The project "Novel Astronomical Instrumentation based on photonic light Reformating" is a DFG-funded collaboration to exploit the recognized potential of photonics solutions for a radically new approach to astronomical instrumentation for optical/infrared high precision spectroscopy and high angular resolution imaging. We present a project overview and initial development results from our Adaptive Optics-photonic test bed, Ultrafast Laser Inscribed waveguides for interferometric beam combination and 3D printing structures for astronomical instrumentation. The project is expected to lead to important technological breakthroughs facilitating uniquely functionality and technical solutions for the next generation of instrumentation.
Recent detections of extended Lyman- α halos around Ly α emitters (LAEs) have been reported on a regular basis, but their origin is still under investigation. Simulation studies predict that the outer regions of the extended halos contain a major contribution from the Ly α emission of faint, individually undetected LAEs. To address this matter from an observational angle, we used halo occupation distribution (HOD) modeling to reproduce the clustering of a spectroscopic sample of 1265 LAEs at 3 < z < 5 from the MUSE-Wide survey. We integrated the Ly α luminosity function to estimate the background surface brightness due to discrete faint LAEs. We then extended the HOD statistics inwards towards small separations and computed the factor by which the measured Ly α surface brightness is enhanced by undetected close physical neighbors. We considered various clustering scenarios for the undetected sources and compared the corresponding radial profiles. This enhancement factor from LAE clustering depends strongly on the spectral bandwidth Δ v over which the Ly α emission is integrated and this value can amount to ≈20 − 40 for small values of Δ v (around 200 − 400 km s −1 ) as achieved by recent studies utilizing integral-field spectrographic data. The resulting inferred Ly α surface brightness of faint LAEs ranges between (0.4 − 2)×10 20 erg s −1 cm −2 arcsec −2 , with a very slow radial decline outwards. Our results suggest that the outer regions of observed Ly α halos ( R ≳ 50 pkpc) could indeed contain a strong component from external (but physically associated) LAEs, and may even be dominated by them. It is only for a relatively shallow faint-end slope of the Ly α luminosity function that this contribution from clustered LAEs would be rendered insignificant. We also confirm that the observed emission from the inner regions ( R ≤ 20 − 30 pkpc) is too bright to be substantially affected by clustering. We compare our findings with predicted profiles from simulations and find good overall agreement. We outline possible future measurements to further constrain the impact of discrete undetected LAEs on observed extended Ly α halos.
The project "Novel Astronomical Instrumentation through photonic Reformatting" is a DFG-funded collaboration to exploit the recognized potential of photonics solutions for a radically new approach to astronomical instrumentation for optical/infrared high precision spectroscopy and high angular resolution imaging. We present a project overview and initial development results from our Adaptive Optics-photonic test bed, Ultrafast Laser Inscribed waveguides for interferometric beam combination and 3D printing structures for astronomical instrumentation. The project is expected to lead to important technological breakthroughs facilitating uniquely functionality and technical solutions for the next generation of instrumentation.
We present the median surface brightness profiles of diffuse Ly α haloes (LAHs) around star-forming galaxies by stacking 155 spectroscopically confirmed Ly α emitters (LAEs) at 3 < z < 4 in the MUSE Extremely Deep Field (MXDF) with a median Ly α luminosity of L Ly α ≈ 10 41.1 erg s −1 . After correcting for a systematic surface brightness offset we identified in the data cube, we detect extended Ly α emission out to a distance of ≈270 kpc. The median Ly α surface-brightness profile shows a power-law decrease in the inner 20 kpc and a possible flattening trend at a greater distance. This shape is similar for LAEs with different Ly α luminosities, but the normalisation of the surface-brightness profile increases with luminosity. At distances over 50 kpc, we observe a strong overlap of adjacent LAHs, and the Ly α surface brightness is dominated by the LAHs of nearby LAEs. We find no clear evidence of redshift evolution of the observed Ly α profiles when comparing with samples at 4 < z < 5 and 5 < z < 6. Our results are consistent with a scenario in which the inner 20 kpc of the LAH is powered by star formation in the central galaxy, while the LAH beyond a radius of 50 kpc is dominated by photons from surrounding galaxies.
[Abbreviated] We investigate the dependence of Lyman-$α$ emitter (LAE) clustering on Lyman-$α$ luminosity. We use 1030 LAEs from the MUSE-Wide survey, 679 LAEs from MUSE-Deep, and 367 LAEs from the to-date deepest ever spectroscopic survey, the MUSE Extremely Deep Field. All objects have spectroscopic redshifts of $3
Detections of extended Ly$α$ halos (LAHs) around Ly$α$ emitters (LAEs) have lately been reported on a regular basis, but their origin is still under investigation. Simulation studies predict that the outer regions of the extended LAHs contain a major contribution from the Ly$α$ emission of faint, individually undetected LAEs. To address this matter from an observational angle, we use halo occupation distribution (HOD) modeling to reproduce the clustering of a spectroscopic sample of 1265 LAEs at $3
We present the median surface brightness profiles of diffuse Ly$\alpha$ haloes (LAHs) around star-forming galaxies by stacking 155 spectroscopically confirmed Ly$\alpha$ emitters (LAEs) at 3
The project Novel Astronomical Instrumentation through photonic Reformatting is a DFG-funded collaboration to exploit the recognized potential of photonics solutions for a radically new approach to astronomical instrumentation for optical/infrared high precision spectroscopy and high angular resolution imaging. We present a project overview and initial development results from our Adaptive Optics-photonic test bed, Ultrafast Laser Inscribed waveguides for interferometric beam combination and 3D printing structures for astronomical instrumentation. The project is expected to lead to important technological breakthroughs facilitating uniquely functionality and technical solutions for the next generation of instrumentation.
