27 research outputs found

    Quasar catalogue for the astrometric calibration of the forthcoming ILMT survey

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    Quasars are ideal targets to use for astrometric calibration of large scale astronomical surveys as they have negligible proper motion and parallax. The forthcoming 4-m International Liquid Mirror Telescope (ILMT) will survey the sky that covers a width of about 27 arcminute. To carry out astrometric calibration of the ILMT observations, we aimed to compile a list of quasars with accurate equatorial coordinates and falling in the ILMT stripe. Towards this, we cross-correlated all the quasars that are known till the present date with the sources in the Gaia-DR2 catalogue, as the Gaia-DR2 sources have position uncertainties as small as a few milli arcsec (mas). We present here the results of this cross-correlation which is a catalogue of 6738 quasars that is suitable for astrometric calibration of the ILMT fields. In this work, we present this quasar catalogue. This catalogue of quasars can also be used to study quasar variability over diverse time scales when the ILMT starts its observations. While preparing this catalogue, we also confirmed that quasars in the ILMT stripe have proper motion and parallax lesser than 20 mas/yr and 10 mas, respectively.Comment: 9 pages, 9 figures, Accepted in Journal of Astrophysics & Astronom

    SS 433: Results of a Recent Multi-wavelength Campaign

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    We conducted a multi-wavelength campaign in September-October, 2002, to observe SS 433. We used 45 meter sized 30 dishes of Giant Meter Radio Telescope (GMRT) for radio observation, 1.2 meter Physical Research Laboratory Infra-red telescope at Mt Abu for IR, 1 meter Telescope at the State Observatory, Nainital for Optical photometry, 2.3 meter optical telescope at the Vainu Bappu observatory for spectrum and Rossi X-ray Timing Explorer (RXTE) Target of Opportunity (TOO) observation for X-ray observations. We find sharp variations in intensity in time-scales of a few minutes in X-rays, IR and radio wavelengths. Differential photometry at the IR observation clearly indicated significant intrinsic variations in short time scales of minutes throughout the campaign. Combining results of these wavelengths, we find a signature of delay of about two days between IR and Radio. The X-ray spectrum yielded double Fe line profiles which corresponded to red and blue components of the relativistic jet. We also present the broadband spectrum averaged over the campaign duration.Comment: 17 pages 10 figures MNRAS (submitted

    Effects of Dietary Fish Oil Substitution with Palm Oil on Growth, Survival, and Muscle Proximate Composition of Cirrhinus mrigala (Hamilton, 1822)

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    A 60-day growth experiment was carried out to evaluate the effect of replacing dietary cod liver oil with palm oil on the growth, survival, and muscle proximate composition of the Indian major carp, Cirrhinus mrigala. Five diets were fed to triplicate groups of 20 advanced C. mrigala fry (2.16±0.01 g): 100% cod liver+0% palm (control), 25% palm+75% cod liver, 50% palm+50% cod liver, 75% palm+25% cod liver, and 100% palm+0% cod liver. At the end of the experiment, mean weight gain, average daily growth, specific growth rate, feed conversion efficiency, feed conversion ratio, and percentage survival were assessed. Growth performance and survival were not compromised when fish oil was substituted with palm oil up to 25%. However, beyond this level, growth was significantly retarded (p0.01) differences in feed efficiency or muscle proximate composition. Results confirm the feasibility of substituting up to 25% dietary fish oil by palm oil in diets for C. mrigala advanced fry without negatively affecting growth or feed utilization efficiency

    Estimation of the size and structure of the broad line region using Bayesian approach

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    20 pages, 16 figures, 5 tables, Accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS), 30 December 2020International audienceUnderstanding the geometry and kinematics of the broad line region (BLR) of active galactic nuclei (AGN) is important to estimate black hole masses in AGN and study the accretion process. The technique of reverberation mapping (RM) has provided estimates of BLR size for more than 100 AGN now, however, the structure of the BLR has been studied for only a handful number of objects. Towards this, we investigated the geometry of the BLR for a large sample of 57 AGN using archival RM data. We performed systematic modeling of the continuum and emission line light curves using a Markov Chain Monte Carlo method based on Bayesian statistics implemented in PBMAP (Parallel Bayesian code for reverberation-MAPping data) code to constrain BLR geometrical parameters and recover velocity integrated transfer function. We found that the recovered transfer functions have various shapes such as single-peaked, double-peaked and top-hat suggesting that AGN have very different BLR geometries. Our model lags are in general consistent with that estimated using the conventional cross-correlation methods. The BLR sizes obtained from our modeling approach is related to the luminosity with a slope of 0.583 (+/-) 0.026 and 0.471 (+/-) 0.084 based on H{\beta} and H{\alpha} lines, respectively. We found a non-linear response of emission line fluxes to the ionizing optical continuum for 93\% objects. The estimated virial factors for the AGN studied in this work range from 0.79 to 4.94 having a mean at 1.78 (+/-) 1.77 consistent with the values found in the literature

