Related papers: Lyman-alpha spectral properties of five newly disc…
Lyman-alpha (Lya) is intrinsically the brightest line emitted from active galaxies. While it originates from many physical processes, for star-forming galaxies the intrinsic Lya luminosity is a direct tracer of the Lyman-continuum (LyC)…
The origin of Lyman Continuum (LyC) photons responsible for reionizing the universe remains a mystery, with the fraction of escaping LyC photons from galaxies at z$\sim$ 6 to 12 being highly uncertain. While direct detection of LyC photons…
We report Hubble Space Telescope/Cosmic Origins Spectrograph observations of the Ly$\alpha$ emission and interstellar absorption lines in a sample of ten star-forming galaxies at $z\sim0.2$. Selected on the basis of high equivalent width…
Green Peas are nearby analogs of high-redshift Ly$\alpha$-emitting galaxies. To probe their Ly$\alpha$ escape, we study the spatial profiles of Ly$\alpha$ and UV continuum emission of 24 Green Pea galaxies using the Cosmic Origins…
Star-forming dwarf galaxies leaking Lyman-continuum (LyC) radiation may have played an important role in the reionization of the Universe. Local galaxies exhibiting LyC leakage could shed light on the escape mechanisms, but so far only two…
The Lyman-$\alpha$ (Lya) line of hydrogen is a well-known tracer of galaxies at high-z. However, the connection between Lya observables and galaxy properties has not fully been established, limiting the use of the line to probe the physics…
The Lya emission line of HI is intrinsically the brightest feature in the spectrum of astrophysical nebulae, making it a very attractive observational tool with which to survey galaxies. Moreover as a UV resonance line, Lya possesses…
We present the first results of our pilot study of 8 photometrically selected Lyman continuum (LyC) emitting galaxy candidates from the COSMOS field and focus on their optical emission line ratios. Observations were performed in the H and K…
While the shape of the Ly$\alpha$ profile is viewed as one of the best tracers of ionizing-photon escape fraction ($f_{esc}$) within low redshift (z~0.3) surveys of the Lyman continuum, this connection remains untested at high redshift.…
The escape fraction of hydrogen ionizing photons (f_esc) from galaxies has been suggested to be evolving with time, but the picture is far from clear. While evidence for significant escape fractions has been found at high redshifts in…
We present a study of 7 star-forming galaxies from the Cosmic Evolution Survey (COSMOS) observed with the Cosmic Origins Spectrograph (COS) on board the Hubble Space Telescope (HST). The galaxies are located at relatively low redshifts,…
The physical conditions giving rise to high escape fractions of ionizing radiation (LyC $f_{\rm{esc}}$) in star-forming galaxies - most likely protagonists of cosmic reionization - are not yet fully understood. Using the VLT/MUSE…
Reliable indirect diagnostics of LyC photon escape from galaxies are required to understand which sources were the dominant contributors to reionization. While multiple LyC escape fraction ($f_{\rm esc}$) indicators have been proposed to…
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…
The Hydrogen Lyman-alpha (Lya) line shows a large variety of shapes which is caused by factors at different scales, from the interstellar medium to the intergalactic medium. This work aims to provide a systematic inventory and…
Using a sample of galaxies at $z\approx 3$ with detected Lyman Continuum (LyC) leakage in the SSA22 field, we attempt to verify a proposed indirect method for identifying cases with high LyC escape fraction $f_\mathrm{esc}$ based on…
We analyze archival Ly$\alpha$ spectra of 12 "Green Pea" galaxies observed with the Hubble Space Telescope, model their Ly$\alpha$ profiles with radiative transfer models, and explore the dependence of Ly$\alpha$ escape fraction on various…
Recent work suggests that strong emission line, star-forming galaxies may be significant Lyman Continuum leakers. We combine archival HST broadband ultraviolet and optical imaging (F275W and F606W, respectively) with emission line catalogs…
Identifying Lyman continuum (LyC) leakers at intermediate redshifts is crucial for understanding the properties of cosmic reionizers, as the opacity of the intergalactic medium (IGM) prevents direct detection of LyC emission from sources…
(Abridged) Lyman-alpha (Lya) is a dominant probe of the galaxy population at high-z. However, interpretation of data drawn from Lya alone hinges on the Lya escape fraction which, due to the complex radiative transport, may vary greatly.…