The AstroSat UV Deep Field South. II. A Diverse Set of Lyman-continuum Leakers at <i>z</i> ∼ 1
Abstract We report the detection of five newly identified Lyman-continuum (LyC) leaker candidates at redshifts 0.99–1.42 in the AstroSat UV Deep Field South F154W image. We derive physical properties of these galaxies using a combination of spectral-energy distribution fitting and information from publicly available spectra. The estimated escape fraction of these objects varies from 14% to 85% after accounting for the intergalactic medium attenuation. With only about a dozen known leakers at these redshifts, these detections significantly raise the fraction of LyC leakers in this redshift-range. High-resolution Hubble Space Telescope UV imaging reveals that a subset of the galaxies in our sample have blue star-forming structures that are likely associated with harder ionizing sources. We find tentative evidence that the LyC emission is spatially offset from the nonionizing UV-continuum centers of these galaxies. The integrated properties of these galaxies, such as the UV-continuum slope, dust attenuation, stellar mass, and [O III] λ 5007/[O II] λ 3727 ratios, make them atypical compared to known LyC leakers. The leakage of LyC photons from these systems presents a compelling challenge.
Authors
- Kanak Saha (ORCID: https://orcid.org/0000-0002-8768-9298)
- Michael J. Rutkowski (ORCID: https://orcid.org/0000-0001-7016-5220)
- Soumil Maulick (ORCID: https://orcid.org/0009-0003-8568-4850)
Institutions
- Minnesota State University, Mankato (US)
- Inter-University Centre for Astronomy and Astrophysics (IN)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2025-04-23
- DOI
- https://doi.org/10.3847/1538-4357/adc10e
- Citations
- 2
- Primary Topic
- Astronomy and Astrophysical Research
- Type
- article
- Field-Weighted Citation Impact
- 2.38