5,975 research outputs found
Gas rich galaxies from the FIGGS survey
The FIGGS (Faint Irregular Galaxy GMRT Survey) is aimed at creating a
multi-wavelength observational data base for a volume limited sample of the
faintest gas rich galaxies. In this paper we discuss two very gas rich galaxies
that were observed as part of the FIGGS survey, viz. NGC 3741 and And IV. These
galaxies are unusual in that they have extremely extended gas disks and very
high ratios of dark to luminous matter. The very extended HI disks provide an
unique opportunity to trace the extended distribution of dark matter around
faint galaxies. We compare the baryon fraction of these galaxies with a sample
of galaxies with well measured rotation curves and discuss whether extremely
gas rich dwarf galaxies have abnormally small baryon fractions.Comment: 5 Pages, 4 Figures. To be published in the proceedings of "Galaxies
in the Local Volume", ed. B. Koribalski, H. Jerje
Development of sustainable aquaculture project (DSAP): mid-term review report
Aquaculture, Fish culture, Pond Culture, Rice field aquaculture, Farmers, Bangladesh,
Dynamic of Two-phase Dusty Nanofluid Flow Past a Vertical Wavy Surface
An analysis is performed to study two-phase natural convection flow with heat transfer of nanofluid along a vertical way surface. The model includes equations expressing conservation of total mass, momentum and thermal energy for two-phase nano fluid. Primitive variable formulations (PVF) are used to transform the dimensionless boundary layer equations into convenient coordinate system and resulting equations are integrated numerically via implicit finite difference iterative scheme. The effects of the controlling parameters on the dimensionless quantities such as skin friction coeffcient, rate of heat transfer and rate of mass transfer are explored. It is concluded from present analysis, that the diffusivity ratio parameter, NA and particle-density increment number, NB has pronounced effect in reduction of heat transfer rate
Evaluation of antifungal activity of seaweed extract (Turbinaria conoides) against Fusarium oxysporum
The purpose of the study was to determine the anti fungal activity of seaweed (Turbinaria conoides) extract against root rot pathogen Fusarium oxysporum. Seaweed extract was prepared from the species T. conoides collected from Rameswaram coastal area of Tamil Nadu during December was used for this study. Different concentrations of the extract viz., 5 %, 10 %, 15 % and 20 % was evaluated for their antifungal activity against F. oxysporum using poisoned food technique along with control and carbendazim (0.2 %) as check. No mycelial growth (0 cm) was observed in 15 % and 20 % sea weed extract weed extract treated plates even after 6 days ofincubation. Though the visible inhibition of mycelial growth was noticed in all the concentrations, the increased concentration of 15 and 20 % had shown 100 % inhibition. So, the lower concentration of 15 % can be best in controlling the F. oxysporum fungi. GC-MS analysis of seaweed extract showing the presence of several antimicrobial compounds in seaweeds may be the reason for such inhibition
HI power spectrum of the spiral galaxy NGC628
We have measured the HI power spectrum of the nearly face-on spiral galaxy
NGC628 (M74) using a visibility based estimator. The power spectrum is well
fitted by a power law , with over the
length scale . The slope is found to be
independent of the width of the velocity channel. This value of the slope is a
little more than one in excess of what has been seen at considerably smaller
length scales in the Milky-Way, Small Magellanic Cloud (LMC), Large Magellanic
Cloud (SMC) and the dwarf galaxy DDO210. We interpret this difference as
indicating a transition from three dimensional turbulence at small scales to
two dimensional turbulence in the plane of the galaxy's disk at length scales
larger than galaxy's HI scale height.
The slope measured here is similar to that found at large scales in the LMC.
