Events Calendar

Molecular Tracers of Star Formation Feedback ..., M. Gorski

Date:
Thursday, February 8, 2018
Time:
1:30 pm - 2:30 pm
Location:
Physics & Astronomy Building (PAB)
Room: 100
Physics & Astronomy Department
London
Cost:
Free

Department of Physics and Astronomy

PHYSICS & ASTRONOMY COLLOQUIUM

Dr. Mark Gorski

Department of Physics & Astronomy
The University of Western Ontario

“Molecular Tracers of Star Formation Feedback in Nearby Galaxies”

ABSTRACT

The energy and momentum injected into the ISM from stars has a drastic effect on the star formation history of a galaxy. This feedback is responsible for the inefficient collapse of the ISM into stars. By using molecular tracers of feedback, we provide insights into the star forming ecosystem of the galaxies NGC 253, IC 342, NGC 6946, and NGC 2146. We have selected the metastable NH_3 lines as a temperature tracer of the dense molecular ISM, the 22 GHz H_2O maser as an indicator of star formation, and the 36 GHz CH_3OH maser which was previously unexplored in the extragalactic context. We uncover evidence for a uniform two-temperature component distribution of the molecular gas across the central kiloparsec of NGC 253 and IC 342. The temperature does not appear to correlate with feedback effects such as supernovae, PDRs, or shocks. We identify several new water masers associated with star formation across all four galaxies. We also show that extragalactic 36 GHz CH_3OH masers are likely related to large scale weak shocks in the dense molecular ISM. In NGC 253 specifically we test models of galactic outflows driven by a nuclear starburst with sub-arcsecond observations of NH_3(3,3) masers, H_2O masers and CH_3OH masers. We uncover evidence for star formation and entrainment of molecular material in the outflow of NGC 253.

STUDENTS – after the talk, you’re encouraged to return to the 2nd floor Atrium lounge to meet with the speaker. 
COFFEE – coffee and cookies will be available in the 2nd floor Atrium lounge at 1:15 p.m.
CELL PHONES – as a courtesy to the speaker and audience, please set your cellphones to “silent” mode. Thanks!
Host:
Prof. P. Barmby
Contact:
Jodi Guthrie - Assistant to the Chair
jodi@uwo.ca
519-661-2111 ext. 86438
Event Type:


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