Prospects of Searching for Type Ia Supernovae with 2.5-m Wide Field Survey Telescope

TL;DR

This paper evaluates the potential of the upcoming 2.5-m Wide Field Survey Telescope (WFST) to discover and observe large numbers of Type Ia supernovae, which are crucial for understanding their explosion mechanisms and cosmological applications.

Contribution

The study provides a detailed assessment of WFST's detection capabilities for SNe Ia using mock observations and models, highlighting its expected impact on supernova research.

Findings

WFST can discover over 30,000 pre-maximum SNe Ia annually.

It could detect about 45 bright SNe Ia and 99 early-phase SNe Ia per year.

Approximately 11,000 well-observed SNe Ia could be identified in various survey modes.

Abstract

Type Ia Supernovae (SNe Ia) are the thermonuclear explosion of a carbon-oxygen white dwarf (WD) and are well-known as a distance indicator. However, it is still unclear how WDs increase their mass near the Chandrasekhar limit and how the thermonuclear runaway happens. The observational clues associated with these open questions, such as the photometric data within hours to days since the explosion, are scarce. Thus, an essential way is to discover SNe Ia at specific epochs with optimal surveys. The 2.5-m Wide Field Survey Telescope (WFST) is an upcoming survey facility deployed in western China. In this paper, we assess the detecability of SNe Ia with mock observations of WFST. Followed by the volumetric rate, we generate a spectral series of SNe Ia based on a data-based model and introduce the line-of-sight extinction to calculate the brightness from the observer. By comparing with the detection limit of WFST, which is affected by the observing conditions, we can count the number of SNe Ia discovered by mock WFST observations. We expect that WFST can find more than $3.0\times10^{4}$ pre-maximum SNe Ia within one-year running. In particular, WFST could discover about 45 bright SNe Ia, 99 early-phase SNe Ia, or $1.1\times10^{4}$ well-observed SNe Ia with the hypothesized Wide, Deep, or Medium mode, respectively, suggesting WFST will be an influential facility in time-domain astronomy.