| Name: | Khundongbam Roshan Chenglei |
| Affiliation: | Bangalore University , JB campus |
| Conference ID : | ASI2024_143 |
| Title : | UV Continuum Properties of NGC1068 Seyfert 2 galaxy from IUE observations |
| Authors : | Vijaykumar H Doddmani 1, Pooja B N 2, Sudha D R3, Nour D4, Kh Roshan Chenglei 5 , Sriram K6 and Chaitra Muddappa Shirahatti 7
|
| Authors Affiliation: | 1,2,3,5,7( Department of Physics, Bangalore University, Bangaluru-560056)
4 (Department of Physics, Faculty of Science, Al Baath University, Homs, Syria)
6 (Dept. of Astronomy, Osmania University, Hyderabad) |
| Mode of Presentation: | Poster |
| Abstract Category : | Galaxies and Cosmology |
| Abstract : | IUE satellite has made very successful long term spectroscopic observations of Seyfert 1, Seyfert 2 galaxies, quasars, blazars, radio-galaxies and HII regions. These observations have significantly improved our knowledge of the relationship between emission line and continuum at ultraviolet wavelength from 1100 Å-3200 Å. IUE has made long term monitoring observations of NGC1068, a prototype of Syfert 2 galaxies from 1978 to 1996. In this Paper, we present our results on the nature of the ultraviolet continuum and its variability characteristics from the analysis of the complete sample of IUE observations. The UV continuum flux have been measured at six different continuum windows 1350-1375 Å, 1425-1475 Å, 1590-1610 Å, 1800-1850 Å, 1940-1970 Å and 2550-2600 Å by fitting power law (Fv = cνα) to all the spectra. The mean UV continuum flux has decreased from 8.079 10-14 erg/cm2/s/Å at 1350-1375 Å window to 6.806 10-14 erg/cm2/s/Å at 2550-2600 Å window. We have found that the UV continuum in NGC1068 has varied by several factors for the long term observational data spread over several years. The relative variability amplitude (Rmax) has been found to be vary from Rmax=11.301 at 1350-1375 Å window to Rmax = 4.766 at 2550-2600 Å. The result of decreasing Rmax value with increasing UV continuum obtained in NGC1068 for the first time is a significant result established from IUE observations. Similar results of decreasing Rmax parameter with increasing wavelengths have been obtained from the analysis of IUE’s spectroscopic data of NGC 4151, Fairall 9, MRK33, NGC5548 and 3C273. We conclude that the NGC1068 harbours a “hidden” BLR similar to many Seyfert 1 galaxies and quasars. A detailed analysis of the nature of the UV continuum and its variability characterisation in a typical Seyfert 2 galaxy NGC1068 is presented in this paper.
Keywords: Active galaxies, seyfert 2 galaxy, UV continuum, variabilities and Rmax parameter. |
