| Name: Kripa Ram Sahu |
| Affiliation: Sant Guru Ghasidas Govt. PG College Kurud Affiliated to School of Studies in Physics & Astrophysics, Pt. Ravishankar Shukla University Raipur, (C.G.) |
| Conference ID: ASI2026_888 |
| Title: Photometric and spectroscopic studies of Type Ia supernova SN 2011at. |
| Abstract Type: Poster |
| Abstract Category: High Energy Phenomena, Fundamental Physics and Astronomy |
| Author(s) and Co-Author(s) with Affiliation: Kripa Ram Sahu(School of Studies in Physics & Astrophysics, Pt. Ravishankar Shukla University Raipur, (C.G.)), Mulchand Kurre(School of Studies in Physics & Astrophysics, Pt. Ravishankar Shukla University Raipur, (C.G.)), Shrutika Tiwari(School of Studies in Physics & Astrophysics, Pt. Ravishankar Shukla University Raipur, (C.G.)), N. K. Chakradhari(School of Studies in Physics & Astrophysics, Pt. Ravishankar Shukla University Raipur, (C.G.)), G. C. Anupama(Indian Institute of Astrophysics, Koramangala II Block, Bengaluru 560034, India), D. K. Sahu(Indian Institute of Astrophysics, Koramangala II Block, Bengaluru 560034, India) |
| Abstract: We present optical UBVRI photometry and spectroscopic observations of Type Ia supernova SN 2011at, from few days before maximum to close to 2 months post-maximum in B-band. The supernova reached maximum light on JD 2455631.1 +/- 0.5, with a B-band apparent magnitude of 14.36 +/-0.04 mag. It’s post maximum decline rate of Δm15(B) = 1.00 +/- 0.06 mag and absolute peak magnitude of M(B) = −18.48 +/- 0.15 mag, indicated that SN 2011at is marginally under-luminous Type Ia event. From the peak quasi bolometric luminosity of log L = 42.86 +/- 0.06 erg/s, mass of 56Ni synthesized in the explosion is estimated as 0.29 +/- 0.02 solar mass. The spectra were modelled using SYN++ synthetic spectral modeling code, presence of Mg II, Si II, S II, Ca II, Fe II, and Fe III, is confirmed. The ratio of pseudo-equivalent width of the Si II 5972 and Si II 6355 features near maximum light classifies it as a core-normal (CN) event. The photospheric velocity, measured from the Si II 6355 absorption minimum at maximum light, is relatively high (∼12,000 km/s), while the velocity gradient is low (∼30 km/s/day), placing SN 2011at in the low-velocity-gradient (LVG) subclass. The photometric and spectroscopic properties of SN 2011at are consistent with those of spectroscopically normal Type Ia supernovae. |
