Observing the high redshift Universe with Euclid

AbstractEuclid enables the exploration of large sky areas with diffraction limited resolution in the optical and near-infrared, and is sensitive enough to detect targets at cosmological distances. This combination of capabilities gives Euclid a clear advantage over telescope facilities with larger apertures, both on ground and in space. The decision to mount in the NISP instrument one extra grism for the wavelength range 0.92-1.3 μm with a spectral resolution of R ≈260 makes possible a rest-frame UV survey of the early Universe in the redshift range 6.5 < z < 9.7. Euclid’s standard imaging with VIS in the 0.55-0.9 μm band and with NISP in the Y, J, H bands provide complementary photometry for further target identification and characterization. Euclid is a suitable facility to discover and map the spatial distribution of rare high-redshift targets and to collect statistically relevant samples, in particular of high redshift Lyα emitters and QSOs, which can be used as signposts of the cosmic structures. The Euclid surveys are also a starting point for deeper follow up observations of the individual high-z objects. We present the Euclid mission and discuss the detectability of high-z objects to probe the epoch of ionization.

Download Full-text

The Lyman-α‎ Line as a Probe of the Early Universe

The First Galaxies in the Universe ◽

10.23943/princeton/9780691144917.003.0011 ◽

2013 ◽

Author(s):

Abraham Loeb ◽

Steven R. Furlanetto

Keyword(s):

Simple Model ◽

High Redshift ◽

Young Star ◽

H Ii Regions ◽

Host Galaxies ◽

Star Forming ◽

Starting Point ◽

Good Starting Point ◽

High Redshift Universe

This chapter investigates a number of specific observational probes of the high-redshift Universe. It examines the Lyman-α‎ line, an extraordinarily rich and useful—albeit complex—probe of both galaxies and the intergalactic medium (IGM). As established in the previous chapter, young star-forming galaxies can produce very bright Lyman-α‎ emissions. Although the radiative transfer of these photons through their host galaxies is typically very complex, a good starting point is a simple model in which a fraction of stellar ionizing photons are absorbed within their source galaxy, forming embedded H II regions. The resulting protons and electrons then recombine, producing Lyman-α‎ photons. Assuming ionization equilibrium, the rate of these recombinations must equal the rate at which ionizing photons are produced.

Download Full-text

Z-scores-based methods and their application to biological monitoring: an example in professional soccer players

Biostatistics ◽

10.1093/biostatistics/kxx044 ◽

2017 ◽

Vol 20 (1) ◽

pp. 48-64

Author(s):

Guillaume Saulière ◽

Jérôme Dedecker ◽

Laurie-Anne Marquet ◽

Pierre Rochcongar ◽

Jean-Francois Toussaint ◽

...

Keyword(s):

Reference Population ◽

Abnormal Behavior ◽

Soccer Players ◽

Clinical Patient ◽

Professional Soccer ◽

Starting Point ◽

Significance Levels ◽

Z Scores ◽

The Individual

Summary The clinical and biological follow-up of individuals, such as the biological passport for athletes, is typically based on the individual and longitudinal monitoring of hematological or urine markers. These follow-ups aim to identify abnormal behavior by comparing the individual’s biological samples to an established baseline. These comparisons may be done via different ways, but each of them requires an appropriate extra population to compute the significance levels, which is a non-trivial issue. Moreover, it is not necessarily relevant to compare the measures of a biomarker of a professional athlete to that of a reference population (even restricted to other athletes), and a reasonable alternative is to detect the abnormal values by considering only the other measurements of the same athlete. Here we propose a simple adaptive statistic based on maxima of Z-scores that does not rely on the use of an extra population. We show that, in the Gaussian framework, it is a practical and relevant method for detecting abnormal values in a series of observations from the same individual. The distribution of this statistic does not depend on the individual parameters under the null hypothesis, and its quantiles can be computed using Monte Carlo simulations. The proposed method is tested on the 3-year follow-up of ferritin, serum iron, erythrocytes, hemoglobin, and hematocrit markers in 2577 elite male soccer players. For instance, if we consider the abnormal values for the hematocrit at a 5% level, we found that 5.57% of the selected cohort had at least one abnormal value (which is not significantly different from the expected false-discovery rate). The approach is a starting point for more elaborate models that would produce a refined individual baseline. The method can be extended to the Gaussian linear model, in order to include additional variables such as the age or exposure to altitude. The method could also be applied to other domains, such as the clinical patient follow-up in monitoring abnormal values of biological markers.

