A large, deep 3 deg$^2$ survey of H$α$, [OIII], and [OII] emitters from LAGER: constraining luminosity functions
Ali Ahmad Khostovan, Sangeeta Malhotra, James E. Rhoads, Chunyan Jiang, Junxian Wang, Isak Wold, Zhen-Ya Zheng, L. Felipe Barrientos, Alicia Coughlin, Santosh H… 展开作者
Ali Ahmad Khostovan, Sangeeta Malhotra, James E. Rhoads, Chunyan Jiang, Junxian Wang, Isak Wold, Zhen-Ya Zheng, L. Felipe Barrientos, Alicia Coughlin, Santosh Harish, Weida Hu, Leopoldo Infante, Lucia A. Perez, John Pharo, Francisco Valdes, Alistair R. Walker, Huan Yang
备注：
21 pages, 12 figures, 6 Tables. Accepted by MNRAS for publication on 6 Jan 2020
We present our measurements of the H$α$, [OIII], and [OII] luminosity functions as part of the Lyman Alpha Galaxies at Epoch of Reionization (LAGER) survey using our samples of 1577 $z = 0.47$ H$α$-, 3933 $z = 0.93$ [OIII]-, and 5367 $z = 1.59$ [OII]-selected emission line galaxies in a single 3 deg$^2$ CTIO/Blanco DECam pointing of the COSMOS field. Our observations reach 5$σ$ depths of $8.2\times10^{-18}$ erg s$^{-1}$ cm$^{-2}$ and comoving volumes of $(1-7)\times10^{5}$ Mpc$^3$ making our survey one of the deepest narrowband surveys. We measure the observed luminosity functions and find best-fits of $ϕ^\star = 10^{-3.16\pm0.09}$ Mpc$^{-3}$ and $L^\star = 10^{41.72\pm0.09}$ erg s$^{-1}$ for H$α$, $ϕ^\star = 10^{-2.16^{+0.10}_{-0.12}}$ Mpc$^{-3}$ and $L^\star = 10^{41.38^{+0.07}_{-0.06}}$ erg s$^{-1}$ for [OIII], and $ϕ^\star = 10^{-1.97^{+0.07}_{-0.07}}$ Mpc$^{-3}$ and $L^\star = 10^{41.66\pm0.03}$ erg s$^{-1}$ for [OII], with $α$ fixed to $-1.75$, $-1.6$, and $-1.3$, respectively. An excess of bright $> 10^{42}$ erg s$^{-1}$ [OIII] emitters is observed and may be due to AGN contamination. Dust corrections are applied assuming $A_{\rm{H}α} = 1$ mag. We also design our own empirical rest-frame $g - r$ calibration using SDSS DR12 data, test it against our $z = 0.47$ H$α$ emitters with $z$COSMOS $1$D spectra, and calibrate it for $(g - r)$ between $-0.8$ and $1.3$ mag. Dust and AGN-corrected star formation rate densities (SFRDs) are measured as $\log_{10}ρ_{\rm{SFR}}/(\rm{M}_\odot\ \rm{yr}^{-1}\ \rm{Mpc}^{-3}) = -1.63\pm0.04$, $-1.07\pm0.06$, and $-0.90\pm0.10$ for H$α$, [OIII], and [OII], respectively. We find our [OIII] and [OII] samples fully trace cosmic star formation activity at their respective redshifts in comparison to multi-wavelength SFRDs, while the H$α$ sample traces $\sim 70$ percent of the total $z = 0.47$ SFRD.
