Sky Coverage and Burst Repetition

To investigate the repeater content of gamma ray burst samples I develop two models where sources burst at a constant average rate. I find that the sky coverage affects the number of repeaters in a sample predominantly through the detector livetime, and that the number of bursts in the sample is the primary parameter. Thus the repeater content of burst samples should be compared within the context of a repetition model; a direct comparison between two samples is possible only if the samples have similar sizes. The observed repeater fraction may not be the actual fraction if the sources burst on average less than once during the detector livetime. Sources which burst repeatedly during active phases separated by more than the observation period must be treated separately.Comment: 12 pages AASTeX 4.0, 3 figures on request from [email protected]

A Note on the Sympatric Collection of \u3ci\u3eChymomyza\u3c/i\u3e (Diptera: Drosophilidae) in Virginia\u27s Allegheny Mountains

The attraction of two Chymomyza species, C. procnemoides and C. aldrichii, to the same damaged tree over 19 days in summer 1987 near Mt. Lake Hotel, Giles Co., Virginia is documented, confirming a previous report that Chymomyza species may be sympatric on the same fresh damaged tree/cut wood. A total of 17 males and 7 females were captured. An excess of males to females captured has been reported in Japan and Hungary

Burst Populations and Detector Sensitivity

The F_T (peak bolometric photon flux) vs. E_p (peak energy) plane is a powerful tool to compare the burst populations detected by different detectors. Detector sensitivity curves in this plane demonstrate which burst populations the detectors will detect. For example, future CZT-based detectors will show the largest increase in sensitivity for soft bursts, and will be particularly well-suited to study X-ray rich bursts and X-ray Flashes. Identical bursts at different redshifts describe a track in the F_T-E_p plane.Comment: 4 pages, 4 figures. To appear in the proceedings of the 2003 GRB Conference (Santa Fe, NM, 2003 Sep 8-12

Drosophilidae (Diptera) Collected in Spring in Michigan

Drosophilids in mid-Michigan overwinter in a preadult stage. One hun- dred twenty-two individuals (84 f, 38 m) representing 14 species were collected over bait in April and May 1992. All appeared recently emerged and had entire wings. This agrees with earlier reports in Michigan and Massachusetts that Drosophila affinis group species overwinter as preadults. Among the species overwintering as preadults in Michigan, Drosophila affinis, D. algonquin, D. athabasca, D. robusta, D. falleni and D. recens have been found to overwinter as adults in New York Latitude and climate may play a role in drosophilid overwintering stage

Burst Detector Sensitivity: Past, Present & Future

I compare the burst detection sensitivity of CGRO's BATSE, Swift's BAT, the GLAST Burst Monitor (GBM) and EXIST as a function of a burst's spectrum and duration. A detector's overall burst sensitivity depends on its energy sensitivity and set of accumulations times Delta t; these two factors shape the detected burst population. For example, relative to BATSE, the BAT's softer energy band decreases the detection rate of short, hard bursts, while the BAT's longer accumulation times increase the detection rate of long, soft bursts. Consequently, Swift is detecting long, low fluence bursts (2-3x fainter than BATSE).Comment: To appear in the proceedings of the 16th Annual October Astrophysics Conference in Maryland, "Gamma Ray Bursts in the Swift Era", Washington DC., November 29-December 2, 2005, 4 pages, 3 figure

Acorns as Breeding Sites for \u3ci\u3eChymomyza Amoena\u3c/i\u3e (Loew) (Diptera: Drosophilidae) in Virginia and Michigan

Chymomyza amoena is the only chymomyzid fly emerging from white oak acorns in Virginia. An average of 2-3 adult flies emerged from a single acorn in July while emergence declined to 0.4 adults/acorns in September. In fall, Drosophila melanogaster was also present. The incidence of drosophilid (Drosophila, Chymomyza) larvae in parasitized acorns in Virginia (400/0) in autumn was significantly greater than in Michigan (14%). The Chymomyza larvae present in the parasitized acorns in Michigan most likely were C. amoena, from the known adaptation of this species in Michigan to frass-breeding