STUDY AND MECHANICAL TESTING OF FIBER REINFORCED PLASTIC LAMINATE AND CARBON FIBER LAMINATE COMPOSITE

The use of composite materials at industrial and domestic levels is increasing day by day, due to which the work in the direction of enhancing its mechanical property is being on a fast pace. In this study, the mechanical properties of Polyester resin and Carbon Fibre Composite were analyzed experimentally. Tensile and Compressive strength of the specimen were determined and compared. It was found both laminates together provides a positive impact in the enhancement of mechanical properties of the composite

Simultaneous evidence of edge collapse and hub-filament configurations: A rare case study of a Giant Molecular Filament G45.3+0.1

We study multiwavelength and multiscale data to investigate the kinematics of molecular gas associated with the star-forming complexes G045.49+00.04 (G45E) and G045.14+00.14 (G45W) in the Aquila constellation. An analysis of the FUGIN $^{13}$CO(1-0) line data unveils the presence of a giant molecular filament (GMF G45.3+0.1; length $\sim$75 pc, mass $\sim$1.1$\times$10$^{6}$ M$_{\odot}$) having a coherent velocity structure at [53, 63] km s$^{-1}$. The GMF G45.3+0.1 hosts G45E and G45W complexes at its opposite ends. We find large scale velocity oscillations along GMF G45.3+0.1, which also reveals the linear velocity gradients of $-$0.064 and $+$0.032 km s$^{-1}$ pc$^{-1}$ at its edges. The photometric analysis of point-like sources shows the clustering of young stellar object (YSO) candidate sources at the filament's edges where the presence of dense gas and HII regions are also spatially observed. The Herschel continuum maps along with the CHIMPS $^{13}$CO(3-2) line data unravel the presence of parsec scale hub-filament systems (HFSs) in both the sites, G45E and G45W. Our study suggests that the global collapse of GMF G45.3+0.1 is end-dominated, with addition to the signature of global nonisotropic collapse (GNIC) at the edges. Overall, GMF G45.3+0.1 is the first observational sample of filament where the edge collapse and the hub-filament configurations are simultaneously investigated. These observations open up the new possibility of massive star formation, including the formation of HFSs.Comment: 23 pages, 12 figures, 1 table, Accepted for publication in The Astrophysical Journa

New Insights into the HII Region G18.88-0.49: Hub-Filament System and Accreting Filaments

We present an analysis of multiwavelength observations of an area of 0.°27 × 0.°27 around the Galactic H ii region G18.88-0.49, which is powered by an O-type star (age ∼ 105 yr). The Herschel column density map reveals a shell-like feature of extension ∼12 pc × 7 pc and mass ∼2.9 × 104 M o˙ around the H ii region; its existence is further confirmed by the distribution of molecular (12CO, 13CO, C18O, and NH3) gas at [60, 70] km s-1. Four subregions are studied toward this shell-like feature and show a mass range of ∼0.8-10.5 × 103 M o˙. These subregions associated with dense gas are dominated by nonthermal pressure and supersonic nonthermal motions. The shell-like feature is associated with the H ii region, Class I protostars, and a massive protostar candidate, illustrating the ongoing early phases of star formation (including massive stars). The massive protostar is found toward the position of the 6.7 GHz methanol maser, and is associated with outflow activity. Five parsec-scale filaments are identified in the column density and molecular maps and appear to be radially directed to the dense parts of the shell-like feature. This configuration is referred to as a "hub-filament"system. Significant velocity gradients (0.8-1.8 km s-1 pc-1) are observed along each filament, suggesting that the molecular gas flows toward the central hub along the filaments. Overall, our observational findings favor a global nonisotropic collapse scenario as discussed in Motte et al., which can explain the observed morphology and star formation in and around G18.88-0.49.Fil: Dewangan, L. K.. Physical Research Laboratory India; IndiaFil: Ojha, D. K.. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Sharma, Saurabh. Aryabhatta Research Institute Of Observational Sciences; IndiaFil: del Palacio, Santiago. Universidad Nacional de La Plata; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Bhadari, N. K.. Indian Institute Of Technology Gandhinagar; India. Physical Research Laboratory India; IndiaFil: Das, A.. University Of Hyderabad; Indi

Galactic `Snake' IRDC G11.11−-0.12: a site of multiple hub-filament systems and colliding filamentary clouds

To probe star formation processes, we present a multi-scale and multi-wavelength investigation of the `Snake' nebula/infrared dark cloud G11.11$-$0.12 (hereafter, G11; length $\sim$27 pc). Spitzer images hint at the presence of sub-filaments (in absorption), and reveal four infrared-dark hub-filament system (HFS) candidates (extent $<$ 6 pc) toward G11, where massive clumps ($>$ 500 $M_{\odot}$) and protostars are identified. The $^{13}$CO(2-1), C$^{18}$O(2-1), and NH$_{3}$(1,1) line data reveal a noticeable velocity oscillation toward G11, as well as its left part (or part-A) around V$_{lsr}$ of 31.5 km s$^{-1}$, and its right part (or part-B) around V$_{lsr}$ of 29.5 km s$^{-1}$. The common zone of these cloud components is investigated toward the center's G11 housing one HFS. Each cloud component hosts two sub-filaments. In comparison to part-A, more ATLASGAL clumps are observed toward part-B. The JWST near-infrared images discover one infrared-dark HFS candidate (extent $\sim$0.55 pc) around the massive protostar G11P1 (i.e., G11P1-HFS). Hence, the infrared observations reveal multiple infrared-dark HFS candidates at multi-scale in G11. The ALMA 1.16 mm continuum map shows multiple finger-like features (extent $\sim$3500-10000 AU) surrounding a dusty envelope-like feature (extent $\sim$18000 AU) toward the central hub of G11P1-HFS. Signatures of forming massive stars are found toward the center of the envelope-like feature. The ALMA H$^{13}$CO$^{+}$ line data show two cloud components with a velocity separation of $\sim$2 km s$^{-1}$ toward G11P1. Overall, the collision process, the ``fray and fragment'' mechanism, and the ``global non-isotropic collapse'' scenario seem to be operational in G11.Comment: 20 pages, 13 figures, 3 Tables, Accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS) Journa