We investigate the properties of $z$=2.23 H$α$ and [OIII]$λ$5007 emitters using the narrow-band-selected samples obtained from the High-$z$ Emission Line Survey (HiZELS: Sobral et al. 2013). We construct two samples of the H$α$ and [OIII] emitters and compare their integrated physical properties. We find that the distribution of stellar masses, dust extinction, star formation rates (SFRs), and specific SFRs, is not statistically different between the two samples. When we separate the full galaxy sample into three subsamples according to the detections of the H$α$ and/or [OIII] emission lines, …
We have found a sample of extreme emission-line galaxies (EELGs) with strong [OIII]$λ$5007 emission at z $\sim$ 0.5. Using broadband photometric selection and requiring small uncertainties in photometry, we searched the 14th Data Release (DR14) of the Sloan Digital Sky Survey (SDSS) and found 2658 candidates with strong i-band excess (i - z $\leqslant$ r - i - 0.7). We further obtained 649 SDSS spectra of these objects, and visually identified 22 [OIII] emitters lying at 0.40 $<$ z $<$ 0.63. Having constructed their UV-IR spectral energy distributions (SED) we found that they have fairly blue …
JWST & ALMA Joint Analysis with [OII]$λλ$3726,3729, [OIII]$λ$4363, [OIII]88$μ$m, and [OIII]52$μ$m: Multi-Zone Evolution of Electron Densities at $\mathbf{z\sim0-14}$ and Its Impact on Metallicity Measurements
In this manuscript, we check the well-known correlation between \oiii luminosity and continuum luminosity (\loiiicon) for AGN by a large sample of 1982 SDSS QSOs with $z<0.8$ and with high quality spectra. The strong correlation of \loiiicon can be found, similar as previous results for AGN. Moreover, among the 1982 QSOs, there are 708 QSOs with the [O~{\sc iii}]$λ$5007Å described by two components: one core component plus one extended component. Based on the luminosity from the core components ($L_{\rm [O~\textsc{iii}],~narrow}$) and from the extended components ($L_{\rm [O~\textsc{iii}],~ext…
Recent work has suggested extreme [OIII] emitting star-forming galaxies are important to reionization. Relatedly, [OIII]/[OII] has been put forward as an indirect estimator of the Lyman Continuum (LyC) escape fraction ($f_{esc}$) at $z\gtrsim4.5$ when the opaque IGM renders LyC photons unobservable. Using deep archival U-band (VLT/VIMOS) imaging of a recently confirmed overdensity at $z\sim3.5$ we calculate tight constraints on $f_{esc}$ for a sample (N=73) dominated by extreme [OIII] emitters. We find no Lyman Continuum signal ($f_{esc}^{rel} < 6.3^{+0.7}_{-0.7} \%$ at $1σ$) in a deep U-band …
Using a large sample of sub-L$_*$ galaxies, with similar UV magnitudes, M$_{\rm UV}\simeq -19$ at $z\simeq6$, extracted from the FirstLight simulations, we show the diversity of galaxies at the end of the reionization epoch. We find a factor $\sim$40 variation in the specific star-formation rate (sSFR). This drives a $\sim$1 dex range in equivalent width of the [OIII]$λ$5007 line. Variations in nebular metallicity and ionization parameter within HII regions lead to a scatter in the equivalent widths and [OIII]/H$α$ line ratio at a fixed sSFR. [OIII]-bright emitters ([OIII]/H$α$>1) have higher …
We present Keck/MOSFIRE spectra of the diagnostic nebular emission lines [OIII]5007,4959, [OII]3727, and H-beta for a sample of 15 redshift z=3.1-3.7 Ly-alpha emitters (LAEs) and Lyman break galaxies (LBGs). In conjunction with spectra from other surveys, we confirm earlier indications that LAEs have a much higher [OIII]/[OII] line ratio than is seen in similar redshift LBGs. By comparing their distributions on a [OIII]/[OII] versus R23 diagram, we demonstrate that this difference cannot arise solely because of their lower metallicities but most likely is due to a harder ionizing spectrum. Usi…
