from an archetypal early universe SF galaxy, A1689-zD1.  Detect its stellar continuum in spectroscopy and determine its redshift to be z=7.5pm0.2 from a spectroscopic detection of the Lya break.  This galaxy is representative of the SF population during reionization, with a total SFR of about 12 Msun/yr.  The galaxy is highly evolved: it has a large stellar mass, and is heavily enriched in dust, with a dust-to-gas ratio close to that of the MW.  Dusty, evolved galaxies are thus present among the fainter SF population at z>7, in spite of the very short time since they first appeared.


1503.00061
Separating weak lensing and intrinsic alignments using radio observations
Whittaker, Brown, Battye

Discuss methods of performing WL using radio observations to recover information about the intrinsic structural properties of the source galaxies.  Radio surveys provide unique information that can benefit WL studies, such as HI emission, which may be used to construct galaxy velocity maps, and polarized synchrotron radiation; both of which provide information about the unlensed galaxy and can be used to reduce galaxy shape noise and the contribution of IA.  Using a proxy for the intrinsic position angle of an observed galaxy, develop techniques for cleanly separating WL signals from IA contamination in forthcoming radio surveys.  Random errors on the intrinsic orientation estimates introduce biases into the shear and IA estimates.  However, show that these biases can be corrected for if the error distribution is accurately known.  Demonstrate methods using simulations, where the shear and IA auto and cross-PS in 3 overlapping z bins are reconstructed.  Find that the intrinsic position angle information can be used to successfully reconstruct both the lensing and IA PS with negligible residual bias.