Optical Tomography of Chemical Elements Synthesized in Type Ia Supernovae.

We report the discovery of optical emission from the nonradiative shocked ejecta of three young type Ia supernova remnants (SNRs): SNR 0519-69.0, SNR 0509-67.5, and N103B. Deep integral field spectroscopic observations reveal broad and spatially resolved [Fe XIV] 5303 Å emission. The width of the broad line reveals, for the first time, the reverse shock speeds. For two of the remnants we can constrain the underlying supernova explosions with evolutionary models. SNR 0519-69.0 is well explained by a standard near-Chandrasekhar mass explosion, whereas for SNR 0509-67.5 our analysis suggests an energetic sub-Chandrasekhar mass explosion. With [S XII], [Fe IX], and [Fe XV] also detected, we can uniquely visualize different layers of the explosion. We refer to this new analysis technique as "supernova remnant tomography".

Measuring the cosmic-ray acceleration efficiency of a supernova remnant.

Cosmic rays are the most energetic particles arriving at Earth. Although most of them are thought to be accelerated by supernova remnants, the details of the acceleration process and its efficiency are not well determined. Here we show that the pressure induced by cosmic rays exceeds the thermal pressure behind the northeast shock of the supernova remnant RCW 86, where the x-ray emission is dominated by synchrotron radiation from ultrarelativistic electrons. We determined the cosmic-ray content from the thermal Doppler broadening measured with optical spectroscopy, combined with a proper-motion study in x-rays. The measured postshock proton temperature, in combination with the shock velocity, does not agree with standard shock heating, implying that >50% of the postshock pressure is produced by cosmic rays.

The range of antistreptolysin-O titer among 3129 healthy individuals in winter and summer in Tehran, Iran.

A rise in ASO titre can be demonstrated in 75-80% of patients following untreated streptococcal upper respiratory infection. The difficulty, however, is that there is no such thing as normal ASO titre. The levels encountered in a given population depend upon age, geographical location, season, etc. It was, therefore, on this basis that sera were taken from 3129 healthy individuals during winter and summer in Tehran for the determination of ASO titres. Sixty-three individuals were treated both during summer and winter. During summer only 4 (6%) had titres above 250 T.U. and 59 (94%) below 250 T.U. The same individuals, when tested during the winter, showed that 7 (11%) had ASO titres above 250 T.U. and 56 (89%) below 250 T.U. This seasonal difference is statistically significant. In another study 320 individuals were tested during summer and another 394 individuals during winter. Among the summer group 31 (10%) were above 250 T.U. and 289 (90%) were below 250 T.U. In the winter group 55 (14%) were above 250 T.U. and 339 (86%) were below 250 T.U. This difference is again statistically significant. Further, 35 samples of pooled sera representing 2289 individuals were treated during the winter. Here 563 (24%) were above and 1723 (76%) were below 250 T.U. The possible sources of error in this group, in comparison with the other, are discussed.

Rheumatic fever and rheumatic heart disease among 56,8000 inhabitants in southeast Teheran from 1972-1974.

A study of the incidence of R. fever in an area in southeast Teheran during the period 1972-1974 revealed 92 cases. The crude annual incidence of R. fever ranged from a high of 58 cases to a low of 51 cases per 100,000 population. The age and sex specific rates revealed the incidence to be strikingly higher in the 5-19 year age group, reaching roughly 80/100,000. There was an approximately similar number of males and females with R. fever. Among the R. fever patients, there were 6 cases of chorea, 5 girls and 1 boy. From 92 R. fever cases, 49 (53%) developed carditis. Among these patients, 35 (71%) were female in contrast to 14 (29%) male cases. Overall there were 59 cases (62%) which were initial attacks and 33 cases (38%) which were recurrences. During the trial there were also 7 recurrences of R fever and 4 deaths. The seasonal pattern showed that the majority of cases occurred during the winter and spring months. From the R. fever/R.H.D. patients, 63 (70%) and from cases with carditis alone, 24 (40%) were hospitalized.