U. Joshi

The central electromagnetic calorimeter for the Collider Detector at Fermilab uses a hybrid design with scintillator and wavelength shifter for energy measurement and an embedded strip chamber for position determination and longitudinal shower development. Complementary calibration systems are incorporated in the design. Calorimeter characteristics and performance are summarized. An average energy resolution, σ(E)E, of 13.5%√E sin θ (with E in GeV), and a position resolution of ±2 mm at 50 GeV are measured.

We present measurements of the pseudorapidity (η) distribution of charged particles (dNchdη) produced within |η|≤3.5 in proton-antiproton collisions at √s of 630 and 1800 GeV. We measure dNchdη at η=0 to be 3.18±0.06(stat)±0.10(syst) at 630 GeV, and 3.95±0.03 (stat)±0.13(syst) at 1800 GeV. Many systematic errors in the ratio of dNchdη at the two energies cancel, and we measure 1.26±0.01±0.04 for the ratio of dNchdη at 1800 GeV to that at 630 GeV within |η|≤3. Comparing to lower-energy data, we observe an increase faster than ln(s) in dNchdη at η=0.Received 2 October 1989DOI:https://doi.org/10.1103/PhysRevD.41.2330©1990 American Physical Society

Measurements of inclusive transverse-momentum spectra for charged particles produced in proton-antiproton collisions at \ensuremath{\surd}2 of 630 and 1800 GeV are presented and compared with data taken at lower energies.

Over the course of three hours on 27 December 2008 we obtained optical (R-band) observations of the blazar S5 0716+714 at a very fast cadence of 10 s. Using several different techniques we find fluctuations with an approximately 15-minute quasi-period to be present in the first portion of that data at a > 3 sigma confidence level. This is the fastest QPO that has been claimed to be observed in any blazar at any wavelength. While this data is insufficient to strongly constrain models for such fluctuations, the presence of such a short timescale when the source is not in a very low state seems to favor the action of turbulence behind a shock in the blazar's relativistic jet.

We have determined mW=79.91±0.39 GeV/c2 from an analysis of W→eν and W→μν data from the Collider Detector at Fermilab in ¯pp collisions at √s=1.8 TeV. From this result and the world-average Z mass, the weak mixing angle is determined to be sin2θW=0.232±0.008. An upper bound on the top-quark mass derived from this result is discussed.Received 13 August 1990DOI:https://doi.org/10.1103/PhysRevD.43.2070©1991 American Physical Society

We report results from our monitoring of the BL Lac object Mrk 421 in the near-IR J band. The observations, aimed at studying the intraday variability (IDV) of the object, were carried out systematically over an extended (and near-continuous) period of eight nights from the 1.2 m Mount Abu Infrared Telescope, India. There are limited studies for Mrk 421 in the J band for such an extended period. The observation epoch for this study (25 February–5 March 2003) was chosen to significantly overlap other concurrent studies of Mrk 421 in the X-ray/γ-ray regions being conducted using the Rossi X-ray timing explorer (RXTE) and the solar tower atmospheric Cherenkov effect experiment (STACEE). Hence these results could be useful for a multi-wavelength analysis of the variability behavior of Mrk 421. We find that Mrk 421 was quite active during the observed period and showed significant IDV and short term variability. A maximum variation of 0.89 mag is seen over the entirety of the observed period. Flaring activity, with typical brightness variations of ~0.4, are also seen on several occasions. The extent of the variability observed by us is compared with the results of other similar studies of Mrk 421 in the J band.

The ISOGAL project is an infrared survey of specific regions sampling the Galactic Plane selected to provide information on Galactic structure, stellar populations, stellar mass-loss and the recent star formation history of the inner disk and Bulge of the Galaxy. ISOGAL combines 7 and 15 μm ISOCAM observations – with a resolution of 6″ at worst – with DENIS IJKs data to determine the nature of the sources and the interstellar extinction. We have observed about 16 square degrees with a sensitivity approaching 10–20 mJy, detecting ~105 sources, mostly AGB stars, red giants and young stars. The main features of the ISOGAL survey and the observations are summarized in this paper, together with a brief discussion of data processing and quality. The primary ISOGAL products are described briefly (a full desciption is given in Schuller et al. 2003): viz. the images and the ISOGAL–DENIS five-wavelength point source catalogue. The main scientific results already derived or in progress are summarized. These include astrometrically calibrated 7 and 15 μm images, determining structures of resolved sources; identification and properties of interstellar dark clouds; quantification of the infrared extinction law and source dereddening; analysis of red giant and (especially) AGB stellar populations in the central Bulge, determining luminosity, presence of circumstellar dust and mass-loss rate, and source classification, supplemented in some cases by ISO/CVF spectroscopy; detection of young stellar objects of diverse types, especially in the inner Bulge with information about the present and recent star formation rate; identification of foreground sources with mid-IR excess. These results are the subject of about 25 refereed papers published or in preparation.

Inclusive jet production at $\sqrt{s}=1.8$ TeV has been measured in the CDF detector at the Fermilab Tevatron $\overline{p}p$ Collider. Jets with transverse energies (${E}_{t}$) up to 250 GeV have been observed. The ${E}_{t}$ dependence of the inclusive jet cross section is consistent with leading-order quantum-chromodynamic calculations, and comparison with lower-energy data shows deviations from scaling consistent with QCD. A lower limit of 700 GeV (95% confidence level) is placed on the quark compositeness scale parameter ${\ensuremath{\Lambda}}_{c}$ associated with an effective contact interaction.

