Probing the Progenitors of Type Ia Supernovae using Circumstellar Material Interaction Signatures

This work aims to study different probes of Type Ia supernova progenitors that have been suggested to be linked to the presence of circumstellar material (CSM). In particular, we have investigated, for the first time, the link between narrow blueshifted NaID absorption profiles and the presence and strength of the broad high-velocity CaII near infrared triplet absorption features seen in Type Ia supernovae around maximum light. With the probes exploring different distances from the supernova; NaID > 10$^{17}$cm, high-velocity CaII features < 10$^{15}$cm. For this, we have used a new intermediate-resolution X-shooter spectral sample of 15 Type Ia supernovae. We do not identify a link between these two probes, implying either that, one (or both) is not physically related to the presence of CSM or that the occurrence of CSM at the distance explored by one probe is not linked to its presence at the distance probed by the other. However, the previously identified statistical excess in the presence of blueshifted (over redshifted) NaID absorption is confirmed in this sample at high significance and is found to be stronger in Type Ia supernovae hosted by late-type galaxies. This excess is difficult to explain as being from an interstellar-medium origin as has been suggested by some recent modelling, as such an origin is not expected to show a bias for blueshifted absorption. However, a circumstellar origin for these features also appears unsatisfactory based on our new results given the lack of link between the two probes of CSM investigated.
PC and KM acknowledge support from the EU H2020 ERC grant no. 758638. MB acknowledges support from the Swedish Research Council (Reg. no. 2020-03330). LG acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities (MICIU) under the 2019 Ramón y Cajal program RYC2019-027683 and from the Spanish MICIU project PID2020-115253GA-I00. SJS acknowledges funding from STFC Grants ST/P000312/1 and ST/N002520/1. This paper is based on data taken at the European Organization for Astronomical Research in the Southern hemisphere, Chile, under program IDs: 098.D-0384(A) and 099.D-0641(A). This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. ATLAS is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogues from the survey area. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen’s University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory (SAAO), and the Millennium Institute of Astrophysics (MAS), Chile.