NOAO >   Observing Info >   Approved Programs >   2017A-0406

Small NOAO Logo

Program Information for 2017A-0406


PI: Claudia Scarlata, U. of Minnesota, scarlata@astro.umn.edu
Address: School of Physics and Astronomy, 116 CHURCH STREET, MINNEAPOLIS, MN 55455 USA

CoI: Matthew Hayes, Stockholm University, dept of Astronomy
CoI: Michael Rutkowski, Stockholm University, dept of Astronomy
CoI: Matthew Lehnert, Institute D'Astrophysique de Paris
CoI: Jens Melinder, Stockholm University, dept of Astronomy
CoI: Goran Ostlin, Stockholm University, dept of Astronomy
CoI: Joop Schaye, Leiden University

Title: Pressure and strange cooling: halo gas in galaxies with OVI emission

Abstract: Hot gas outflows from galaxies are likely responsible for regulating star formation and driving a number of galactic scaling relations, but winds also lose energy by radiation. Over a wide temperature range of 5<log(T/K)<6, the cooling of the hot circumgalactic flow is dominated by OVI (1032,1038 ). Thus OVI plays a vital role in cooling and observationally probing galaxy outflows. Typically this gas is probed in absorption, but we have recently begun an innovative new HST study to image OVI in emission from a sample of low-z starbursts. HST observations allow us to measure the pressure and density of the coronal gas. In the one case where the data exist, the pressure matches that in the HII regions. We will now test whether this is causal or coincidental by performing GMOS observations of the new HST sample. In one galaxy we have also identified a luminous, compact source of OVI emission. This could be photoionized or shock excited, but there are difficulties with both explanations and no current data can distinguish between the two. An AO-assisted NIFS spectrum will allow us to determine how this unique and enigmatic system is powered. The combination of HST and Gemini observations is likely to have significant consequences for the cooling of gas in galaxy halos and outflows.

Program Type: Standard/Extragalactic

Scheduled Nights:
Run 1 (2017A):  GEM-NQ/GMOSN -- 12hrs band 2 (GN-2017A-Q-36)


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2017A-0406

noaoprop-help@noao.edu

Small NOAO Logo