An analysis of high-transverse-momentum electrons using data from the Collider Detector at Fermilab (CDF) of ¯pp collisions at √s=1800 GeV yields values of the production cross section times branching ratio for W and Z0 bosons of σ(¯pp→WX→eνX)=2.19±0.04(stat)±0.21(syst) nb and σ(¯pp→Z0X→e+e−X)=0.209±0.013(stat)±0.017(syst) nb. Detailed descriptions of the CDF electron identification, background, efficiency, and acceptance are included. Theoretical predictions of the cross sections that include a mass for the top quark larger than the W mass, current values of the W and Z0 masses, and higher-order QCD corrections are in good agreement with these measured values.Received 13 November 1990DOI:https://doi.org/10.1103/PhysRevD.44.29©1991 American Physical Society

We report the detection of intra-night variability in some radio-quiet quasi-stellar objects (RQQSOs) and one lobe-dominated radio-loud quasi-stellar object (LDQ). To study intra-night variability, we carried out photometric monitoring of seven RQQSOs and one LDQ in Johnson V-passband using 1.2 m optical/IR telescope at Gurushikhar, Mount Abu, India. Observations were made in nine nights during the first half of the year 2000; seven RQQSOs: 0748+291, 0945+438, 1017+280, 1029+329, 1101+319, 1225+317, 1252+020 and one LDQ: 1103-006 were observed. RQQSOs 0748+291, 1225+317 and LDQ 1103-006 have shown intra-night variations. In the case of 1017+280 (RQQSO) there is indication of intra-night variation on one night where as the observations on another night do not convincingly show the existence of intra-night variability. RQQSOs 0945+438, 1029+329, 1101+319 and 1252+020 have not shown any intra-night variations. We compiled intra-night variability data for radio-loud and radio-quiet AGNs from the literature for statistical analysis. It is found that some radio-quiet AGNs show intra-night variations with the maximum amplitude of variation being about 10%. On the other hand blazars at times show intra-night flux variability up to 100%. In the case of radio-loud AGNs (excluding blazars), the maximum amplitude of intra-night variation lies between the variability amplitude of radio-quiet AGNs and blazars i.e. the flux variation is close to 50%. The results indicate that the energy generation mechanism and the environment around the central engine in different classes of AGNs may be similar, if not identical. The standard model for radio-loud AGNs, where shocks are propagating down relativistic jets or models based on disturbances in accretion disks can also explain the micro-variability in RQQSOs.

We report rapid optical variability for the blazar S5 0716+71 during 2010 March 08-10 & 19-20 in the CCD observations made from Mt.Abu Infrared Observatory. The light curves are constructed for the duration longer than 3-hours each night, with very high temporal resolution(~ 45 seconds in R-band). During 2010 March 08 source smoothly decayed by about 0.15 mag in 2.88 hours, apart from a fast flicker lasting about 30 mins. S5 0716+71 brightened up during March 09 and 10 showing high activity while it was relatively faint (> 14 mag in R) albeit variable during March 19-20. During March 9 & 10, rapid flickers in the intensity modulate the long term intra-night (~ 3 hours) variation. The present observations suggest that the blazar S5 0716+71 showed night-to-night and intra-night variability at various time scales with 100% duty cycle for variation along with microvariability at significant levels. On night-to-night basis, the source exhibits mild bluer when brighter nature. The interaction of shocks with local inhomogeneities in the jet appears to cause intra-night variations while microvariations could be due to small scale perturbations intrinsic to the jet.

We have carried out optical (R band) intraday variability (IDV) monitoring of a sample of 10 bright low energy peaked blazars (LBLs). 40 photometric observations, of an average of ∼4 h each, were made between 2008 September and 2009 June using two telescopes in India. Measurements with good signal-to-noise ratios were typically obtained within 1–3 min, allowing the detection of weak, fast variations using N-star differential photometry. We employed both structure function and discrete correlation function analysis methods to estimate any dominant time-scales of variability and found that in most of the cases any such time-scales were longer than the duration of the observation. The calculated duty cycle of IDV in LBLs during our observing run is ∼52 per cent, which is low compared to many earlier studies; however, the relatively short periods for which each source was observed can probably explain this difference. We briefly discuss possible emission mechanisms for the observed variability.

We present the dijet invariant-mass distribution in the region between 60 and 500 GeV, measured in 1.8-TeV $\overline{p}p$ collisions in the Collider Detector at Fermilab. Jets are restricted to the pseudorapidity interval $|\ensuremath{\eta}|<0.7$. Data are compared with QCD calculations; axigluons are excluded with 95% confidence in the region $120<{M}_{A}<210$ GeV for axigluon width ${\ensuremath{\Gamma}}_{A}=\frac{N{\ensuremath{\alpha}}_{s}{M}_{A}}{6}$, with $N=5$.

We report results based on the monitoring of the BL Lac object Mrk 501 in the optical (B, V and R) passbands from March to May 2000. Observations spread over 12 nights were carried out using 1.2 m Mount Abu Telescope, India and 61 cm Telescope at Sobaeksan Astronomy Observatory, South Korea. The aim is to study the intra-day variability (IDV), short term variability and color variability in the low state of the source. We have detected flux variation of 0.05 mag in the R-band in time scale of 15 min in one night. In the B and V passbands, we have less data points and it is difficult to infer any IDVs. Short term flux variations are also observed in the V and R bands during the observing run. No significant variation in color (B–R) has been detected but (V–R) shows variation during the present observing run. Assuming the shortest observed time scale of variability (15 min) to represent the disk instability or pulsation at a distance of five Schwarschild radii from the black hole (BH), mass of the central BH is estimated ∼1.20 × 108M⊙.

The continuum polarization observations, spread over a period from October 1996 to May 1997, of the coma region of comet Hale Bopp are made at various phase angles, varying from 17.1 to 47.4 degrees, using IAU/IHW filter set. The linear polarization measured through 3650, 4845 and 6840 Å bands shows stronger wavelength dependence as compared to what is seen in comet Halley at similar phase angles. Comparisons are made with Comet Halley polarization properties and it is inferred that Comet Hale Bopp has smaller grains than those found for Comet Halley. However, this comet shows similarity with Comet Halley so far as the albedo of the grains is concerned. This comet appears to belong to the high polarization class in the classification scheme based on polarization characteristics.

Mass and age distributions of stars, based on homogeneous photoelectric UBV data and reliable cluster membership, are studied in 11 young open clusters. Stellar masses and ages are determined by fitting the theoretical stellar models to each star's position in the HR diagram by means of an interpolation procedure. The main conclusions about the mass function derived from the analysis of seven appropriate clusters are: (i) The slope of the mass spectrum of stars, x in the five young and well populated clusters is approximately the same, the average value being x = 1.4. (ii) Contrary to some results on the initial mass function of field stars, no substantial increase in slope for massive stars (say, M>5 M⊙). (iii) In general, the clusters under discussion do not show significant variations of mass function slope x with galactocentric distance, although two inner ones have a flat mass function (x = 0.85).