Download Full-text

Combination of strontium chloride and photobiomodulation in the control of tooth sensitivity post-bleaching: A split-mouth randomized clinical trial

PLoS ONE ◽

10.1371/journal.pone.0250501 ◽

2021 ◽

Vol 16 (4) ◽

pp. e0250501

Author(s):

Danielle da Silva Pompeu ◽

Brennda Lucy Freitas de Paula ◽

Antônia Patricia Oliveira Barros ◽

Samir Costa Nunes ◽

Alexandra Melo Pingarilho Carneiro ◽

...

Keyword(s):

Clinical Trial ◽

Near Infrared ◽

Laser System ◽

Tooth Bleaching ◽

Infrared Light ◽

Controlled Clinical Trial ◽

Strontium Chloride ◽

Tooth Sensitivity ◽

The Individual

Objective This split-mouth randomized controlled clinical trial assessed the effect of 10% strontium chloride in combination with photobiomodulation (PBM) for the control of tooth sensitivity (TS) post-bleaching. Methods The upper/lower, right and left quadrants of fifty volunteers were randomized and allocated to four groups (n = 25): PLACEBO—placebo gel + simulation of PBM; Placebo + PBM; STRONTIUM—10% strontium chloride + simulation of PBM; and PBM + STRONTIUM—10% strontium chloride + PBM. All groups received tooth bleaching treatment with 35% hydrogen peroxide. For the PBM treatment, the laser tip was positioned in the apical and cervical regions of the teeth bleached in the respective hemi-arch. The laser system was operated in continuous mode, using 1.7 J of energy. A dose of 60 J/cm2 was applied to each point for 16 seconds under 808 nm near-infrared light (100mW of power), with a point area of 0.028 cm2. TS was assessed during a 21-day follow-up, using the modified visual analogue scale. Results In the intragroup assessment, the Friedman test indicated that PBM + STRONTIUM promoted the greatest reduction in TS after the second week of treatment (p ≤ 0.05). The Wilcoxon-Mann-Whitney test indicated that the groups Placebo + PBM, STRONTIUM, and STRONTIUM + PBM did not differ statistically (p ≥ 0.05) in the first and third weeks of treatment The group PLACEBO exhibited the greatest TS in the first three days after each bleaching session. Conclusion The combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, the combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, it did not differ from the individual use of Placebo + PBM or STRONTIUM groups assessed after 21 days of follow-up.

Download Full-text

Polarized Optical and Infrared Emission from High Redshift Radio Galaxies

Symposium - International Astronomical Union ◽

10.1017/s0074180900176491 ◽

1994 ◽

Vol 159 ◽

pp. 470-470 ◽

Cited By ~ 1

Author(s):

Buell T. Jannuzi

Keyword(s):

Active Galactic Nucleus ◽

Rest Frame ◽

Near Infrared ◽

Uv Light ◽

High Redshift ◽

Radio Galaxies ◽

Infrared Emission ◽

Significant Component ◽

Extended Radio ◽

Polarized Emission

We have detected highly polarized (> 5%) optical and/or infrared emission (rest frame UV to near infrared) from 5 of the 8 high redshift radio galaxies (HZRG; z > 0.7) we have observed. There are now a total of 9 (out of 12 observed) HZRG known to be polarized in spatially integrated measurements (cf.). We have made images of the extended polarized emission from two radio galaxies (3C 265 and 3C 256). Detection of extended polarized emission from a HZRG has previously been reported for 3C 368. All of the existing polarization observations support the hypothesis that the “alignment effect” (the tendency of the extended UV light to be aligned with the extended radio emission, e.g.) is not solely produced by a burst of star formation, but contains a very significant component produced by the scattering of the light from a hidden active galactic nucleus (AGN). Our modeling of the frequency dependence of the polarized flux from 3C 265 suggests that the most probable scatterer is dust.

