Report
The CO emission in the Taffy Galaxies (UGC 12914/5) at 60pc resolution-I: The battle for star formation in the turbulent Taffy Bridge
| العنوان: | The CO emission in the Taffy Galaxies (UGC 12914/5) at 60pc resolution-I: The battle for star formation in the turbulent Taffy Bridge |
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| المؤلفون: | Appleton, P. N., Emonts, B., Lisenfeld, U., Falgarone, E., Guillard, P., Boulanger, F., Braine, J., Ogle, P., Struck, C., Vollmer, B., Yeager, T. |
| سنة النشر: | 2022 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | We present ALMA observations at a spatial resolution of 0.2 arcsec (60 pc) of CO emission from the Taffy galaxies (UGC 12914/5). The observations are compared with narrow-band Pa$\alpha$, mid-IR, radio continuum and X-ray imaging, plus optical spectroscopy. The galaxies have undergone a recent head-on collision, creating a massive gaseous bridge which is known to be highly turbulent. The bridge contains a complex web of narrow molecular filaments and clumps. The majority of the filaments are devoid of star formation, and fall significantly below the Kennicutt-Schmidt relationship for normal galaxies, especially for the numerous regions undetected in Pa$\alpha$ emission. Within the loosely connected filaments and clumps of gas we find regions of high velocity dispersion which appear gravitationally unbound for a wide range of likely values of $X_{\rm CO}$. Like the "Firecracker" region in the Antennae system, they would require extremely high external dynamical or thermal pressure to stop them dissipating rapidly on short crossing timescales of 2-5~Myrs. We suggest that the clouds may be transient structures within a highly turbulent multi-phase medium which is strongly suppressing star formation. Despite the overall turbulence in the system, stars seem to have formed in compact hotspots within a kpc-sized extragalactic HII region, where the molecular gas has a lower velocity dispersion than elsewhere, and shows evidence for a collision with an ionized gas cloud. Like the shocked gas in the Stephan's Quintet group, the conditions in the Taffy bridge shows how difficult it is to form stars within a turbulent, multi-phase, gas. Comment: 23 pages, 1 Appendix, 17 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.3847/1538-4357/ac63b2 |
| URL الوصول: | http://arxiv.org/abs/2203.17142 |
| رقم الانضمام: | edsarx.2203.17142 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.3847/1538-4357/ac63b2 |
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