1861-08-17 John H. Quimby requests payment of bill of Captain S.M. Fuller

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1861-07-18 John H. Quimby requests payment of invoice

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1861-07-25 John H. Quimby requests payment of bill submitted to Captain Silas Fuller

https://digitalmaine.com/cw_me_4th_regiment_corr/1058/thumbnail.jp

The Sloan Digital Sky Survey-II Supernova Survey: Search Algorithm and Follow-up Observations

The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in a 300 sq. deg. region along the celestial equator during its first two seasons of a three-season campaign. Multi-band (ugriz) light curves were measured for most of the sources, which include solar system objects, Galactic variable stars, active galactic nuclei, supernovae (SNe), and other astronomical transients. The imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure their redshifts, and study the physical conditions of the explosions and their environment through spectroscopic diagnostics. During the survey, light curves are rapidly evaluated to provide an initial photometric type of the SNe, and a selected sample of sources are targeted for spectroscopic observations. In the first two seasons, 476 sources were selected for spectroscopic observations, of which 403 were identified as SNe. For the Type Ia SNe, the main driver for the Survey, our photometric typing and targeting efficiency is 90%. Only 6% of the photometric SN Ia candidates were spectroscopically classified as non-SN Ia instead, and the remaining 4% resulted in low signal-to-noise, unclassified spectra. This paper describes the search algorithm and the software, and the real-time processing of the SDSS imaging data. We also present the details of the supernova candidate selection procedures and strategies for follow-up spectroscopic and imaging observations of the discovered sources.Comment: Accepted for publication in The Astronomical Journal (66 pages, 13 figures); typos correcte

The Fast, Luminous Ultraviolet Transient AT2018cow: Extreme Supernova, or Disruption of a Star by an Intermediate-Mass Black Hole?

Wide-field optical surveys have begun to uncover large samples of fast (t_rise < 5d), luminous (M_peak < -18), blue transients. While commonly attributed to the breakout of a supernova shock into a dense wind, the great distances to the transients of this class found so far have hampered detailed investigation of their properties. We present photometry and spectroscopy from a comprehensive worldwide campaign to observe AT2018cow (ATLAS18qqn), the first fast-luminous optical transient to be found in real time at low redshift. Our first spectra (<2 days after discovery) are entirely featureless. A very broad absorption feature suggestive of near-relativistic velocities develops between 3-8 days, then disappears. Broad emission features of H and He develop after >10 days. The spectrum remains extremely hot throughout its evolution, and the photospheric radius contracts with time (receding below R<10^14 cm after 1 month). This behaviour does not match that of any known supernova, although a relativistic jet within a fallback supernova could explain some of the observed features. Alternatively, the transient could originate from the disruption of a star by an intermediate-mass black hole, although this would require long-lasting emission of highly super-Eddington thermal radiation. In either case, AT2018cow suggests that the population of fast luminous transients represents a new class of astrophysical event. Intensive follow-up of this event in its late phases, and of any future events found at comparable distance, will be essential to better constrain their origins.Comment: Corrected Figure 8 / Table 4 to use final fits. Includes machine-readable photometry table (hopefully for real this time

1861-08-17 John H. Quimby requests payment of bill of Captain S.M. Fuller

https://digitalmaine.com/cw_me_4th_regiment_corr/1066/thumbnail.jp

1861-07-25 John H. Quimby requests payment of bill submitted to Captain Silas Fuller

https://digitalmaine.com/cw_me_4th_regiment_corr/1058/thumbnail.jp

1861-07-18 John H. Quimby requests payment of invoice

https://digitalmaine.com/cw_me_4th_regiment_corr/1057/thumbnail.jp

1863-02-16 John H. Quimby recommends Sergeant Russell H. White for promotion

https://digitalmaine.com/chamberlain_corr/1322/thumbnail.jp

Richard Schindler Collection 1938-1980

The collection contains Richard Schindler's article "Principles of a New Therapy with High Speed Electrons," accompanied by correspondence concerning the article and Schindler's related research.Physician, born 1891 in Strassburg. Emigrated from Germany to the United States in 1935.The original inventory is available in the folderProcessed for digitizationSent for digitizationReturned from digitizationLinked to online manifestationdigitize