Abstract Details
| Name: Arijit Maiti Affiliation: Physical Research Laboratory Conference ID: ASI2025_207 Title : On-sky Characterization of ProtoPol: a medium resolution echelle spectro-polarimeter for PRL telescopes Authors and Co-Authors : Arijit Maiti 1, Mudit K. Srivastava 1, Vipin Kumar 1,2, Bhaveshkumar Mistry 1, Ankita Patel 1, Vaibhav Dixit 1,3, and Kevikumar Lad 1 Abstract Type : Poster Abstract Category : Facilities, Technologies and Data science Abstract : ProtoPol is a medium-resolution echelle spectro-polarimeter initially conceived as a prototype instrument for the currently under development M-FOSC-EP (Mt. Abu Faint Object Spectrograph and Camera-Echelle Polarimeter) instrument - a two-channel multimode instrument which is currently being designed for PRL 1.2m and 2.5m telescopes at Mt. Abu. Though ProtoPol was initially conceived to evaluate the development methodology of the spectro-polarimetric arm of M-FOSC-EP with commercially available off-the-shelf components, it was later elevated to the level of a full-fledged back-end instrument for PRL telescopes. ProtoPol was designed on the concept of echelle and cross-disperser gratings to record the cross-dispersed spectra in the wavelength range from 390 to 940 nm with a resolution (λ/δλ) in the range of 7000-8000. ProtoPol has been successfully developed and commissioned on PRL 1.2m and 2.5m telescopes since December 2023, and a variety of observations are being carried out for instrument characterization and scientific purposes. Observations of standard unpolarized stars conducted during on-sky characterization revealed an instrumental polarization of 0.1-0.2 %. ProtoPol achieved a spectral resolution of 7000-8000, with a polarimetric accuracy of δP < 0.2% for linear polarization. Preliminary results of the observed polarization profiles of Hα line for Be stars and the observed continuum polarization of red giant stars are also presented. A dedicated fully-automated spectro-polarimetric data reduction pipeline was developed to help in the analysis process of the spectro-polarimetric data. The pipeline takes raw echelle spectro-polarimetric data frames as input and gives the variation in polarization as a function of wavelength at output. The pipeline can be used for data-reduction of any such similar echelle spectro-polarimeters and/or echelle spectrometers. In this proposed talk, the speaker shall discuss the design and features, laboratory, and on-sky performance of ProtoPol along with the development of a dedicated echelle spectro-polarimetric data reduction pipeline. |