Multiwavelength Observations of EXO 0748-676. I. Reprocessing of X-Ray Bursts

We present high time-resolution multiwavelength observations of X-ray bursts in the low-mass X-ray binary UY Vol. Strong reprocessed signals are present in the ultraviolet and optical, lagged and smeared with respect to the X-rays. The addition of far-ultraviolet coverage for one burst allows much tighter constraints on the temperature and geometry of the reprocessing region than previously possible. A blackbody reprocessing model for this burst suggests a rise in temperatures during the burst from 18,000 to 35,000 K and an emitting area comparable to that expected for the disk and/or irradiated companion star. The lags are consistent with those expected. The single-zone blackbody model cannot reproduce the ratio of optical to ultraviolet flux during the burst, however. The discrepancy seems too large to explain with deviations from a local blackbody spectrum and more likely indicates that a range of reprocessing temperatures are required. Comparable results are derived from other bursts, and in particular the lag and smearing both appear shorter when the companion star is on the near side of the disk as predicted. The burst observed by HST also yielded a spectrum of the reprocessed light. It is dominated by continuum, with a spectral shape consistent with the temperatures derived from lightcurve modeling. Taken as a whole, our observations confirm the standard paradigm of prompt reprocessing distributed across the disk and companion star, with the response dominated by a thermalized continuum rather than by emission lines.

Table I. Composition of till in north Greenland

From 1950 through 1900 studies on the glacial geology of northern Greenland have been made in cooperation with the U.S. Air Force Cambridge Research Laboratories. As a result of these studies four distinct phases of the latest glaciation have been recognized. The last glaciation extended over most of the land and removed traces of previous anes. Retreat of the ice mass began some time previous to 6000 years ago. This was followed by a rtse in sea level which deposited clay-silt succeeded by karne gravels around stagnant ice lobes in the large valleys. Marine terraces, up to 129 meters above present sea level, developed as readjustment occurred in the land free of ice. About 3700 years ago an advance of glaciers down major fjords took place followed by retreat to approximately the present position of the ice. Till in Peary Land, north of Frederick E. Hyde Fjord, contains only locally derived matertals indicating that the central Greenland ice cap did not cover the area.

The picture gallery of Charles I.

Mode of access: Internet.

Fair Em, the miller's daughter of Manchester : with the love of William the Conqueror /

Imprint fictitious. Printed by the editor for private circulation. Cf. Jaggard, William. Shakespeare bibliography, 1911, page 552.

The crusade of Richard I, 1189-92 : extracts from the Itinerarium Ricardi, Bohãadin, Ernoul, Roger of Howden, Richard of Devizes, Rigord, Ibn Alathãir, Li Livres, Eracles, &c. /

Disbound original held in Oak Street Library Facility.

A dream of John Ball : and A king's lesson /

"A dream of John Ball" first appeared in the "Commonweal", 1886-87; issued in book-form, 1888. "A king's lesson", a story based on the life of Matthias Corvinus, also appeared in the "Commonweal", Sept. 18, 1886.

Itinerary of King Edward the First throughout his reign, A. D. 1272-1307, exhibiting his movements from time to time, so far as they are recorded.

Mode of access: Internet.

King George of Greece /

Cover title: The life of King George of Greece.

The story of King Constantine as revealed in the Greek white book,

Mode of access: Internet.

Anhang zu den Gedanken und erinnerungen von Otto fürst von Bismarck ...

Mode of access: Internet.

Blücher and the uprising of Prussia against Napoleon, 1806-1815,

Mode of access: Internet.

The progresses, processions, and magnificent festivities of King James the First, his royal consort, family, and court, collected from original manuscripts, scarce pamphlets, corporation records, parochial registers, ec. ec.; comprising forty masques and entertainments, ten civic pageants, numerous original letters and annotated lists of the peers, baronets, and knights who received those honours during the reign of King James. Illustrated with notes, historical, topographical, biographical, and bibliographical.

"First published London 1828."

Historie om Ditmarskerkrigen aar femten hundrede og Ditmarskens erobring under Kong Frederik den Anden med en historisk udsigt over Ditmarskerfolkets vilkaar og skiebne i aeldre tider.

Bibliographical foot-notes.

Statement of Prince Frederick of Schleswig Holstein Noer. The crown of Denmark disposed of by a religious minister through a fraudulent treaty /

Mode of access: Internet.

Davideis: The life of David King of Israel: A sacred poem. In five books.

Mode of access: Internet.