In an experiment at Fermilab we have measured the lifetime of ${K}_{S}^{0}$ mesons produced by 800-GeV/c protons on tungsten. ${K}_{S}^{0}$\ensuremath{\rightarrow}${\ensuremath{\pi}}^{+}$${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$ decays from 100 to 350 GeV/c, between 9.3 and 25.3 m from production, were selected for the measurement. The result was (0.8920\ifmmode\pm\else\textpm\fi{}0.0044)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ sec, in excellent agreement with measurements performed for 2--5-GeV/c ${K}_{S}^{0}$. The lifetime was also calculated for seven momentum bins. The results were completely consistent with Lorentz invariance. No evidence was found for the mometnum dependence suggested by the intermediate-range ``fifth-force'' hypothesis.

An analysis of W- and Z-boson production using data from the Collider Detector at Fermilab at \ensuremath{\surd}s =1.8 TeV yields \ensuremath{\sigma}(W\ensuremath{\rightarrow}ev)/\ensuremath{\sigma}(Z\ensuremath{\rightarrow}ee)=10.2\ifmmode\pm\else\textpm\fi{}0.8(stat)\ifmmode\pm\else\textpm\fi{}0.4(syst). The width of the W boson, \ensuremath{\Gamma}(W), and a limit on the top-quark mass independent of decay mode are extracted from this measurement.

The cross section for the production and subsequent decay to electron and neutrino of the W intermediate vector boson has been measured in 1.8-TeV p\ifmmode\bar\else\textasciimacron\fi{}p collisions at the Fermilab Tevatron Collider. An analysis of events with missing transverse energy greater than 25 GeV and with an electron of transverse energy greater than 15 GeV from a datum sample of 25.3 ${\mathrm{nb}}^{\mathrm{\ensuremath{-}}1}$ gives \ensuremath{\sigma}B=2.6\ifmmode\pm\else\textpm\fi{}0.6\ifmmode\pm\else\textpm\fi{}0.5 nb.

Photoelectric magnitudes and colours in the UBV system have been determined for 101 stars in the field of NGC 6530. The interstellar reddening across the cluster varies from 0.25 to 0.48 mag, with an average value of 0.35 mag. The distance modulus to the cluster is estimated at 11.3 mag and an age of 2 × 106 yr is ascribed. The cluster luminosity function is compared with the general luminosity function and the initial luminosity function. Star numbers 304 and 338 are in the early stages of their evolution while star numbers 171, 284 and 338 are probably variables.

Context. L-type ultra-cool dwarfs and brown dwarfs have cloudy atmospheres that could host weather-like phenomena. The detection of photometric or spectral variability would provide insight into unresolved atmospheric heterogeneities, such as holes in a global cloud deck. Indeed, a number of ultra-cool dwarfs have been reported to vary. Additional time-resolved spectral observations of brown dwarfs offer the opportunity for further constraining and characterising atmospheric variability. Aims. It has been proposed that growth of heterogeneities in the global cloud deck may account for the L- to T-type transition when brown dwarf photospheres evolve from cloudy to clear conditions. Such a mechanism is compatible with variability. We searched for variability in the spectra of five L6 to T6 brown dwarfs to test this hypothesis. Methods. We obtained spectroscopic time series using the near-infrared spectrographs ISAAC on VLT–ANTU, over 0.99−1.13 μm, and SpeX on the Infrared Telescope Facility for two of our targets in the J, H ,a ndK bands. We searched for statistically variable lines and for a correlation between those. Results. High spectral-frequency variations are seen in some objects, but these detections are marginal and need to be confirmed. We find no evidence of large-amplitude variations in spectral morphology and we place firm upper limits of 2 to 3% on broad-band variability, depending on the targets and wavelengths, on the time scale of a few hours. In contrast to the rest of the sample, the T2 transition brown dwarf SDSS J1254−0122 shows numerous variable features, but a secure variability diagnosis would require further observations. Conclusions. Assuming that any variability arises from the rotation of patterns of large-scale clear and cloudy regions across the surface, we find that the typical physical scale of cloud-cover disruption should be smaller than 5−8% of the disk area for four of our targets, using simplistic heterogeneous atmospheric models. The possible variations seen in SDSS J1254−0122 are not strong enough to allow us to confirm the cloud-breaking hypothesis.

Context: L-type ultra-cool dwarfs and brown dwarfs have cloudy atmospheres that could host weather-like phenomena. The detection of photometric or spectral variability would provide insight into unresolved atmospheric heterogeneities, such as holes in a global cloud deck. Aims: It has been proposed that growth of heterogeneities in the global cloud deck may account for the L- to T-type transition as brown dwarf photospheres evolve from cloudy to clear conditions. Such a mechanism is compatible with variability. We searched for variability in the spectra of five L6 to T6 brown dwarfs in order to test this hypothesis. Methods: We obtained spectroscopic time series using VLT/ISAAC, over 0.99-1.13um, and IRTF/SpeX for two of our targets, in J, H and K bands. We search for statistically variable lines and correlation between those. Results: High spectral-frequency variations are seen in some objects, but these detections are marginal and need to be confirmed. We find no evidence for large amplitude variations in spectral morphology and we place firm upper limits of 2 to 3% on broad-band variability, on the time scale of a few hours. The T2 transition brown dwarf SDSS J1254-0122 shows numerous variable features, but a secure variability diagnosis would require further observations. Conclusions: Assuming that any variability arises from the rotation of patterns of large-scale clear and cloudy regions across the surface, we find that the typical physical scale of cloud cover disruption should be smaller than 5-8% of the disk area for four of our targets. The possible variations seen in SDSS J1254-0122 are not strong enough to allow us to confirm the cloud breaking hypothesis.

The charged-particle fractional momentum distribution within jets, D(z), has been measured in dijet events from 1.8-TeV p\ifmmode\bar\else\textasciimacron\fi{}p collisions in the Collider Detector at Fermilab. As expected from scale breaking in quantum chromodynamics, the fragmentation function D(z) falls more steeply as dijet invariant mass increases from 60 to 200 GeV/${\mathit{c}}^{2}$. The average fraction of the jet momentum carried by charged particles is 0.65\ifmmode\pm\else\textpm\fi{}0.02(stat)\ifmmode\pm\else\textpm\fi{}0.08(syst).

A search was made for heavy stable charged particles produced in 1.8-TeV proton-antiproton collisions. No such particles were found in 26.2 ${\mathrm{nb}}^{\mathrm{\ensuremath{-}}1}$ of data. Cross-section limits are presented and mass limits of the order of 100 GeV are set for particles containing excited quarks in higher color representations.