Recent observations with the Atacama Large Millimeter/submillimeter Array (ALMA) detected far-infrared emission lines such as the [OIII] 88 μm line from galaxies at $z \sim 7 - 9$. Far-infrared lines can be used to probe the structure and kinematics of such high-redshift galaxies as well as to accurately determine their spectroscopic redshifts. We use a cosmological simulation of galaxy formation to study the physical properties of [OIII] 88 μm emitters. In a comoving volume of 50 $h^{-1}$ Mpc on a side, we locate 34 galaxies with stellar masses greater than $10^8\ {\rm M_\odot}$ at $z = 9$, a…
We characterise ionised gas outflows using a large sample of ~330 high-luminosity (45.5 < log(L_bol/erg s^-1) < 49.0), high-redshift (1.5 < z < 4.0) quasars via their [OIII]4960,5008 emission. The median velocity width of the [OIII] emission line is 1540 kms^-1, increasing with increasing quasar luminosity. Broad, blue-shifted wings are seen in the [OIII] profiles of 42 per cent of the sample. Rest-frame ultraviolet spectra with well-characterised CIV 1550 emission line properties are available for more than 210 quasars, allowing an investigation of the relationship between the Broad Line Regi…
This study explores the link between the [OIII]88mu emission, a well-known tracer of HII regions, and 24mu continuum, often used to trace warm dust in the ionized phases of galaxies. We investigate the local conditions driving the relation between those tracers in the Magellanic Clouds, comparing observations with Cloudy models consisting of an HII region plus a photodissociation region (PDR) component, varying the stellar age, the initial density (at the illuminated edge of the cloud), and the ionization parameter. We introduce a new parameter, cPDR, to quantify the proportion of emission ari…
We discuss the rest-frame optical emission line spectra of a large (~50) sample of z=3.1 Lyman alpha emitters (LAEs) whose physical properties suggest such sources are promising analogs of galaxies in the reionization era. Reliable Lyman continuum escape fractions have now been determined for a large sample of such LAEs from the Lyman Continuum Escape Survey (LACES) undertaken via deep HST imaging in the SSA22 survey area reported in Fletcher et al. (2019). Using new measures of [OII] emission secured from Keck MOSFIRE spectra we re-examine, for a larger sample, earlier claims that Lyman conti…
For a sample of $\sim$80 local ($0.02 \leq z \leq 0.1$) Seyfert-1 galaxies with high-quality long-slit Keck spectra and spatially-resolved stellar-velocity dispersion ($σ_{\star}$) measurements, we study the profile of the [OIII]$λ$5007A emission line to test the validity of using its width as a surrogate for $σ_{\star}$. Such an approach has often been used in the literature, since it is difficult to measure $σ_{\star}$ for type-1 active galactic nuclei (AGNs) due to the AGN continuum outshining the stellar-absorption lines. Fitting the [OIII] line with a single Gaussian or Gauss-Hermite poly…
The James Webb Space Telescope will allow to spectroscopically study an unprecedented number of galaxies deep into the reionization era, notably by detecting [OIII] and H$β$ nebular emission lines. To efficiently prepare such observations, we photometrically select a large sample of galaxies at $z\sim8$ and study their rest-frame optical emission lines. Combining data from the GOODS Re-ionization Era wide-Area Treasury from Spitzer (GREATS) survey and from HST, we perform spectral energy distribution (SED) fitting, using synthetic SEDs from a large grid of photoionization models. The deep Spit…
We present the results of the deep Subaru/FOCAS and Keck/MOSFIRE spectroscopy for four spatially extended [O III]$λλ$4959,5007 sources, dubbed [O III] blobs, at $z=0.6-0.8$ that are originally pinpointed by large-area Subaru imaging surveys. The line diagnostics of the rest-frame optical lines suggests that only one [O III] blob, OIIIB-3, presents an AGN signature, indicating that hot gas of the rest of the [O III] blobs is heated by star formation. One of such star-forming [O III] blobs, OIIIB-4, at $z=0.838$ has an [O III] equivalent width of $845\pm27$ Å and an [O III] to [O II]$λλ$3726,372…
