Cosmic Newsflash

ZTF team meets in Berlin

The ZTF collaboration held its bi-annual team meeting during the week of May 8-12 at the Humboldt University of Berlin, Germany. In addition to the usual updates from the science working groups and operations, much time was devoted to a discussion on what the legacy of ZTF will be and how to best manage the survey data and unique datasets beyond the official ending of the project.

Astronomers Discover Extremely Warped Supernova

Kishalay, De et al.; Nature

Astronomers have captured a bizarre image of a supernova, the powerful explosion of a star, whose light was so warped by the gravity of another galaxy that it appears as multiple images in the sky. This effect, known as gravitational lensing, occurs when the gravity of a dense object distorts and brightens the light of an object behind it.

Pre-supernova mass loss in double peaked supernovae

Das, Kaustav K. et al.,

Authors review a sample of 14 double peaked Type Ibc supernovae out of 475 detected by the Zwicky Transient Facility to perform a systematic photometric and spectroscopic analysis in order to better understand the physics behind these eruptions in supernovae with low and high mass progenitors.

Volumetric rate for long-rising Type II supernovae

Sit, Tawny et al.,

ZTF astronomers have used the Census of the Local Universe galaxy catalog (2018-2021) to identify  long-rising Type II supernovae. Doubling the number of such events recorded to date, the authors derive their volumetric rate. This is the first time a volumetric rate for long-rising Type II  supernovae is estimated from a large, systematic, volumetric-limited experiment.

A Search for Extragalactic Fast Blue Optical Transients

Ho, Anna Y.Q. et al.,

Authors present a search for extragalactic fast blue optical transients (FBOTs) during Phase I of the Zwicky Transient Facility (ZTF) and perform multiwavelength (radio, millimeter, and/or X-ray) observations for five FBOTs. They conclude that exotic transients similar to AT2018cow, the Koala, and the Camel represent a rare subset of FBOTs and use ZTF's SN classification experiments to measure the rate to be at most 0.1% of the local core-collapse SN rate.

Forced Photometry service for the Zwicky Transient Facility

Masci, Frank J. et al.,

In this paper, ZTF partners at Caltech/IPAC who lead survey data management for ZTF describe the forced photometry service (ZFPS) available to the astronomy community since early 2020. With ZFPS users can request forced-photometry lightcurves for up to 1500 sky positions per request in a single web-application submission. The underlying software has been recoded to take advantage of a parallel processing architecture with the most compute-intensive component rewritten in C and optimized for the available hardware.

Early detection of a supernova reveals its origin

Mcguire, Kate et al.,

Discovered just 7 hours of estimated first light, supernova 2020udy was studied extensively by a team of astronomers led by ZTF partners at the Trinity College Dublin. They find the most plausible explosion scenario to be the incomplete disruption of a CO white dwarf near the Chandrasekhar-mass limit, with a helium-star companion.