High energy gamma ray results from the second small astronomy satellite

A high energy (35 MeV) gamma ray telescope employing a thirty-two level magnetic core spark chamber system was flown on SAS 2. The high energy galactic gamma radiation is observed to dominate over the general diffuse radiation along the entire galactic plane, and when examined in detail, the longitudinal and latitudinal distribution seem generally correlated with galactic structural features, particularly with arm segments. The general high energy gamma radiation from the galactic plane, explained on the basis of its angular distribution and magnitude, probably results primarily from cosmic ray interactions with interstellar matter

Cyg X-3: Not seen in high-energy gamma rays by COS-B

COS-B had Cyg X-3 within its field of view during 7 observation periods between 1975 and 1982 for in total approximately 300 days. In the skymaps (70 meV E 5000 meV) of the Cyg-X region produced for each of these observations and in the summed map, a broad complex structure is visible in the region 72 deg approximately less than 1 approximately less than 85 deg, approximately less than 5 deg. No resolved source structure is visible at the position of Cyg X-3, but a weak signal from Cyg X-3 could be hidden in the structured gamma-ray background. Therefore, the data has been searched for a 4.8 h timing signature, as well as for a source signal in the sky map in addition to the diffuse background structure as estimated from tracers of atomic and molecular gas

Lynx Mission Concept Status

Lynx is a concept under study for prioritization in the 2020 Astrophysics Decadal Survey. Providing orders of magnitude increase in sensitivity over Chandra, Lynx will examine the first black holes and their galaxies, map the large-scale structure and galactic halos, and shed new light on the environments of young stars and their planetary systems. In order to meet the Lynx science goals, the telescope consists of a high-angular resolution optical assembly complemented by an instrument suite that may include a High Definition X-ray Imager, X-ray Microcalorimeter and an X-ray Grating Spectrometer. The telescope is integrated onto the spacecraft to form a comprehensive observatory concept. Progress on the formulation of the Lynx telescope and observatory configuration is reported in this paper

Early-Time Observations of the GRB 050319 Optical Transient

We present the unfiltered ROTSE-III light curve of the optical transient associated with GRB 050319 beginning 4 s after the cessation of gamma-ray activity. We fit a power-law function to the data using the revised trigger time given by Chincarini et al. (2005), and a smoothly broken power-law to the data using the original trigger disseminated through the GCN notices. Including the RAPTOR data from Wozniak et al. (2005), the best fit power-law indices are alpha=-0.854 (+/- 0.014) for the single power-law and alpha_1=-0.364 (+/- 0.020), alpha_2= -0.881 (+/- 0.030), with a break at t_b = 418 (+/- 30) s for the smoothly broken fit. We discuss the fit results with emphasis placed on the importance of knowing the true start time of the optical transient for this multi-peaked burst. As Swift continues to provide prompt GRB locations, it becomes more important to answer the question, "when does the afterglow begin" to correctly interpret the light curves

Prompt optical observations of GRB 080330 and GRB 080413A

We report on the results of rapid responses to GRB 080330 and GRB 080413A by the ROTSE-IIIb and ROTSE-IIIc telecopes. In both cases, optical follow-up started during the prompt emission phase and recorded optical flares peaking at similar times as the last hard X-ray pulses detected by the Swift BAT. For both events, the XRT observations started at the end of the prompt BAT detection and displayed an evolution in time opposite to the optical lightcurve. These very early observations provide us an opportunity to probe the onset of afterglow for these two events

Scintillating fiber detectors for the HypHI project at GSI

The construction and properties of three sets of two-dimensional scintillating fiber detector arrays for tracking of charged particles used in the HypHI Phase 0 experiment at GSI will be reported in this paper. The position resolutions and the detection efficiency of detectors have been obtained for each layer of detectors by using (6)Li primary beams and particles with Z = 1 produced by fragment reactions of (136)Xe projectiles on the hydrogen target. Besides, the response of energy deposition of charged particles in the first detector set placed right behind the target has been studied by using light projectile fragments with Z = 1, 2 and 3 produced by (58)Ni and (12)C beams. Extracted resolutions for energy deposition and position as well as the detection efficiency fulfill the requirements of the HypHl Phase 0 experiment. (C) 2009 Elsevier B.V. All rights reserved.</p

Search for evidence of (3)(Lambda)n by observing d + pi(-) and t + pi(-) final states in the reaction of Li-6+C-12 at 2A GeV

<p>The experimental data obtained from the reaction of Li-6 projectiles at 2A GeV on a fixed graphite target were analyzed to study the invariant mass distributions of d + pi(-) and t + pi(-). Indications of a signal in the d + pi(-) and t + pi(-) invariant mass distributions were observed with significances of 5.3 sigma and 5.0 sigma, respectively, when including the production target, and 3.7 sigma and 5.2 sigma, respectively, when excluding the target. The estimated mean values of the invariant mass for d + pi(-) and t + pi(-) signal were 2059.3 +/- 1.3 +/- 1.7 MeV/c(2) and 2993.7 +/- 1.3 +/- 0.6 MeV/c(2) respectively. The lifetime estimation of the possible bound states yielding to d + pi(-) and t + pi(-) final states were deduced to be as 181(-24)(+30) +/- 25 ps and 190(-35)(+47) +/- 36 ps, respectively. Those final states may be interpreted as the two-body and three-body decay modes of a neutral bound state of two neutrons and a Lambda hyperon, (3)(Lambda)n.</p>