The Sizes of 1720 MHz OH Masers: VLBA and MERLIN Observations of the Supernova Remnants W44 and W28

We have used the NRAO Very Long Baseline Array (VLBA) to image OH(1720 MHz) masers in the supernova remnants W28 and W44 at a resolution of 40 mas. We also used MERLIN to observe the same OH(1720 MHz) masers in W44 at a resolution of 290 x 165 mas. All the masers are resolved by these VLBA and MERLIN observations. The measured sizes range from 50 to 180 mas and yield brightness temperature estimates from 0.3--20 x 10**8 K. We investigate whether these measured angular sizes are intrinsic and hence originate as a result of the physical conditions in the supernova remnant shock, or whether they are scatter broadened sizes produced by the turbulent ionized gas along the line of sight. While the current data on the temporal and angular broadening of pulsars, masers and extragalactic soures toward W44 and W28 can be understood in terms of scattering, we cannot rule out that these large sizes are intrinsic. Recent theoretical modeling by Lockett et al. suggests that the physical parameters in the shocked region are indicative of densities and OH abundances which lead to estimates of sizes as large as what we measure. If the sizes and structure are intrinsic, then the OH(1720 MHz) masrs may be more like the OH(1612 MHz) masers in circumstellar shells than OH masers associated with HII regions. At two locations in W28 we observe the classical S-shapes in the Stokes V profiles caused by Zeeman splitting and use it to infer magnetic fields of order 2 milliGauss.Comment: 24 pages, 6 figures, accepted by Ap

Peculiar Broad Absorption Line Quasars found in DPOSS

With the recent release of large (i.e., > hundred million objects), well-calibrated photometric surveys, such as DPOSS, 2MASS, and SDSS, spectroscopic identification of important targets is no longer a simple issue. In order to enhance the returns from a spectroscopic survey, candidate sources are often preferentially selected to be of interest, such as brown dwarfs or high redshift quasars. This approach, while useful for targeted projects, risks missing new or unusual species. We have, as a result, taken the alternative path of spectroscopically identifying interesting sources with the sole criterion being that they are in low density areas of the g - r and r - i color-space defined by the DPOSS survey. In this paper, we present three peculiar broad absorption line quasars that were discovered during this spectroscopic survey, demonstrating the efficacy of this approach. PSS J0052+2405 is an Iron LoBAL quasar at a redshift z = 2.4512 with very broad absorption from many species. PSS J0141+3334 is a reddened LoBAL quasar at z = 3.005 with no obvious emission lines. PSS J1537+1227 is a Iron LoBAL at a redshift of z = 1.212 with strong narrow Mgii and Feii emission. Follow-up high resolution spectroscopy of these three quasars promises to improve our understanding of BAL quasars. The sensitivity of particular parameter spaces, in this case a two-color space, to the redshift of these three sources is dramatic, raising questions about traditional techniques of defining quasar populations for statistical analysis.Comment: 27 pages, 13 figures, Accepted to the Astronomical Journa

Earth‐Moon‐Mars Radiation Environment Module framework

[1] We are preparing to return humans to the Moon and setting the stage for exploration to Mars and beyond. However, it is unclear if long missions outside of low-Earth orbit can be accomplished with acceptable risk. The central objective of a new modeling project, the Earth-Moon-Mars Radiation Exposure Module (EMMREM), is to develop and validate a numerical module for characterizing time-dependent radiation exposure in the Earth-Moon-Mars and interplanetary space environments. EMMREM is being designed for broad use by researchers to predict radiation exposure by integrating over almost any incident particle distribution from interplanetary space. We detail here the overall structure of the EMMREM module and study the dose histories of the 2003 Halloween storm event and a June 2004 event. We show both the event histories measured at 1 AU and the evolution of these events at observer locations beyond 1 AU. The results are compared to observations at Ulysses. The model allows us to predict how the radiation environment evolves with radial distance from the Sun. The model comparison also suggests areas in which our understanding of the physics of particle propagation and energization needs to be improved to better forecast the radiation environment. Thus, we introduce the suite of EMMREM tools, which will be used to improve risk assessment models so that future human exploration missions can be adequately planned for

Critical analysis of the drug promotional literatures advertised in a tertiary care hospital

Background: The objective of the study was to critically analyse the drug promotional literatures (DPLs) advertised in a tertiary care hospital.Methods: This observational study was conducted in department of pharmacology, grant government medical college. The data was collected over a period of 3 months after obtaining permission from Institutional Ethics Committee. Around 200 DPLs were collected from different specialty OPDs. Promotional literatures in the form of medical equipment’s, ayurvedic medicine, drug monography, reminder advertisement, identical advertisement and drug name list were excluded from the study. Data compiled was compiled in an excel sheet. The complied data were analyzed with the help of tables and graphs.Results: In our study, the name of the active ingredient, their brand name and the therapeutic uses were mentioned in all the DPLs (100%). The dosage form of the drug was addressed in 85%, whereas the schedule was present in 58% of the DPLs. Most of the DPLs had mentioned about the positive effects of the drug, while few of them described the negative effects of the drugs, namely, adverse drug reactions (39%), precautions to be taken (36%), contraindications (36%) and various drug interactions (33%).Conclusions: A diverse set of results were obtained when a cohort of 200 promotional literatures were analyzed wherein the advantageous effects were highlighted covering the detrimental effects of the drug. DPLs were not in line and accordance with WHO guidelines, but where modified according to the company preferences

Can We Do Away With PTBD?

