Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userSignificant evolution of the stellar mass-metallicity relation since z~0.65
96
0
0.0
(
0
)
Authors
Y. C. Liang
Ask ChatGPT about the research
No Arabic abstract
We present the stellar mass-metallicity relation for 34 0.4<z<1 galaxies selected from CFRS and Marano fields, and compare it to those derived from three local samples of galaxies (NFGS, KISS and SDSS). Our metal abundance estimates account for extinction effects, as estimated from IR/optical ratios and Balmer line ratios. All three comparisons show that the intermediate mass galaxies at z~0.65 are more metal-deficient by 0.3 dex at a given M_K or stellar mass relative to z=0. We find no evidence that this discrepancy could be related to different methods used to derive mass and metallicity. Assuming a closed box model predicts a gas fraction converted into stars of 20-25% since z~0.65, if the gas fraction is 10-20% in present-day galaxies with intermediate masses. This result is in excellent agreement with previous findings that most of the decline of the cosmic star formation density is related to the population of intermediate mass galaxies, which is composed of 75% spirals today. We find no evidence for a change of the slope of the M_{star}-Z relation from z~0.65 to z=0 within the intermediate mass range (10.5<log(M_{star}) < 11.5).
rate research
Read More
We measure the gas-phase oxygen abundances of ~3000 star-forming galaxies at z=0.05-0.75 using optical spectrophotometry from the AGN and Galaxy Evolution Survey (AGES), a spectroscopic survey of I_AB<20.45 galaxies over 7.9 deg^2 in the NOAO Deep Wide Field Survey (NDWFS) Bootes field. We use state-of-the-art techniques to measure the nebular emission lines and stellar masses, and explore and quantify several potential sources of systematic error, including the choice of metallicity diagnostic, aperture bias, and contamination from unidentified active galactic nuclei (AGN). Combining volume-limited AGES samples in six independent redshift bins and ~75,000 star-forming galaxies with r_AB<17.6 at z=0.05-0.2 selected from the Sloan Digital Sky Survey (SDSS) that we analyze in the identical manner, we measure the evolution of the stellar mass-metallicity (M-Z) between z=0.05 and z=0.75. We find that at fixed stellar mass galaxies at z~0.7 have just 30%-60% the metal content of galaxies at the present epoch, where the uncertainty is dominated by the strong-line method used to measure the metallicity. Moreover, we find no statistically significant evidence that the M-Z relation evolves in a mass-dependent way for M=10^9.8-10^11 Msun star-forming galaxies. Thus, for this range of redshifts and stellar masses the M-Z relation simply shifts toward lower metallicity with increasing redshift without changing its shape.
We present the brightest cluster galaxies (BCGs) catalog for SPectroscoic IDentification of eROSITA Sources (SPIDERS) DR14 cluster program value-added catalog. We list the 416 BCGs identified as part of this process, along with their stellar mass, star formation rates, and morphological properties. We identified the BCGs based on the available spectroscopic data from SPIDERS and photometric data from SDSS. We computed stellar masses and SFRs of the BCGs on the basis of SDSS, WISE, and GALEX photometry using spectral energy distribution fitting. Morphological properties for all BCGs were derived by Sersic profile fitting using the software package SIGMA in different optical bands (g,r,i). We combined this catalog with the BCGs of galaxy groups and clusters extracted from the deeper AEGIS, CDFS, COSMOS, XMM-CFHTLS, and XMM-XXL surveys to study the stellar mass - halo mass relation using the largest sample of X-ray groups and clusters known to date. This result suggests that the mass growth of the central galaxy is controlled by the hierarchical mass growth of the host halo. We find a strong correlation between the stellar mass of BCGs and the mass of their host halos. This relation shows no evolution since z $sim$ 0.65. We measure a mean scatter of 0.21 and 0.25 for the stellar mass of BCGs in a given halo mass at low ( $0.1<z < 0.3$ ) and high ( $0.3<z<0.65$ ) redshifts, respectively. We further demonstrate that the BCG mass is covariant with the richness of the host halos in the very X-ray luminous systems. We also find evidence that part of the scatter between X-ray luminosity and richness can be reduced by considering stellar mass as an additional variable.
We use KMOS Deep Survey (KDS) galaxies, combined with results from a range of spectroscopic studies in the literature, to investigate the evolution of the stellar-mass Tully-Fisher relation since z ~ 4. We determine the slope and normalisation of the local rotation-velocity -- stellar-mass (Vc - $M_{star}$) relationship using a reference sample of local spiral galaxies; thereafter we fix the slope, and focus on the evolution of velocity normalisation with redshift. The rotation-dominated KDS galaxies at z ~ 3.5 have rotation velocities ~ -0.1 dex lower than local reference galaxies at fixed stellar mass. By fitting 16 distant comparison samples spanning 0 < z < 3 (containing ~ 1200 galaxies), we show that the size and sign of the inferred Vc offset depends sensitively on the fraction of the parent samples used in the Tully-Fisher analysis, and how strictly the criterion of rotation dominated is enforced. Confining attention to subsamples of galaxies that are especially disky results in a consistent positive offset in Vc of ~ +0.1 dex, however these galaxies are not representative of the evolving-disk population at z > 1. We investigate the addition of pressure support, traced by intrinsic velocity dispersion ($sigma_{int}$) to the KDS dynamical mass budget by adopting a total effective velocity of form $V_{tot} = (Vc^{2} + 4.0sigma_{int}^{2})^{0.5}$. The rotation-dominated and dispersion-dominated KDS galaxies fall on the same locus in the total-velocity versus stellar-mass plane, removing the need for debate over the precise selection threshold for rotation-dominated galaxies. The comparison sample offsets are in the range +0.08 to +0.15 dex in total-velocity zero-point (-0.30 to -0.55 dex in stellar-mass zero-point) from the local Tully-Fisher relation at z > 1, consistent with steady evolution of the ratio of dynamical to stellar mass with cosmic time.
We present our recent results on the cosmic evolution of the outskirst of disk galaxies. In particular we focus on disk-like galaxies with stellar disk truncations. Using UDF, GOODS and SDSS data we show how the position of the break (i.e. a direct estimator of the size of the stellar disk) evolves with time since z~1. Our findings agree with an evolution on the radial position of the break by a factor of 1.3+-0.1 in the last 8 Gyr for galaxies with similar stellar masses. We also present radial color gradients and how they evolve with time. At all redshift we find a radial inside-out bluing reaching a minimum at the position of the break radius, this minimum is followed by a reddening outwards. Our results constraint several galaxy disk formation models and favour a scenario where stars are formed inside the break radius and are relocated in the outskirts of galaxies through secular processes.
The stellar mass-halo mass relation is a key constraint in all semi-analytic, numerical, and semi-empirical models of galaxy formation and evolution. However, its exact shape and redshift dependence remain debated. Several recent works support a relation in the local Universe steeper than previously thought. Based on the comparisons with a variety of data on massive central galaxies, we show that this steepening holds up to z~1, for stellar masses Mstar>2e11 Msun. Specifically, we find significant evidence for a high-mass end slope of beta>0.35-0.70, instead of the usual beta~0.20-0.30 reported by a number of previous results. When including the independent constraints from the recent BOSS clustering measurements, the data, independent of any systematic errors in stellar masses, tend to favor a model with a very small scatter (< 0.15 dex) in stellar mass at fixed halo mass, in the redshift range z < 0.8 and for Mstar>3e11 Msun, suggesting a close connection between massive galaxies and host halos even at relatively recent epochs. We discuss the implications of our results with respect to the evolution of the most massive galaxies since z~1.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
