Kirill Makan
A5029743743- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
University of Potsdam
2021-2022
Abstract The origins of Lyman continuum (LyC) photons responsible for the reionization universe are as yet unknown and highly contested. Detecting LyC from Epoch Reionization is not possible due to absorption by intergalactic medium, which has prompted development several indirect diagnostics infer rate at galaxies contribute reionize studying lower-redshift analogs. We present Low-redshift Continuum Survey (LzLCS) comprising measurements made with Hubble Space Telescope Cosmic Origins...
The Lyman continuum (LyC) cannot be observed at the epoch of reionization (z {\gtrsim} 6) due to intergalactic H I absorption. To identify emitters (LCEs) and infer fraction escaping LyC, astronomers have developed various indirect diagnostics LyC escape. Using measurements from Low-redshift Continuum Survey (LzLCS), we present first statistical test these diagnostics. While optical depth indicators based on Lyα, such as peak velocity separation equivalent width, perform well, also find that...
Combining 66 ultraviolet (UV) spectra and ancillary data from the Low-Redshift Lyman Continuum Survey (LzLCS) 23 LyC observations by earlier studies, we form a statistical sample of star-forming galaxies at $z \sim 0.3$ to study role cold interstellar medium (ISM) gas in leakage ionizing radiation. We first constrain massive star content (ages metallicities) UV attenuation, fitting stellar continuum with combination simple population models. The models, together accurate flux measurements,...
Abstract Star-forming galaxies are considered the likeliest source of H i ionizing Lyman continuum (LyC) photons that reionized intergalactic medium at high redshifts. However, above z ≳ 6, neutral prevents direct observations LyC. Therefore, recent years have seen development indirect indicators for LyC can be calibrated lower redshifts and applied in epoch reionization. Emission from Mg ii λλ 2796, 2803 doublet has been proposed as a promising proxy. In this paper, we present new Hubble...
Abstract We present new high-resolution ( R = λ /Δ ∼ 14,000) spectra of the two brightest He ii -transparent quasars in far-UV at z em > 3.5, HE2QS J2311−1417 3.70) and J1630+0435 3.81), obtained with Cosmic Origins Spectrograph on Hubble Space Telescope. In predominantly saturated absorption spectra, both sight lines show several isolated resolved (FWHM ≳ 50 km s −1 ) transmission spikes Ly α β . The incidence such decreases increasing redshift, but significant signaling presence fully...
We present statistics of HeII Lya transmission spikes and large-scale absorption troughs using archival high-resolution ($R=\lambda /\Delta \lambda \simeq 12,500$-$18,000$) far-UV spectra eight HeII-transparent quasars obtained with the Cosmic Origins Spectrograph on Hubble Space Telescope. The sample covers redshift range 2.5<z<3.8, thereby probing rapidly evolving at end reionization epoch. measured lengths decrease dramatically from L>100cMpc z>3 to L~30cMpc z~2.7, signaling a significant...
The relationship between galaxy characteristics and the reionization of universe remains elusive, mainly due to observational difficulty in accessing Lyman continuum (LyC) at these redshifts. It is thus important identify low-redshift LyC-leaking galaxies that can be used as laboratories investigate physical processes allow LyC photons escape. weakness [S II] nebular emission lines relative typical star-forming has been proposed a predictor. In this paper, we show II]-deficiency an effective...