Economic Deposits at Blue Hill

Guidebook for field trips in east-central and north-central Maine: 66th annual meeting October 12 and 13, 1974: Trip B-

Deep Chandra Survey of the Small Magellanic Cloud. II. Timing Analysis of X-ray Pulsars

We report the timing analysis results of X-ray pulsars from a recent deep Chandra survey of the Small Magellanic Cloud (SMC). We have analyzed a total exposure of 1.4 Ms from 31 observations over a 1.2 deg$^2$ region in the SMC under a Chandra X-ray Visionary Program. Using the Lomb-Scargle and epoch folding techniques, we have detected periodic modulations from 20 pulsars and a new candidate pulsar. The survey also covers 11 other pulsars with no clear sign of periodic modulation. The 0.5-8 keV X-ray luminosity ($L_X$) of the pulsars ranges from $10^{34}$ to $10^{37}$ erg s$^{-1}$ at 60 kpc. All the Chandra sources with $L_X$ $\gtrsim 4 \times 10^{35}$ erg s$^{-1}$ exhibit X-ray pulsations. The X-ray spectra of the SMC pulsars (and high mass X-ray binaries) are in general harder than those of the SMC field population. All but SXP~8.02 can be fitted by an absorbed power-law model with a photon index of $\Gamma$ $\lesssim$ 1.5. The X-ray spectrum of the known magnetar SXP~8.02 is better fitted with a two-temperature blackbody model. Newly measured pulsation periods of SXP~51.0, SXP~214 and SXP~701 are significantly different from the previous XMM-Newton and RXTE measurements. This survey provides a rich data set for energy-dependent pulse profile modeling. Six pulsars show an almost eclipse-like dip in the pulse profile. Phase-resolved spectral analysis reveals diverse spectral variation during pulsation cycle: e.g., for an absorbed power-law model, some exhibit an (anti)-correlation between absorption and X-ray flux, while others show more intrinsic spectral variation.Comment: 24 pages, 19 figures, 11 tables, submitted to Ap

Recurrence Formulas for Fully Exponentially Correlated Four-Body Wavefunctions

Formulas are presented for the recursive generation of four-body integrals in which the integrand consists of arbitrary integer powers (>= -1) of all the interparticle distances r_ij, multiplied by an exponential containing an arbitrary linear combination of all the r_ij. These integrals are generalizations of those encountered using Hylleraas basis functions, and include all that are needed to make energy computations on the Li atom and other four-body systems with a fully exponentially correlated Slater-type basis of arbitrary quantum numbers. The only quantities needed to start the recursion are the basic four-body integral first evaluated by Fromm and Hill, plus some easily evaluated three-body "boundary" integrals. The computational labor in constructing integral sets for practical computations is less than when the integrals are generated using explicit formulas obtained by differentiating the basic integral with respect to its parameters. Computations are facilitated by using a symbolic algebra program (MAPLE) to compute array index pointers and present syntactically correct FORTRAN source code as output; in this way it is possible to obtain error-free high-speed evaluations with minimal effort. The work can be checked by verifying sum rules the integrals must satisfy.Comment: 10 pages, no figures, accepted by Phys. Rev. A (January 2009

Three Early Novels of Political Satire and Disillusionment in the Post-Civil War Period

Englis

Area Coverage of Expanding E.T. Signals in the Galaxy: SETI and Drake's N

The Milky Way Galaxy contains an unknown number, $N$, of civilizations that emit electromagnetic radiation (of unknown wavelengths) over a finite lifetime, $L$. Here we are assuming that the radiation is not produced indefinitely, but within $L$ as a result of some unknown limiting event. When a civilization stops emitting, the radiation continues traveling outward at the speed of light, $c$, but is confined within a shell wall having constant thickness, $cL$. We develop a simple model of the Galaxy that includes both the birthrate and detectable lifetime of civilizations to compute the possibility of a SETI detection at the Earth. Two cases emerge for radiation shells that are (1) thinner than or (2) thicker than the size of the Galaxy, corresponding to detectable lifetimes, $L$, less than or greater than the light-travel time, $\sim 100,000$ years, across the Milky Way, respectively. For case (1), each shell wall has a thickness smaller than the size of the Galaxy and intersects the galactic plane in a donut shape (annulus) that fills only a fraction of the Galaxy's volume, inhibiting SETI detection. But the ensemble of such shell walls may still fill our Galaxy, and indeed may overlap locally, given a sufficiently high birthrate of detectable civilizations. In the second case, each radiation shell is thicker than the size of our Galaxy. Yet, the ensemble of walls may or may not yield a SETI detection depending on the civilization birthrate. We compare the number of different electromagnetic transmissions arriving at Earth to Drake's $N$, the number of currently emitting civilizations, showing that they are equal to each other for both cases (1) and (2). However, for $L < 100,000$ years, the transmissions arriving at Earth may come from distant civilizations long extinct, while civilizations still alive are sending signals yet to arrive.Comment: 10 pages, 2 figures, to be published in PAS

Recent Legal Literature

Noyes: American Railroad Rates; Meyer: Railway Legislation in the United States; Diccy: Lectures on the Relation between Law and Public Opinion in England During the Nineteenth Century; Page: Law of Contracts; Camp: The Encyclopaedia of Evidence; Clement: Fire Insurance as a Void Conttract and as Affected by Construction and Waiver of Estoppel, including miscellaneous provisions and an analysis and comparison of the various standard forms, all reduced to rules with the relevant statutory provisions of all the states. Volume II.; Woodruff: A Selection of Cases on Domestic Relations and the Law of Persons; Kinkead: Jurisprudence Law and Ethics; Schouler: Law of the Domestic Relations Embracing Husband and Wife, Parent and Child, Fuardian and Ward, Infancy and Master and Servant; Hoyt (ed.): Report of the Colorado Bar Association. Volume 8

New Discoveries in Planetary Systems and Star Formation through Advances in Laboratory Astrophysics

As the panel on Planetary Systems and Star Formation (PSF) is fully aware, the next decade will see major advances in our understanding of these areas of research. To quote from their charge, these advances will occur in studies of solar system bodies (other than the Sun) and extrasolar planets, debris disks, exobiology, the formation of individual stars, protostellar and protoplanetary disks, molecular clouds and the cold ISM, dust, and astrochemistry. Central to the progress in these areas are the corresponding advances in laboratory astro- physics which are required for fully realizing the PSF scientific opportunities in the decade 2010-2020. Laboratory astrophysics comprises both theoretical and experimental studies of the underlying physics and chemistry which produce the observed spectra and describe the astrophysical processes. We discuss four areas of laboratory astrophysics relevant to the PSF panel: atomic, molecular, solid matter, and plasma physics. Section 2 describes some of the new opportunities and compelling themes which will be enabled by advances in laboratory astrophysics. Section 3 provides the scientific context for these opportunities. Section 4 discusses some experimental and theoretical advances in laboratory astrophysics required to realize the PSF scientific opportunities of the next decade. As requested in the Call for White Papers, we present in Section 5 four central questions and one area with unusual discovery potential. We give a short postlude in Section 6.Comment: White paper submitted by the AAS Working Group on Laboratory Astrophysics (WGLA) to the PSF SFP of the Astronomy and Astrophysics Decadal Survey (Astro2010