We analyze VLT/X-shooter data for 7 quasars, where we study the relationships between their broad absorption line (BAL) and emission line outflows. We find: 1) the luminosity of the [OIII] $λ$5007 emission profile decreases with increasing electron number density (n$_e$) derived from the BAL outflow in the same quasar, 2) the measured velocity widths from the [OIII] emission features and CIV absorption troughs in the same object are similar, and 3) the mean radial velocity derived from the BAL outflow is moderately larger than the one from the [OIII] emission outflow. These findings can be exp…
We present VLT-SINFONI near infra-red spectra of 26 new heavily reddened quasar candidates selected from the UKIDSS-LAS, VISTA VHS and VIKING imaging surveys. This new sample extends our reddened quasar search to both brighter and fainter luminosities. 25 of the 26 candidates are confirmed to be broad line quasars with redshifts $0.7<z<2.6$ and dust extinctions $0.5<E(B-V)<3.0$. Combining with previously identified samples, we study the H$α$, H$β$ and [OIII] emission line properties in 22 heavily reddened quasars with $L_{bol}\approx 10^{47}$ erg/s and $z>2$. We present the first comparison of…
We investigate the redshift evolution of the [OIII]/Hb nebular emission line ratio for a sample of galaxies spanning the redshift range 0 < z < 4. We compare the observed evolution to a set of theoretical models which account for the independent evolution of chemical abundance, ionization parameter and interstellar-medium (ISM) pressure in star-forming galaxies with redshift. Accounting for selection effects in the combined datasets, we show that the evolution to higher [OIII]/Hb ratios with redshift is a real physical effect which is best accounted for by a model in which the ionization param…
We conduct a systematic search for galaxies at $z=0.1-1.5$ with [OII]$\lambda3727$, [OIII]$\lambda5007$, or H$α\lambda6563$ emission lines extended over at least 30 kpc by using deep narrowband and broadband imaging in Subaru-XMM Deep Survey (SXDS) field. These extended emission-line galaxies are dubbed [OII], [OIII], or H$α$ blobs. Based on a new selection method that securely selects extended emission-line galaxies, we find 77 blobs at $z=0.40-1.46$ with the isophotal area of emission lines down to $1.2\times10^{-18}$ erg s$^{-1}$ cm$^{-2}$ kpc$^{-2}$. Four of them are spectroscopically conf…
We investigate the properties of $\sim7000$ narrow-band selected galaxies with strong H$β+$[OIII] and [OII] nebular emission lines from the High-$z$ Emission Line Survey (HiZELS) between $z \sim 0.8 - 5.0$. Our sample covers a wide range in stellar mass ($M\sim10^{7.5 - 12.0}$ M$_\odot$), rest-frame equivalent widths (EW$_\mathrm{rest}\sim 10 - 10^5$ Å), and line luminosities ($L\sim10^{40.5 - 43.2}$ erg s$^{-1}$). We measure the H$β+$[OIII] and [OII]-selected stellar mass functions out to $z \sim 3.5$ and find that both $M_\star$ and $ϕ_\star$ increases with cosmic time, which may be due to t…
We investigate Extremely Red Quasars (ERQs), a remarkable population of heavily-reddened quasars at redshift z$\sim$2 - 3 that might be caught during a short-lived 'blow-out' phase of quasar/galaxy evolution. We perform a near-IR observational campaign using Keck/NIRSPEC, VLT/X-shooter and Gemini/GNIRS to measure rest-frame optical spectra of 28 ERQs with median infrared luminosity $\langle$log L(erg/s)$\rangle$ $\sim$46.2. They exhibit the broadest and most blue-shifted [OIII] $λ$4959,5007 emission lines ever reported, with widths (w90) ranging between 2053 and 7227 km/s, and maximum outflow …
Galaxies in the reionization-era have been shown to have prominent [OIII]+H$β$ emission. Little is known about the gas conditions and radiation field of this population, making it challenging to interpret the spectra emerging at $z\gtrsim6$. Motivated by this shortcoming, we have initiated a large MMT spectroscopic survey identifying rest-frame optical emission lines in 227 intense [OIII] emitting galaxies at $1.3<z<2.4$. This sample complements the MOSDEF and KBSS surveys, extending to much lower stellar masses ($10^7-10^8 M_\odot$) and larger specific star formation rates ($5-300$ Gyr$^{-1}$…
