X-raying the coronae of HD~155555

We present an analysis of the high-resolution Chandra observation of the multiple system, HD 155555 (an RS CVn type binary system, HD 155555 AB, and its spatially resolved low-mass companion HD 155555 C). This is an intriguing system which shows properties of both an active pre-main sequence star and a synchronised (main sequence) binary. We obtain the emission measure distribution, temperature structures, plasma densities, and abundances of this system and compare them with the coronal properties of other young/active stars. HD 155555 AB and HD 155555 C produce copious X-ray emission with log Lx of 30.54 and 29.30, respectively, in the 0.3-6.0 keV energy band. The light curves of individual stars show variability on timescales of few minutes to hours. We analyse the dispersed spectra and reconstruct the emission measure distribution using spectral line analysis. The resulting elemental abundances exhibit inverse first ionisation potential effect in both cases. An analysis of He-like triplets yields a range of coronal electron densities ~10^10-10^13 cm-3. Since HD 155555 AB is classified both as an RS CVn and a PMS star, we compare our results with those of other slightly older active main-sequence stars and T Tauri stars, which indicates that the coronal properties of HD 155555 AB closely resemble that of an older RS CVn binary rather than a younger PMS star. Our results also suggests that the properties of HD 155555 C is very similar to those of other active M dwarfs.Comment: 17 pages, 23 figues, Accepted in Ap

Agricultural growth and structural changes in the Punjab economy: an input-output analysis

Agriculture Economic aspects India Punjab., Punjab (India) Economic conditions., Input-output analysis India Punjab.,

In-silico single nucleotide polymorphisms (SNP) mining of Sorghum bicolor genome

Single nucleotide polymorphisms (SNPs) may be considered the ultimate genetic markers as they represent the finest resolution of a DNA sequence (a single nucleotide), and are generally abundant in populations with a low mutation rate. SNPs are important tools in studying complex genetic traits and genome evolution. SNP mining can be done by experimental and computational methods. Computational strategies for SNP discovery make use of a large number of sequences present in public databases [in most cases as expressed sequence tags (ESTs)] and are considered to be faster and more cost-effective than experimental procedures. A major challenge in computational SNP discovery is distinguishing allelic variation from sequence variation between paralogous sequences, in addition to recognizing sequencing errors. For the majority of the public EST sequences, trace or quality files are lacking which makes detection of reliable SNPs even more difficult because it has to rely on sequence comparisons only. In the present study, online SNP and allele detection tool HaploSNPer (based on QualitySNP pipeline) and Sorghum bicolor genome was used. As a result, 77094 potential SNPs and 40589 reliable SNPs were detected in S. bicolor. In the 77094 potential SNPs detectedtransitions, transversions and indels were 34398, 35871 and 6825, respectively. In the 40589 reliable SNPs detected transitions, transversions and indels were 17042, 20500 and 3047, respectively.Key words: Single nucleotide polymorphisms (SNP), expressed sequence tags (EST), HaploSNPer

FK Comae Berenices, King of Spin: The COCOA-PUFS Project

COCOA-PUFS is an energy-diverse, time-domain study of the ultra-fast spinning, heavily spotted, yellow giant FK Com (HD117555; G4 III). This single star is thought to be a recent binary merger, and is exceptionally active by measure of its intense ultraviolet and X-ray emissions, and proclivity to flare. COCOA-PUFS was carried out with Hubble Space Telescope in the UV (120-300 nm), using mainly its high-performance Cosmic Origins Spectrograph, but also high-precision Space Telescope Imaging Spectrograph; Chandra X-ray Observatory in the soft X-rays (0.5-10 keV), utilizing its High-Energy Transmission Grating Spectrometer; together with supporting photometry and spectropolarimetry in the visible from the ground. This is an introductory report on the project. FK Com displayed variability on a wide range of time scales, over all wavelengths, during the week-long main campaign, including a large X-ray flare; "super-rotational broadening" of the far-ultraviolet "hot-lines" (e.g., Si IV 139 nm (T~80,000 K) together with chromospheric Mg II 280 nm and C II 133 nm (10,000-30,000 K); large Doppler swings suggestive of bright regions alternately on advancing and retreating limbs of the star; and substantial redshifts of the epoch-average emission profiles. These behaviors paint a picture of a highly extended, dynamic, hot (10 MK) coronal magnetosphere around the star, threaded by cooler structures perhaps analogous to solar prominences, and replenished continually by surface activity and flares. Suppression of angular momentum loss by the confining magnetosphere could temporarily postpone the inevitable stellar spindown, thereby lengthening this highly volatile stage of coronal evolution.Comment: to be published in ApJ

