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arXiv · 2504.06483

Extraplanar [C II] and Halpha in the Edge-On Galaxy NGC 5775

William T. Reach·Dario Fadda·Richard J. Rand·Gordon J. Stacey
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Abstract

Spiral galaxies are thin and susceptible to being disrupted vertically. The largest star clusters, and nuclear starbursts, generate enough energy from winds and supernovae to send disk material to the halo. % METHODS Observations of edge-on galaxies allow for the clearest view of vertical disruptions. We present new observations of the nearby, edge-on galaxy NGC 5775 with SOFIA [C II] 157.7 micron and archival images from Hubble in Halpha to search for extraplanar gas. The extraplanar [C II] extends 2 kpc from the midplane over much of the star-forming disk. The extraplanar [C II] at 2 kpc from the midplane approximately follows the rotation of the disk, with a lag of approximately 40 km/s; this lag is similar to what has been previously reported in Halpha. Significant vertical extensions (to 3 kpc) are seen on the northeast side of the galaxy, potentially due to super star clusters in the NGC 5775 disk combined with gravitational interaction with the companion galaxy NGC 5774. The Halpha narrow-band image reveals a narrow plume that extends 7 kpc from the nucleus and is almost exactly perpendicular to the disk. The plume shape is similar to that seen from the comparable galaxy NGC 3628 and may arise from the nuclear starburst. Alternatively, the Halpha plume could be a relic of past activity.

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William T. Reach, Dario Fadda, Richard J. Rand, Gordon J. Stacey. 2025-04-08. Extraplanar [C II] and Halpha in the Edge-On Galaxy NGC 5775. https://arxiv.org/abs/2504.06483

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