17 research outputs found
The Highly Ionized Circumgalactic Medium is Kinematically Uniform around Galaxies
Large scale structure and cosmolog
Understanding the strong intervening O VI absorber at z_abs 0.93 towards PG1206+459
Large scale structure and cosmolog
Large-scale periodicity in the distribution of QSO absorption-line systems
The spatial-temporal distribution of absorption-line systems (ALSs) observed
in QSO spectra within the cosmological redshift interval z = 0.0--4.3 is
investigated on the base of our updated catalog of absorption systems. We
consider so called metallic systems including basically lines of heavy
elements. The sample of the data displays regular variations (with amplitudes ~
15 -- 20%) in the z-distribution of ALSs as well as in the eta-distribution,
where eta is a dimensionless line-of-sight comoving distance, relatively to
smoother dependences. The eta-distribution reveals the periodicity with period
Delta eta = 0.036 +/- 0.002, which corresponds to a spatial characteristic
scale (108 +/- 6) h(-1) Mpc or (alternatively) a temporal interval (350 +/- 20)
h(-1) Myr for the LambdaCDM cosmological model. We discuss a possibility of a
spatial interpretation of the results treating the pattern obtained as a trace
of an order imprinted on the galaxy clustering in the early Universe.Comment: AASTeX, 13 pages, with 9 figures, Accepted for publication in
Astrophysics & Space Scienc
ZFOURGE catalogue of AGN candidates: an enhancement of 160-Όm-derived star formation rates in active galaxies to z  = 3.2
We investigate active galactic nuclei (AGN) candidates within the FourStar Galaxy Evolution Survey (ZFOURGE) to determine the impact they have on star formation in their host galaxies. We first identify a population of radio, X-ray, and infrared-selected AGN by cross-matching the deep Ks-band imaging of ZFOURGE with overlapping multiwavelength data. From this, we construct a mass-complete (log(Mâ/MâMâ/Mâ) â„9.75), AGN luminosity limited sample of 235 AGN hosts over z = 0.2â3.2. We compare the rest-frame U â V versus V â J (UVJ) colours and specific star formation rates (sSFRs) of the AGN hosts to a mass-matched control sample of inactive (non-AGN) galaxies. UVJ diagnostics reveal AGN tend to be hosted in a lower fraction of quiescent galaxies and a higher fraction of dusty galaxies than the control sample. Using 160 ÎŒm Herschel PACS data, we find the mean specific star formation rate of AGN hosts to be elevated by 0.34 ± 0.07 dex with respect to the control sample across all redshifts. This offset is primarily driven by infrared-selected AGN, where the mean sSFR is found to be elevated by as much as a factor of âŒ5. The remaining population, comprised predominantly of X-ray AGN hosts, is found mostly consistent with inactive galaxies, exhibiting only a marginal elevation. We discuss scenarios that may explain these findings and postulate that AGN are less likely to be a dominant mechanism for moderating galaxy growth via quenching than has previously been suggested
ZFIRE: The Evolution of the Stellar Mass Tully-Fisher Relation to Redshift ~ 2.2
Large scale structure and cosmolog
The Size Evolution of Star-forming Galaxies since z ~ 7 Using ZFOURGE
Interstellar matter and star formationGalaxie
Discovery of Extreme [O III]+HÎČ Emitting Galaxies Tracing an Overdensity at z ~ 3.5 in CDF-South
Large scale structure and cosmolog
Effect of Local Environment and Stellar Mass on Galaxy Quenching and Morphology at 0.5 < z < 2.0
Large scale structure and cosmolog