XMM observations of the narrow-line QSO PHL 1092: Detection of a high and variable soft component

We present results based on an XMM-Newton observation of the high luminosity narrow-line QSO PHL 1092 performed in 2003 January. The 0.3 - 10 keV spectrum is well described by a model which includes a power-law (Gamma ~ 2.1) and two blackbody components (kT ~ 130 eV and kT ~ 50 eV). The soft X-ray excess emission is featureless and contributes ~ 80% to the total X-ray emission in the 0.3 - 10 keV band. The most remarkable feature of the present observation is the detection of X-ray variability at very short time scale: the X-ray emission varied by 35% in about 5000 s. We find that this variability can be explained by assuming that only the overall normalization varied during the observation. There was no evidence for any short term spectral variability and the spectral shape was similar even during the ASCA observation carried out in 1997. Considering the high intrinsic luminosity (~ 2x10^45 erg/s) and the large inferred mass of the putative black hole (~ 1.6x10^8 M_sun), the observed time scale of variability indicates emission at close to Eddington luminosity arising from very close to the black hole. We suggest that PHL 1092 in particular (and narrow line Seyfert galaxies in general) is a fast rotating black hole emitting close to its Eddington luminosity and the X-ray emission corresponds to the high-soft state seen in Galactic black hole sources.Comment: 7 figures, 8 pages, emulateapj style, ApJ in pres

Star-forming site RAFGL 5085: Is a perfect candidate of hub-filament system ?

To investigate the star formation process, we present a multi-wavelength study of a massive star-forming site RAFGL 5085, which has been associated with the molecular outflow, HII region, and near-infrared cluster. The continuum images at 12, 250, 350, and 500 $\mu$m show a central region (having M$_{\rm clump}$ $\sim$225 M$_{\odot}$) surrounded by five parsec-scale filaments, revealing a hub-filament system (HFS). In the {\it Herschel} column density ($N({{\rm{H}}}_{2})$) map, filaments are identified with higher aspect ratios (length/diameter) and lower $N({{\rm{H}}}_{2})$ values ($\sim$0.1--2.4 $\times$10$^{21}$ cm$^{-2}$), while the central hub is found with a lower aspect ratio and higher $N({{\rm{H}}}_{2})$ values ($\sim$3.5--7.0 $\times$10$^{21}$ cm$^{-2}$). The central hub displays a temperature range of [19, 22.5]~K in the {\it Herschel} temperature map, and is observed with signatures of star formation (including radio continuum emission). The JCMT $^{13}$CO(J= 3--2) line data confirm the presence of the HFS and its hub is traced with supersonic and non-thermal motions having higher Mach number and lower thermal to non-thermal pressure ratio. In the $^{13}$CO position-velocity diagrams, velocity gradients along the filaments toward the HFS appear to be observed, suggesting the gas flow in the RAFGL 5085 HFS and the applicability of the clump-fed scenario.Comment: 15 pages, 8 figures; Accepted for publication in Journal of Astrophysics and Astronomy (JOAA

A high-density relativistic reflection origin for the soft and hard X-ray excess emission from Mrk 1044

We present the first results from a detailed spectral-timing analysis of a long ($\sim$130 ks) XMM-Newton observation and quasi-simultaneous NuSTAR and Swift observations of the highly-accreting narrow-line Seyfert 1 galaxy Mrk 1044. The broadband (0.3$-$50 keV) spectrum reveals the presence of a strong soft X-ray excess emission below $\sim$1.5 keV, iron K$_{\alpha}$ emission complex at $\sim$6$-$7 keV and a `Compton hump' at $\sim$15$-$30 keV. We find that the relativistic reflection from a high-density accretion disc with a broken power-law emissivity profile can simultaneously explain the soft X-ray excess, highly ionized broad iron line and the Compton hump. At low frequencies ($[2-6]\times10^{-5}$ Hz), the power-law continuum dominated 1.5$-$5 keV band lags behind the reflection dominated 0.3$-$1 keV band, which is explained with a combination of propagation fluctuation and Comptonization processes, while at higher frequencies ($[1-2]\times10^{-4}$ Hz), we detect a soft lag which is interpreted as a signature of X-ray reverberation from the accretion disc. The fractional root-mean-squared (rms) variability of the source decreases with energy and is well described by two variable components: a less variable relativistic disc reflection and a more variable direct coronal emission. Our combined spectral-timing analyses suggest that the observed broadband X-ray variability of Mrk~1044 is mainly driven by variations in the location or geometry of the optically thin, hot corona.Comment: 23 pages, 19 figures, 4 tables, Published in MNRA