We present observations with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope of five star-forming galaxies at redshifts z in the range 0.2993-0.4317 and with high emission-line flux ratios O32=[OIII]5007/[OII]3727 ~ 8-27 aiming to detect the Lyman continuum (LyC) emission. We detect LyC emission in all galaxies with the escape fractions fesc(LyC) in a range of 2-72 per cent. A narrow Ly-alpha emission line with two peaks in four galaxies and with three peaks in one object is seen in medium-resolution COS spectra with a velocity separation between the peaks Vsep varying from …
Intensity mapping is now becoming a useful tool to study the large-scale structure of the universe through spatial variations in the integrated emission from galaxies and the intergalactic medium. We study intensity mapping of the H-alpha 6563AA, [OIII]5007AA, [OII]3727AA and H-beta 4861AA lines at 0.8<z<5.2. The mean intensities of these four emission lines are estimated using the observed luminosity functions (LFs), cosmological simulations, and the star formation rate density (SFRD) derived from observations at z<5. We calculate the intensity power spectra and consider the foreground contam…
We investigate the clustering properties of $\sim 7000$ H$β$+[OIII] and [OII] narrowband-selected emitters at $z \sim 0.8 - 4.7$ from the High-$z$ Emission Line Survey. We find clustering lengths, $r_0$, of $1.5 - 4.0h^{-1}$ Mpc and minimum dark matter halo masses of $10^{10.7 - 12.1}\rm{M}_\odot$ for our $z = 0.8 - 3.2$ H$β$+[OIII] emitters and $r_0 \sim 2.0 - 8.3h^{-1}$ Mpc and halo masses of $10^{11.5 - 12.6}\rm{M}_\odot$ for our $z = 1.5 - 4.7$ [OII] emitters. We find $r_0$ to strongly increase both with increasing line luminosity and redshift. By taking into account the evolution of the c…
We present new results from near-infrared spectroscopy with Keck/MOSFIRE of [OIII]-selected galaxies at $z\sim3.2$. With our $H$ and $K$-band spectra, we investigate the interstellar medium (ISM) conditions, such as ionization states and gas metallicities. [OIII] emitters at $z\sim3.2$ show a typical gas metallicity of $\mathrm{12+log(O/H) = 8.07\pm0.07}$ at $\mathrm{log(M_*/M_\odot) \sim 9.0-9.2}$ and $\mathrm{12+log(O/H) = 8.31\pm0.04}$ at $\mathrm{log(M_*/M_\odot) \sim 9.7-10.2}$ when using the empirical calibration method. We compare the [OIII] emitters at $z\sim3.2$ with UV-selected galax…
With the Atacama Large Millimeter/sub-millimeter Array (ALMA), we report detections of the far-infrared (FIR) [OIII] 88 $μ$m line and the underlying dust continuum in the two quasars in the reionization epoch, J205406.48-000514.8 (hereafter J2054-0005) at $z=6.0391\pm0.0002$ and J231038.88+185519.7 (hereafter J2310+1855) at $z=6.0035\pm0.0007$. The [OIII] luminosity of J2054-0005 and J2310+1855 are $L_{\rm [OIII]} = (6.8\pm0.6) \times 10^{9}$ and $(2.4\pm0.6) \times 10^{9}$ $L_{\rm \odot}$, corresponding to $\approx$ 0.05\%\ and 0.01\%\ of the total infrared luminosity, $L_{\rm TIR}$, respecti…
A GLIMPSE into the very faint-end of the H$β$+[OIII]$λλ$4960,5008 luminosity function at z=7-9 behind Abell S1063
Observatoire de Genève, Université de Genève（日内瓦天文台，日内瓦大学）；Institut d’Astrophysique de Paris, CNRS, Sorbonne Université（巴黎天体物理研究所，法国国家科学研究中心，索邦大学）；Department of Physics, Ben-Gurion University of the Negev（内盖夫本-古里安大学物理系）；Department of Astronomy, The University of Texas at Austin（德克萨斯大学奥斯汀分校天文学系）；CNRS, IRAP（法国国家科学研究中心，天体物理研究所）；Department of Astronomy, Oskar Klein Centre, Stockholm University（斯德哥尔摩大学奥斯卡·克莱因中心天文学系）
We quantify the distribution of [OIII]+H$β$ line strengths at z$\simeq$7 using a sample of 20 bright (M$_{\mathrm{UV}}$ $\lesssim$ $-$21) galaxies. We select these systems over wide-area fields (2.3 deg$^2$ total) using a new colour-selection which precisely selects galaxies at z$\simeq$6.63$-$6.83, a redshift range where blue Spitzer/IRAC [3.6]$-$[4.5] colours unambiguously indicate strong [OIII]$+$H$β$ emission. These 20 galaxies suggest a log-normal [OIII]$+$H$β$ EW distribution with median EW = 759$^{+112}_{-113}$ $\mathrm{\mathring{A}}$ and standard deviation = 0.26$^{+0.06}_{-0.05}$ dex.…