We have measured dijet angular distributions at \ensuremath{\surd}s =1.8 TeV with the Collider Detector at Fermilab and the Tevatron p\ifmmode\bar\else\textasciimacron\fi{}p Collider and find agreement with leading-order QCD. By comparing the distribution for the highest dijet invariant masses with the prediction of a model of quark compositeness, we set a lower limit on the associated scale parameter ${\ensuremath{\Lambda}}_{c}$ at 330 GeV (95% C.L.).

Photoelectric UBV magnitudes and colours have been determined for 138 stars in NGC 2264, having membership probability greater than 50 per cent on the basis of proper motion studies. The reddening across the cluster is variable. The distance modulus to the cluster is estimated at 9.5 ± 0.2 mag.

Measurements of inclusive transverse-momentum spectra for ${K}_{S}^{0}$ mesons produced in proton-antiproton collisions at $\sqrt{s}$ of 630 and 1800 GeV are presented and compared with data taken at lower energies. The ratio, as a function of ${p}_{T}$, of the cross section for ${K}_{S}^{0}$ to that for charged hadrons is very similar to what is observed at lower energies. At 1800 GeV, we calculate the strangeness-suppression factor $\ensuremath{\lambda}=0.40\ifmmode\pm\else\textpm\fi{}0.05$.

Optically, thin two-temperature accretion flows may be thermally and viscously stable, but acoustically unstable. Here, we propose that the O-mode instability of a cooling-dominated optically thin two-temperature inner disk may explain the 23-day quasi-periodic oscillation (QPO) period observed in the TeV and X-ray light curves of Mkn 501 during its 1997 high state. In our model the relativistic jet electrons Compton upscatter the disk soft X-ray photons to TeV energies, so that the instability-driven X-ray periodicity will lead to a corresponding quasi-periodicity in the TeV light curve and produce correlated variability. We analyse the dependence of the instability-driven quasi-periodicity on the mass (M) of the central black hole, the accretion rate (M˙) and the viscous parameter (α) of the inner disk. We show that in the case of Mkn 501 the first two parameters are constrained by various observational results, so that for the instability occurring within a two-temperature disk where α = 0.05–1.0, the quasi-period is expected to lie within the range of 8–100 days, as indeed the case. In particular, for the observed 23-day QPO period our model implies a viscosity coefficient α ⩽ 0.28, a sub-Eddington accretion rate M˙≃0.02M˙Edd and a transition radius to the outer standard disk of r0 ∼ 60rg, and predicts a period variation δP/P ∼ 0.23 due to the motion of the instability region.

Comet 17P/Holmes was observed for linear polarization using the optical polarimeter mounted on the 1.2-m telescope atop Gurushikhar peak near Mt. Abu during the period 2007 November–December. Observations were conducted through the International Halley Watch narrow-band (continuum) filters. During the observing run, the phase angle was near 13° at which the comet showed negative polarization. On the basis of the observed polarization data, we find comet 17P/Holmes to be a typical comet with usual dust characteristics. We note that radial rate of change of brightness in coma in red band is higher than that in blue band; it has decreased by a factor of 3.6 and 2.5, respectively, in red and blue bands during the November–December run, indicating relative increase in the abundance of smaller dust particles outward. Radial brightness variation seen near the nucleus on November 6 is indicative of the presence of a blob or shocked region beyond 10 arcsec from the nucleus which has gradually smoothened by December 13. The brightness distribution is found steeper during November 5–7 as compared to that on December 13.

Spectra of comet C/2014 Q2 (Lovejoy) were taken with a low resolution spectrograph mounted on the 0.5 m telescope at the Mount Abu Infrared Observatory (MIRO), India during January to May 2015 covering the perihelion and post-perihelion periods. The spectra showed strong molecular emission bands (C2, C3 and CN) in January, close to perihelion. We have obtained the scale lengths for these molecules by fitting the Haser model to the observed column densities. The variation of gas production rates and production rate ratios with heliocentric distance were studied. The extent of the dust continuum using the Af-rho parameter and its variation with the heliocentric distance were also investigated. The comet is seen to become more active in the post-perihelion phase, thereby showing an asymmetric behaviour about the perihelion.

Model calculations have been made to explain the polarization observed during the passage of comet Austin. The observations were spread over four nights during the pre- and post-perihelion periods and were carried out at the IHW interference filters. The Austin data are compared with that of comet P/Halley reported in an earlier work (Sen et al.). The comparison, with the help of Mie theory, indicates that the polarizations in the two comets are probably caused by scattering due to two different types of grains, characterized by a change either in complex refractive index or size distribution or both. There are indications that comet Austin may contain finer grains as compared to P/Halley. Also a possible interpretation of these data with the help of scattering by large fluffy dark grains (Dollfus) is discussed.

Abstract All CDF event data are collected in a multilevel FASTBUS network. At the lowest level of this network, MEP/MX and SSP scanners read and buffer data from RABBIT and FASTBUS front end systems. Operation of these front end scanners is coordinated by the Trigger Supervisor module which initiates parallel readout after receiving Level 1 and Level 2 triggers. Dataflow from scanners to consumer processes on host VAX computers is supervised by the Buffer Manager which directs an Event Builder to collect and format data from a set of scanner modules. This system is designed to allow partitioning into semi-independent sections for parallel development and calibration studies.

We have observed the BL Lac object 1ES2344+514 (z = 0.044) in Very High Energy (VHE) gamma-ray and near-infrared wavelength bands with TACTIC and MIRO telescopes respectively. The observations were made from 18th October to 9th December 2004 and 27th October 2005 to 1st January 2006. Detailed analysis of the TACTIC data indicates absence of a statistically significant gamma-ray signal both in overall data and on a nightly basis from the source direction. We estimate an upper limit of I($\geq$1.5 TeV)$\leq 3.84 \times 10^{-12}$ photons cm$^{-2}$ s$^{-1}$ at a 3$σ$ confidence level on the integrated $γ$-ray flux. In addition, we have also compared TACTIC TeV light curves with those of the RXTE ASM (2-12keV) for the contemporary period and find that there are no statistically significant increases in the signal strengths from the source in both these energy regions. During 2004 IR observations, 1ES2344+514 shows low level (~0.06 magnitude) day-to-day variation in both, J & H bands. However, during 2005 observation epoch, the source brightens up by about 0.41 magnitude from its October 2005 level J magnitude= 12.64 to J = 12.23 on December 6, 2005. It then fades by about 0.2 magnitude during 6 to 10 December, 2005. The variation is seen in both, J & H, bands simultaneously. The light travel time arguments suggest that the emission region size is of the order of $10^{17}$ cms.

