A Giant Lyα 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 Lyα and broad metal emission lines. Although recent studies have suggested that a proximate damped Lyα absorption (PDLA) system causes this peculiar spectrum, the origin of the gas associated with the PDLA is unknown. Here we report the results of observations with the Multi Unit Spectroscopic Explorer (MUSE) that reveal a new giant (≈100 physical kpc) Lyα nebula. The detailed analysis of the Lyα velocity, velocity dispersion, and surface brightness profiles suggests that the J0952+0114 Lyα nebula shares similar properties with other QSO nebulae previously detected with MUSE, implying that the PDLA in J0952+0144 is covering only a small fraction of the solid angle of the QSO emission. We also detected bright and spectrally narrow C IV λ1550 and He II λ1640 extended emission around J0952+0114 with velocity centroids similar to the peak of the extended and central narrow Lyα emission. The presence of a peculiarly bright, unresolved, and relatively broad He II λ1640 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 −1. The smaller velocity dispersion of the large-scale Lyα emission suggests that the high-speed outflow is confined to the central region. Lastly, the derived spatially resolved He II/Lyα and C IV/Lyα maps show a positive gradient with the distance to the QSO, hinting at a non-homogeneous distribution of the ionization parameter.

Revealing the impact of quasar luminosity on giant Ly α nebulae

“…This is consistent with the bright B16 sample shown in the same figure, and the results of Arrigoni Battaia et al (2019). As a viability check we have included the exotic quasar of Marino et al (2019). This broad line quasar lacks a broad Ly line as it is totally absorbed by a pDLA.…”

“…In Marino et al (2019) it was observed that in the Ly surface brightness and kinematics there was no change in behaviour at small radii, suggesting that either the contribution from the ISM was negligible or there was a smooth transition from the CGM to the ISM. If the same behaviour extends to our faint sample and the narrow central emission is coming from the inner extent of the nebulae then we cannot determine if the emission arises from the ISM or CGM.…”

“…also see e.g. B16, Marino et al 2018Marino et al , 2019Cantalupo et al 2019). Due to the the low number of exposures per field (4) we combined the exposures using median statistics.…”

“…Arrigoni Battaia et al (2019) extended quasar studies with MUSE to a larger sample of 61 giant nebulae, again targeting = 3 − 4 quasars with luminosities only slightly lower than those of Borisova et al (2016b). More targeted efforts have also studied the nebulae of special QSOs, such as Broad Absorption Line objects (Ginolfi et al 2018), systems with proximate Damped Ly absorption (pDLAs, North et al 2017;Marino et al 2019) and 6 QSOs (e.g. Drake et al 2019;Farina et al 2019a).…”

The REQUIEM Survey. I. A Search for Extended Lyα Nebular Emission Around 31 z > 5.7 Quasars

“…Data points have been slightly shifted along the x-axis, for the sake of clarity. The average surface brightness profiles of the extended emission around quasars at z∼2.27 (magenta line; Cai et al 2019), z∼3.21 (light blue line; Arrigoni Battaia et al 2019a), and z∼3.36 (olive green line; Marino et al 2019) are also plotted. The corresponding exponential best fits are shown in the same color palette.…”