Study of X-ray and γ-ray flare from Mkn-421 during February 2010 using Swift and Fermi observations     

K.K. Singh  S. Bhattacharyya  N. Bhatt  A.K. Tickoo 《New Astronomy》2012,17(8):679-686

In this work, we report on the intense flaring activity from Mkn-421 in X-ray and γ-ray regimes simultaneously observed by Swift-XRT/BAT and Fermi-LAT satellite telescopes in February 2010. With the aim of understanding the underlying physics of the flaring state in Mkn-421, we have performed a detailed spectral analysis of Swift/XRT and Fermi/LAT observations of Mkn-421 during February 12–25, 2010 (MJD 55239–55252). Over this period, we study the daily light curves and spectral variability of the source in 1–10 keV, 0.1–1 GeV and 1–100 GeV energy bands. We have performed the spectral analysis of Swift-XRT and Fermi/LAT observations to study the spectral evolution in the X-ray and gamma-ray energy domains respectively. We also compute the fractional variability amplitude in both the energy bands during the above period. We study trends between spectral parameters and physical insights provided by the parameter responsible for X-ray and γ-ray emission from the source. We search for energetic features phenomenologically linked to the single zone SSC model for blazar emission. We also produce the broad band SED with a leptonic single zone SSC model for the source.  相似文献   

Subsurface profiling of granite pluton using microtremor method: southern Aravalli,Gujarat, India     

Joshi  Aditya U.  Sant  Dhananjay A.  Parvez  Imtiyaz A.  Rangarajan  Govindan  Limaye  Manoj A.  Mukherjee  Soumyajit  Charola  Mitesh J.  Bhatt  Meghnath N.  Mistry  Sagar P. 《International Journal of Earth Sciences》2018,107(1):191-201

International Journal of Earth Sciences - We report, using the microtremor method, a subsurface granitic pluton underneath the Narukot Dome and in its western extension along a WNW profile, in...  相似文献   

Ichnology of the Goradongar Formation,Goradongar hill range,Patcham island,Kachchh, Western India     

Satish J. Patel  Jaquilin K. Joseph  Nishith Y. Bhatt 《Journal of the Geological Society of India》2014,84(2):129-154

The middle Jurassic Goradongar Formation exposed in Goradongar hill represents a mixed siliciclasticcarbonate succession with shales and limestones. They contain a large number of well preserved trace fossils. Total 44 ichnospecies of 31 ichnogenera; representing diverse ethology, were grouped in five ichnoassemblages (Planolites, Palaeophycus, Gyrochorte, Rhizocorallium and Arenicolites assemblage). These recurring ichnoassemblages represent the Cruziana ichnofacies and occasionally a mixed Skolithos-Cruziana ichnofacies. Patterns of diversity and density of the trace fossils reveal changes in bathymetry, oxygen level, trophic level and the sub-strate conditions at the time of deposition. These paleoenvironment and palaeo-oceanography changes are co-relatable to world-wide Bathonian-Callovian (middle Jurassic) deposits.  相似文献   

Magnetic fields in cometary globules – II. CG 30–31 complex     

H. C. Bhatt 《Monthly notices of the Royal Astronomical Society》1999,308(1):40-44

Optical linear polarization measurements of stars in the region of the cometary globules CG 30–31 in Vela–Puppis are presented. A polarization map representing the geometry of the magnetic field in the cometary globule complex is produced. The magnetic field is found to be nearly perpendicular to the cometary tails. This is unlike the case of the cometary globule CG 22 in which the field had earlier been found to be aligned with the tail. The observed field direction is more or less parallel to the bipolar molecular outflow from the young stellar object IRS 4 embedded in the head of CG 30.  相似文献