Searching for candidates of Lyman continuum sources - revisiting the SSA22 field

Abstract

We present the largest to date sample of hydrogen Lyman continuum (LyC) emitting galaxy candidates at any redshift, with 18 Ly$\alpha$ Emitters (LAEs) and 7 Lyman Break Galaxies (LBGs), obtained from the SSA22 field with Subaru/Suprime-Cam. The sample is based on the 159 LAEs and 136 LBGs observed in the field, all with spectroscopically confirmed redshifts, and these LyC candidates are selected as galaxies with counterpart in a narrow-band filter image which traces LyC at $z\ge 3.06$. Many LyC candidates show a spatial offset between the rest-frame non-ionizing ultraviolet (UV) detection and the LyC-emitting substructure or between the Ly$\alpha$ emission and LyC. The possibility of foreground contamination complicates the analysis of the nature of LyC emitters, although statistically it is highly unlikely that all candidates in our sample are contaminated by foreground sources. Many viable LyC LAE candidates have flux density ratios inconsistent with standard models, while also having too blue UV slopes to be foreground contaminants. Stacking reveals no significant LyC detection, suggesting that there is a dearth of objects with marginal LyC signal strength, perhaps due to a bimodality in the LyC emission. The foreground contamination-corrected $3\sigma$ upper limits of the observed average flux density ratios are $f_{LyC}/f_{UV}<0.08$ from stacking LAEs and $f_{LyC}/f_{UV}<0.02$ from stacking LBGs. There is a sign of a positive correlation between LyC and Ly$\alpha$, suggesting that both types of photons escape via a similar mechanism. The LyC detection rate among proto-cluster LBGs is seemingly lower compared to the field.

24 pages, 23 figures, 4 tables. Accepted

References in corpus (21)

• Ly-alpha Emission-Line Galaxies at z = 3.1 in the Extended Chandra Deep Field South
• The Direct Detection of Lyman-Continuum Emission from Star-forming Galaxies at z~3
• Lyman continuum leaking from the compact star-forming dwarf galaxy J0925+1403
• Population III stars: hidden or disappeared ?
• Deep U band and R imaging of GOODS-South: Observations,data reduction and first results
• New Constraints on the Lyman Continuum Escape Fraction at z~1.3
• Direct Detection of Lyman Continuum Escape from Local Starburst Galaxies with the Cosmic Origins Spectrograph
• A Deep Hubble and Keck Search for Definitive Identification of Lyman Continuum Emitters at z~3.1
• Deficiency of large equivalent width Lyman-alpha emission in luminous Lyman break galaxies at z~5-6?
• The Lyman Continuum escape fraction of galaxies at z=3.3 in the VUDS-LBC/COSMOS field
• A High-Resolution Hubble Space Telescope Study of Apparent Lyman Continuum Leakers at $z\sim 3$
• A Monte Carlo simulation of the intergalactic absorption and the detectability of the Lyman continuum from distant galaxies
• Peering through the holes: the far UV color of star-forming galaxies at z~3-4 and the escaping fraction of ionizing radiation
• An enhanced merger fraction within the galaxy population of the SSA22 protocluster at z ~ 3.1
• Lyman continuum galaxies and the escape fraction of Lyman break galaxies
• Protocluster Discovery in Tomographic Ly$\alpha$ Forest Flux Maps
• Limits on the LyC signal from z~3 sources with secure redshift and HST coverage in the E-CDFS field
• Eddington ratios of faint AGN at intermediate redshift: Evidence for a population of half-starved black holes
• The Stellar Initial Mass Function at the Epoch of Reionization
• The UV Continuum of z > 1 Star-forming Galaxies in the Hubble Ultraviolet UltraDeep Field
• Optical Variability of Infrared Power Law-Selected Galaxies & X-ray Sources in the GOODS-South Field

Cited by in corpus (25)

• The Lyman Continuum Escape Survey: Ionizing Radiation from [O III]-Strong Sources at a Redshift of 3.1
• No evidence for a significant AGN contribution to cosmic hydrogen reionization
• New synthesis models of consistent extragalactic background light over cosmic time
• The LyA-LyC Connection: Evidence for an Enhanced Contribution of UV-faint Galaxies to Cosmic Reionization
• The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC
• The Low-Redshift Lyman Continuum Survey. Unveiling the ISM properties of low-$z$ Lyman continuum emitters
• The Mean Ultraviolet Spectrum of a Representative Sample of Faint z~3 Lyman Alpha Emitters
• SILVERRUSH. VI. A simulation of Ly$\alpha$ emitters in the reionization epoch and a comparison with Subaru Hyper Suprime-Cam survey early data
• Ly$\alpha$-Lyman Continuum connection in 3.5 < z < 4.3 star-forming galaxies from the VUDS survey
• The X-SHOOTER Lyman-$\alpha$ survey at z=2 (XLS-z2) I: What makes a galaxy a Lyman-$\alpha$ emitter?
• Predictions and sensitivity forecasts for reionization-era [C II] line intensity mapping
• Intergalactic Lyman continuum photon budget in the past 5 billion years
• Mrk 71/NGC 2366: The nearest Green Pea analog
• Large 21 cm signals from AGN-dominated reionization
• Radiative properties of the first galaxies: rapid transition between blue and red
• The source of leaking ionizing photons from Haro11 -- Clues from HST/COS spectroscopy of knots A, B and C
• IGM Transmission Bias for $z$ $\ge$ 2.9 Lyman Continuum Detected Galaxies
• On the Nature of AGN and Star Formation Enhancement in the $z=3.1$ SSA22 Protocluster: The HST WFC3 IR View
• Upper limits on the escape fraction of ionizing radiation from galaxies at $2\lesssim z<6$
• Ionizing radiation from AGNs at z>3.3 with the Subaru Hyper Suprime-Cam Survey and the CFHT Large Area U-band Deep Survey (CLAUDS)
• Subaru narrow-band imaging search for Lyman continuum from galaxies at z>3 in the GOODS-N field
• CDFS-6664: A candidate of Lyman-continuum Emission at z~3.8 detected by HDUV
• Testing an indirect method for identifying galaxies with high levels of Lyman continuum leakage
• Detections of [C II] 158 $\mu$m and [O III] 88 $\mu$m in a Local Lyman Continuum Emitter, Mrk 54, and its Implications to High-redshift ALMA Studies
• A Lyman continuum analysis for $\sim 100$ galaxies at $z_{\text{spec}}\sim 3$ in the Abell 2744 Cluster Field