Our analysis also places an upper limit to the galaxy's scale height at $800\
{\rm pc}$ .Comment: 4 Pages, 2 Figures, 1 Table. Accepted for Publication in MNRAS
LETTER
Development of two high yielding mutant varieties of mustard [Brassica juncea (L.) Czern.] through gamma rays irradiation
Seeds of the well-adapted and popular mustard variety BARIsarisha-11 were irradiated with gamma ray using 60Co gamma cells. Irradiated seeds were grown as M1 during 2004-05. Selection was made from M2 generation during 2005-06. Desirable mutants were confirmed in M4 generation during 2007-08 and ten true breeding mutants having higher seed yield per plant with desirable morphological characters and yield attributes were selected. Selected mutants were evaluated along with the mother variety BARIsarisha-11 to select the most desirable ones considering higher seed yield and improved yield attributes under different replicated yield trials during 2008-09 to 2010-11. Results showed that two mutants, MM-10-04 and MM-08-04 selected from 700 Gy produced higher seed yield than BARIsarisha-11 in most of the trials conducted in 13 locations of Bangladesh. Mean of three years trial showed that seed yield of MM-10-04 and MM-08-04 was 2043 and 1893 kg ha-1, respectively, which was 23% and 14% higher than BARIsarisha-11 (parental plant). Mutants MM-10-04 and MM-08-04 also had the higher number of siliquae plant-1, 1000-seed weight and oil content than BARIsarisha-11. These two mutants also showed tolerance against Alternaria blight disease and lower aphid infestation. Results of the yield trials as well as screening against Alternaria blight disease and aphid carried out across the country indicated that MM-10-04 and MM-08-04 were suitable for widespread cultivation. Consequently, the National Seed Board of Bangladesh registered MM-10-04 and MM-08-04 in 2011 as two high yielding mustard varieties, Binasarisha-7 and Binasarisha-8, respectively for commercial cultivation
The Nearby and Extremely Metal-Poor Galaxy CGCG 269-049
We present Hubble Space Telescope (HST) and Spitzer Space Telescope images
and photometry of the extremely metal-poor (Z = 0.03 Z_sol) blue dwarf galaxy
CGCG 269-049. The HST images reveal a large population of red giant and
asymptotic giant branch stars, ruling out the possibility that the galaxy has
recently formed. From the magnitude of the tip of the red giant branch, we
measure a distance to CGCG 269-049 of only 4.9 +/- 0.4 Mpc. The spectral energy
distribution of the galaxy between ~3.6 - 70 microns is also best fitted by
emission from predominantly ~10 Gyr old stars, with a component of thermal dust
emission having a temperature of 52 +/- 10 K. The HST and Spitzer photometry
indicate that more than 60% of CGCG 269-049's stellar mass consists of stars
~10 Gyr old, similar to other local blue dwarf galaxies. Our HST H-alpha image
shows no evidence of a supernova-driven outflow that could be removing metals
from the galaxy, nor do we find evidence that such outflows occurred in the
past. Taken together with CGCG 269-049's large ratio of neutral hydrogen mass
to stellar mass (~10), these results are consistent with recent simulations in
which the metal deficiency of local dwarf galaxies results mainly from
inefficient star formation, rather than youth or the escape of supernova
ejecta.Comment: 35 Pages, 7 Figures, accepted for publication in ApJ; new version
corrects errors in Table 1, Figure 3, and related calculations in tex
Diffuse Ionized Gas in the Dwarf Irregular Galaxy DDO 53
The spectral characteristics throughout the dwarf irregular galaxy DDO 53 are
studied. The results are very similar to those for other irregular galaxies:
high excitation and low values of the [SII]/Halpha ratio. The most likely
ionization source is photon leakage from the classical HII regions, without any
other source, although the interstellar medium of the galaxy is quite
perturbed. Moreover, the physical conditions throughout the galaxy do not
change very much because both the photon leakage percentage and the ionization
temperature are very similar. In addition, the determined metal content for two
HII regions indicates that DDO 53 is a low-metallicity galaxy.Comment: 32 pages, 9 figures, 7 tables. AJ, in pres
Crystal structure of (Z)-4-methylbenzyl 3-[1-(5-methylpyridin-2-yl)ethylidene]dithiocarbazate
In the title dithiocarbazate compound, C17H19N3S2, the central CN2S2 residue is essentially planar (r.m.s. deviation = 0.0288 Å) and forms dihedral angles of 9.77 (8) and 77.47 (7)° with the substituted-pyridyl and p-tolyl rings, respectively, indicating a highly twisted molecule; the dihedral angle between the rings is 85.56 (8)°. The configuration about the C=N bond is Z, which allows for the formation of an intramolecular N—H...N(pyridyl) hydrogen bond. The packing features tolyl-methyl-C—H...N(imine), pyridyl-C—H...π(tolyl) and π–π interactions [between pyridyl rings with a distance = 3.7946 (13) Å], which generates jagged supramolecular layers that stack along the b axis with no directional interactions between them
- …