Download Full-text

AGNs at the cosmic dawn: predictions for future surveys from a ΛCDM cosmological model

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa024 ◽

2020 ◽

Vol 492 (2) ◽

pp. 2535-2552

Author(s):

Andrew J Griffin ◽

Cedric G Lacey ◽

Violeta Gonzalez-Perez ◽

Claudia del P Lagos ◽

Carlton M Baugh ◽

...

Keyword(s):

Black Holes ◽

Galaxy Formation ◽

Near Infrared ◽

Accretion Rate ◽

High Redshift ◽

Host Galaxies ◽

Accretion Rates ◽

Infrared Wavelengths ◽

The Masses ◽

High Redshift Universe

ABSTRACT Telescopes to be launched over the next decade and a half, such as JWST, EUCLID, ATHENA, and Lynx, promise to revolutionize the study of the high-redshift Universe and greatly advance our understanding of the early stages of galaxy formation. We use a model that follows the evolution of the masses and spins of supermassive black holes (SMBHs) within a semi-analytic model of galaxy formation to make predictions for the active galactic nucleus luminosity function at $z$ ≥ 7 in the broadband filters of JWST and EUCLID at near-infrared wavelengths, and ATHENA and Lynx at X-ray energies. The predictions of our model are relatively insensitive to the choice of seed black hole mass, except at the lowest luminosities (Lbol < 1043 erg s−1) and the highest redshifts ($z$ > 10). We predict that surveys with these different telescopes will select somewhat different samples of SMBHs, with EUCLID unveiling the most massive, highest accretion rate SMBHs, Lynx the least massive, lowest accretion rate SMBHs, and JWST and ATHENA covering objects inbetween. At $z$ = 7, we predict that typical detectable SMBHs will have masses, MBH ∼ 105–8 M⊙, and Eddington normalized mass accretion rates, $\dot{M}/\dot{M}_{\mathrm{Edd}}\sim 0.6{-}2$. The SMBHs will be hosted by galaxies of stellar mass M⋆ ∼ 108–10 M⊙, and dark matter haloes of mass Mhalo ∼ 1011–12 M⊙. We predict that the detectable SMBHs at $z$ = 10 will have slightly smaller black holes, accreting at slightly higher Eddington normalized mass accretion rates, in slightly lower mass host galaxies compared to those at $z$ = 7, and reside in haloes of mass Mhalo ∼ 1010–11 M⊙.

Download Full-text

Ultradeep Near-Infrared ISAAC Observations of the Hubble Deep Field South: Selecting High-Redshift Galaxies in the Rest-Frame Optical

The Mass of Galaxies at Low and High Redshift - ESO ASTROPHYSICS SYMPOSIA ◽

10.1007/10899892_65 ◽

2006 ◽

pp. 256-261

Author(s):

Ivo Labbé ◽

Marijn Franx ◽

Gregory Rudnick ◽

Alan Moorwood ◽

Natascha Förster Schreiber ◽

...

Keyword(s):

Rest Frame ◽

Near Infrared ◽

High Redshift ◽

High Redshift Galaxies ◽

Hubble Deep Field ◽

Redshift Galaxies

Download Full-text

Wide-Field Slitless Spectroscopy with JWST's NIRISS

Proceedings of the International Astronomical Union ◽

10.1017/s1743921315009862 ◽

2015 ◽

Vol 11 (S319) ◽

pp. 11-11

Author(s):

William V. Dixon ◽

Swara Ravindranath ◽

Chris J. Willott

Keyword(s):