Standardization of packaging material, storage durations and chemical treatments on vase life of soft shield fern Polystichum squarrosum (D. Don)

Polystichum species, native to warm-temperate and montane-tropical environments (including some alpine regions), are terrestrial or rock-dwelling ferns. These plants exhibit dark green, leather-like, and lustrous fronds, which are highly valued in floral arrangements due to their aesthetic elegance and longevity. Polystichum squarrosum is not being cultivated commercially but collected from forests for its use as cut green in the florist industry. Hence the collected material should be handled carefully to utilize every frond. Therefore, the present study aimed to develop suitable post-harvest handling procedures for this valued cut green. A Completely Randomized Design (CRD) Factorial layout with 19 treatment modules (M0 to M18) was employed. Treatment modules included packaging material as poly mesh net bags and packing materials as corrugated fiberboard boxes , two storage durations (3 and 6 days) and chemical treatments [glycerol (4%) and Benzyl adenine (25mg L-1)]. Results revealed that spraying cut fronds with 4% glycerol, wrapping them in cellophane sheets and storing them for three days (M9) resulted in significant improvements in appearance, weight change, vase life and water uptake. Fronds from Season-II (March-April 2020) exhibited excellent performance over Season-I (August-September 2019). The interaction between M9 and Season-II further enhanced the postharvest parameters. The combination of glycerol treatment and cellophane wrapping for three-day storage proved most effective in preserving the quality of cut fronds.

Soft X-ray emission lines of Fe XV in solar flare observations and the Chandra spectrum of Capella

Recent calculations of atomic data for Fe XV have been used to generate theoretical line ratios involving n = 3-4 transitions in the soft X-ray spectral region (52-83 A), for a wide range of electron temperatures and densities applicable to solar and stellar coronal plasmas. A comparison of these with solar flare observations from a rocket-borne spectrograph (XSST) reveals generally good agreement between theory and experiment. In particular, the 82.76 A emission line in the XSST spectrum is identified, for the first time to our knowledge in an astrophysical source. Most of the Fe XV transitions which are blended have had the species responsible clearly identified, although there remain a few instances where this has not been possible. The line ratio calculations are also compared with a co-added spectrum of Capella obtained with the Chandra satellite, which is probably the highest signal-to-noise observation achieved for a stellar source in the 25-175 A soft X-ray region. Good agreement is found between theory and experiment, indicating that the Fe XV lines are reliably detected in Chandra spectra, and hence may be employed as diagnostics to determine the temperature and/or density of the emitting plasma. However the line blending in the Chandra data is such that individual emission lines are difficult to measure accurately, and fluxes may only be reliably determined via detailed profile fitting of the observations. The co-added Capella spectrum is made available to hopefully encourage further exploration of the soft X-ray region in astronomical sources.Comment: 27 pages, 10 figures, Astrophysical Journal, in pres

Observation of Replica Symmetry Breaking in the 1D Anderson Localization Regime in an Erbium-Doped Random Fiber Laser

The analogue of the paramagnetic to spin-glass phase transition in disordered magnetic systems, leading to the phenomenon of replica symmetry breaking, has been recently demonstrated in a two-dimensional random laser consisting of an organic-based amorphous solid-state thin film. We report here the first demonstration of replica symmetry breaking in a one-dimensional photonic system consisting of an erbium-doped random fiber laser operating in the continuous-wave regime based on a unique random fiber grating system, which plays the role of the random scatterers and operates in the Anderson localization regime. The clear transition from a photonic paramagnetic to a photonic spin glass phase, characterized by the probability distribution function of the Parisi overlap, was verified and characterized. In this unique system, the radiation field interacts only with the gain medium, and the fiber grating, which provides the disordered feedback mechanism, does not interfere with the pump