Percutaneous Transhepatic Biliary Drainage (PTBD) is performed in surgical jaundice to decompress the biliary tree and improve hepatic functions. However, the risk of sepsis is high in these patients due to immunosuppression and surgical outcome remains poor. This raises a question—can we do away with PTBD? To answer this query a study was carried out in 4 groups of patients bearing in mind the high incidence of sepsis and our earlier studies, which have demonstrated immunotherapeutic potential of Tinospora cordifolia (TC): (A) those undergoing surgery without PTBD (n = 14), (B) those undergoing surgery after PTBD (n = 13). The mortality was 57.14% in Group A as compared to 61.54% in Group B. Serial estimations of bilirubin levels carried out during the course of drainage (3 Wks) revealed a gradual and significant decrease from 12.52 ± 8.3 mg% to 5.85 ± 3.0 mg%. Antipyrine half-life did not change significantly (18.35 ± 4.2 hrs compared to basal values 21.96 ± 3.78 hrs). The phagocytic and intracellular killing (ICK) capacities of PMN remained suppressed (Basal: 22.13 ± 3.68% phago, and 19.1 ± 4.49% ICK; Post drainage: 20 ± 8.48% Phago and 11.15 ± 3.05% ICK). Thus PTBD did not improve the metabolic capacity ofthe liver and mortality was higher due to sepsis. Group (C) patientg received TC during PTBD (n = 16) and Group (D) patients received TC without PTBD (n = 14). A significant improvement in PMN functions occurred by 3 weeks in both groups (30.29 ± 4.68% phago, 30 ± 4.84% ICK in Group C and 30.4 ± 2.99% phago, 27.15 ± 6.19% ICK in Group D). The mortality in Groups C and D was 25% and 14.2% respectively during the preoperative period. There was no mortality after surgery. It appears from this study that host defenses as reflected by PMN functions play an important role in influencing prognosis. Further decompression of the biliary tree by PTBD seems unwarranted

How efficient are coronal mass ejections at accelerating solar energetic particles?

The largest solar energetic particle (SEP) events are thought to be due to particle acceleration at a shock driven by a fast coronal mass ejection (CME). We investigate the efficiency of this process by comparing the total energy content of energetic particles with the kinetic energy of the associated CMEs. The energy content of 23 large SEP events from 1998 through 2003 is estimated based on data from ACE, GOES, and SAMPEX, and interpreted using the results of particle transport simulations and inferred longitude distributions. CME data for these events are obtained from SOHO. When compared to the estimated kinetic energy of the associated coronal mass ejections (CMEs), it is found that large SEP events can extract ~10% or more of the CME kinetic energy. The largest SEP events appear to require massive, very energetic CMEs

Finite-size behaviour of the microcanonical specific heat

For models which exhibit a continuous phase transition in the thermodynamic limit a numerical study of small systems reveals a non-monotonic behaviour of the microcanonical specific heat as a function of the system size. This is in contrast to a treatment in the canonical ensemble where the maximum of the specific heat increases monotonically with the size of the system. A phenomenological theory is developed which permits to describe this peculiar behaviour of the microcanonical specific heat and allows in principle the determination of microcanonical critical exponents.Comment: 15 pages, 7 figures, submitted to J. Phys.

XMM-Newton detection of two clusters of galaxies with strong SPT Sunyaev-Zel'dovich effect signatures

We report on the discovery of two galaxy clusters, SPT-CL J2332-5358 and SPT-CL J2342-5411, in X-rays. These clusters were also independently detected through their Sunyaev-Zel'dovich effect by the South Pole Telescope, and confirmed in the optical band by the Blanco Cosmology Survey. They are thus the first clusters detected under survey conditions by all major cluster search approaches. The X-ray detection is made within the frame of the XMM-BCS cluster survey utilizing a novel XMM-Newton mosaic mode of observations. The present study makes the first scientific use of this operation mode. We estimate the X-ray spectroscopic temperature of SPT-CL J2332-5358 (at redshift z=0.32) to T = 9.3 (+3.3/-1.9) keV, implying a high mass, M_{500} = 8.8 +/- 3.8 \times 10^{14} M_{sun}. For SPT-CL J2342-5411, at z=1.08, the available X-ray data doesn't allow us to directly estimate the temperature with good confidence. However, using our measured luminosity and scaling relations we estimate that T = 4.5 +/- 1.3 keV and M_{500} = 1.9 +/- 0.8 \times 10^{14} M_{sun}. We find a good agreement between the X-ray masses and those estimated from the Sunyaev-Zel'dovich effect.Comment: Submitted to A&A, 8 pages, 5 figures, 1 tabl