A giant Ly$\hat{I}\pm$ nebula and a small-scale clumpy outflow in the system of the exotic quasar J0952+0114 unveiled by MUSE

Abstract

The well-known quasar SDSS J095253.83+011421.9 (J0952+0114) at z=3.02 has one of the most peculiar spectra discovered so far, showing the presence of narrow Ly$\hat{I}\pm$ and broad metal emission lines. Although recent studies have suggested that a Proximate Damped Ly$\hat{I}\pm$ system (PDLA) causes this peculiar spectrum, the origin of the gas associated with the PDLA is unknown. Here we report the results of MUSE observations that reveal a new giant ($\approx$ 100 physical kpc) Lyman $\hat{I}\pm$ nebula. The detailed analysis of the Ly$\hat{I}\pm$ velocity, velocity dispersion, and surface brightness profiles suggests that the J0952+0114 Ly$\hat{I}\pm$ nebula shares similar properties of other QSO nebulae previously detected with MUSE, implying that the PDLA in J0952+0144 is covering only a small fraction of the QSO emission solid angle. We also detected bright and spectrally narrow CIV$\hat{I}»$1550 and HeII$\hat{I}»$1640 extended emission around J0952+0114 with velocity centroids similar to the peak of the extended and central narrow Ly$\hat{I}\pm$ emission. The presence of a peculiarly bright, unresolved, and relatively broad HeII$\hat{I}»$1640 emission in the central region at exactly the same PDLA redshift hints at the possibility that the PDLA originates in a clumpy outflow with a bulk velocity of about 500 km/s. The smaller velocity dispersion of the large scale Ly$\hat{I}\pm$ emission suggests that the high-speed outflow is confined to the central region. Lastly, the derived spatially resolved HeII/Ly$\hat{I}\pm$ and CIV/Ly$\hat{I}\pm$ maps show a positive gradient with the distance to the QSO hinting at a non-homogeneous ionization parameter distribution.

17 pages, 13 figures and 2 tables; Accepted for publication in ApJ