Hot Gas Outflow Properties of the Starburst Galaxy NGC 4945

Natalia Porraz Barrera; Sebastian Lopez; Laura A. Lopez; Adi Foord; Dustin D. Nguyen; Todd A. Thompson; Smita Mathur; Alberto D. Bolatto

doi:10.3847/1538-4357/ad4606

The Astrophysical Journal (Jan 2024)

Hot Gas Outflow Properties of the Starburst Galaxy NGC 4945

Natalia Porraz Barrera,
Sebastian Lopez,
Laura A. Lopez,
Adi Foord,
Dustin D. Nguyen,
Todd A. Thompson,
Smita Mathur,
Alberto D. Bolatto

Affiliations

Natalia Porraz Barrera: ORCiD; Department of Astronomy, The Ohio State University , 140 W. 18th Ave., Columbus, OH 43210, USA
Sebastian Lopez: ORCiD; Department of Astronomy, The Ohio State University , 140 W. 18th Ave., Columbus, OH 43210, USA; Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 W. Woodruff Ave., Columbus, OH 43210, USA
Laura A. Lopez: ORCiD; Department of Astronomy, The Ohio State University , 140 W. 18th Ave., Columbus, OH 43210, USA; Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 W. Woodruff Ave., Columbus, OH 43210, USA
Adi Foord: ORCiD; Department of Physics, University of Maryland Baltimore County , 1000 Hilltop Circle, Baltimore, MD 21250, USA
Dustin D. Nguyen: ORCiD; Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 W. Woodruff Ave., Columbus, OH 43210, USA; Department of Physics, The Ohio State University , 191 W. Woodruff Ave., Columbus, OH 43210, USA
Todd A. Thompson: ORCiD; Department of Astronomy, The Ohio State University , 140 W. 18th Ave., Columbus, OH 43210, USA; Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 W. Woodruff Ave., Columbus, OH 43210, USA
Smita Mathur: ORCiD; Department of Astronomy, The Ohio State University , 140 W. 18th Ave., Columbus, OH 43210, USA; Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 W. Woodruff Ave., Columbus, OH 43210, USA
Alberto D. Bolatto: ORCiD; Department of Astronomy, University of Maryland , College Park, MD 20742, USA; Joint Space-Science Institute, University of Maryland , College Park, MD 20742, USA

DOI: https://doi.org/10.3847/1538-4357/ad4606
Journal volume & issue: Vol. 968, no. 2
p. 54

Abstract

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We analyze 330 ks of Chandra X-ray imaging and spectra of the nearby, edge-on starburst and Seyfert type 2 galaxy NGC 4945 to measure the hot gas properties along the galactic outflows. We extract and model spectra from 15 regions extending from −0.55 to +0.85 kpc above and below the galactic disk to determine the best-fit parameters and metal abundances. We find that the hot gas temperatures and number densities peak in the central regions and decrease along the outflows. These profiles are inconsistent with a spherical, adiabatically expanding wind model, suggesting the need to include mass loading and/or a nonspherical outflow geometry. We estimate the mass outflow rate of the hot wind to be 1.6 M _⊙ yr ^−1 . Emission from charge exchange is detected in the northern outflow, and we estimate it contributes 12% to the emitted, broadband (0.5–7 keV) X-ray flux.

Published in The Astrophysical Journal

ISSN: 1538-4357 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/0004-637X

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