Characterizing the Circumgalactic Medium of Quasars at z $\sim$ 2.2 through H$\alpha$ and Ly$\alpha$ Emission

Abstract

The discovery of giant quasar Ly$\alpha$ nebulae at $z>2$ has opened up the possibility to directly study in emission the Circumgalactic and Intergalactic Medium (CGM/IGM). However, the resonant nature of the Ly$\alpha$ line and its different emission mechanisms hamper the ability to constrain both the kinematics and physical properties of the CGM/IGM. Here, we present results of a pilot project aiming at the detection of CGM H$\alpha$ emission, a line which does not suffer from these limitations. To this end, we first used KCWI to detect Ly$\alpha$ emission around three bright quasars with $2.25<z<2.27$, a range which is free from bright IR sky lines for H$\alpha$, and then selected the most extended nebula for H$\alpha$ follow-up with MOSFIRE. Within the MOSFIRE slit, we detected H$\alpha$ emission extending up to 20 physical kpc with a total H$\alpha$ flux of F${}_{\text{H}\alpha }$=(9.5 $\pm$ 0.9) $\times$ 10${}^{-18}$ erg s${}^{-1}$ cm${}^{-2}$. Considering the Ly$\alpha$ flux in the same region, we found F${}_{\text{Ly}\alpha }$/F${}_{\text{H}\alpha }$=3.7 $\pm$ 0.3 consistent with that obtained for the Slug Nebula at z$=2.275$ and with recombination radiation. This implies high densities or a very broad density distribution within the CGM of high-redshift quasars. Moreover, the H$\alpha$ line profile suggests the presence of multiple emitting components overlapping along our line-of-sight and relatively quiescent kinematics, which seems incompatible with either quasar outflows capable of escaping the potential well of the host halo or disk-like rotation in a massive halo ($>10^{12}$M${}_{\odot }$).

arXiv comment15 pages, 12 figures, 2 tables

References in corpus (45)

• How Do Galaxies Get Their Gas?
• Galaxy Bimodality due to Cold Flows and Shock Heating
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• The Cosmic Baryon Budget
• How Filaments are Woven into the Cosmic Web
• Virial shocks in galactic haloes?
• The MAPPINGS III Library of Fast Radiative Shock Models
• The MUSE second-generation VLT instrument
• Optimal Techniques in Two-dimensional Spectroscopy: Background Subtraction for the 21st Century
• Spectral Classification and Redshift Measurement for the SDSS-III Baryon Oscillation Spectroscopic Survey
• Strong Nebular Line Ratios in the Spectra of z~2-3 Star-forming Galaxies: First Results from KBSS-MOSFIRE
• The physics of galactic winds driven by active galactic nuclei
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• A cosmic web filament revealed in Lyman-alpha emission around a luminous high-redshift quasar
• Lyman Alpha Radiation From Collapsing Protogalaxies I: Characteristics of the Emergent Spectrum
• Cooling Radiation and the Lyman-alpha Luminosity of Forming Galaxies
• Nebular Emission Line Ratios in z~2-3 Star-Forming Galaxies with KBSS-MOSFIRE: Exploring the Impact of Ionization, Excitation, and Nitrogen-to-Oxygen Ratio
• Quasar Quartet Embedded in Giant Nebula Reveals Rare Massive Structure in Distant Universe
• Ionised outflows in z $\sim$ 2.4 quasar host galaxies
• The Keck Cosmic Web Imager Integral Field Spectrograph
• Fluorescent Ly-alpha emission from the high-redshift intergalactic medium
• Escape of about five per cent of Lyman-alpha photons from high-redshift star-forming galaxies
• QSO MUSEUM I: A sample of 61 extended Ly$\alpha$-emission nebulae surrounding $z\sim 3$ quasars
• Giant Clumps in Simulated High-z Galaxies: Properties, Evolution and Dependence on Feedback
• The origin of fast molecular outflows in quasars: molecule formation in AGN-driven galactic winds
• Discovery of an Enormous Ly$\alpha$ nebula in a massive galaxy overdensity at $z=2.3$
• Detection of dark galaxies and circum-galactic filaments fluorescently illuminated by a quasar at z=2.4
• Imaging the Lyman-alpha Forest
• Evolution of the Cool Gas in the Circumgalactic Medium (CGM) of Massive Halos -- A Keck Cosmic Web Imager (KCWI) Survey of Ly$\alpha$ Emission around QSOs at $z\approx 2$
• The large and small scale properties of the intergalactic gas in the Slug Ly-alpha nebula revealed by MUSE HeII emission observations
• Inspiraling Halo Accretion Mapped in Lyman-$\alpha$ Emission around a $z\sim 3$ Quasar
• Lyman alpha Emitting Galaxies in the Nearby Universe
• MUSE Analysis of Gas around Galaxies (MAGG) -- III: The gas and galaxy environment of z = 3-4.5 quasars
• Mapping Neutral Hydrogen During Reionization with the Ly-alpha Emission from Quasar Ionization Fronts
• The MOSDEF Survey: Kinematic and Structural Evolution of Star-Forming Galaxies at $1.4\le z\le 3.8$
• Witnessing galaxy assembly in an extended z~3 structure
• Host galaxies of high-redshift quasars: supermassive black hole growth and feedback
• The FLASHES Survey I: Integral Field Spectroscopy of the CGM around 48 $z=2.3-3.1$ QSOs
• The KBSS-KCWI Survey: The connection between extended Ly$\alpha$ halos and galaxy azimuthal angle at $z\sim 2-3$
• Revealing the Impact of Quasar Luminosity on Giant Ly$\alpha$ Nebulae
• Revealing the physical properties of gas accreting to haloes in the EAGLE simulations
• Baryonic mass budgets for haloes in the EAGLE simulation, including ejected and prevented gas
• The Detection of Intergalactic Halpha Emission from the Slug Nebula at z~2.3
• A high baryon fraction in massive haloes at z~3
• The density distribution of accreting cosmic filaments as shaped by Kelvin-Helmholtz instability

Cited by in corpus (6)

• QSO MUSEUM II: Search for extended Ly$\alpha$ emission around eight $z\sim 3$ quasar pairs
• Direct high-resolution observation of feedback and chemical enrichment in the circumgalactic medium at redshift z ~ 2.8
• A weak Ly$\alpha$ halo for an extremely bright Little Red Dot: Indications of enshrouded SMBH growth
• KBSS-InCLOSE I: Design and First Results from the Inner CGM of QSO Line Of Sight Emitting Galaxies at z~2-3
• Quasar lifetime measurements from extended Ly$\alpha$ nebulae at $z\sim 6$
• ODIN: A New Lyman Alpha Blob Selection Method, Sample, and Statistical Analysis at $z\sim 3.1$