Joint NRAO/Chandra Accepted Cycle 23 Targets & Abstracts

Proposal Number Subject Category PI Name Chandra Time Title
23500672 SN, SNR AND ISOLATED NS Plotkin 20.00ks VLA+Chandra Observations of Ic-BL Supernovae with ZTF High-Cadence Light Curves
23400677 BH AND NS BINARIES Ho 50.00ks Clarification of a Double X-ray Source in a Metal-poor Dwarf Galaxy

Subject Category: SN, SNR AND ISOLATED NS
Proposal Number: 23500672
Title: VLA+Chandra Observations of Ic-BL Supernovae with ZTF High-Cadence Light Curves
PI Name: Plotkin
Abstract: Broad-lined Ic supernovae (Ic-BL) are a subclass of stripped-envelope core-collapse supernovae notable for their high energies, high velocities, and association with long-duration gamma-ray bursts (GRBs). After decades of follow-up efforts, it remains unknown why most Ic-BL SNe lack a detected GRB. Nearby (z<0.06) Ic-BL SNe associated with low-luminosity GRBs (LLGRBs) may represent the answer: LLGRB-SNe have been argued to be jets viewed off-axis, jets choked inside the stellar envelope or circumstellar material, or successful jets that are less powerful than classical GRBs. Here we propose a novel approach, based on the fact that nearby LLGRB-SNe exhibit an early (<1d) flash of optical light that can be routinely resolved by high-cadence optical surveys like the Zwicky Transient Facility.

Proposal Number: 23400677
Subject Category: BH AND NS BINARIES
Title: Clarification of a Double X-ray Source in a Metal-poor Dwarf Galaxy
PI Name: Ho
Abstract: One way to learn about the formation and growth of black holes in the early Universe is to find local analogs. We identified a nearby (z=0.007) metal-poor dwarf galaxy that contains two luminous hard X-ray sources (both with Xray luminosities ~10e40 erg/s). It is unclear, however, if these sources are super-Eddington stellar mass black holes or weakly accreting intermediate mass black holes (IMBHs). Any scenario (i.e., two stellar mass black holes, two IMBHs, or one of each) will have fascinating implications, either in terms of a local case study that illustrates an early phase of hierarchical black hole growth, or for investigating how stellar mass black hole populations evolve with metallicity.