Running summarizing tools on a new article
Check the paper below, then start its synthesis.
Early Near-IR Echo and the Time-variable Mass-loss History of Type IIn SN 2024kgi
Naveen Dukiya (M.J.P. Rohilkhand University, Aryabhatta Research Institute of Observational Sciences), Kuntal Misra (Aryabhatta Research Institute of Observational Sciences), A. Pastorello (Osservatorio Astronomico di Padova, National Institute for Astrophysics), A. Reguitti (Brera Astronomical Observatory, Osservatorio Astronomico di Padova), Anjasha Gangopadhyay (Stockholm University), Aravind Pazhayath Ravi (University of California, Davis), Brian Hsu (University of Arizona), Noah Franz (University of Arizona), David J. Sand (University of Arizona), Nathan Smith (University of Arizona), Jennifer E. Andrews (International Gemini Observatory), Moira Andrews (Las Cumbres Observatory Global Telescope Network), K. Azalee Bostroem (University of Arizona), Collin T. Christy (University of Arizona), Monalisa Dubey (M.J.P. Rohilkhand University, Aryabhatta Research Institute of Observational Sciences), Joseph R. Farah (Las Cumbres Observatory Global Telescope Network, University of California, Santa Barbara), Archana Gupta (M.J.P. Rohilkhand University), Estefania Padilla Gonzalez (Johns Hopkins University), Emily Hoang (University of California, Davis), D. Andrew Howell (Las Cumbres Observatory Global Telescope Network, University of California, Santa Barbara), C. McCully (Las Cumbres Observatory Global Telescope Network, University of California, Santa Barbara), Darshana Mehta (University of California, Davis), Megan Newsome (The University of Texas at Austin), Jeniveve Pearson (University of Arizona), Nicolas Meza Retamal (University of California, Davis), Jeonghee Rho (Seoul National University, Search for Extraterrestrial Intelligence), Manisha Shrestha (University of Arizona), Bhagya Subrayan (University of Arizona), G. Terreran (Adler Planetarium), L. Tomasella (Osservatorio Astronomico di Padova, National Institute for Astrophysics), Stefano Valenti (University of California, Davis), G. Valerin (Osservatorio Astronomico di Padova, National Institute for Astrophysics), Kathryn Wynn (Las Cumbres Observatory Global Telescope Network, University of California, Santa Barbara)
Abstract: Abstract We present a comprehensive analysis of the long-term photometric and spectroscopic monitoring campaign of the Type IIn supernova (SN) 2024kgi. The SN reaches a peak r -band absolute magnitude of −19.81 ± 0.06 mag and a bolometric luminosity of ∼2 × 10 43 erg s −1 . We observe a break in the lightcurve at day ∼312, after which the luminosity decline changes from t −1.0 to t −4.5 , likely due to the shock sweeping the dense circumstellar matter (CSM). We introduce a semi-analytical lightcurve modeling approach for CSM interaction in transients that accounts for variable diffusion time. We hence estimate a CSM mass of 2.3 4 − 1.6 + 11.8 M ⊙ , with a density profile of ρ csm ∝ r −2.74 , indicating progressively increasing mass loss toward the SN explosion. The ejecta signatures emerge as broad H, He, and Ca ii triplet lines at day ∼80, much earlier than expected from a spherically symmetric CSM, suggesting asymmetry in the CSM. After the lightcurve break, the H lines exhibit a wavelength-dependent deficit in the red-wing flux, indicating new dust formation in the ejecta and/or in the postshock gas. We observe a near-IR (NIR) excess from day ∼40 onward. We attribute the early NIR excess before the lightcurve break solely to the NIR echo from preexisting dust, as there are no other indications for new dust formation. The late-time NIR excess likely has contributions from both the preexisting and newly formed dust. The steady increase in mass loss, slow CSM velocity, and asymmetric CSM favor a binary interaction-induced mass loss.