Earlham College

About: Earlham College is a education organization based out in Richmond, Indiana, United States. It is known for research contribution in the topics: Population & Turtle (robot). The organization has 388 authors who have published 556 publications receiving 14286 citations. The organization is also known as: Earlham.

The first data release (DR1) of the LAMOST regular survey

Abstract: The Large sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of stars, galaxies and QSOs. Objects in both the pilot survey and the first year regular survey are included in the LAMOST DR1. The pilot survey started in October 2011 and ended in June 2012, and the data have been released to the public as the LAMOST Pilot Data Release in August 2012. The regular survey started in September 2012, and completed its first year of operation in June 2013. The LAMOST DR1 includes a total of 1202 plates containing 2 955 336 spectra, of which 1 790 879 spectra have observed signal-to-noise ratio (SNR)>= 1 0. All data with SNR >= 2 are formally released as LAMOST DR1 under the LAMOST data policy. This data release contains a total of 2 204 696 spectra, of which 1 944 329 are stellar spectra, 12 082 are galaxy spectra and 5017 are quasars. The DR1 not only includes spectra, but also three stellar catalogs with measured parameters: late A, FGK-type stars with high quality spectra (1 061 918 entries), A-type stars (100 073 entries), and M-type stars (121 522 entries). This paper introduces the survey design, the observational and instrumental limitations, data reduction and analysis, and some caveats. A description of the FITS structure of spectral files and parameter catalogs is also provided.

Atmospheric Mercury Speciation: Concentrations and Behavior of Reactive Gaseous Mercury in Ambient Air

Abstract: Knowledge of atmospheric mercury speciation is critical to understanding its fate once released from point sources. The water-soluble compounds of Hg that exist in flue gases (termed reactive gaseo...

Black holes, gravitational waves and fundamental physics: a roadmap

Abstract: The grand challenges of contemporary fundamental physics-dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem-all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions. The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature. The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics'. © 2019 IOP Publishing Ltd.

A 1,000-year sediment record of tsunami recurrence in northern Sumatra

Abstract: Nothing known from written history gave reason to expect the Indian Ocean tsunami that took nearly a quarter million lives on 26 December 2004. That tsunami entered geological history by laying down centimetres of sand on the coastal plains that it overran. Jankaew et al. have now found such sedimentary records of earlier tsunamis preserved in the dark soils of marshy swales at Phra Thong, a barrier island in western Thailand. The cover shows an example from a pit dug there in 2007: the topmost light-coloured layer represents the 2004 tsunami, while a similar layer below records a tsunami in the fourteenth or fifteenth century AD. The ruler divisions are 10 cm long. In a separate study in Aceh, Indonesia, Monecke et al. found the 2004 sand sheet preceded by the deposits of three tsunamis from the past 1,200 years. One of these earlier deposits may match the medieval one found in Thailand. The combined findings suggest that the 2004 tsunami is neither the first nor the last of its kind. The Indian Ocean tsunami of 26 December 2004 reached maximum wave heights of 35 m in Aceh, the northernmost province of Sumatra1,2. Both the tsunami and the associated Sumatra–Andaman earthquake were unprecedented in Acehnese history3,4. Here we use sand sheets to extend tsunami history 1,000 years into Aceh’s past. The 2004 tsunami deposited a sand sheet up to 1.8 km inland on a marshy beach ridge plain. Sediment cores from these coastal marshes revealed two older extensive sand sheets with similar sediment characteristics. These sheets, deposited soon after ad 1290–1400 and ad 780–990, probably resulted from earlier tsunamis. An additional sand sheet of limited extent might correlate with a documented smaller tsunami of ad 1907. These findings, a first step towards a palaeotsunami record for northern Sumatra, suggest that damage-causing tsunamis in Aceh recur infrequently enough for entire human lifetimes to typically elapse between them. Such recurrence adds to the challenge of preparing communities along the northern Indian Ocean shorelines for future tsunamis.