The origins of Lyman continuum (LyC) photons responsible for the reionization of the universe are as of yet unknown and highly contested. Detecting LyC photons from the Epoch of Reionization is not possible due to absorption by the intergalactic medium, which has prompted the development of several indirect diagnostics to infer the rate at which galaxies contribute LyC photons to reionize the universe by studying lower-redshift analogs. We present the Low-redshift Lyman Continuum Survey (LzLCS) comprising measurements made with the Hubble Space Telescope Cosmic Origins Spectrograph for a z = 0.2–0.4 sample of 66 galaxies. After careful processing of the far-UV spectra, we obtain a total of 35 Lyman continuum emitters (LCEs) detected with 97.725% confidence, nearly tripling the number of known local LCEs. We estimate escape fractions from the detected LyC flux and upper limits on the undetected LyC flux, finding a range of LyC escape fractions up to 50%. Of the 35 LzLCS LCEs, 12 have LyC escape fractions greater than 5%, more than doubling the number of known local LCEs with cosmologically relevant LyC escape.

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? First data on the ARGUS® sling was published in 2006 by Romano SV et al. as a multicentre study, evaluating the data of 48 patients with a mean follow up (FU) of 7.5 months, with the conclusion that this new adjustable sling was effective in treatment of SUI and the complication rate was acceptable. In 2009, Romano SV et al. published a long‐term FU (mean: 45 months) of the same patient group, demonstrating the long‐term efficacy of the sling. Our study evaluated the data of 101 cases of moderate to severe male stress urinary incontinence (SUI) after implantation of the ARGUS® sling at mean follow‐up of 2.1 (0.1–4.5) years. In addition we made a subgroup analysis of representative “index patients”, patients after external beam radiation therapy (EBRT) and of a subgroup after differentiation of the retrograde leak point pressure (RLPP). OBJECTIVES To report our experience using an adjustable bulbourethral sling since April 2005 for male stress urinary incontinence (SUI) after prostatic surgery. To evaluate the safety, efficacy and health‐related quality of life in recipients of the Argus® (Promedon SA; Cordoba, Argentina) adjustable bulbourethral sling. PATIENTS AND METHODS Between April 2005 and April 2009, 101 men with moderate‐to‐severe SUI after prostatic surgery were implanted with the Argus sling. The radio‐opaque Argus system comprises a thick silicone‐foam pad for soft bulbar urethral support. The pad is attached to silicone columns that, after being passed with needles from the perineum to the abdominal wall, are adjusted with silicone washers to maintain the desired position. Between prostatic surgery and Argus sling placement, most patients (74.3%) had undergone various procedures for SUI or bladder neck pathologies: 22 had undergone secondary irradiation therapy after surgery (19 after retropubic radical prostatectomy [RP], one after perineal RP and two after transurethral resection of the prostate). All patients were evaluated before and after sling placement with 20‐min pad tests, the Urinary Incontinence Quality of Life Scale (I‐QoL), cystoscopy and uroflowmetry. The study was designed in a retrospective longitudinal fashion. RESULTS The mean (range) follow‐up was 2.1 (0.1–4.5) years. The mean (range) sling surgery duration was 49 (28–105) min. Adjustment was necessary in 39 cases (38.6%), either loosening (10/101; 9.9%) or tightening (29/101; 28.7%) at a mean of 104.3 (14–910) days after the initial implantation. The sling had to be removed in 16/101 patients (15.8%) at a mean of 371.1 (20–1260) days after implantation due to urethral erosion or infection. However, six of the 16 patients were within the first 22 placements and probably represent the ‘learning curve’. In all, 13 of these patients received later successful treatment (seven with an artificial urinary sphincter, five with re‐implantation of the sling). Four of these patients were lost for follow‐up. After a media...

