Evidence for a low Lyman Continuum Escape fraction in three Massive, UV-bright galaxies at z > 7

Abstract

Although low-mass star-forming galaxies are the leading candidates of the reionisation process, we cannot conclusively rule out high-mass star-forming galaxies as candidates. While most simulations indicate the former is the best candidate some models suggest that at z > 6 massive, UV-bright galaxies - "oligarchs" - account for at least 80% of the ionising budget. To test this hypothesis we target massive (log10 (M*[Msol]) > 10), UV-bright (MUV ~ -22) Lya emitters at z > 7 in archival data, observed with similar resolution spectrographs (VLT/X-shooter and Keck/MOSFIRE). To increase the reliability of our conclusions we stack all spectra and obtain a deep-stacked spectrum of 24.75 hrs. The stacked Lya profile displays a clear asymmetric red peak and an absence of a blue peak. We additionally estimate the intrinsic stacked Lya profile of our targets by correcting for IGM transmission using a range of neutral hydrogen fractions, finding no significant change in the profile. We measure a velocity offset Vred > 300 km/s and an asymmetry in our red peak A ~3. Using various models and estimators such as the peak separation, the asymmetry of the red peak, the ratio between Lya and Hb and the beta slope, we conclude that the escape fraction in these three UV bright, massive (10^10 Msol), z > 7 galaxies is fesc(LyC) < 10%.

arXiv comment11 pages, 4 figures, 2 tables. Accepted for publication in ApJ

References in corpus (52)

• On the variation of the Initial Mass Function
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• Dust Absorption And The Ultraviolet Luminosity Density At z \approx 3 As Calibrated By Local Starburst Galaxies
• On the Maximum Luminosity of Galaxies and Their Central Black Holes: Feedback From Momentum-Driven Winds
• 3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses
• Cosmic Reionization and Early Star-Forming Galaxies: A Joint Analysis of New Constraints from Planck and Hubble Space Telescope
• Inferring the star-formation histories of massive quiescent galaxies with BAGPIPES: Evidence for multiple quenching mechanisms
• The Evolution of the Galaxy Rest-Frame Ultraviolet Luminosity Function Over the First Two Billion Years
• 3D-HST: A wide-field grism spectroscopic survey with the Hubble Space Telescope
• The Growth of HII Regions During Reionization
• An updated analytic model for the attenuation by the intergalactic medium
• UV-Continuum Slopes of >4000 z~4-8 Galaxies from the HUDF/XDF, HUDF09, ERS, CANDELS-South, and CANDELS-North Fields
• Lyman-alpha and CIII] Emission in z=7-9 Galaxies: Accelerated Reionization Around Luminous Star Forming Systems?
• Detection of high Lyman continuum leakage from four low-redshift compact star-forming galaxies
• The Great Observatories Origins Deep Survey. VLT/FORS2 Spectroscopy in the GOODS-South Field: Part III
• Low-redshift Lyman continuum leaking galaxies with high [OIII]/[OII] ratios
• Hydrogen reionisation ends by $z=5.3$: Lyman-$\alpha$ optical depth measured by the XQR-30 sample
• Unusually Large Fluctuations in the Statistics of Galaxy Formation at High Redshift
• Using Lyman-alpha to detect galaxies that leak Lyman continuum
• Rapid Reionization by the Oligarchs: The Case for Massive, UV-Bright, Star-Forming Galaxies with High Escape Fractions
• Keck Spectroscopy of Faint 3<z<8 Lyman Break Galaxies:- Evidence for a Declining Fraction of Emission Line Sources In the Redshift Range 6<z<8
• Large Lyman-alpha opacity fluctuations and low CMB tau in models of late reionization with large islands of neutral hydrogen extending to z<5.5
• Lyman-alpha Emission from a Luminous z=8.68 Galaxy: Implications for Galaxies as Tracers of Cosmic Reionization
• Spectroscopic detection of CIV in a galaxy at z=7.045: Implications for the ionizing spectra of reionization-era galaxies
• J1154+2443: a low-redshift compact star-forming galaxy with a 46 per cent leakage of Lyman continuum photons
• A Spectroscopic Redshift Measurement for a Luminous Lyman Break Galaxy at z=7.730 using Keck/MOSFIRE
• The Extreme Faint End of the UV Luminosity Function at $z\sim 6$ Through Gravitational Telescopes: a comprehensive assessment of strong lensing uncertainties
• A lack of evolution in the very bright-end of the galaxy luminosity function from z = 8-10
• The bright end of the galaxy luminosity function at z ~ 7: before the onset of mass quenching?
• Intergalactic Transmission and its Impact on the Lyα Line
• The spectral evolution of the first galaxies. II. Spectral signatures of Lyman continuum leakage from galaxies in the reionization epoch
• Properties of Ly-alpha emitters around the radio galaxy MRC 0316-257
• Tracing the reionization epoch with ALMA: [CII] emission in z~7 galaxies
• The environment of bright QSOs at z ~ 6: Star forming galaxies and X-ray emission
• A spectroscopic search for AGN activity in the reionization era
• The origin of the escape of Lyman alpha and ionizing photons in Lyman Continuum Emitters
• Lyman Radiation Hydrodynamics of Turbulent H II Regions in Molecular Clouds: A Physical Origin of LyC Leakage and the Associated Ly$\alpha$ Spectra
• Onset of Cosmic Reionization: Evidence of An Ionized Bubble Merely 680 Myrs after the Big Bang
• Probing Cosmic Dawn : Ages and Star Formation Histories of Candidate $z\ge$9 Galaxies
• Spectroscopic Constraints on UV Metal Line Emission at z~6-9: The Nature of Lyman-alpha Emitting Galaxies in the Reionization-Era
• LBT observations of compact star-forming galaxies with extremely high [OIII]/[OII] flux ratios: HeI emission-line ratios as diagnostics of Lyman continuum leakage
• RASCAS: RAdiation SCattering in Astrophysical Simulations
• The spectral evolution of the first Galaxies. III. Simulated James Webb Space Telescope spectra of reionization-epoch galaxies with Lyman continuum leakage
• Lyman-$\alpha$ as a tracer of cosmic reionisation in the SPHINX radiation-hydrodynamics cosmological simulation
• The physics of Lyman-alpha escape from disc-like galaxies
• A lensed protocluster candidate at $z=7.66$ identified in JWST observations of the galaxy cluster SMACS0723-7327
• The Prevalence of Galaxy Overdensities Around UV-Luminous Lyman $\alpha$ Emitters in the Epoch of Reionization
• Winds of change: reionization by starburst galaxies
• Double-peaked Lyman-$\alpha$ emission at z=6.803: a reionisation-era galaxy self-ionising its local HII bubble
• Predicting LyC emission of galaxies using their physical and Ly$\alpha$ emission properties
• The impact of modified gravity on the Sunyaev-Zel'dovich effect
• Astraeus VI: Hierarchical assembly of AGN and their large-scale effect during the Epoch of Reionization

Cited by in corpus (5)

• Extreme N-emitters at high-redshift: signatures of supermassive stars and globular cluster or black hole formation in action?
• Deciphering Lyman-$\alpha$ Emission Deep into the Epoch of Reionisation
• GN-z11: The environment of an AGN at $z=$10.603
• The density-bounded twilight of starbursts in the early Universe
• The THESAN-ZOOM project: central starbursts and inside-out quenching govern galaxy sizes in the early Universe