ZTF SN Ia DR2: Searching for late-time interaction signatures in Type Ia supernovae from the Zwicky Transient Facility

Open Access

Table 6.

Parameters used for rate estimation simulations for each object.

Object	Start epoch	Duration	Strength	N_sample	Late-time CSM	Late-time CSM
	(d)	(d)	(SN 2015cp)		fraction	rate (Gpc⁻³ yr⁻¹)
SN 2018grt (worst)	1375 ^( * )	100	60	748	$0 . 0084_{- 0.0041}^{+ 0.0183}$ $0.0084_{-0.0041}^{+0.0183}$	$203_{- 97}^{+ 438}$ $203_{-97}^{+438}$
SN 2018grt (best)	1275 ^( * )	200	100	988	$0 . 0015_{- 0.0007}^{+ 0.0032}$ $0.0015_{-0.0007}^{+0.0032}$	$36_{- 18}^{+ 76}$ $36_{-18}^{+76}$
SN 2019ldf (worst)	1050 ^( * )	200	60	1931	$0 . 0019_{- 0.0009}^{+ 0.0036}$ $0.0019_{-0.0009}^{+0.0036}$	$45_{- 22}^{+ 87}$ $45_{-22}^{+87}$
SN 2019ldf (best)	875 ^( * )	500	60	2505	$0 . 0023_{- 0.0011}^{+ 0.0038}$ $0.0023_{-0.0011}^{+0.0038}$	$54_{- 26}^{+ 91}$ $54_{-26}^{+91}$
SN 2020tfc (worst)	550	250	100	3439	$0 . 0004_{- 0.0002}^{+ 0.0009}$ $0.0004_{-0.0002}^{+0.0009}$	$10_{- 5}^{+ 22}$ $10_{-5}^{+22}$
SN 2020tfc (best)	450	500	150	3493	$0 . 0003_{- 0.0002}^{+ 0.0008}$ $0.0003_{-0.0002}^{+0.0008}$	$8_{- 4}^{+ 20}$ $8_{-4}^{+20}$

Notes. For each of the three SNe we assumed a worst and best case scenario for detecting them in our sample, giving upper and lower limits for a simulated observing campaign. The efficiency curves generated from these simulations were then used to determine the intrinsic fraction of SNe Ia with late-time CSM interaction in an MCMC process, with the assumption that only one object was recovered in a sample size that is the same as the amount of DR2 objects with observations after the start epoch (N_sample). The last two columns show the found late-time CSM interaction fraction of the total SN Ia rate and the late-time CSM interaction rate.

^( * )When the start epoch of the late-time excess is > 750 d, 750 d is used as the start epoch because of limitations of the available ZTF survey plan. See Sect. 4.3 for more details.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.