Hot Gas Outflow Properties of the Starburst Galaxy NGC 4945

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2312.08444.pdf (1.59 MB)

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https://arxiv.org/abs/2312.08444

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https://doi.org/10.48550/arXiv.2312.08444
 http://hdl.handle.net/11603/31290

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UMBC Physics Department
UMBC Faculty Collection

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Author/Creator ORCID

https://orcid.org/0000-0002-1616-1701

Date

2023-12-13

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journal articles
preprints
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Abstract

We analyze 330 ks of {\it 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 kpc 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 non-spherical outflow geometry. We estimate the mass outflow rate of the hot wind to be 2.1M⊙ yr⁻¹. Emission from charge exchange is detected in the northern outflow, and we estimate it contributes 12\% to the emitted, broad-band (0.5−7~keV) X-ray flux.