    Effect of substituting live feed with formulated feed on the reproductive performance and fry survival of Siamese fighting fish, Betta splendens (Regan, 1910)

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    This study aimed to elucidate the effect of partial or complete replacement of live feed (LF) (Tubifex) with formulated feed (FF) on the reproductive performance of Betta splendens. Three hundred B. splendens fry (average weight 0.19 +/- 0.01 g) were equally distributed into five different groups, each with three replicates. They were fed for 105 days with following different diets: control (C)-100% LF; T1-75% LF, 25% FF; T2-50% LF, 50% FF; T3-25% LF, 75% FF, and T4-100% FF. Results showed that the average number of hatched larvae (654 +/- 101) and fry survival after 2 weeks of rearing (428 +/- 70), after completion of three spawning, were recorded highest in the control group, which was, however, not significantly different from the T1, T2, and T3 groups. At the end of the feeding trial, the highest hatching percentage (90.3%) was registered in the T2 group, which was not significantly different from the control and T1 groups. The T2 group also recorded highest fry survival (65.54%) after completion of three spawning, which was not significantly (P < 0.05) different from the T1 and T3 groups. Control diet contained higher saturated fatty acid (63.23%) than formulated diet (29.80%). In the whole-body tissue, highest level of EPA (0.42%) and DHA (3.13%) were found in the T4 group followed by T3 group. The DHA/EPA ration was recorded highest in the T2 group (10.96%), which did not differ significantly from the T1 and T3 groups. Significant positive correlation was observed between saturated fatty acid levels in fish whole-body tissue and number of hatched larvae (Y = 30.81 x -825.3, R-2 = 0.968) and fry survival after 2 weeks of rearing (Y = 21.38 x -580.9, R-2 = 0.967). Considering all these factors, it can be concluded that the live feed Tubifex can be replaced up to 50% without any adverse effect on the reproductive performance and fry survival of B. splendens

    Effects of Dietary Fish Oil Substitution with Palm Oil on Growth, Survival, and Muscle Proximate Composition of Cirrhinus mrigala (Hamilton, 1822)

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    Abstract A 60-day growth experiment was carried out to evaluate the effect of replacing dietary cod liver oil with palm oil on the growth, survival, and muscle proximate composition of the Indian major carp, Cirrhinus mrigala. Five diets were fed to triplicate groups of 20 advanced C. mrigala fry (2.16±0.01 g): 100% cod liver+0% palm (control), 25% palm+75% cod liver, 50% palm+50% cod liver, 75% palm+25% cod liver, and 100% palm+0% cod liver. At the end of the experiment, mean weight gain, average daily growth, specific growth rate, feed conversion efficiency, feed conversion ratio, and percentage survival were assessed. Growth performance and survival were not compromised when fish oil was substituted with palm oil up to 25%. However, beyond this level, growth was significantly retarded (p&lt;0.01). There were no significant (p&gt;0.01) differences in feed efficiency or muscle proximate composition. Results confirm the feasibility of substituting up to 25% dietary fish oil by palm oil in diets for C. mrigala advanced fry without negatively affecting growth or feed utilization efficiency. The IJA appears exclusively as a peer-reviewed on-line open-access journal at http://www.siamb.org.il. To read papers free of charge, please register online at registration form. Sale of IJA papers is strictly forbidden. Sale of IJA papers is strictly forbidden. 2 Singh et al

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    Not AvailableA 60-day growth experiment was carried out to evaluate the effect of replacing dietary cod liver oil with palm oil on the growth, survival, and muscle proximate composition of the Indian major carp, Cirrhinus mrigala. Five diets were fed to triplicate groups of 20 advanced C. mrigala fry (2.16±0.01 g): 100% cod liver+0% palm (control), 25% palm+75% cod liver, 50% palm+50% cod liver, 75% palm+25% cod liver, and 100% palm+0% cod liver. At the end of the experiment, mean weight gain, average daily growth, specific growth rate, feed conversion efficiency, feed conversion ratio, and percentage survival were assessed. Growth performance and survival were not compromised when fish oil was substituted with palm oil up to 25%. However, beyond this level, growth was significantly retarded (p0.01) differences in feed efficiency or muscle proximate composition. Results confirm the feasibility of substituting up to 25% dietary fish oil by palm oil in diets for C. mrigala advanced fry without negatively affecting growth or feed utilization efficiency.Not Availabl
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