HST/ACS Observations of Star Formation Driven Outflows in Nearby Edge-on Spiral Galaxies: Dependence of Halo Morphology on Star Formation Activity
| dc.creator | Rossa, Joern | |
| dc.creator | Dahlem, Michael | |
| dc.creator | Dettmar, Ralf-Juergen | |
| dc.creator | van der Marel, Roeland P. | |
| dc.date | 2008-04-24 | |
| dc.date.accessioned | 2026-07-07T09:34:55Z | |
| dc.date.available | 2026-07-07T09:34:55Z | |
| dc.description | (Abridged). We present new high spatial resolution narrowband imaging observations of extraplanar diffuse ionized gas (eDIG) in four late-type, actively star forming edge-on spirals, obtained with ACS on-board HST. Our F658N (H-alpha) observations reveal a multitude of structures on both small and large scales. Whereas all four galaxies have been studied with ground-based telescopes before, here the small scale structure of the extended emission line gas is presented for the first time at a spatial resolution of 0.05", corresponding to 5.0 pc at the mean distance to the target galaxies. The eDIG morphology is very different for all four targets, probably as a result of their different levels of star formation activity. We find that the morphology of the eDIG, in particular the break-up of diffuse emission into filaments in galaxy halos, shows a strong dependence on the level of star formation activity per unit area, and eDIG can be arranged into a morphological sequence. NGC4634 and NGC5775 have the highest SF rate per unit area in our sample and the observed morphology suggests that the break-up of the smooth eDIG layer into individual resolved filaments occurs only above a certain threshold of SF activity per unit area. Combined with ground-based data for samples that span a larger range of galaxy mass our results indicate that the gravitational potential also plays an important role in the eDIG morphology. In low-mass galaxies the gas can be expelled due to shallow gravitational potentials more easily and couple with strong star formation driven outflows on a local scale. This is in contrast to the more massive galaxies, which show smooth eDIG layers, unless they are powered by a superwind, as in the case of nucleated starburst galaxies. | |
| dc.description | submitted to The Astronomical Journal, 21 pages, 9 figures, 4 tables, article with full resolution figures is available at http://www.astro.ufl.edu/~jrossa/transfer/acsdighalos042308.pdf | |
| dc.identifier | https://arxiv.org/abs/0804.3819 | |
| dc.identifier | http://arxiv.org/abs/0804.3819 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/159666 | |
| dc.subject | Astrophysics | |
| dc.title | HST/ACS Observations of Star Formation Driven Outflows in Nearby Edge-on Spiral Galaxies: Dependence of Halo Morphology on Star Formation Activity | |
| dc.type | text |