Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userEvolution of the H$beta$+[OIII] and [OII] luminosity functions and the [OII] star-formation history of the Universe up to $z$ ~ 5 from HiZELS
135
0
0.0
(
0
)
Added by
Ali Ahmad Khostovan
Publication date
2015
fields
Physics
and research's language is
English
Ask ChatGPT about the research
No Arabic abstract
We investigate the evolution of the H$beta$+[OIII] and [OII] luminosity functions from $z sim 0.8$ to $sim5$ in four redshift slices per emission line using data from the High-{it z} Emission Line Survey (HiZELS). This is the first time that the H$beta$+[OIII] and [OII] luminosity functions have been studied at these redshifts in a self-consistent analysis. This is also the largest sample of [OII] and H$beta$+[OIII] emitters (3475 and 3298 emitters, respectively) in this redshift range, with large co-moving volumes $sim 1 times 10^6$ Mpc$^{-3}$ in two independent volumes (COSMOS and UDS), greatly reducing the effects of cosmic variance. The emitters were selected by a combination of photometric redshift and color-color selections, as well as spectroscopic follow-up, including recent spectroscopic observations using DEIMOS and MOSFIRE on the Keck Telescopes and FMOS on Subaru. We find a strong increase in $L_star$ and a decrease in $phi_star$ for both H$beta$+[OIII] and [OII] emitters. We derive the [OII] star-formation history of the Universe since $zsim5$ and find that the cosmic SFRD rises from $z sim 5$ to $sim 3$ and then drops towards $z sim 0$. We also find that our star-formation history is able to reproduce the evolution of the stellar mass density up to $zsim 5$ based only on a single tracer of star-formation. When comparing the H$beta$+[OIII] SFRDs to the [OII] and H$alpha$ SFRD measurements in the literature, we find that there is a remarkable agreement, suggesting that the H$beta$+[OIII] sample is dominated by star-forming galaxies at high-$z$ rather than AGNs.
rate research
Read More
We investigate the clustering properties of $sim 7000$ H$beta$+[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$beta$+[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 characteristic line luminosity, $L^star(z)$, and using our model predictions of halo mass given $r_0$, we find a strong, redshift-independent increasing trend between $L/L^star(z)$ and minimum halo mass. The faintest H$beta$+[OIII] emitters are found to reside in $10^{9.5}rm{M}_odot$ halos and the brightest emitters in $10^{13.0}rm{M}_odot$ halos. For [OII] emitters, the faintest emitters are found in $10^{10.5} rm{M}_odot$ halos and the brightest emitters in $10^{12.6}rm{M}_odot$ halos. A redshift-independent stellar mass dependency is also observed where the halo mass increases from $10^{11}rm{M}_odot$ to $10^{12.5} rm{M}_odot$ for stellar masses of $10^{8.5}rm{M}_odot$ to $10^{11.5}rm{M}_odot$, respectively. We investigate the interdependencies of these trends by repeating our analysis in a $L_textrm{line} - rm{M}_textrm{star}$ grid space for our most populated samples (H$beta$+[OIII] $z = 0.84$ and [OII] $z = 1.47$) and find that the line luminosity dependency is stronger than the stellar mass dependency on halo mass. For $L > L^star$ emitters at all epochs, we find a relatively flat trend with halo masses of $10^{12.5 - 13}rm{M}_odot$ which may be due to quenching mechanisms in massive halos which is consistent with a transitional halo mass predicted by models.
