| Name: | Jincen Jose |
| Affiliation: | Aryabhatta research institute of observational sciences ,Nainital |
| Conference ID : | ASI2024_1022 |
| Title : | Polarized view of gamma-ray emitting narrow-line Seyfert 1 galaxies: The case of 1H0323+342 |
| Authors : | Jincen Jose (1), Suvendu Rakshit (1), Swayamtrupta Panda (2) |
| Authors Affiliation: | 1) Aryabhatta Research Institute of Observational Sciences, Nainital-263001, India
2) Laboratório Nacional de Astrofísica (LNA), Minas Gerais-37504-364, Brazil |
| Mode of Presentation: | Oral |
| Abstract Category : | Galaxies and Cosmology |
| Abstract : | The gamma-ray emitting narrow-line Seyfert 1 galaxies are unique objects that launch powerful jets. However, due to the projection effect, the black hole masses estimated by total flux spectra have high uncertainty. Polarized spectra provide a unique view of the central engine through scattered light. We performed spectro-polarimetric observations of 1H0323+342, one of the closest jetted NLSy1, using SPOL/MMT. The source shows a low degree of polarisation of the line profile with a value of 0.12%, and the polarisation angle obtained is 175.27 deg. We performed a detailed spectroscopic analysis, investigating the spectral lines' line widths, shifts, and profiles. The polarized spectrum is found to have a similar width as the flux spectra for the H$\alpha$ emission line. We used the relation between velocities and polarization angles across the line profile proposed by Afanasiev et al. (2014) to estimate black hole mass giving Log(M/M_sun) ~ 10^{7.91}, closely align with values obtained from other methods, such as reverberation mapping. Using the polarization radiative transfer code STOKES, we model the observed spectra of natural and polarized light. Assuming cylindrical geometry for BLR and flared disk geometry for the scattering region and concluded that the source has a small viewing angle of nearly 9 deg. |