Photomultiplier tubes for the Collider Detector at Fermilab were subjected to preinstallation testing for stability, linearity and other properties. An apparatus is described which provided computer control of light sources, monitoring of environmental conditions and data logging of responses from up to 48 photomultipliers simultaneously. Statistical summaries of the test results are included for 1041 tubes for the central electromagnetic calorimeter and 687 tubes for the endwall hadron calorimeter.

Comet P/Halley was imaged polarimetrically in the coma and tail region on 5th January 1986. In the inner coma a small region has been found which has very low (<2%) polarization. But in the tailward direction beyond the outer coma (>105 km) two separate regions of enhanced polarizations (>8%) are found. These two regions are probably connected with jet ativities in the comet. The low polarization region in the inner coma can also be connected with a fresh dust jet ejecta, where the low polarization is resulting from multiple scattering in a region of high dust concentration, in the fresh ejecta. In general the polarization vectors have been found to be perpendicular to the scattering plane.

A measurement of the QCD jet-broadening parameter ⟨QT⟩ is described for high-ET jet data in the central calorimeter of the Collider Detector at Fermilab. As an alternate approach to clustering analysis, this method involves the use of a global event parameter which is free from the ambiguities associated with the definition and separation of individual clusters. The parameter QT is defined as the scalar sum of the transverse momentum perpendicular to the transverse thrust axis. Parton-level QCD predictions are made for ⟨QT⟩ as a function of ET, the total transverse energy in the events, and suggest that a measurement would show a dependence on the running of the strong coupling constant αs. Comparisons are made to first-order QCD parton-level calculations, as well as to fully evolved and hadronized leading-log simulations. The data are well described by the QCD predictions.Received 25 January 1991DOI:https://doi.org/10.1103/PhysRevD.44.601©1991 American Physical Society

A consistent, fully hierarchical design methodology and design techniques developed to create the first single-chip full-duplex OC48 traffic manager and ATM SAR (segmentation and reassembly) IC are presented. The IC achieves a sustained throughput of 5 Gbps for 1 M simultaneous SAR flows. /spl sim/78 M transistors are integrated in a 0.15 /spl mu/m CMOS 8-metal process. Functional and electrical design requirements were achieved with the first silicon.

Linear polarization observations were carried out on comet C/2000 WM1 with the 1.2 m telescope at Mt. Abu Observatory during November 2001 and March 2002. The observations in November were at low phase angle (<) when the polarization is negative and where the data for most of the comets are rather meager. The observations during March were made when the phase angle was ~47°. Observations were conducted through the IHW narrow band and BVR broad band filters. Based on these polarization observations we infer that the comet C/2000 WM1 belongs to high polarization class i.e. the dusty comet family.

Assessment of the qualitative losses in different varieties of sorghum following Pyrilla perpusilla Walker infestation revealed the significant decrease in vitro dry matter digestibility of whole plant, leaves and stem by about 6.0, 3.5 and 3.0 per cent, respectively at more than 60 per cent infestation level and was mainly due to the corresponding increase in tannin content. The fibre components (NDF and ADF) were acting as an additional factor in reducing the dry matter digestibility. The dry fodder yield was also reduced by 46 to 53 per cent in different varieties of sorghum with an increase in infestation level from 0 to >60 per cent. The stem of all the varieties was more fibreous than the leaves as it had high content of NDF, ADF, cellulose and lignin. Leaves on the other hand had high amount of protein, total soluble sugars and reducing sugars than stem and were therefore more digestible than stem.

Comet NEAT C/2001 Q4 was observed for linear polarization using the optical polarimeter mounted at the 1.2m telescope at Mt. Abu Observatory, during the months of May and June 2004. Observations were conducted through the International Halley Watch narrow band (continuum) and B,V,R broad band filters. During the observing run the phase angle ranged from 85.6 deg in May to 55 deg in June. As expected, polarization increases with wavelength in this phase angle range. Polarization colour in the narrow bands changes at different epochs, perhaps related to cometary activity or molecular emission contamination. The polarization was also measured in the cometary coma at different locations along a line, in the direction of the tail. As expected, we notice minor decrease in the polarization as photocenter (nucleus) is traversed while brightness decreases sharply away from it. Based on these polarization observations we infer that the comet NEAT C/2001 Q4 has high polarization and a typical grain composition- mixture of silicates and organics.

We report the detection of high polarization in the first detailed optical linear polarization measurements on the BL Lac object CGRaBS J0211+1051, which flared in $\gamma$-rays on 2011 January 23 as reported by Fermi. The observations were made during 2011 January 30 - February 3 using photo-polarimeter mounted at the 1.2m telescope of Mt Abu InfraRed Observatory(MIRO). The CGRaBS J0211+1051 was detected to have $\sim21.05\pm 0.41%$ degree of polarization (DP) with steady position angle (PA) at 43$^\circ$ on 2011 January 30. During Jan 31 and Feb 1, while polarization shows some variation, position angle remains steady for the night. Several olarization flashes occurred during February 2 and 3 resulting in changes in the DP by more than 4% at short time scales ($\sim$ 17 to 45 mins). A mild increase in the linear polarization with frequency is noticed during the nights of February 2 & 3. The source exhibited significant inter-night variations in the degree of polarization (changed by about 2 to 9%) and position angle (changed by 2 to 22$^\circ$) during the five nights of observations. The intra-night activity shown by the source appears to be related to turbulence in the relativistic jet. Sudden change in the PA accompanied by a rise in the DP could be indicative of the fresh injection of electrons in the jet. The detection of high and variable degree of polarization categorizes the source as low energy peaked blazar.

We discuss the architecture, operation, and performance of the Level 3 trigger used in the Fermilab CDF experiment in 1988–1989. This trigger used an on-line computer farm of 58 Motorola 68020 processors operating in parallel. The on-line programs were written mainly in Fortran and run in an environment similar to that used for off-line analysis.

Polarimetric observations of stars in the region of the globule B5 have been made. A polarization map representing the magnetic field geometry in the globule has been produced. It is suggested that, parallel to the rotation axis, the bulk of the cloud is supported against gravity by stellar wind from the embedded IR sources. The strength of the magnetic field in the cloud is estimated to be about 100 μG. The wavelength of maximum polarization is found to be significantly larger than the normal interstellar value, indicating that the dust grains in B5 might be larger than the interstellar grain size.

