Inspiraling halo accretion mapped in Ly α emission around a z ∼ 3 quasar

Abstract

In an effort to search for Lyα emission from circum-and intergalactic gas on scales of hundreds of kpc around z ∼ 3 quasar, and thus characterise the physical properties of the gas in emission, we have initiated an extensive fast-survey with the Multi Unit Spectroscopic Explorer (MUSE): Quasar Snapshot Observations with MUse: Search for Extended Ultraviolet eMission (QSO MUSEUM). In this work, we report the discovery of an enormous Lyα nebula (ELAN) around the quasar SDSS J102009.99+104002.7 at z = 3.164, which we followed-up with deeper MUSE observations. This ELAN spans ∼ 297 projected kpc, has an average Lyα surface brightness SB Lyα ∼ 6.04 × 10 −18 erg s −1 cm −2 arcsec −2 (within the 2σ isophote), and is associated with an additional four, previously unknown embedded sources: two Lyα emitters and two faint active galactic nuclei (one Type-1 and one Type-2 quasar). By mapping at high significance the line-of-sight velocity in the entirety of the observed structure, we unveiled a largescale coherent rotation-like pattern spanning ∼ 300 km s −1 with a velocity dispersion of < 270 km s −1 , which we interpret as a signature of the inspiraling accretion of substructures within the quasar's host halo. Future multiwavelength data will complement our MUSE observations, and are definitely needed to fully characterise such a complex system. None the less, our observations reveal the potential of new sensitive integral-field spectrographs to characterise the dynamical state of diffuse gas on large scales in the young Universe, and thereby witness the assembly of galaxies.

The large- and small-scale properties of the intergalactic gas in the Slug Ly α nebula revealed by MUSE Heiiemission observations

“…Deep narrow-band imaging campaigns around bright quasars (e.g. Cantalupo et al 2012Cantalupo et al , 2014Martin et al 2014;Hennawi et al 2015;Arrigoni Battaia et al 2016) and, more recently, integral-field spectroscopic campaigns with the Multi Unit Spectroscopic Explorer (MUSE) (e.g., Borisova et al 2016;Arrigoni Battaia et al 2018) and the Palomar/Keck Cosmic Web Imager (P/KCWI) (e.g., Martin et al 2014;Cai et al 2018) are finally revealing giant Lyα nebulae with size exceeding 100 kpc around essentially all bright quasars (at least at z > 3 while at z 2 they seem to be detected more rarely, see e.g., Arrigoni Battaia et al 2016 andCantalupo 2017 for discussion).…”

Jet-driven Galaxy-scale Gas Outflows in the Hyperluminous Quasar 3C 273

“…Large reservoirs of ionized gas on tens to hundreds kpcs scales have been detected around many luminous radio-loud and radio-quiet AGN at low redshifts (Stockton & MacKenty 1983;Danziger et al 1984;van Breugel et al 1985;Stockton & MacKenty 1987;Prieto et al 1993;Shopbell et al 1999;Tadhunter et al 2000;Stockton et al 2002;Villar-Martín et al 2005Husemann et al 2010Husemann et al , 2011Greene et al 2012;Liu et al 2013aLiu et al , 2014Hainline et al 2014;Villar-Martín et al 2017 as well as at high redshifts (e.g. Heckman et al 1991;McCarthy 1993;Christensen et al 2006;North et al 2012;Cantalupo et al 2014;Hennawi et al 2015;Borisova et al 2016;Cai et al 2017;Arrigoni Battaia et al 2018;Husemann et al 2018). These are often referred to as extended emission-line regions (EELRs) or extended narrow-line regions (ENLRs) in the literature without a clear distinction between the two.…”

Lyman α photons through rotating outflows

“…Addressing the second question we posed in the introduction (To what extent is it possible to constrain rotational kinematics from the Lyα emission line? ) we show that the most straightforward approach is measuring Lyα spectra from two different regions of a galaxy to detect approaching/receding gas motions (Prescott et al 2015;Arrigoni Battaia et al 2018). In that case, we also show that the distances between these two peaks is four times shorter than the naively expected value of 2 × vrot.…”

“…For instance Prescott et al (2015) presented observational results of a Doppler shift when taking spectra at two opposite sides of a large (≈ 80kpc) LAE. In more recent work Arrigoni Battaia et al (2018) mapped Lyα emission around a quasar. In this case one could measure the displacement between the peaks in the two different spectra.…”

“…Recent advances in instrumentation have revealed the presence of gas rotation on vastly different physical scales. For instance, spatially resolved spectra on compact dwarf galaxies have measured clear signs of gas showing pure rotation kinematics (Cairós et al 2015;Cairós & González-Pérez 2017) and the recent mapping of high redshift circumgalactic regions have also revealed kinematic evidence for large scale rotation (Arrigoni Battaia et al 2018). Systems with star formation, neutral gas and low dust contents can produce a Lyα emission line (Partridge & Peebles 1967) motivating the observational work to phenomenologically link tracers of galaxy rotation such as Hα to Lyα spectra (e.g.…”