We present the first results of our pilot study of 8 photometrically selected Lyman continuum (LyC) emitting galaxy candidates from the COSMOS field and focus on their optical emission line ratios. Observations were performed in the H and K bands using the Multi-Object Spectrometer for Infra-Red Exploration (MOSFIRE) instrument at the Keck Observatory, targeting the [OII], H$β$, and [OIII] emission lines. We find that photometrically selected LyC emitting galaxy candidates have high ionization parameters, based on their high [OIII]/[OII] ratios (O32), with an average ratio for our sample of 2.…
To understand how strong emission line galaxies (ELGs) contribute to the overall growth of galaxies and star formation history of the universe, we target Strong ELGs (SELGs) from the ZFOURGE imaging survey that have blended (Hb+[OIII]) rest-frame equivalent widths of >230A and 2.5<zphot<4.0. Using Keck/MOSFIRE, we measure 49 redshifts for galaxies brighter than Ks=25 mag as part of our Multi-Object Spectroscopic Emission Line (MOSEL) survey. Our spectroscopic success rate is ~53% and zphot uncertainty is sigma_z= [Delta(z)/(1+z)]=0.0135. We confirm 31 ELGs at 3<zspec<3.8 and show that Strong E…
Recent surveys have identified a seemingly ubiquitous population of galaxies with elevated [OIII]/H$β$ emission line ratios at $z > 1$, though the nature of this phenomenon continues to be debated. The [OIII]/H$β$ line ratio is of interest because it is a main component of the standard diagnostic tools used to differentiate between active galactic nuclei (AGN) and star-forming galaxies, as well as the gas-phase metallicity indicators $O_{23}$ and $R_{23}$. Here, we investigate the primary driver of increased [OIII]/H$β$ ratios by median-stacking rest-frame optical spectra for a sample of star-…
We investigate electron temperature (Te) and gas-phase oxygen abundance (Z_Te) measurements for galaxies in the local Universe (z < 0.25). Our sample comprises spectra from a total of 264 emission-line systems, ranging from individual HII regions to whole galaxies, including 23 composite HII regions from "star-forming main sequence" galaxies in the MaNGA survey. We utilise 130 of these systems with directly measurable Te(OII) to calibrate a new metallicity-dependent Te(OIII) - Te(OII) relation that provides a better representation of our varied dataset than existing relations from the literatu…
Strong [OIII]$+$H$β$ emitters dominated the ionizing budget at $z\sim7$
Astrophysics Science Division, Goddard Space Flight Center（天体物理学科学部，戈达德太空飞行中心）；The Catholic University of America（美国天主教大学）；Center for Research and Exploration in Space Science and Technology, NASA/GSFC（NASA/戈达德太空飞行中心空间科学与技术研究与探索中心）
We make use of \textit{JWST} medium and broad-band NIRCam imaging, along with ultra-deep MIRI $5.6 \rm μm$ imaging, in the Hubble eXtreme Deep Field (XDF) to identify prominent line emitters at $z\simeq 7-8$. Out of a total of 58 galaxies at $z\simeq 7-8$, we find 18 robust candidates ($\simeq$31\%) for (H$β$ + [OIII]) emitters, based on their enhanced fluxes in the F430M and F444W filters, with EW$_{0}$(H$β$ +[OIII]) $\simeq 87 - 2100$ Å. Among these emitters, 16 lie in the MIRI coverage area and 12 exhibit a clear flux excess at $5.6 \, \rm μm$, indicating the simultaneous presence of a prom…
We present new ALMA observations and physical properties of a Lyman Break Galaxy at z=7.15. Our target, B14-65666, has a bright ultra-violet (UV) absolute magnitude, $M_{\rm UV}\approx-22.4$, and has been spectroscopically identified in Ly$α$ with a small rest-frame equivalent width of $\approx4$ Å. Previous HST image has shown that the target is comprised of two spatially separated clumps in the rest-frame UV. With ALMA, we have newly detected spatially resolved [OIII] 88 $μ$m, [CII] 158 $μ$m, and their underlying dust continuum emission. In the whole system of B14-65666, the [OIII] and [CII]…