Observations of comet C/2007 N3 (Lulin) were made at phase angles close to opposition (). Photometric observations were carried out during 2009 February 24–28, in the International Halley Watch (IHW) blue and red continuum and R broad-band using a photopolarimeter mounted on the 1.2-m telescope at Mount Abu Infrared Observatory. In all the bands, a significant linear increase in brightness with decreasing phase angle is detected for the above phase angle range. The phase coefficient [β= 0.040 ± 0.001 mag deg−1 estimated in the IHW red (6840 Å) filter band] is found to be independent of wavelength. No non-linear opposition surge is observed for phase angle . The linear increase in brightness with decreasing phase angle in the range mentioned earlier can be explained using the shadow hiding model. The colour of the comet is found to be similar to the solar colour, indicating the dominance of grains larger than 0.1 μm. A dip in the brightness of about 0.20 mag is seen at the phase angle .

Linear polarization measurements of the R Aqr system are reported here. The R Aqr system shows strong wavelength dependence of percent polarization and position angle, which are strongly time dependent also. There is a large variation in percent polarization in the ultraviolet, whereas the variation decreases toward the red region. Contrary to the variation of percent polarization, the variation of polarization angle is small in the U band and large in the other bands, toward the red region. These observations support a binary model in which a hot white subdwarf accretes material from a Mira variable forming a disk around the subdwarf. When the accreting mass exceeds a critical limit, a jet-like structure at the polar regions of the subdwarf is formed. The U-band position-angle variations are suggestive of precession of the jet-like structure.

Level 3 uses 32-bit microprocessors installed in VME crates to execute FORTRAN filter algorithms. The system is integrated into the CDF FASTBUS data acquisition network which is designed to support event rates of 100 Hz into level 3. Filter algorithms access event data in the same detector bank format as used for off-line analysis.

Physical Research Laboratory's (PRL) Optical Polarimeter has been used on various telescopes in India since its development in-house in the mid 1980s. To make the instrument more efficient and effective we have designed the acquisition and control system and written the software to run on the GNU/Linux Operating System. CCD cameras have been used, in place of eyepieces, which allow to observe fainter sources with smaller apertures. The use of smaller apertures provides dramatic gains in the signal-to-noise ratio. The polarimeter is now fully automated resulting in increased efficiency. With the advantage of networking being built-in at the operating system level in GNU/Linux, this instrument can now be controlled from anywhere on the PRL local area network which means that the observer can be stationed in Ahmedabad / Thaltej as well or via ssh anywhere on the internet. The current report provides an overview of the system as implemented.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation U. C. Joshi, S. Ganesh, K. S. Baliyan; Optical polarization observations on R Aquarii during 1995-2008: What do they tell us?. AIP Conf. Proc. 2 May 2012; 1429 (1): 222–225. https://doi.org/10.1063/1.3701929 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

Dear Reader, The field of Education has a new buzzword, Artificial Intelligence (AI). AI is set to reshape the path of learning of an undergraduate, postgraduate and even a doctoral student. AI will open the door to a number of opportunities to help beat the obstacles on the road of learning. AI not only helps in correcting grammar, paraphrasing, searching for relevant references, analysing and summarizing articles and making PowerPoint Presentations but also assists in writing resumes, cover letters and even in the writing of funding applications. And the story continues. AI has a potential to transform education by enabling personalized learning experiences, automating administrative tasks and improving student outcomes. AI tools can analyse student performance data, provide real time feedback and adapt learning materials to suit individual needs.

Sign language is a form of communication that uses hand movements and gestures to convey meaning to deaf and mute individuals. We attempted to create a real-time finger spelling system using a convolutional neural network based on American Sign Language (ASL). The paper presents the recognition of 26 alphabet hand gestures in ASL. The system has several modules, including pre-processing, training, and testing, and achieved an accuracy of 95.8% in extracting, processing, training, and testing the model, as well as converting ASL into text. In this model, we utilized deep learning, OpenCV, and TensorFlow to identify hand gestures and found that our dataset yielded improved recognition results.

In this paper the relatively new technique of artificial neural networks (ANNs) has been investigated for use in forecasting short-term water demand. Other methods investigated for comparison purposes include regression and time series analyses. The data employed in this study consist of the weekly water demand at the Indian Institute of technology (IIT) Kanpur campus, and the rainfall and maximum temperature from the City of Kanpur, India. The ANN models consistently outperformed the regression and time series models developed in this study. An average error in forecasting of 3.28% was achieved from the best ANN model. It was found that the water demand at IIT Kanpur is better correlated with the rainfall occurrence rather than the amount of rainfall.

Polarimetric observations of comet P/Halley, for seven nights in International Halley Watch and other continuum filters, during its pre- and post-perihelion passages are combinated with the observations taken by other investigators, to get a complete picture of phase angle and wavelength dependence of polarization of comet P/Halley. Assuming Mie type scattering by cometary grains, the observed polarization data for different complex values of refractive indices of cometary grains are fitted. It is found that a power law grain size distribution, suggested by Mazets E. P. et al. (1987, Astron. Astrophys., 187), with grain size spectrum from 0.001 μm to 20 μm, fits into the observed data and the refractive indices of the grains are different at different values of the incident wavelength.

Observations for the linear polarization of comet Hyakutake(C/1996B2)arecarriedoutatthreecontinuumwave- bands: 3650A, 4845A and 6840A. These observations were taken on March 13 and March 18, 1996 when the phase an- gles were 38.1 and 36.9 o , respectively. These results indicate an increaseinthedegreeofpolarizationwithphaseangleandwave- length, in general. Present results show that comet Hyakutake (C/1996 B2) exhibits similar behaviour as comet P/Halley so far as the polarization property is concerned, indicating thereby that the grain size distribution may not be very much differ- ent from that of the comet Halley. We also produce theoretical curve for the polarization percentage as a function of phase an- gle and compare with the observed data. The polarization at various wavebands shows a sensitive behaviour in the phase angle range 20 40 o .

