GBT25A-413

The Origin Story of a Young Halo Star Cluster: Mapping its Birthplace

Abstract

Price-Whelan 1 (PW 1) is a young star cluster residing in the Galactic halo with an unusual origin story that we have yet to decipher. It could have been formed from a HVC that was since destroyed or out of the Leading Arm (LA) of the Magellanic Clouds after it crashed through the Milky Way's (MW) disk. There is compelling evidence for both of these scenarios like a prominent high-velocity cloudlet near PW 1 or that PW 1 is kinematically and chemically consistent with an origin in the LA. We propose to conduct a deep HI 21-cm emission mapping using the GBT on two regions: (1) the north edge of the LA II complex and (2) the HI cloudlet near the cluster. We will search for residual, diffuse gas structures that trace PW 1 to its birth site. We request 20 hours of L-Band time with the VEGAS receiver for observations with a sensitivity of log(NHI) = 17.13. These observations will allow us to not only directly measure the impact that ram-pressure stripping has had to displace the gas from its birth site but also to assess star formation in the unlikely environment of the Galactic halo.

Investigators

Name	Institution
Erica Chwalik	Montana State University
April Horton *	Texas Christian University; Macalester College
Jo Vazquez	Texas Christian University
David Nidever	Montana State University
Kathleen Barger	Texas Christian University

* indicates the PI