As the James Webb Space Telescope approaches scientific operation, there is much interest in exploring the redshift range beyond that accessible with Hubble Space Telescope imaging. Currently, the only means to gauge the presence of such early galaxies is to age-date the stellar population of systems in the reionisation era. As a significant fraction of $z\simeq7-8$ galaxies are inferred from Spitzer photometry to have extremely intense [OIII] emission lines, it is commonly believed these are genuinely young systems that formed at redshifts $z<10$, consistent with a claimed rapid rise in the s…
We present a study of the [OIII]5007/[OII]3727 (O32) ratios of star-forming galaxies drawn from MUSE data spanning a redshift range 0.28<z<0.85. Recently discovered Lyman continuum (LyC) emitters have extremely high oxygen line ratios: O32>4. Here we aim to understand the properties and the occurrences of galaxies with such high line ratios. Combining data from several MUSE GTO programmes, we select a population of star-forming galaxies with bright emission lines, from which we draw 406 galaxies for our analysis based on their position in the z-dependent star formation rate (SFR) - stellar mas…
Of the almost 40 star forming galaxies at z>~5 (not counting QSOs) observed in [CII] to date, nearly half are either very faint in [CII], or not detected at all, and fall well below expectations based on locally derived relations between star formation rate (SFR) and [CII] luminosity. Combining cosmological zoom simulations of galaxies with SIGAME (SImulator of GAlaxy Millimeter/submillimeter Emission) we have modeled the multi-phased interstellar medium (ISM) and its emission in [CII], [OI] and [OIII], from 30 main sequence galaxies at z~6 with star formation rates ~3-23Msun/yr, stellar masse…
Origins of Extreme Emission-Line Ratios in z > 3 Galaxies: Insights from the Lumen Model
École Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）；INAF-Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）；Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris（索邦大学、法国国家科学研究中心、巴黎天体物理研究所）；Center for Computational Astrophysics, Flatiron Institute（平顿研究所计算天体物理学中心）；University of Hertfordshire（赫特福德大学）；INAF – Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿尔切特里天文台）；Département d’Astronomie, Université de Genève（日内瓦大学天文学系）
We present new ALMA Band 8 (rest-frame $90\,μ$m) observations of three massive ($M_\star \approx 10^{10}\,M_\odot$) galaxies at $z\approx7$ previously detected in [CII]$158\,μ$m and underlying dust continuum emission in the Reionization Era Bright Emission Line Survey (REBELS). We detect the dust continuum emission of two of our targets in Band 8 (REBELS-25 and REBELS-38), while REBELS-12 remains undetected. Through modified blackbody fitting we determine cold dust temperatures ($T_\mathrm{dust} \approx 30 - 35\,$K) in both of the dual-band detected targets, given a fiducial model of optically…
We study statistics of the 21-cm signal from the epoch of reionization. We propose to use [OIII] line emitting galaxies to cross-correlate with the 21-cm signal from $z = 7 - 10$. To this aim, we employ simulations of reionization obtained post-processing the high-resolution cosmological hydrodynamic simulation Massive Black-II with the three-dimensional (3D) radiative transfer code CRASH to follow the propagation of ionizing photons from a variety of sources. We show that, during the early phases of reionization, the 21-cm signal is positively correlated with the spatial distribution of the […
We present spatially-resolved morphological properties of [CII] 158 $μ$m, [OIII] 88 $μ$m, dust, and rest-frame ultraviolet (UV) continuum emission for A1689-zD1, a strongly lensed, sub-L* galaxy at $z=7.13$, by utilizing deep Atacama Large Millimeter/submillimeter Array (ALMA) and Hubble Space Telescope (HST) observations. While the [OIII] line and UV continuum are compact, the [CII] line is extended up to a radius of $r \sim 12$ kpc. Using multi-band rest-frame far-infrared (FIR) continuum data ranging from 52-400 $μ$m, we find an average dust temperature and emissivity index of $T_{\rm dust}…