We present the results of a detailed morphological analysis of ten starburst galaxies selected from the Markarian catalog of uv-excess objects. CCD surface photometry of these galaxies was carried out based on observations made in B, V (Johnson) and R, I (Kron-Cousins) band passes. We present the radial variations of surface brightness, ellipticity, position angle and the colour indices for each galaxy obtained using ellipse fitting isophotal analysis. The residual images constructed for extracting the fine structure are also presented. A variety of morphological types are found to host the starburst phenomenon. The star formation activity is not confined to the nuclear region alone, but it also occurs at various locations in the galaxy and is seen as clumpy regions. The colour index and the residual images are used for deriving information about the sites of enhanced star formation activity and the triggers of the starburst. The luminosity profiles show an exponential behaviour in the outer region. The disk scale lengths and the half-light radii are derived. The contribution of the burst component has been estimated and the colours of the burst component are presented. Strong isophotal twisting is detected in all the S0 and E galaxies: Mrk 1002, Mrk 1308 and Mrk 14, in the sample. This is accompanied by boxiness in some cases, suggesting that a merger is responsible for the starburst activity in these galaxies. In case of isolated spirals, a bar or a central oval distortion appear to be the likely trigger for the starburst.

Polarized laser Raman and i.r. absorption spectra of dibenzyl sulphide have been investigated. Vibrational frequencies observed in both the spectra have been correlated and assigned to different normal modes of vibrations assuming Cs point group symmetry for the molecule.

In this paper we present a novel macroblock mode decision algorithm to speedup H.264/SVC Intra frame encoding. We replace the complex mode-decision calculations by a classifier which has been trained specifically to minimize the reduction in RD performance. This results in a significant speedup in encoding. The results show that machine learning has a great potential and can reduce the complexity substantially with negligible impact on quality. The results show that the proposed method reduces encoding time to about 70% in base layer and up to 50% in enhancement layer of the reference implementation with a negligible loss in quality.

Une etude photopolarimetrique a ete effectuee dans la chevelure et la queue de la comete de Halley relativement aux bandes d'emission moleculaire de CN, C 3 , CO + , C 2 et H 2 O + . Les parametres de Stokes sont utilises pour calculer les valeurs de la polarisation en fluorescence de resonance dans differentes bandes d'emission

The authors describe a FASTBUS readout controller (FRC) for high-speed data acquisition in FASTBUS-based systems. The controller has two main interfaces: to FASTBUS and to a readout port. The FASTBUS interface performs FASTBUS master and slave operations at a maximum transfer rate exceedings 40 Mbytes/s. The readout port can be adapted for a variety of protocols. Currently, it will be interfaced to a VME-based processor with a VSB port. The on-board LR33000 embedded processor controls the readout, executing a list of operations downloaded into its memory. It scans the FASTBUS modules and stores the data in a triple port dynamic random-access memory (TPDRAM), through one of the serial access memory (SAM) ports of the TPDRAM. Later it transfers these data to the readout port using the other SAM. The FRC also supports serial communication via RS232 and Ethernet interfaces. The device is intended for use in the data acquisition systems at the Collider Detector at Fermilab.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Solar system astronomy would be an important field of study with the 3.6-m Devasthal Optical Telescope (DOT) and the 4-m International Liquid Mirror Telescope (ILMT). In this contribution, we highlight the work that could be done in reaching a better understanding of the Solar system and its constituents - particularly the minor bodies and other smaller objects. There may be a large number of very faint objects in the vicinity of the Earth orbit. In fact only recently a 'second moon' of the Earth has been found and has been designated 2016 H03. This is a quasi-satellite with the same period of revolution around Earth and Sun. There could be many such objects and it is important to have a full characterization and understanding of these potentially hazardous objects. They are generally fainter than 18th magnitude and one would need a lot of telescope time to fully characterize these objects using techniques of spectropolarimetry. In a similar fashion, a deep census of the Kuiper Belt Objects and the TNOs is needed. In this census, the concept of pencil beam surveys could be extended to cylindrical transit imaging technique available with the 4-m ILMT.

The asteroid 2014 JO25, considered to be potentially hazardous by the Minor Planet Center, was spectroscopically followed during its close-Earth encounter on 2017 April 19 and 20. The spectra of the asteroid were taken with the low-resolution spectrograph (LISA), mounted on the 1.2 m telescope at the Mount Abu Infrared Observatory, India. Coming from a region close to the Hungaria population of asteroids, this asteroid follows a comet-like orbit with a relatively high inclination and large eccentricity. Hence, we carried out optical spectroscopic observations of the asteroid to look for comet-like molecular emissions or outbursts. However, the asteroid showed a featureless spectrum, devoid of any comet-like features. The light curve of the asteroid was analyzed using V-band magnitudes derived from the spectra and the most likely solution for the rotation of the asteroid was obtained. The absolute magnitude H and the slope parameter G were determined for the asteroid in the V filter band using the IAU accepted standard two-parameter H–G model. A peculiar, rarely found result from these observations is its phase bluing trend. The relative B–V color index seems to decrease with increasing phase angle, which indicates a phase bluing trend. Such trends have seldom been reported in the literature. However, phase reddening in asteroids is very common. The asymmetry parameter g and the single-scattering albedo w were estimated for the asteroid by fitting the Hapke phase function to the observed data. The asteroid shows a relatively large value for the single-scattering albedo and a highly back-scattering surface.

An Andor 1K $\times$ 1K EMCCD detector has been used to develop an optical imaging polarimeter for use at the Cassegrain focus of 1.2 m telescope of PRL. The optics is derived from an older single-element detector instrument and consists of a rotating half-wave plate as modulator and a Foster prism as an analyser. The field of view of the instrument is 3 $\times$ 3 sq arcmin. We describe the instrument and the observational methodology in this document. Extensive observations have been carried out with this instrument covering a large variety of sources e.g. near-Earth asteroids, comets, Lynds dark nebulae, open clusters and AGN such as blazars. In the current communication, we discuss some results from the initial calibration runs while the other results will be presented elsewhere.

A catalogue is described, which lists the evolutionary masses and ages of about 1030 stars in twelve open clusters, for which UBV photoelectric photometry has been carried out at the U.P. State Observatory Naini Tal, India.

The laser Raman and i.r. spectra of 2,4-, 3,4- and 3,5-dichlorobenzoylchlorides have been recorded and analysed. A complete assignment of vibrational frequencies has been proposed assuming Cs point group symmetry for these molecules. Complex carbonyl absorption has been noticed in the case of 2,4-dichlorobenzoylchloride and the same has been explained in terms of Fermi resonance.

The evolution of IT technology Cloud computing shows the strength in past year. It takes controls in all three services Saas, Paas and Iaas. But with gradual increment of technology the quality of services also main issues. Services should be accurate up to date and secure. The level of approval for any computing model is calculated by its strength quality and weakness. The current note is focusing on the security of data in Cloud network, it calculate the current scenario and proposed the Hybrid Secure solution. The paper provides the idea implementation to secure the data in cloud. It provides the hybrid secure solution which combine attribute based cryptography with hashing function MD5. It implements the idea on Cloudsim and provides the improved result in tested environment.