The Lyman continuum (LyC) cannot be observed at the epoch of reionization (z ≳ 6) owing to intergalactic H i absorption. To identify LyC emitters (LCEs) and infer the fraction of escaping LyC, astronomers have developed various indirect diagnostics of LyC escape. Using measurements of the LyC from the Low-redshift Lyman Continuum Survey (LzLCS), we present the first statistical test of these diagnostics. While optical depth indicators based on Lyα, such as peak velocity separation and equivalent width, perform well, we also find that other diagnostics, such as the [O iii]/[O ii] flux ratio and star formation rate surface density, predict whether a galaxy is an LCE. The relationship between these galaxy properties and the fraction of escaping LyC flux suggests that LyC escape depends strongly on H i column density, ionization parameter, and stellar feedback. We find that LCEs occupy a range of stellar masses, metallicities, star formation histories, and ionization parameters, which may indicate episodic and/or different physical causes of LyC escape.

Star-forming galaxies are considered the likeliest source of the H i ionizing Lyman continuum (LyC) photons that reionized the intergalactic medium at high redshifts. However, above z ≳ 6, the neutral intergalactic medium prevents direct observations of LyC. Therefore, recent years have seen the development of indirect indicators for LyC that can be calibrated at lower redshifts and applied in the epoch of reionization. Emission from the Mg ii λλ2796, 2803 doublet has been proposed as a promising LyC proxy. In this paper, we present new Hubble Space Telescope/Cosmic Origins Spectrograph observations for eight LyC emitter candidates, selected to have strong Mg ii emission lines. We securely detect LyC emission in 50% (4/8) of the galaxies with 2σ significance. This high detection rate suggests that strong Mg ii emitters might be more likely to leak LyC than similar galaxies without strong Mg ii. Using photoionization models, we constrain the escape fraction of Mg ii as ∼15%–60%. We confirm that the escape fraction of Mg ii correlates tightly with that of Lyα, which we interpret as an indication that the escape fraction of both species is controlled by resonant scattering in the same low column density gas. Furthermore, we show that the combination of the Mg ii emission and dust attenuation can be used to estimate the escape fraction of LyC statistically. These findings confirm that Mg ii emission can be adopted to estimate the escape fraction of Lyα and LyC in local star-forming galaxies and may serve as a useful indirect indicator at the epoch of reionization.

Most of the hydrogen in the intergalactic medium (IGM) was rapidly ionized at high-redshifts. While observations have established that reionization occurred, observational constraints on the high-redshift ionizing emissivity remain elusive. Here, we present a new analysis of the Low-redshift Lyman Continuum Survey (LzLCS) and literature observations, a combined sample of 89 star-forming galaxies at redshifts near 0.3 with Hubble Space Telescope observations of their ionizing continua (or Lyman Continuum, LyC). We find a strong (6σ significant) inverse correlation between the continuum slope at 1550 Å (defined as F$_\lambda \propto \lambda ^{\beta ^{1550}_{\rm obs}}$) and both the LyC escape fraction (fesc, LyC) and fesc, LyC times the ionizing photon production efficiency (ξion). On average, galaxies with redder continuum slopes have smaller fesc, LyC than galaxies with bluer slopes mainly due to higher dust attenuation. More than 5% (20%) of the LyC emission escapes galaxies with $\beta _{\rm obs}^{1550}$ <−2.1 (-2.6). We find strong correlations between $\beta _{\rm obs}^{1550}$ and the [O iii]/[O ii] flux ratio (at 7.5σ significance), galaxy stellar mass (at 5.9σ), the gas-phase metallicity (at 4.6σ), and the observed FUV absolute magnitude (at 3.4σ). Using previous observations of $\beta _{\rm obs}^{1550}$ at high-redshift, we estimate the evolution of fesc, LyC with both redshift and galaxy magnitude. The LzLCS observations suggest that fainter and lower mass galaxies dominate the ionizing photon budget at higher redshift, possibly due to their rapidly evolving metal and dust content. Finally, we use our correlation between $\beta _{\rm obs}^{1550}$ and fesc, LyC × ξion to predict the ionizing emissivity of galaxies during the epoch of reionization. Our estimated emissivities match IGM observations, and suggest that star-forming galaxies emit sufficient LyC photons into the IGM to exceed recombinations near redshifts of 7–8.