We present an analysis of the spatial clustering of 695 Ly α -emitting galaxies (LAEs) in the MUSE-Wide survey. All objects have spectroscopically confirmed redshifts in the range 3.3 < z < 6. We employed the K-estimator, an alternative clustering statistic, adapted and optimized for our sample. We also explore the standard two-point correlation function approach, which is however less suited for a pencil-beam survey such as ours. The results from both approaches are consistent. We parametrize the clustering properties in two ways, (i) following the standard approach of modelling the clustering signal with a power law (PL), and (ii) adopting a halo occupation distribution (HOD) model of the two-halo term. Using the K-estimator and applying HOD modelling, we infer a large-scale bias of b HOD = 2.80 −0.38 +0.38 at a median redshift of the number of galaxy pairs ⟨ z pair ⟩ ≃ 3.82, while the best-fit power-law analysis gives b PL = 3.03 −0.52 +1.51 ( r 0 = 3.60 −0.90 +3.10 comoving h −1 Mpc and γ = 1.30 −0.45 +0.36 ). The implied typical dark matter halo (DMH) mass is log( M DMH /[ h −1 M ⊙ ]) = 11.34 −0.27 +0.23 (adopting b = b HOD and assuming σ 8 = 0.8). We study possible dependencies of the clustering signal on object properties by bisecting the sample into disjoint subsets, considering Ly α luminosity, UV absolute magnitude, Ly α equivalent width, and redshift as variables. We find no evidence for a strong dependence on the latter three variables but detect a suggestive trend of more luminous Ly α emitters clustering more strongly (thus residing in more massive DMHs) than their lower Ly α luminosity counterparts. We also compare our results to mock LAE catalogs based on a semi-analytic model of galaxy formation and find a stronger clustering signal than in our observed sample, driven by spikes in the simulated z -distributions. By adopting a galaxy-conserving model we estimate that the Ly α -bright galaxies in the MUSE-Wide survey will typically evolve into galaxies hosted by halos of log( M DMH /[ h −1 M ⊙ ]) ≈ 13.5 at redshift zero, suggesting that we observe the ancestors of present-day galaxy groups.
We investigate the dependence of Ly α emitter (LAE) clustering on Ly α luminosity and connect the clustering properties of ≈ L ⋆ LAEs with those of much fainter ones, namely, ≈0.04 L ⋆ . We use 1030 LAEs from the MUSE-Wide survey, 679 LAEs from MUSE-Deep, and 367 LAEs from the to-date deepest ever spectroscopic survey, the MUSE Extremely Deep Field. All objects have spectroscopic redshifts of 3 < z < 6 and cover a large dynamic range of Ly α luminosities: 40.15 < log( L Ly α /erg s −1 ) < 43.35. We apply the Adelberger et al. K-estimator as the clustering statistic and fit the measurements with state-of-the-art halo occupation distribution (HOD) models. We find that the large-scale bias factor increases weakly with an increasing line luminosity. For the low-luminosity (log⟨ L Ly α /[erg s −1 ]⟩ = 41.22) and intermediate-luminosity (log⟨ L Ly α /[erg s −1 ]⟩ = 41.64) LAEs, we compute consistent bias factors b low = 2.43 −0.15 +0.15 and b interm. = 2.42 −0.09 +0.10 , whereas for the high-luminosity (log⟨ L Ly α /[erg s −1 ]⟩ = 42.34) LAEs we calculated b high = 2.65 −0.11 +0.13 . Consequently, high-luminosity LAEs occupy dark matter halos (DMHs) with typical masses of log( M h /[ h −1 M ⊙ ]) = 11.09 −0.09 +0.10 , while low-luminosity LAEs reside in halos of log( M h /[ h −1 M ⊙ ]) = 10.77 −0.15 +0.13 . The minimum masses to host one central LAE, M min , and (on average) one satellite LAE, M 1 , also vary with Ly α luminosity, growing from log( M min /[ h −1 M ⊙ ]) = 10.3 −0.3 +0.2 and log( M 1 /[ h −1 M ⊙ ]) = 11.7 −0.2 +0.3 to log( M min /[ h −1 M ⊙ ]) = 10.7 −0.3 +0.2 and log( M 1 /[ h −1 M ⊙ ]) = 12.4 −0.6 +0.4 from low- to high-luminosity samples, respectively. The satellite fractions are ≲10% (≲20%) at 1 σ (3 σ ) confidence level, supporting a scenario in which DMHs typically host one single LAE. We next bisected the three main samples into disjoint subsets to thoroughly explore the dependence of the clustering properties on L Ly α . We report a strong (8 σ ) clustering dependence on Ly α luminosity, not accounting for cosmic variance effects, where the highest luminosity LAE subsample (log( L Ly α /erg s −1 ) ≈ 42.53) clusters more strongly ( b highest = 3.13 −0.15 +0.08 ) and resides in more massive DMHs (log( M h /[ h −1 M ⊙ ] )= 11.43 −0.10 +0.04 ) than the lowest luminosity one (log( L Ly α /erg s −1 ) ≈ 40.97), which presents a bias of b lowest = 1.79 −0.06 +0.08 and occupies log( M h /[ h −1 M ⊙ ]) = 10.00 −0.09 +0.12 halos. We discuss the implications of these results for evolving Ly α luminosity functions, halo mass dependent Ly α escape fractions, and incomplete reionization signatures.