Comet P/Halley was observed polarimetrically for seven nights in IHW and other continuum filters, during the pre and post perihelion passages. The polarimetric observations have been combined with the observations taken by other investigators, to get a complete picture of phase angle and wavelength dependence of polarization of comet P/Halley. Assuming Mie type scattering by cometary grains, the observed polarization data were fitted for a set of complex refractive indices which are (1.387,. 032), (1.375,. 040) and (1.374,. 052) at. 365,. 484 and. 684μm respectively.

The Collider Detector Facility collaboration at Fermilab is developing a three level on-line event filtering system for high speed data acquisition. The third level of the trigger uses the Fermilab Advanced Computer Program system of parallel processors in VME crates which are managed by a MicroVAX II and are interfaced to the FASTBUS data acquisition system. In section 1, the author briefly describes the Collider Detector Facility and the goals of the trigger system. Section 2 is a short discussion of the first two levels of the trigger. In section 3, he describes the hardware components of the Level 3 trigger and Section 4 is devoted to hardware test and results. Section 5 concludes this paper with a summary of on-line test and results of the Level 3 trigger system.

We present broad bandR and narrow band Hα emission line images of a sample of optically selected starburst galaxies from the Markarian lists. The emission line morphology is studied and global properties like luminosities, equivalent widths and star formation rates are derived. The radial distribution of Ha flux and the EW are determined using concentric aperture photometry on the emission line and the continuum images. Ha flux is generally found to peak in the nuclear region and fall off outwards. The EW is found to peak off-center in most of the cases implying that though the intensity of emission is maximum at the nucleus, the star formation activity relative to the underlying continuum often peaks away from the center in Markarian starburst galaxies.

Polarimetry of the BL Lac object OJ 287 has been carried out over the last decade in optical bands with the 1.2-m telescope of Mt. Abu Observatory, operated by Physical Research Laboratory, India. OJ 287 underwent several polarization outbursts during this period.

Aims. We identify the stellar populations (mostly red giants and young stars) detected in the ISOGAL survey at 7 and 15 μm towards a field (LN45) in the direction , .

Photoelectric magnitudes and colours in the UBV system have been determined for 169 stars in IC 1805. The reddening is variable across the cluster. The distance modulus to the cluster is estimated at 11m.7. Star-formation activities are still in progress in the cluster region.

Abstract. The study of variability in blazars is an important tool to un-derstand their energetics. Such a study is required to be made in all bandsof spectral energy distribution. Hence, we propose to make UV observationsof blazars using the TAUVEX facility for sources in the region |Dec| > 50 ◦ .These observations will be complemented with simultaneous ground based ob-servations in near IR, optical and radio frequencies using the facilities availablein the country. The data will be used to study the nature of emission processes.Keywords : (galaxies:) active – (galaxies:) BL Lacertae objects: general –techniques: photometry – ultraviolet: general 1. Introduction Ultraviolet astronomy is a field in space astronomy that was explored in the sixties andseventies, largely by rocket experiments and even today this window is not well explored.As ultraviolet astronomy is an extension of visible spectrum towards short wavelengths,there will be intimate interactions with ground-based observations in the visible. IUEwas one of the most successful ventures in UV, but limited to spectroscopic mode only.The GALEX mission is an important step in UV window which will provide importantinput to plan observations with TAUVEX.Blazars are a subclass of active galactic nuclei (AGNs) characterized by rapid vari-ability, high polarization, a compact radio structure and weak or absent emission lines.Flux variability has been detected in time scales ranging from a few tens of minutes tohours and days (Smith et al. 1987; Carini et al. 1992; Heidt & Wagner 1996; Jang &

Image segmentation methodology is a part of nearly all computer schemes as a pre-processing phase to excerpt more meaningful and useful information for analysing the objects within an image.Segmentation of an image is one of the most conjoint scientific matter, essential technology and critical constraint for image investigation and dispensation.There has been a lot of research work conceded in several emerging algorithms and approaches for segmentation.Segmentation is one of the popular and efficient technique in context to medical image analysis.The purpose of the segmentation is to clearly extract the Region of Interest from the medical images.The main focus of this paper is to review and analyze the effect of segmentation over different tumor images for different parts of the body.In this paper fast adaptive bilateral filter is used with morphological segmentation of image and their application to medical imaging.

Polarization measurements are very helpful to understand the nature of some of the stellar and extra-galactic sources. Light from astronomical objects is in general polarized to some degree and its measurement gives additional information related to the magnetic field, the distribution of scattering material, the non-thermal nature of light, etc. Since the degree of polarization in the majority of astronomical sources is 1-5%, and polarimetry requires additional optics with respect to classical imaging, these measurements require much more photons to achieve a good signal-to-noise ratio for which the 3.6-m Devasthal Optical Telescope (DOT) facility is suitable.

Background: Objectives: To identify the clinical &amp; etiological profile of children and the characteristics of seizures in them along with therapeutic response. Subjects and Methods: All patients who attended the Epilepsy Clinic &amp; fulfilled the selection criteria were enrolled in study. This is a descriptive study of 18 months &amp; involved analysis of records of the patients who came to specialty OPD. Three groups were formed accordingly - focal, generalized &amp; unknown onset with further etiological sub-divisions -Genetic, Structural/Metabolic, Immune, Infectious &amp; Unknown. Results: In all, 417 patients were studied. The distribution as per clinical presentation was- group I (generalized) 215(58.5%) - group II (focal) 154(36.9%), group III (unknown) 48(4.6%). The main etiologies were perinatal asphyxia (28.3%) NHBI (11.4%) in (structural-metabolic) sub group. In Genetic &amp; Infectious, Channelopathies (10.5%) &amp; Post Meningitis Sequelae (4.7%)were main etiology. 56.3% of the patient in group II were on more than 3 AEDs. 14.3% in group I were weaned of AEDs. 61.4% patients in group II were having neurodevelopmental Sequelae. EEG revealed abnormal activity in 30(6.2%) in group I &amp; 31(19.3%) in group II. Maximum patient with refractory epilepsy were seen in group III. Conclusion: To have a good management of epilepsy we need to have multi-dimensional classification of epilepsy based on both clinical &amp; etiological spectrum. Perinatal Asphyxia &amp; NHBI are one of the most common yet avertible etiologies.