We present results from the largest contiguous narrow-band survey in the near-infrared. We have used WIRCam/CFHT and the lowOH2 filter (1.187$pm$0.005 $mu$m) to survey ~10 deg$^2$ of contiguous extragalactic sky in the SA22 field. A total of ~6000 candidate emission-line galaxies are found. We use deep ugrizJK data to obtain robust photometric redshifts. We combine our data with the High-redshift Emission Line Survey (HiZELS), explore spectroscopic surveys (VVDS, VIPERS) and obtain our own spectroscopic follow-up with KMOS, FMOS and MOSFIRE to derive large samples of high-redshift emission-line selected galaxies: 3471 H$alpha$ emitters at z=0.8, 1343 [OIII]+H$beta$ emitters at z=1.4 and 572 [OII] emitters at z=2.2. We probe co-moving volumes of >10$^6$ Mpc$^3$ and find significant over-densities, including an 8.5$sigma$ (spectroscopically confirmed) over-density of H$alpha$ emitters at z=0.81. We derive H$alpha$, [OIII]+H$beta$ and [OII] luminosity functions at z=0.8,1.4,2.2, respectively, and present implications for future surveys such as Euclid. Our uniquely large volumes/areas allow us to sub-divide the samples in thousands of randomised combinations of areas and provide a robust empirical measurement of sample/cosmic variance. We show that surveys for star-forming/emission-line galaxies at a depth similar to ours can only overcome cosmic-variance (errors <10%) if they are based on volumes >5x10$^{5}$ Mpc$^{3}$; errors on $L^*$ and $phi^*$ due to sample (cosmic) variance on surveys probing ~10$^4$ Mpc$^{3}$ and ~10$^5$ Mpc$^{3}$ are typically very high: ~300% and ~40-60%, respectively.
We present our measurements of the H$alpha$, [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$alpha$-, 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$sigma$ depths of $8.2times10^{-18}$ 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 $phi^star = 10^{-3.16pm0.09}$ Mpc$^{-3}$ and $L^star = 10^{41.72pm0.09}$ erg s$^{-1}$ for H$alpha$, $phi^star = 10^{-2.16^{+0.10}_{-0.12}}$ Mpc$^{-3}$ and $L^star = 10^{41.38^{+0.07}_{-0.06}}$ erg s$^{-1}$ for [OIII], and $phi^star = 10^{-1.97^{+0.07}_{-0.07}}$ Mpc$^{-3}$ and $L^star = 10^{41.66pm0.03}$ erg s$^{-1}$ for [OII], with $alpha$ 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 $A_{rm{H}alpha} = 1$ mag. We also design our own empirical rest-frame $g - r$ calibration using SDSS DR12 data, test it against our $z = 0.47$ H$alpha$ 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 $log_{10}rho_{rm{SFR}}/(rm{M}_odot rm{yr}^{-1} rm{Mpc}^{-3}) = -1.63pm0.04$, $-1.07pm0.06$, and $-0.90pm0.10$ for H$alpha$, [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$alpha$ sample traces $sim 70$ percent of the total $z = 0.47$ SFRD.
We present the [OII] luminosity function measured in the redshift range 0.1<z<1.65 with unprecedented depth and accuracy. Our measurements are based on medium resolution flux-calibrated spectra of emission line galaxies with the FORS2 instrument at VLT and with the SDSS-III/BOSS spectrograph. The FORS2 spectra and the corresponding catalog containing redshifts and line fluxes are released along with this paper. In this work we use a novel method to combine the aforementioned surveys with GAMA, zCOSMOS and VVDS, which have different target selection, producing a consistent weighting scheme to derive the [OII] luminosity function. The measured luminosity function is in good agreement with previous independent estimates. The comparison with two state-of-the-art semi-analytical models is good, which is encouraging for the production of mock catalogs of [OII] flux limited surveys. We observe the bright end evolution over 8.5 Gyr: we measure the decrease of log L* from 42.4 erg/s at redshift 1.44 to 41.2 at redshift 0.165 and we find that the faint end slope flattens when redshift decreases. This measurement confirms the feasibility of the target selection of future baryonic acoustic oscillation surveys aiming at observing [OII] flux limited samples.
The measurement of the Star Formation Rate density of the Universe is of prime importance in understanding the formation and evolution of galaxies. The [OII]3727 emission line flux, easy to measure up to z~1.4 within deep redshift surveys in the optical and up to z~5.4 in the near infrared, offers a reliable means of characterizing the star formation properties of high-z objects. In order to provide the high-z studies with a local reference, we have measured total [OII]3727 fluxes for the well analyzed local sample of star-forming galaxies from the Universidad Complutense de Madrid Survey. This data is used to derive the [OII]3727 luminosity function for local star-forming galaxies. When compared with similar luminosity densities published for redshift up to z~1, the overall evolution already observed in the star formation activity of the Universe is confirmed.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
