## Detection of the Diffuse H i Emission in the Circumgalactic Medium of NGC 891 and NGC 4565

### Description

We present detections of 21 cm emission from neutral hydrogen (Hi) in the circumgalactic medium (CGM) of the local edge-on galaxies NGC 891 and NGC 4565 using the Robert C. Byrd Green Bank Telescope (GBT). With our 5σ sensitivity of $8.2\times {10}^{16}$ cm-2 calculated over a 20 km s-1 channel, we achieve $\gt 5\sigma$ detections out to $90\mbox{--}120\,\mathrm{kpc}$ along the minor axes. The velocity width of the CGM emission is as large as that of the disk $\approx 500$ km s−1, indicating...[Show more]

Collections ANU Research Publications 2020-07-17 Journal article http://hdl.handle.net/1885/269857 The Astrophysical Journal 10.3847/1538-4357/ab97b9 Open Access