%0 Generic %1 yoshida2015giant %A Yoshida, Michitoshi %A Yagi, Masafumi %A Ohyama, Youichi %A Komiyama, Yutaka %A Kashikawa, Nobunari %A Tanaka, Hisashi %A Okamura, Sadanori %D 2015 %K Ha diffuse emission galaxy merger nebula %T Giant H$\alpha$ nebula surrounding the starburst merger NGC 6240 %U http://arxiv.org/abs/1512.09208 %X We revealed the detailed structure of a vastly extended H$\alpha$-emitting nebula ("H$\alpha$ nebula") surrounding the starburst/merging galaxy NGC 6240 by deep narrow-band imaging observations with the Subaru Suprime-Cam. The extent of the nebula is $\sim$90 kpc in diameter and the total H$\alpha$ luminosity amounts to $1.6 10^42$ erg s$^-1$. The volume filling factor and the mass of the warm ionized gas are $\sim$10$^-4$--10$^-5$ and $\sim$$5 10^8$ $M_ødot$, respectively. The nebula has a complicated structure, which includes numerous filaments, loops, bubbles, and knots. We found that there is a tight spatial correlation between the H$\alpha$ nebula and the extended soft X-ray-emitting gas, both in large and small scales. The overall morphology of the nebula is dominated by filamentary structures radially extending from the center of the galaxy. A large-scale bi-polar bubble extends along the minor axis of the main stellar disk. The morphology strongly suggests that the nebula was formed by intense outflows - superwinds - driven by starbursts. We also found three bright knots embedded in a looped filament of ionized gas that show head-tail morphologies in both emission-line and continuum, suggesting close interactions between the outflows and star forming regions. Based on the morphology and surface brightness distribution of the H$\alpha$ nebula, we propose the scenario that three major episodes of starburst/superwind activities which were initiated $\sim$10$^2$ Myr ago formed the extended ionized gas nebula of NGC 6240.

@misc{yoshida2015giant, abstract = {We revealed the detailed structure of a vastly extended H$\alpha$-emitting nebula ("H$\alpha$ nebula") surrounding the starburst/merging galaxy NGC 6240 by deep narrow-band imaging observations with the Subaru Suprime-Cam. The extent of the nebula is $\sim$90 kpc in diameter and the total H$\alpha$ luminosity amounts to $\approx 1.6 \times 10^{42}$ erg s$^{-1}$. The volume filling factor and the mass of the warm ionized gas are $\sim$10$^{-4}$--10$^{-5}$ and $\sim$$5 \times 10^8$ $M_\odot$, respectively. The nebula has a complicated structure, which includes numerous filaments, loops, bubbles, and knots. We found that there is a tight spatial correlation between the H$\alpha$ nebula and the extended soft X-ray-emitting gas, both in large and small scales. The overall morphology of the nebula is dominated by filamentary structures radially extending from the center of the galaxy. A large-scale bi-polar bubble extends along the minor axis of the main stellar disk. The morphology strongly suggests that the nebula was formed by intense outflows - superwinds - driven by starbursts. We also found three bright knots embedded in a looped filament of ionized gas that show head-tail morphologies in both emission-line and continuum, suggesting close interactions between the outflows and star forming regions. Based on the morphology and surface brightness distribution of the H$\alpha$ nebula, we propose the scenario that three major episodes of starburst/superwind activities which were initiated $\sim$10$^2$ Myr ago formed the extended ionized gas nebula of NGC 6240.}, added-at = {2016-01-01T10:44:58.000+0100}, author = {Yoshida, Michitoshi and Yagi, Masafumi and Ohyama, Youichi and Komiyama, Yutaka and Kashikawa, Nobunari and Tanaka, Hisashi and Okamura, Sadanori}, biburl = {https://www.bibsonomy.org/bibtex/25b5af12c69b131a08dbc58e9b22b177a/miki}, description = {[1512.09208] Giant H$\alpha$ nebula surrounding the starburst merger NGC 6240}, interhash = {1032d39ab8e70798d922f9c56d090798}, intrahash = {5b5af12c69b131a08dbc58e9b22b177a}, keywords = {Ha diffuse emission galaxy merger nebula}, note = {cite arxiv:1512.09208Comment: 17 pages, 12 figures. Accepted by ApJ}, timestamp = {2016-01-01T10:44:58.000+0100}, title = {Giant H$\alpha$ nebula surrounding the starburst merger NGC 6240}, url = {http://arxiv.org/abs/1512.09208}, year = 2015 }