Gamma-ray bursts as probes of high-redshift Lyman-alpha emitters and radiative transfer models

Superwind galaxies at high-redshift are now considered to be the important clue for understanding the interaction and evolution of both galaxies and intergalactic matter. In order to improve our knowledge of superwind galaxies at high redshift, a large sample of superwind candidates is needed. During the course of our new search for Lyman alpha emitters at z = 5.7, we have found a candidate superwind galaxy, LAE J1044-0130, at z = 5.69. The emission-line profile of this object is asymmetric, showing excess red-wing emission and the observed broad line width (= 340 km/s). In this poster, we report detailed observed properties of LAE J1044-0130 as an example of a superwind galaxy.

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Distinguishing AGN from starbursts as the origin of double-peaked Lyman-alpha emitters in the reionization era

Astronomy and Astrophysics ◽

10.1051/0004-6361/202040107 ◽

2021 ◽

Vol 646 ◽

pp. L10

Author(s):

Hamsa Padmanabhan ◽

Abraham Loeb

Keyword(s):

Active Galactic Nuclei ◽

Peak Velocity ◽

High Redshift ◽

Galactic Nuclei ◽

Radio Observations ◽

Space Telescope ◽

X Ray ◽

Lyman Alpha ◽

Alpha Emitters ◽

Lyman Alpha Emitters

We discuss the possible origin of the double-peaked profiles recently observed in Lyman-alpha emitters (LAEs) at the epoch of reionization (z ≳ 6.5) from obscured active galactic nuclei (AGN). In combining the extent of the Lyman-α near-zones estimated from the blue peak velocity offset in these galaxies, with the ionizing emissivity of quasars at z ≳ 6, we forecast the intrinsic UV and X-ray luminosities of the AGN needed to give rise to their double-peaked profiles. We also estimate the extent of the obscuration of the AGN by comparing their luminosities to those of similar quasar samples at these epochs. Future X-ray and radio observations, as well as those with the James Webb Space Telescope, will be valuable tools to test the AGN contribution to the intergalactic-scale ionization zones of high-redshift LAEs.

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Galaxies at high z: The MUSE revolution

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320001313 ◽

2019 ◽

Vol 15 (S352) ◽

pp. 325-325

Author(s):

Roland Bacon

Keyword(s):

High Redshift ◽

Lyman Alpha ◽

Alpha Emitters ◽

Spectroscopic Observations ◽

Alpha Emission ◽

Order Of Magnitude ◽

Low Mass ◽

Deep Fields ◽

Lyman Alpha Emitters ◽

High Redshift Universe

AbstractSpectroscopic observations of galaxies at high redshift has recently been revolutionised by the Multi Unit Spectroscopic Explorer (MUSE) instrument in operation at the VLT since 2014. Thanks to its unrivalled capabilities, MUSE has been able to increase by an order of magnitude the number of spectroscopic redshifts in these fields. The most spectacular increase is at high redshift (z > 3), where MUSE was able to detect thousands of Lyman-alpha emitters. In the deepest exposures, MUSE is even able to goes beyond the limiting magnitude of the deepest HST exposures. These observations have led to a breakthrough in our understanding of the high redshift universe: e.g. the discovery of Lyman-alpha emission from the circumgalactic medium around individual galaxies, the role and property of low mass galaxies. In this talk I will present the latest results obtained with the MUSE observations of the Hubble deep and ultra-deep fields.

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Are Ly α emitters segregated in protoclusters regions?

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3027 ◽

2020 ◽

Vol 499 (2) ◽

pp. 2104-2115

Author(s):

Tomás Hough ◽

Siddhartha Gurung-López ◽

Álvaro Orsi ◽

Sofía A Cora ◽

Cedric G Lacey ◽

...

Keyword(s):

Galaxy Formation ◽

High Redshift ◽

Neutral Hydrogen ◽

High Density ◽

Lyman Alpha ◽

Alpha Emitters ◽

Galaxy Formation And Evolution ◽

Galaxy Sample ◽

Formation And Evolution ◽

Lyman Alpha Emitters

ABSTRACT The presence of neutral hydrogen in the interstellar medium (ISM) and intergalactic medium (IGM) induces radiative transfer (RT) effects on $\rm {Ly}\,\alpha$ photons that affect the observability of Lyman alpha emitters (LAEs). We use the galform semi-analytic model of galaxy formation and evolution to analyse how these effects shape the spatial distribution of LAEs with respect to $\rm {H}\,\alpha$ emitters (HAEs) around high-density regions at high redshift. We find that when a large sample of protoclusters is considered, HAEs showing also $\rm {Ly}\,\alpha$ emission (HAEs + LAEs) populate the same regions as those that do not display the $\rm {Ly}\,\alpha$ line at $z$ = 2.2. We compare against the protocluster USS1558-003, one of the most massive protoclusters located at $z$ = 2.53. Our results indicate that the strong depletion of HAEs + LAEs present in the high-density regions of USS1558-003 may be due to cosmic variance. We find that at $z$ = 2.2 and $z$ = 3.0, RT of the ISM produces a strong decline (30–50 per cent) of the clustering amplitude of HAEs + LAEs with respect to HAEs towards the protoclusters centre. At $z$ = 5.7, given the early evolutionary state of protoclusters and galaxies, the clustering of HAEs + LAEs has a smaller variation (10–20 per cent) towards the protoclusters centre. Depending on the equivalent width and luminosity criteria of the emission-line galaxy sample, the IGM can have a mild or a null effect on galaxy properties and clustering in high-density regions.

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