Light Curve and Spectral Evolution of Type IIb Supernovae
Anjasha Gangopadhyay,
Aryabhatta Research Institute of observational sciencES, Nainital, 263002, India and Pt. Ravi Shankar Shukla University, Raipur, 492001, India,
anjashagangopadhyay@gmail.com
Kuntal Misra,
Aryabhatta Research Institute of observational sciencES, Nainital, 263002, India
Andrea Pastorello,
INAF - Astronomical Observatory of Padova, Italy
Devendra Kumar Sahu,
Indian Institute of Astrophysics, Bangalore, Karnataka, 560034, India
Mridweeka Singh,
Aryabhatta Research Institute of observational sciencES, Nainital, 263002, India and Pt. Ravi Shankar Shukla University, Raipur, 492001, India
Raya Dastidar,
Aryabhatta Research Institute of observational sciencES, Nainital, 263002, India
Gadiyara Chakrapani Anupama,
Indian Institute of Astrophysics, Bangalore, Karnataka, 560034, India
Brijesh Kumar,
Aryabhatta Research Institute of observational sciencES, Nainital, 263002, India
Shashi Bhushan Pandey,
Aryabhatta Research Institute of observational sciencES, Nainital, 263002, India
Abstract
Stripped-Envelope Supernovae constitute the sub-class of core-collapse supernovae that strip off their outer hydrogen envelope due to high stellar winds or due to interaction with a binary companion where mass transfer occurs as a result of Roche lobe overflow. We present here the photometric and spectroscopic analysis of a member of this class : SN 2015as classified as a type IIb supernova. Light curve features are similar to those of SN 2011fu while spectroscopic features are quite similar to those of SN 2008ax and SN 2011dh. Early epoch spectra have been modelled with SYN++ which indicates a photospheric velocity of 8500 km sec-1 and temperature of 6500K. Spectroscopic lines show transitioning from H to He features confirming it to be a type IIb supernova. Prominent oxygen and calcium emission features are indicative of the asymmetry of the ejecta. We also estimate the signal to noise ratio of the 3.6m telescope data. This telescope is located at ARIES, Devasthal, Nainital at an altitude of 2450m. We also show the comparison plots of spectra taken with a 2m and 4m class telescopes to enlighten the importance of spectral features displayed by bigger diameter telescopes.
Keywords : astronomy, astrophysics, extragalactic, photometry, supernovae
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Anjasha Gangopadhyay, Kuntal Misra, Andrea Pastorello, Devendra Kumar Sahu, Mridweeka Singh, Raya Dastidar, Gadiyara Chakrapani Anupama, Brijesh Kumar & Shashi Bhushan Pandey, «Light Curve and Spectral Evolution of Type IIb Supernovae», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 87 - Année 2018, Actes de colloques, First Belgo-Indian Network for Astronomy & Astrophysics (BINA) workshop - November 2016 - Nainital, India, 351 - 355 URL : http://popups.ulg.be/0037-9565/index.php?id=7781.
