On the narrowband detection properties of high-redshift Lyman-alpha emitters

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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An Intermediate-Band Imaging Survey for High-Redshift Lyman Alpha Emitters: The Mahoroba-11

Publications of the Astronomical Society of Japan ◽

10.1093/pasj/57.6.881 ◽

2005 ◽

Vol 57 (6) ◽

pp. 881-903 ◽

Cited By ~ 15

Author(s):

Sanae F. Yamada ◽

Shunji S. Sasaki ◽

Ryoko Sumiya ◽

Kazuyoshi Umeda ◽

Yasuhiro Shioya ◽

...

Keyword(s):

High Redshift ◽

Intermediate Band ◽

Lyman Alpha ◽

Alpha Emitters ◽

Lyman Alpha Emitters

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Detecting Lyman alpha emitters in the submillimetre

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2009.16164.x ◽

2010 ◽

Vol 403 (2) ◽

pp. 620-624 ◽

Cited By ~ 26

Author(s):

Pratika Dayal ◽

Hiroyuki Hirashita ◽

Andrea Ferrara

Keyword(s):

Lyman Alpha ◽

Alpha Emitters ◽

Lyman Alpha Emitters

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The galaxy environment of a QSO at z ~ 5.7

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314004232 ◽

2013 ◽

Vol 9 (S304) ◽

pp. 341-342

Author(s):

E. Bañados ◽

B. P. Venemans ◽

Fabian Walter ◽

Jaron Kurk ◽

Roderik Overzier ◽

...

Keyword(s):

Narrow Band ◽

Narrow Band Imaging ◽

High Redshift ◽

Local Universe ◽

Lyman Alpha ◽

The Galaxy ◽

Massive Halos ◽

Galaxy Environment ◽

Lyman Alpha Emitters ◽

First Time

AbstractHigh-redshift quasars are thought to reside in the most massive halos in the early universe and should therefore be located in fields with overdensities of galaxies, which are expected to evolve into galaxy clusters seen in the local Universe. In Bañados et al. (2013), we used deep narrow-band imaging to study the environment of the z=5.72 quasar ULAS J0203 + 0012. The redshift range probed by our narrow band selection is Δz ~ 0.1. This was the first time that Lyman alpha emitters (LAEs) were searched for near a z ~ 6 quasar, to provide clues on the surroundings of quasars at the end of the epoch of reionization. The main result of this work is that no enhancement of LAEs has been found in the surroundings of ULAS J0203 + 0012. We discuss different explanations and interpretations for this non-detection of a galaxy overdensity.

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A Subaru Search for Lyman$\alpha$ Emitters atz= 5.8 with an Intermediate-Band Filter

Publications of the Astronomical Society of Japan ◽

10.1093/pasj/56.4.597 ◽

2004 ◽

Vol 56 (4) ◽

pp. 597-603 ◽

Cited By ~ 27

Author(s):

Masaru Ajiki ◽

Yoshiaki Taniguchi ◽

Shinobu S. Fujita ◽

Yasuhiro Shioya ◽

Tohru Nagao ◽

...

Keyword(s):

Intermediate Band ◽

Lyman Alpha ◽

Alpha Emitters ◽

Band Filter ◽

Lyman Alpha Emitters

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Upper limits on the escape fraction of ionizing radiation from galaxies at 2 ≲ z < 6

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab2615 ◽

2021 ◽

Author(s):

U Meštrić ◽

E V Ryan-Weber ◽

J Cooke ◽

R Bassett ◽

L J Prichard ◽

...

Keyword(s):

Ionizing Radiation ◽

Equivalent Width ◽

Density Ratio ◽

Groups Of Galaxies ◽

Lyman Alpha ◽

Alpha Emitters ◽

Upper Limit ◽

Lyman Continuum ◽

Upper Limits ◽

Lyman Alpha Emitters

Abstract In this work, we investigate upper limits on the global escape fraction of ionizing photons ($f_{\rm esc/global}^{\rm abs}$) from a sample of galaxies probed for Lyman-continuum (LyC) emission characterized as non-LyC and LyC leakers. We present a sample of 9 clean non-contaminated (by low redshift interlopers, CCD problems and internal reflections of the instrument) galaxies which do not show significant (> 3σ) LyC flux between 880Å <λrest < 910Å. The 9 galaxy stacked spectrum reveals no significant LyC flux with an upper limit of $f_{\rm esc}^{\rm abs} \le 0.06$. In the next step of our analysis, we join all estimates of $f_{\rm esc}^{\rm abs}$ upper limits derived from different samples of 2 ≲ z < 6 galaxies from the literature reported in last ∼20 years and include the sample presented in this work. We find the $f_{\rm esc}^{\rm abs}$ upper limit ≤ 0.084 for the galaxies recognized as non-LyC leakers. After including all known detections from literature $f_{\rm esc/global}^{\rm abs}$ upper limit ≤ 0.088 for all galaxies examined for LyC flux. Furthermore, $f_{\rm esc}^{\rm abs}$ upper limits for different groups of galaxies indicate that the strongest LyC emitters could be galaxies classified as Lyman alpha emitters. We also discuss the possible existence of a correlation among the observed flux density ratio $(F_{\nu }^{LyC}/F_{\nu }^{UV})_{\rm obs}$ and Lyman alpha equivalent width EW(Lyα), where we confirm the existence of moderately significant correlation among galaxies classified as non-LyC leakers.

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