Near Infrared ◽

High Redshift ◽

Galaxy Cluster ◽

Optical Emission ◽

Resolving Power ◽

Wide Field ◽

First Stars ◽

James Webb Space Telescope ◽

Infrared Imager ◽

High Redshift Universe

AbstractThe Near Infrared Imager and Slitless Spectrograph (NIRISS) aboard the James Webb Space Telescope (JWST) will offer wide-field slitless spectroscopy (WFSS) with a resolving power R = 150 at wavelengths from 0.8 to 2.25 microns. In this band, NIRISS will be sensitive to Lyman α emission lines and continuum breaks in the spectra of galaxies with redshifts 6 < z < 17, allowing it to probe the first stars and ionizing sources in the early universe. NIRISS observations of the high-redshift universe will provide a wealth of information on foreground objects, creating a unique library of optical emission-line spectra from the faintest galaxies at lower redshifts. To explore its ability to identify and characterize galaxies at all redshifts, we have modeled a NIRISS observation of a massive strong-lensing galaxy cluster and analyzed the synthetic images using standard software tools. Our simulations demonstrate that WFSS with NIRISS will provide a powerful tool for the exploration of galaxies near and far.

Download Full-text

NIR Follow-Up of the VVDS 02hr Field: First Results

Proceedings of the International Astronomical Union ◽

10.1017/s1743921306010593 ◽

2006 ◽

Vol 2 (S235) ◽

pp. 432-437

Author(s):

S. Temporin ◽

A. Iovino ◽

H. J. McCracken ◽

M. Bolzonella ◽

M. Scodeggio ◽

...

Keyword(s):

Near Infrared ◽

High Redshift ◽

First Results ◽

Band Survey ◽

K Band

AbstractWe present a new K-band survey covering 623 arcmin2 in the VVDS 0226-0430 deep field down to a limiting magnitude KVega ≤ 20.5. We use the spectroscopic sample extracted from this new K-band catalogue to assess the effectiveness of optical-near infrared color selections in identifying extreme classes of objects at high redshift.

Download Full-text

The GLEAMing of the first supermassive black holes

Publications of the Astronomical Society of Australia ◽

10.1017/pasa.2020.6 ◽

2020 ◽

Vol 37 ◽

Author(s):

Guillaume Drouart ◽

Nick Seymour ◽

Tim J. Galvin ◽

Jose Afonso ◽

Joseph R. Callingham ◽

...

Keyword(s):

Near Infrared ◽

High Redshift ◽

Pilot Project ◽

Radio Galaxies ◽

Host Galaxy ◽

Wide Field ◽

Powerful Radio ◽

Massive Galaxies ◽

Luminous Objects

Abstract We present the results of a new selection technique to identify powerful ( $L_{\rm 500\,MHz} \gt 10^{27}\,\text{WHz}^{-1}$ ) radio galaxies towards the end of the Epoch of Reionisation. Our method is based on the selection of bright radio sources showing radio spectral curvature at the lowest frequency ( ${\sim}100\,\text{MHz}$ ) combined with the traditional faintness in K-band for high-redshift galaxies. This technique is only possible, thanks to the Galactic and Extra-galactic All-sky Murchison Wide-field Array survey which provides us with 20 flux measurements across the 70– $230\,\text{MHz}$ range. For this pilot project, we focus on the GAMA 09 field to demonstrate our technique. We present the results of our follow-up campaign with the Very Large Telescope, Australian Telescope Compact Array, and the Atacama Large Millimetre Array to locate the host galaxy and to determine its redshift. Of our four candidate high-redshift sources, we find two powerful radio galaxies in the $1<z<3$ range, confirm one at $z=5.55$ , and present a very tentative $z=10.15$ candidate. Their near-infrared and radio properties show that we are preferentially selecting some of the most radio luminous objects, hosted by massive galaxies very similar to powerful radio galaxies at $1<z<5$ . Our new selection and follow-up technique for finding powerful radio galaxies at $z>5.5$ has a high 25–50% success rate.

Download Full-text