MusE GAs FLOw and Wind (MEGAFLOW) VIII. Discovery of a Mgii emission halo probed by a quasar sightline.
In: Monthly Notices of the Royal Astronomical Society, Jg. 507 (2021-11-01), Heft 3, S. 4294-4315
Online
academicJournal
Zugriff:
Using deep (|$11.2\, \rm{h}$|) VLT/MUSE data from the MEGAFLOW survey, we report the first detection of extended |$\rm{Mg\, \small {II}}$| emission from a galaxy's halo that is probed by a quasar sightline. The |$\rm{Mg\, \small {II}}\, \lambda \lambda \, 2796, 2803$| emission around the z = 0.702 galaxy (|$\log (M_*/\rm{M_\odot })=10.05_{-0.11}^{+0.15}{}$|) is detected out to |$\approx 25\, \hbox{kpc}$| from the central galaxy and covers |$1.0\times 10^3\, \hbox{kpc}^2$| above a surface brightness of |$14\times 10^{-19}\, \rm{erg}\, \rm{s}^{-1}\, \rm{cm}^{-2}\, \rm{arcsec}^{-2}{}$| (|$2\, \sigma$| ; integrated over |$1200\, \rm{km\, s}^{-1}= 19\mathring{\rm A}$| and averaged over |$1.5\, \rm{arcsec}^{2}$|). The |$\rm{Mg\, \small {II}}$| emission around this highly inclined galaxy (i ≃ 75 deg) is strongest along the galaxy's projected minor axis, consistent with the |$\rm{Mg\, \small {II}}$| gas having been ejected from the galaxy into a bi-conical structure. The quasar sightline, which is aligned with the galaxy's minor axis, shows strong |$\rm{Mg\, \small {II}}$| absorption (|$\hbox{$EW_0^{\lambda 2796}$}{}=1.8{}\, \mathring{\rm A}$|) at an impact parameter of |$39{}\, \hbox{kpc}$| from the galaxy. Comparing the kinematics of both the emission and the absorption − probed with VLT/UVES − to the expectation from a simple toy model of a bi-conical outflow, we find good consistency when assuming a relatively slow outflow (|$v_\rm{out}=130{}\, \rm{km\, s}^{-1}$|). We investigate potential origins of the extended |$\rm{Mg\, \small {II}}$| emission using simple toy models. With continuum scattering models we encounter serious difficulties in explaining the luminosity of the |$\rm{Mg\, \small {II}}$| halo and in reconciling density estimates from emission and absorption. Instead, we find that shocks might be a more viable source to power the extended |$\rm{Mg\, \small {II}}$| (and non-resonant |$[\rm{O\, \small {II}}]$|) emission. [ABSTRACT FROM AUTHOR]
Titel: |
MusE GAs FLOw and Wind (MEGAFLOW) VIII. Discovery of a Mgii emission halo probed by a quasar sightline.
|
---|---|
Autor/in / Beteiligte Person: | Zabl, Johannes ; Bouché, Nicolas F ; Wisotzki, Lutz ; Schaye, Joop ; Leclercq, Floriane ; Garel, Thibault ; Wendt, Martin ; Schroetter, Ilane ; Muzahid, Sowgat ; Cantalupo, Sebastiano ; Contini, Thierry ; Bacon, Roland ; Brinchmann, Jarle ; Richard, Johan |
Link: | |
Zeitschrift: | Monthly Notices of the Royal Astronomical Society, Jg. 507 (2021-11-01), Heft 3, S. 4294-4315 |
Veröffentlichung: | 2021 |
Medientyp: | academicJournal |
ISSN: | 0035-8711 (print) |
DOI: | 10.1093/mnras/stab2165 |
Schlagwort: |
|
Sonstiges: |
|